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Background: Stenotrophomonas maltophilia, a pathogen that colonizes medical equipment and causes nosocomial infections due to its ability to form biofilms, has high mortality rates. This study investigated the risk factors related to mortality in patients who were diagnosed with S. maltophilia bacteremia. Methods: It is a multi-center, retrospective ad observational cohort study. The demographic characteristics, clinical findings, microbiological data, and risk factors for patients were obtained from the medical records of patients at ten different hospitals between January 1, 2018, and June 30, 2023. Results: The study included a total of 321 patients. The observed thirty-day mortality rate was 46.1%. A central venous catheter (CVC) was present in 276 patients (86%), and in 66 of these patients (23.9%) the CVC was removed. While only 18 patients (5.6%) received appropriate empirical antibiotics, 242 (75.4%) patients received appropriate antibiotics according to antimicrobial susceptibility test (AST) results and treatment revisions. Multivariate analysis revealed that advanced age (hazard ratio [HR] = 1.02; 95% confidence interval [CI]: 1.00– 1.03), appropriate antibiotic treatment (HR = 0.35; 95% CI: 0.23–0.52), and removal of central venous catheters (HR = 0.31; 95% CI: 0.16–0.60) were significantly related to reduced mortality. Conclusions: S. maltophilia is a significant pathogen, and to reduce its high mortality rate, removal of the CVC and switching to appropriate antibiotics should be performed as soon as possible. [ABSTRACT FROM AUTHOR]

Previous reports focusing on cefiderocol susceptibility against Stenotrophomonas maltophilia have included a large number of noninvasive or colonized isolates, and data focusing on invasive S. maltophilia strains are still lacking. We retrospectively investigated the cefiderocol susceptibility of stored S. maltophilia strains that caused bacteremia at two Japanese hospitals. The MIC50 and MIC90 were 0.06 μg/mL and 0.25 μg/mL, respectively, while the susceptibility rate was 99.3% (current CLSI breakpoint criteria). Our results provide the MIC distribution of bacteremic S. maltophilia isolates in Japan and show the preserved cefiderocol susceptibility of S. maltophilia among clinically invasive pathogenic strains. [ABSTRACT FROM AUTHOR]

Background: Limited information exists on carriage of multidrug-resistant organisms (MDRO) by health workers (HWs) in primary care settings. This study aims to determine the prevalence of MDRO carriage among HWs in primary care and to identify associated risk factors. Methods: A cross-sectional study was conducted across all 12 primary care units in São Caetano do Sul-SP, Brazil, from October to December 2023. Self-collected samples (nasal, oropharyngeal, and inguinal) were obtained. Environment cultures (potable water, sewage and stream water) were evaluated. Stenotrophomonas maltophilia isolates (human and environmental) were typed. Results: The study included 265/288 (92%) of HWs in primary care teams, mostly women with a median age of 47 years (IQR 38—57); 78% had no comorbidities. MDRO colonisation was found in 8.7% (23 HWs). The following bacteria were found: S. maltophilia (n = 9; 3.4%) in inguinal swabs; methicillin-resistant Staphylococcus aureus (n = 8; 3%) from all sites; extended-spectrum ß-lactamase-producing bacteria (n = 5; 2%) in inguinal swabs; and vancomycin-resistant enterococci in an inguinal swab (n = 1; 0.4%). Previous antibiotic use was significantly associated with MDRO colonisation (OR 2.91, 95% CI 1.19–7.09, p = 0.018), mainly narrow spectrum oral beta-lactams and macrolides. S. malthophilia was polyclonal and human and environmental isolates differed. Conclusion: Colonisation by MRSA, VRE, and ESBL-producing bacteria was low; however, 4% were surprisingly colonized by polyclonal S. maltophilia. This pathogen may also suggest using narrow-spectrum rather than the expected broad-spectrum antimicrobials. Antibiotic use was the only risk factor found, mainly with oral narrow-spectrum drugs. [ABSTRACT FROM AUTHOR]

Previously, some bacteria were shown to harbour enzymes capable of catalysing the oxidative cleavage of the double bond of t -anethole and related compounds. The cofactor dependence of these enzymes remained enigmatic due to a lack of biochemical information. We report on catalytic and structural details of a representative of this group of oxidative enzymes: t -anethole oxygenase from Stenotrophomonas maltophilia (TAO Sm). The bacterial enzyme could be recombinantly expressed and purified, enabling a detailed biochemical study that has settled the dispute on its cofactor dependence. We have established that TAO Sm contains a tightly bound b-type heme and merely depends on dioxygen for catalysis. It was found to accept t -anethole, isoeugenol and O-methyl isoeugenol as substrates, all being converted into the corresponding aromatic aldehydes without the need of any cofactor regeneration. The elucidated crystal structure of TAO Sm has revealed that it contains a unique active site architecture that is conserved for this distinct class of heme-containing bacterial oxygenases. Similar to other hemoproteins, TAO Sm has a histidine (His121) as proximal ligand. Yet, unique for TAOs, an arginine (Arg89) is located at the distal axial position. Site directed mutagenesis confirmed crucial roles for these heme-liganding residues and other residues that form the substrate binding pocket. In conclusion, the results reported here reveal a new class of bacterial heme-containing oxygenases that can be used for the cleavage of alkene double bonds, analogous to ozonolysis in organic chemistry. • Identification of a new class of heme-containing enzymes. • Cofactor-independent biocatalytic C C cleavage. • Crystal structure of a trans-anethole oxygenase. • Novel active site architecture of a heme-containing enzyme. [ABSTRACT FROM AUTHOR]

The spread of carbapenemase-producing gram-negative pathogens, especially those producing metallo-β-lactamases (MBLs), has become a major health concern. MBLs are molecularly the most diverse carbapenemases, produced by a wide spectrum of gram-negative organisms, including the Enterobacterales, Pseudomonas spp., Acinetobacter baumannii, and Stenotrophomonas maltophilia, and can hydrolyze most β-lactams using metal ion cofactors in their active sites. Over the years, the prevalence of MBL-carrying isolates has increased globally, particularly in Asia. MBL infections are associated with adverse clinical outcomes including longer length of hospital stay, ICU admission, and increased mortality across the globe. The optimal treatment for MBL infections not only depends on the pathogen but also on the underlying resistance mechanisms. Currently, there are only few drugs or drug combinations that can efficiently offset MBL-mediated resistance, which makes the treatment of MBL infections challenging. The rising concern of MBLs along with the limited treatment options has led to the need and development of drugs that are specifically targeted towards MBLs. This review discusses the prevalence of MBLs, their clinical impact, and the current treatment options for MBL infections and their limitations. Furthermore, this review will discuss agents currently in the pipeline for treatment of MBL infections. [ABSTRACT FROM AUTHOR]

This study aimed to identify and characterize actinobacteria and rhizobia with plant growth-promoting (PGP) traits from chickpea plants. Out of 275 isolated bacteria, 25 actinobacteria and 5 chickpea rhizobia showed 1-aminocyclopropane-1-carboxylate deaminase (ACCd) activity. Selected chickpea rhizobia were tested for their nodulating capacity under sterile and non-sterile soil conditions. Further screening on salinity and PGP traits identified three promising isolates: Nocardiopsis alba KG13, Sinorhizobium meliloti KGCR17, and Bacillus safensis KGCR11. These three isolates were analyzed for their compatibility and made into a consortium (Consortium 1). This along with another consortium made from our salinity-tolerant lab strains Chryseobacterium indologenes ICKM4 and Stenotrophomonas maltophilia ICKM15 (Consortium 2) was compared in planta studies. Trials revealed that Consortium 2 showed significant (p < 0.05) tolerance and on above-ground, below-ground traits and yield components than Consortium 1. Moreover, both consortia induced nodulation in saline-stressed plants, alleviated electrolyte leakage (2.3 vs. 0.4 in ICCV 2; 1.8 vs. 0.6 in JG 11), and increased chlorophyll content. Histochemical staining indicated reduced oxidative stress and lipid peroxidation in consortium-treated plants under salinity stress. Further, gene expression studies revealed mixed patterns, with up-regulation of antioxidant and transporter genes observed in consortium-treated plants, particularly in Consortium 2. Overall, Consortium 2 showed better gene expression levels for antioxidant and transporter genes, indicating its superior efficacy in mitigating salinity stress in chickpea plants. This study provides valuable insights into the potential use of these microbial isolates in improving chickpea productivity by enhancing salinity tolerance. [ABSTRACT FROM AUTHOR]

Microorganisms are evolving to withstand the effect of antimicrobial agents and thereby pose a global threat known as antimicrobial resistance. Resistance towards multiple drugs due to various intrinsic as well environmental factors leads to an even more dangerous drug resistance property known as multi-drug resistance (MDR). WHO has recognized MDR bacteria as a top global threat as they complicate the treatment and augment mortality and morbidity risks. Gram-negative bacteria produce beta-lactamase enzymes that can hydrolyze beta-lactam antibiotics, impacting drug susceptibility. Stenotrophomonas maltophilia, an opportunistic pathogen, exemplifies MDR due to the production of two types of beta-lactamases. The metallo-beta-lactamase (MBL) L1 produced by the bacteria is a class B1 zinc-dependent MBL that is broadly substrate-specific and is a challenge to the currently available treatment options. This study constructs and analyzes a protein-protein interaction network of L1 beta-lactamase to comprehend its role in the MDR property of the bacteria. The network encompasses 51 proteins including L1 MBL (Smlt2667) and 382 interactions, revealing key players in MDR and potential drug targets. The network analysis aids the discernment of antimicrobial gene impact on cellular function, informing drug discovery strategies. This research addresses the emerging challenge of antibiotic resistance and identifies pathways for therapeutic intervention. [ABSTRACT FROM AUTHOR]

Antibiotic resistance in bacteria leads to high mortality rates and healthcare costs, a significant concern for public health. A colonizer of the human respiratory system, Stenotrophomonas maltophilia is frequently associated with hospital-acquired infections in individuals with cystic fibrosis, cancer, and other chronic illnesses. The importance of this study is underscored by its capacity to meet the critical demand for effective preventive strategies against this pathogen, particularly among susceptible groups of cystic fibrosis and those undergoing cancer treatment. In this study, we engineered a multi-epitope vaccine targeting S. maltophilia through genomic analysis, reverse vaccination strategies, and immunoinformatic techniques by examining a total of 81 complete genomes of S. maltophilia strains. Our investigation revealed 1945 core protein-coding genes alongside their corresponding proteomic sequences, with 191 of these genes predicted to exhibit virulence characteristics. Out of the filtered proteins, three best antigenic proteins were selected for epitope prediction while seven epitopes each from CTL, HTL, and B cell were chosen for vaccine development. The vaccine was refined and validated, showing highly antigenic and desirable physicochemical features. Molecular docking assessments revealed stable binding with TLR-4. Molecular dynamic simulation demonstrated stable dynamics with minor alterations. The originality of this investigation is rooted in the thorough techniques aimed at designing a vaccine that directly targets S. maltophilia, a microorganism of considerable clinical relevance that currently lacks an available vaccine. This study not only responds to a pressing public health crisis but also lays the groundwork for subsequent research endeavors focused on the prevention of S. maltophilia outbreaks. Further evidence from studies in mice models is needed to confirm immune protection against S. maltophilia. [ABSTRACT FROM AUTHOR]

Oak decline is a major concern in Iran. A literature search with the terms 'Iran' AND 'oak' OR 'Quercus' from 1963 through 2023 resulted in 635 articles with over 200 dealing specifically with oak decline. In Iran, oak decline is most severe in the Zagros forests, followed by the Arasbaran and Hyrcanian forests. Of Iran's 11 native oak species, Quercus brantii is the most affected. Several factors have been identified as contributing to oak decline in Iran. Some economic and social factors include high rural unemployment, livestock overgrazing and uncontrolled cutting of live tree branches with the wood used for firewood and foliage used as food for farm animals. These pruning wounds can serve as entry points for pathogens and attract insects. Important abiotic factors included extended drought, increasing air temperature and wind speed, and increased levels of airborne dust and heavy metals. Important pathogens identified in the early 2000s included Armillaria mellea and charcoal rot fungus (Biscogniauxia mediterranea). More recently, many other fungal pathogens (e.g., Discula quercina, Neoscytalidium dimidiatum, Obolarina persica, Paecilomyces formosus and Phaeoacremonium tuscanicum) and bacterial pathogens (e.g., Bacillus pumilus, Brenneria goodwinii, Gibbsiella quercinecans, Rahnella victoriana and Stenotrophomonas maltophilia) were found in association with declining oaks. Among the insects, severe oak defoliation has resulted from various Lepidoptera in the families Erebidae, Geometridae and Tortricidae. Similarly, several bark‐ and wood‐boring beetles in the families Buprestidae and Cerambycidae were reported from declining oaks, with the buprestid Agrilus hastulifer being one of the most common. It is hoped that this review will improve our understanding of the many factors involved in oak decline in Iran and promote the development of management strategies. [ABSTRACT FROM AUTHOR]

Objectives Patients with reported Stenotrophomonas maltophilia (S. maltophilia) growth in lower respiratory tract samples were investigated. The results of these patients were assessed by clinicians as either infection or colonization. The data of patients considered to have S. maltophilia infection were compared to those considered to have colonization to explore factors associated with infection. Methods Parameters including as age, length of hospital stay, duration of S. maltophilia growth after hospital admission, sex, unit, department, specimen type, mechanical ventilation treatment status, antimicrobial susceptibility results, comorbidities, survival, and antimicrobials used during the period from hospital admission to S. maltophilia growth were investigated. Additionally, some biochemical parameters that were examined include the day of hospital admission, the day of sample collection when the bacterium was isolated (±1 day), and the day of discharge/died. Results The infection group had a significantly higher rate of admissions to internal medical departments and more cases of discharge/died. The infection group showed a lower amount of aminoglycoside antibiotic usage and significantly higher levels of BUN, creatinine, neutrophils, and neutrophil-to-lymphocyte ratio on their day of discharge/died. Conclusion Being admitted to internal medical departments and receiving aminoglycoside treatment were identified to be factors associated with S. maltophilia infection. These patients should be monitored for infection markers such as CRP and neutrophil count, as well as renal function tests. It should be noted that being infected with S. maltophilia is an independent risk factor for mortality. [ABSTRACT FROM AUTHOR]

Nucleases of the S1/P1 family have important applications in biotechnology and molecular biology. We have performed structural analyses of SmNuc1 nuclease from Stenotrophomonas maltophilia, including RNA cleavage product binding and mutagenesis in a newly discovered flexible Arg74‐motif, involved in substrate binding and product release and likely contributing to the high catalytic rate. The Arg74Gln mutation shifts substrate preference towards RNA. Purine nucleotide binding differs compared to pyrimidines, confirming the plasticity of the active site. The enzyme–product interactions indicate a gradual, stepwise product release. The activity of SmNuc1 towards c‐di‐GMP in crystal resulted in a distinguished complex with the emerging product 5′‐GMP. This enzyme from an opportunistic pathogen relies on specific architecture enabling high performance under broad conditions, attractive for biotechnologies. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia causes challenging infections in immunocompromised patients, exhibiting increasing resistance to multiple antimicrobials and possessing various virulence genes, including emerging resistance to trimethoprim‐sulfamethoxazole. A total of 80 clinical isolates of S. maltophilia were collected from multiple hospitals in Tehran, Iran. This study conducted an analysis of antibiotic susceptibility by disc diffusion method and E‐test assay, resistance and virulence gene frequencies were examined by PCR‐sequencing, and multilocus sequencing typing (MLST) was performed for strain typing. Across the tested isolates, we observed notably high resistance rates for imipenem 80 (100%), meropenem 78(97.5%), and ceftazidime 72 (90%), while trimethoprim‐sulfamethoxazole (SXT) showed a lower resistance rate of 2 (2.5%). Minocycline and levofloxacin demonstrated the highest susceptibility rates, with 70 (87.5%) and 80 (100%), respectively. The prevalence of antibiotic resistance genes blaL1, and blaL2 was 71 (88.75%) and 76 (95%), respectively. Additionally, the PCR analysis revealed that the frequency of virulence genes (fliC, virB, papD, pilU, hlyIII, stmPr1, and stmPr2) was 78 (97.5%), 77 (96.25%), 58 (72.5%), 77 (96.2%), 76 (95%), 31 (38.75%), and 80 (100%), respectively. Resistance to SXT isolate belong to the sequence type (ST15) and exhibits allelic profiles of (10, 29, 21, 21, 32, 32, and 10). The data obtained from our investigation have indicated that SXT remains an efficacious antibiotic and also highlighted the importance of effective management, identification of resistant isolates, and typing methods to address the global prevalence of antibiotic resistance in S. maltophilia. [ABSTRACT FROM AUTHOR]

The existence of viable human pathogens in bioaerosols which can cause infection or affect human health has been the subject of little research. In this study, data provided by 10 tropospheric aircraft surveys over Japan in 2014 confirm the existence of a vast diversity of microbial species up to 3,000 m height, which can be dispersed above the planetary boundary layer over distances of up to 2,000 km, thanks to strong winds from an area covered with massive cereal croplands in Northeast (NE) Asia. Microbes attached to aerosols reveal the presence of diverse bacterial and fungal taxa, including potential human pathogens, originating from sewage, pesticides, or fertilizers. Over 266 different fungal and 305 bacterial genera appeared in the 10 aircraft transects. Actinobacteria, Bacillota, Proteobacteria, and Bacteroidetes phyla dominated the bacteria composition and, for fungi, Ascomycota prevailed over Basidiomycota. Among the pathogenic species identified, human pathogens include bacteria such as Escherichia coli, Serratia marcescens, Prevotella melaninogenica, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus saprophyticus, Cutibacterium acnes, Clostridium difficile, Clostridium botulinum, Stenotrophomonas maltophilia, Shigella sonnei, Haemophillus parainfluenzae and Acinetobacter baumannii and health-relevant fungi such as Malassezia restricta, Malassezia globosa, Candida parapsilosis and Candida zeylanoides, Sarocladium kiliense, Cladosporium halotolerans, and Cladosporium herbarum. Diversity estimates were similar at heights and surface when entrainment of air from high altitudes occurred. Natural antimicrobial-resistant bacteria (ARB) cultured from air samples were found indicating long-distance spread of ARB and microbial viability. This would represent a novel way to disperse both viable human pathogens and resistance genes among distant geographical regions. [ABSTRACT FROM AUTHOR]

The body temperature of Warm-blooded hosts impedes and informs responses of bacteria accustomed to cooler environments. The second messenger c-di-GMP modulates bacterial behavior in response to diverse, yet largely undiscovered, stimuli. A long-standing debate persists regarding whether a local or a global c-di-GMP pool plays a critical role. Our research on a Stenotrophomonas maltophilia strain thriving at around 28°C, showcases BtsD as a thermosensor, diguanylate cyclase, and effector. It detects 37°C and diminishes c-di-GMP synthesis, resulting in a responsive sequence: the periplasmic c-di-GMP level is decreased, the N-terminal region of BtsD disengages from c-di-GMP, activates the two-component signal transduction system BtsKR, and amplifies sod1-3 transcription, thereby strengthening the bacterium′s pathogenicity and adaptation during infections in 37°C warm Galleria mellonella larvae. This revelation of a single-protein c-di-GMP module introduces unrecognized dimensions to the functional and structural paradigms of c-di-GMP modules and reshapes our understanding of bacterial adaptation and pathogenicity in hosts with a body temperature around 37°C. Furthermore, the discovery of a periplasmic c-di-GMP pool governing BtsD-BtsK interactions supports the critical role of a local c-di-GMP pool. Author summary: The body temperature of mammals, typically around 37°C, serves as an important host-derived signal for pathogens thriving at substantially lower temperatures. The ability to detect and respond to this host-derived temperature signal is essential for a bacterium′s life cycle shift from a free-living state to pathogenicity. The c-di-GMP signaling network is predominant in detecting signals and regulating bacterial behaviors, leaving many input signals and their sensing mechanisms remain elusive. The significance of our research lies in uncovering the mechanism by which a single-protein c-di-GMP module detects 37°C and enhances the virulence and adaptability of Stenotrophomonas maltophilia during infection, broadening our understanding of the role played by a compartmentalized c-di-GMP pool and our knowledge of the simplicity of c-di-GMP modules. This breakthrough deepens our insight into how this bacterium transforms between free-living state and pathogenicity at 37°C, and opens new avenues for developing treatments targeting this pathway. [ABSTRACT FROM AUTHOR]

Background: Biofilm production in nonfermenting Gram-negative bacteria influences drug resistance. The aim of this work was to evaluate the effect of different antibiotics on biofilm eradication of clinical isolates of Achromobacter, Burkholderia, and Stenotrophomonas maltophilia. Methods: Clinical isolates were identified by matrix-assisted laser desorption ionization–time of flight mass spectrometry in a third-level hospital in Monterrey, Mexico. Crystal violet staining was used to determine biofilm production. Drug susceptibility testing was determined by broth microdilution in planktonic cells and biofilm cells. Results: Resistance in planktonic cells was moderate to trimethoprim-sulfamethoxazole, and low to chloramphenicol, minocycline, levofloxacin (S. maltophilia and Burkholderia), ceftazidime, and meropenem (Burkholderia and Achromobacter). Biofilm eradication required higher drug concentrations of ceftazidime, chloramphenicol, levofloxacin, and trimethoprim-sulfamethoxazole than planktonic cells (p < 0.05). Levofloxacin showed biofilm eradication activity in S. maltophilia, minocycline and meropenem in Burkholderia, and meropenem in Achromobacter. Conclusions: Drug resistance increased due to biofilm production for some antibiotics, particularly ceftazidime and trimethoprim-sulfamethoxazole for all three pathogens, chloramphenicol for S. maltophilia and Burkholderia, and levofloxacin for Burkholderia. Some antibiotics could be used for the treatment of biofilm-associated infections in our population, such as levofloxacin for S. maltophilia, minocycline and meropenem for Burkholderia, and meropenem for Achromobacter. [ABSTRACT FROM AUTHOR]

Introduction The material of a bandage plays an important role in wound management. Microorganisms can colonize the dressing and release toxins, which create dead cells in the wound. This allows the microorganisms to bind the dead cells and infect the wound. Thus, a dressing is needed that kills bacteria in the bandage. To combat health care–associated infections, antimicrobial treatment of medical textiles, such as gauze, uniforms, curtains, bed sheets, gowns, and masks, is required. Besides, antimicrobial resistance is another major problem of this century. Antibacterial overuse has contributed to drug-resistant bacteria. To combat these two problems, we synthesized new organo-selenium compounds that can be attached to the cotton of the dressing. We then used an in vivo wound model, which allowed us to measure the effectiveness of selenium attached to a cotton dressing, to prevent bacteria from infecting a wound. Materials and Methods Organo-selenium was attached to cotton fabric, resulting in a fabric with 0.1% selenium covalently attached to it. Staphylococcus aureus (as well as methicillin-resistant S. aureus [MRSA]), Stenotrophomonas maltophilia , Enterococcus faecalis , Staphylococcus epidermidis , and Pseudomonas aeruginosa were chosen for the wound infection study. All the bacteria were enumerated in the wound dressing and in the wound tissue under the dressing. Wounds were made on the backs of mice. The material was used as a bandage over the wound. Bacteria were injected into the wound under the bandage. The amount of bacteria in the wound after 5 days was determined. A similar study was performed using dressing material that was soaked in phosphate buffered saline at 37 °C for 3 months before use. Results Cotton dressing with selenium attached showed complete inhibition (7 logs, as compared with control dressing) of different bacterial strains, in both the dressing and "the tissue" of the wound. Similar results were obtained using selenium cotton dressing that was soaked for 3 months before use. Control cotton with no selenium showed complete infiltration of bacteria into the wound and the dressing. In addition, a study was performed under Food and Drug Administration standard methods to show the ability of the selenium to kill bacteria in the fabric, using material that was washed 5 times in detergent. This also showed complete killing of bacteria in the fabric. Conclusions The results show that the selenium remains in the dressing after washing and is able to completely protect the wound from bacterial infection. In the selenium bandage, no bacteria were found in the bandage or the wound after 5 days. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia (S. maltophilia) is a spoilage microorganism widely distributed in vegetables, dairy products, and various environments and can cause serious foodborne illnesses. Renowned for its environmentally friendly, safe, and non-toxic properties, rose essential oil (REO) is widely recognized as an exceptional natural antibacterial agent. In the present study, we conducted a comprehensive analysis to elucidate the inhibition mechanism of REO against S. maltophilia at both cellular and metabolic levels. The results demonstrated that REO treatment of cells resulted in the disruption of cell structure and leakage of cellular contents. Remarkable changes in the morphology of bacterial cells were observed under both scanning electron microscopy and transmission electron microscopy. At the metabolic level, multiple metabolic pathways were disrupted after REO treatment, including amino acid metabolism, nucleotide metabolism, and aminoacyl tRNA biosynthesis. These results shed new light to the inhibition mechanism of REO against S. maltophilia and provide a theoretical basis for the development of effective essential oil preservatives. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia, a ubiquitous environmental bacterium, is an important cause of nosocomial infections. Although banned in some countries, paraquat (PQ) is commonly used to control weeds. In this study, we investigated the effects of increasing concentrations of PQ on S. maltophilia and its antimicrobial resistance. The sequential exposure of S. maltophilia K279a to increasing concentrations of PQ induces the formation of strains with increased resistance to PQ. Among the 400 PQ-resistant isolates tested, 70 clones were resistant to 16 μg/ml ciprofloxacin (CIP), and around 18% of the PQ/CIP-resistant isolates showed increased resistance to all the tested antimicrobials including, the aminoglycosides, quinolones, cephalosporin, chloramphenicol, and co-trimoxazole. The results of the expression analysis of the antimicrobial resistance genes in the five selected PQ/CIP-resistant isolates demonstrated the high expression of genes encoding efflux pumps (smeYZ, smaAB, smaCDEF, smeDEF, smeVWX, and smtcrA) and the enzymes aph(3')-IIc, blaL1, and blaL2. However, expression of the genes known for PQ resistance (i.e., mfsA and sod) were not altered relative to the wild-type levels. Whole genome sequence analysis identified gene mutations that could account for the antimicrobial resistance, namely, smeT (TetR family regulatory protein), rplA (ribosomal protein L1), and acnA (aconitase A). Ectopic expression of wild-type AcnA partially complemented the fluoroquinolone-resistant phenotype of the mutant with mutated acnA, which suggests the role of aconitase A in antimicrobial susceptibility. Exposure of S. maltophilia to PQ thus induces the development of strains that increase resistance to multiple antimicrobials. [ABSTRACT FROM AUTHOR]

Background Lysins (cell wall hydrolases) targeting gram-negative organisms require engineering to permeabilize the outer membrane and access subjacent peptidoglycan to facilitate killing. In the current study, the potential clinical utility for the engineered lysin CF-370 was examined in vitro and in vivo against gram-negative pathogens important in human infections. Methods Minimum inhibitory concentration (MICs) and bactericidal activity were determined using standard methods. An in vivo proof-of-concept efficacy study was conducted using a rabbit acute pneumonia model caused by Pseudomonas aeruginosa. Results CF-370 exhibited potent antimicrobial activity, with MIC50/90 values (in µg/mL) for: P aeruginosa , 1/2; Acinetobacter baumannii , 1/1; Escherichia coli , 0.25/1; Klebsiella pneumoniae , 2/4; Enterobacter cloacae 1/4; and Stenotrophomonas maltophilia 2/8. CF-370 furthermore demonstrated bactericidal activity, activity in serum, a low propensity for resistance, anti-biofilm activity, and synergy with antibiotics. In the pneumonia model, CF-370 alone decreased bacterial densities in lungs, kidneys, and spleen versus vehicle control, and demonstrated significantly increased efficacy when combined with meropenem (vs either agent alone). Conclusions CF-370 is the first engineered lysin described with potent broad-spectrum in vitro activity against multiple clinically relevant gram-negative pathogens, as well as potent in vivo efficacy in an animal model of severe invasive multisystem infection. [ABSTRACT FROM AUTHOR]

Background: Bloodstream infections (BSI) are a significant health concern, necessitating effective diagnostic tools. This study evaluates the performance of the BD Bactec FX system in comparison to the established BacT/Alert system, examining mean time till detection (TTD) across various blood culture bottles. Methods: The study involves 148 blood culture bottles, inoculated with representative bacterial ATCC strains (n= 15) and 04 yeast isolates. Parallel testing is conducted by seeding 10-30 colony-forming units (CFU) in duplicate in both BD Bactec FX and BacT/Alert systems. TTD is assessed across aerobic, anaerobic, and pediatric bottles for diverse microbial species. Results: All 148 bottles tested in parallel show positive signals in both systems. BD Bactec FX demonstrates significantly shorter TTD for adult-seeded cultures in aerobic and anaerobic bottles compared to BacT/Alert Similarly, pediatric bottles with BD Bactec FX exhibit a shorter TTD compared to BacT/Alert. The statistical significance of TTD, 95% confidence intervals (CI), and p-values is evident for Bactec FX aerobic, anaerobic, and pediatric bottles across tested organisms. Notable examples of faster TTD include; Bacteroides ovatus (16.6h by Bactec FX vs. 70.5h by Bact/Alert 3D), Stenotrophomonas maltophilia (33.7h vs. 72.5h), and Streptococcus pyogenes (8.1h vs. 11.9h). Conclusions: In conclusion, the study's findings demonstrate that BD Bactec FX surpasses BacT/Alert in prompt microbial detection, showcasing potential for early identification of bacteremia and fungemia. Faster TTD implies the potential to initiate timely antimicrobial treatment, thereby reducing patient morbidity and mortality. However, exceptions in certain microbial species highlight the need for comprehensive clinical validation to establish the broad applicability of these findings. [ABSTRACT FROM AUTHOR]

Background Stenotrophomonas maltophilia is a carbapenem-resistant Gram-negative pathogen increasingly responsible for difficult-to-treat nosocomial infections. Objectives To describe the contemporary clinical characteristics and genome epidemiology of patients colonized or infected by S. maltophilia in a multicentre, prospective cohort. Methods All patients with a clinical culture growing S. maltophilia were enrolled at six tertiary hospitals across Japan between April 2019 and March 2022. The clinical characteristics, outcomes, antimicrobial susceptibility and genomic epidemiology of cases with S. maltophilia were investigated. Results In total, 78 patients were included representing 34 infection and 44 colonization cases. The median age was 72.5 years (IQR, 61–78), and males accounted for 53 cases (68%). The most common comorbidity was localized solid malignancy (39%). Nearly half of the patients (44%) were immunosuppressed, with antineoplastic chemotherapy accounting for 31%. The respiratory tract was the most common site of colonization (86%), whereas bacteraemia accounted for most infection cases (56%). The 30 day all-cause mortality rate was 21%, which was significantly higher in infection cases than colonization cases (35% versus 9%; adjusted HR, 3.81; 95% CI, 1.22–11.96). Susceptibility rates to ceftazidime, levofloxacin, minocycline and sulfamethoxazole/trimethoprim were 14%, 65%, 87% and 100%, respectively. The percentage of infection ranged from 13% in the unclassified group to 86% in genomic group 6A. The percentage of non-susceptibility to ceftazidime ranged from 33% in genomic group C to 100% in genomic groups 6 and 7 and genomic group geniculate. Conclusions In this contemporary multicentre cohort, S. maltophilia primarily colonized the respiratory tract, whereas patients with bacteraemia had the highest the mortality from this pathogen. Sulfamethoxazole/trimethoprim remained consistently active, but susceptibility to levofloxacin was relatively low. The proportions of cases representing infection and susceptibility to ceftazidime differed significantly based on genomic groups. [ABSTRACT FROM AUTHOR]

The screening and identification of attachment genes is important to exploring the formation mechanism of biofilms at the gene level. It is helpful to the development of key culture technologies for aerobic granular sludge (AGS). In this study, genome-wide sequencing and gene editing were employed for the first time to investigate the effects and functions of attachment genes in AGS. With the help of whole-genome analysis, ten attachment genes were screened from thirteen genes, and the efficiency of gene screening was greatly improved. Then, two attachment genes were selected as examples to further confirm the gene functions by constructing gene-knockout recombinant mutants of Stenotrophomonas maltophilia ; when the two attachment genes were knocked out, the attachment potential was reduced by 50.67% and 43.93%, respectively. The results provide a new theoretical principle and efficient method for the development of AGS from the perspective of attachment genes. [Display omitted] [ABSTRACT FROM AUTHOR]

Key Clinical Message: Stenotrophomonas maltophilia can cause rare odontogenic brain abscesses in immunocompetent patients, highlighting the importance of considering uncommon pathogens in central nervous system infections. With only three reported cases of cerebral abscesses and one pituitary abscess caused by this microorganism, tailored diagnostic methods and individualized treatment regimens are crucial for accurate management. Brain abscesses present diagnostic and therapeutic challenges, with Stenotrophomonas maltophilia infections being exceptionally rare in the central nervous system. We present a case of odontogenic brain abscesses caused by S. maltophilia in an immunocompetent patient, highlighting the rarity and complexity of such infections. A 66‐year‐old male presented with spatial–temporal disorientation and left‐sided weakness. Radiological investigations revealed an expansive lesion in the right posterior frontal region. A craniotomy and drainage were performed, identifying S. maltophilia in the purulent material. The patient responded well to tailored antibiotic therapy. S. maltophilia‐related central nervous system infections are infrequent, emphasizing the need for a heightened clinical suspicion in atypical cases. This case contributes to the literature, emphasizing the importance of a multidisciplinary approach for successful diagnosis and management. [ABSTRACT FROM AUTHOR]

The article in the Journal of Clinical Investigation discusses the effects of Elexacaftor/tezacaftor/ivacaftor (ETI) on cystic fibrosis infections over 3.5 years of treatment. The study found that while ETI maintained reductions in sputum pathogen density, it did not increase the effects of treatment. The research suggests that the durability of ETI-associated infection responses may be influenced by bacterial adaptations and the initial pathogen burden. Additionally, the study highlights the challenges in eradicating infections and the importance of continued research in understanding the long-term effects of ETI treatment on cystic fibrosis infections. [Extracted from the article]

Stenotrophomonas maltophilia is a nonfermenting gram-negative bacterium associated with multiple nosocomial outbreaks. Antibiotic resistance increases healthcare costs, disease severity, and mortality. Multidrug-resistant infections (such as S. maltophilia infection) are difficult to treat with conventional antimicrobials. This study aimed to investigate the isolation rates, and resistance trends of S. maltophilia infections over the past 19 years, and provide future projections until 2030. In total, 4466 patients with S. maltophilia infection were identified. The adult and main surgical intensive care unit (ICU) had the highest numbers of patients (32.2%), followed by the cardiology department (29.8%), and the paediatric ICU (10%). The prevalence of S. maltophilia isolation increased from 7% [95% confidence interval (CI) 6.3–7.7%] in 2004–2007 to 15% [95% CI 10.7–19.9%] in 2020–2022. Most S. maltophilia isolates were resistant to ceftazidime (72.5%), levofloxacin (56%), and trimethoprim-sulfamethoxazole (14.05%), according to our study. A consistent and significant difference was found between S. maltophilia-positive ICU patients and non-ICU patients (P = 0.0017) during the three-year pandemic of COVID-19 (2019–2021). The prevalence of S. maltophilia isolates is expected to reach 15.08% [95% CI 12.58–17.59%] by 2030. Swift global action is needed to address this growing issue; healthcare authorities must set priorities and monitor infection escalations and treatment shortages. [ABSTRACT FROM AUTHOR]

Background: Stenotrophomonas maltophilia, a multidrug-resistant gram-negative bacteria (GNB), is an emerging nosocomial pathogen. This study assessed the clinical outcomes of GNB infections in surgical intensive care unit (SICU) patients post-abdominal surgery, focusing on the differences between S. maltophilia and other GNBs, including Pseudomonas aeruginosa. Methods: A retrospective study was conducted on SICU patients at Kaohsiung Chang Gung Memorial Hospital from 2010 to 2020, who developed GNB infections following abdominal surgery. Results: Of 442 patients, 237 had S. maltophilia and 205 had non-S. maltophilia GNB infections (including 81 with P. aeruginosa). The overall mortality rate was 44.5%, and S. maltophilia infection emerged as a significant contributor to the mortality rate in patients with GNB infections. S. maltophilia patients had longer mechanical ventilation and SICU stays, with a 30-day mortality rate of 35.4%, higher than the non-S. maltophilia GNB (22.9%) and P. aeruginosa (21%) groups. In-hospital mortality was also higher in the S. maltophilia group (53.2%) compared to the non-S. maltophilia GNB (34.6%) and P. aeruginosa groups (29.6%). Risk factors for acquiring S. maltophilia included a higher Sequential Organ Failure Assessment score and prior broad-spectrum antibiotics use. Older age, polymicrobial infections, and elevated bilirubin were associated with increased 30-day mortality in S. maltophilia patients. Conclusion: S. maltophilia infections in post-abdominal surgery patients are linked to higher mortality than non-S. maltophilia GNB and P. aeruginosa infections, emphasizing the need for early diagnosis and treatment to improve outcomes. [ABSTRACT FROM AUTHOR]

Background: Urinary tract infection is one of the most common infections in humans, affecting women in more proportion. The bladder was considered sterile, but it has a urinary microbiome. Moreover, intracellular bacteria (IB) were observed in uroepithelial cells from children and women with urinary tract infections (UTIs). Here, we evaluated the presence of IB in urine from healthy people and patients with UTI symptoms. Methods: Midstream urine was self-collected from 141 donors, 77 females and 64 males; 72 belonged to the asymptomatic group and 69 were symptomatic. IB was characterized by a culture-dependent technique and visualized by confocal microscopy. Urine was also subjected to the classical uroculture and isolated bacteria were identified by MALDI-TOF. Results: One-hundred and fifteen uroculture were positive. A significant association was observed between the presence of symptoms and IB (P = 0.007). Moreover, a significant association between the presence of IB, symptoms and being female was observed (P = 0.03). From the cases with IB, Escherichia coli was the most frequent microorganism identified (34.7%), followed by Stenotrophomonas maltophilia (14.2%), Staphylococcus spp (14.2%), and Enterococcus faecalis (10.7%). Intracellular E. coli was associated with the symptomatic group (P = 0.02). Most of the intracellular Staphylococcus spp. were recovered from the asymptomatic group (P = 0.006). Conclusions: Intracellular bacteria are present in patients with UTI but also in asymptomatic people. Here, we report for the first time, the presence of S. maltophilia, Staphylococcus spp., and Enterobacter cloacae as intracellular bacteria in uroepithelial cells. These findings open new insights into the comprehension of urinary tract infections, urinary microbiome and future therapies. Uroculture as the gold standard could not be enough for an accurate diagnosis in recurrent or complicated cases. [ABSTRACT FROM AUTHOR]

Objective: Evaluate the effects of five disinfection methods on bacterial concentrations in hospital sink drains, focusing on three opportunistic pathogens (OPs): Serratia marcescens, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. Design: Over two years, three sampling campaigns were conducted in a neonatal intensive care unit (NICU). Samples from 19 sink drains were taken at three time points: before, during, and after disinfection. Bacterial concentration was measured using culture-based and flow cytometry methods. High-throughput short sequence typing was performed to identify the three OPs and assess S. marcescens persistence after disinfection at the genotypic level. Setting: This study was conducted in a pediatric hospitals NICU in Montréal, Canada, which is divided in an intensive and intermediate care side, with individual rooms equipped with a sink. Interventions: Five treatments were compared: self-disinfecting drains, chlorine disinfection, boiling water disinfection, hot tap water flushing, and steam disinfection. Results: This study highlights significant differences in the effectiveness of disinfection methods. Chlorine treatment proved ineffective in reducing bacterial concentration, including the three OPs. In contrast, all other drain interventions resulted in an immediate reduction in culturable bacteria (4–8 log) and intact cells (2–3 log). Thermal methods, particularly boiling water and steam treatments, exhibited superior effectiveness in reducing bacterial loads, including OPs. However, in drains with well-established bacterial biofilms, clonal strains of S. marcescens recolonized the drains after heat treatments. Conclusions: Our study supports thermal disinfection (>80°C) for pathogen reduction in drains but highlights the need for additional trials and the implementation of specific measures to limit biofilm formation. [ABSTRACT FROM AUTHOR]

Salinity is one of the most severe abiotic stresses that limit global crop productivity by affecting the growth of plants. However, the need of the hour is to expand the agricultural areas to saline regions for food security amidst growing human populations. Plant growth-promoting bacteria (PGPB) offer a promising solution to enhance plant growth in saline environments. The present study evaluates the plant growth-promoting characteristics of potential plant growthpromoting bacteria (PGPB) i.e. Burkholderia seminalis, Stenotrophomonas maltophilia, and Enterobacter sp. (JJG_Zn) under varying levels of simulated salinity stress (0 mM, 50 mM, 100 mM, and 150 mM). All the three PGPBs exhibited plant growth-promoting traits i.e Indole-3-acetic acid (IAA) production, gibberellic acid production, Phosphate solubilization, ammonia production, siderophore production, and ACC deaminase activity even at the highest concentration i.e. at 150 mM of saline stress. Furthermore, the beneficial effect of bacterial inoculants of aforesaid bacterial cultures on saline stress tolerance in forage sorghum through bio priming was also evaluated under in vitro conditions. The dual inoculation of B. seminalis + S. maltophilia (T5 ) was found to improve the germination parameters viz., germination percentage, germination speed, mean germination, and physiological traits such as shoot length, root length, fresh and dry shoot and root weight, and seed vigor index I and II over the uninoculated controls across different salt concentrations. Thus, the study suggests that bio-priming of forage sorghum seeds with potential liquid bacterial inoculants may mitigate the detrimental effects of saline soil and promote seedling growth and development. Therefore, these promising bacterial cultures can be further exploited under the salinity-affected regions across agro-climatic zones. Also, a thorough biosafety analysis of these cultures should be conducted, considering the ‘one health’ concept. [ABSTRACT FROM AUTHOR]

Botrytis cinerea and Oidium neolycopersici represent two of the key fungal pathogens of tomato. In this study, 142 isolates were screened for their biocontrol potential against these pathogens. They were initially isolated from rhizospheric and from non-rhizospheric soil samples collected near healthy tomato plants grown in unheated greenhouses showing severe epidemics of grey mould in the Jijel region of Algeria. All the isolates were tested in vitro against B. cinerea using dual culture assays, and a subsample of 40 isolates (20 rhizospheric isolates and 20 non-rhizospheric isolates) was retained. The antagonistic effect of these candidates on spore germination of B. cinerea and their effect against O. neolycopersici and B. cinerea on tomato plants were then evaluated. The dual culture assays showed that non-rhizospheric bacteria were significantly more effective than rhizospheric bacteria in inhibiting the mycelial growth of B. cinerea. In planta, however, rhizospheric isolates showed significantly higher protective levels. This protective effect was significantly correlated to the ability of bacterial isolates to inhibit spore germination of B. cinerea. Taken together, these results allowed us to retain seven isolates with over 90% of efficacy against B. cinerea. These isolates were also able to protect tomato plants against O. neolycopersici, and they were identified as, P. argentinensis (SJ2), Serratia marcescens (SJ11), Pseudomonas lactis (SJ55), Pseudomonas veronii (RSAB3), Stenotrophomonas maltophilia (RTB17), Bacillus subtilis (SA14) and Bacillus toyonensis (SA87). This study showed promising results that could be exploited for a potential application of bacterial-based biocontrol agents efficient against both B. cinerea and O. neolycopersici. [ABSTRACT FROM AUTHOR]

Cutaneous pseudolymphomas are a wide group of diseases mimicking cutaneous lymphoma. They comprise several skin conditions with different etiopathogenesis, clinical–pathological features, and prognosis, which may occur in the absence of an identifiable trigger factor or after administration of medications or vaccinations, tattoos, infections, or arthropod bites. They present with different manifestations: from solitary to regionally clustered lesions, up to generalized distribution and, in rare cases, erythroderma. They persist variably, from weeks to years, and resolve spontaneously or after antibiotics, but may recur in some cases. CD30+ T‐cell pseudolymphomas are characterized by the presence of large, activated lymphoid cells, generally in response to viral infections, arthropod assault reactions, and drug eruptions. Stenotrophomonas maltophilia is a ubiquitous Gram‐negative bacillus responsible for opportunistic infections in immunocompromised patients. Infection of intact skin in immunocompetent patients is particularly rare. Here, we report a case of a man presenting an isolated nodule histopathologically mimicking a primary cutaneous CD30+ T‐cell lymphoproliferative disorder. [ABSTRACT FROM AUTHOR]

Acute respiratory distress syndrome (ARDS) due to severe coronavirus disease 2019 (COVID-19) pneumonia is associated with a high incidence of ventilator-associated pneumonia (VAP). We aimed to evaluate the epidemiology of VAP associated with severe COVID-19 pneumonia. This retrospective observational study recruited patients with COVID-19-associated ARDS admitted to our center from April 1, 2020, to September 30, 2021. The primary outcome was the survival-to-discharge rate. The secondary outcomes were the VAP rate, time to VAP, length of ICU stay, length of ventilator support, and isolated bacteria. Sixty-eight patients were included in this study; 23 developed VAP. The survival-to-discharge rate was 60.9 % in the VAP group and 84.4 % in the non-VAP group. The median time to VAP onset was 16 days. The median duration of ventilator support and of ICU stay were higher in the VAP group than in the non-VAP group. The VAP rate was 33.8 %. The most common isolated species was Stenotrophomonas maltophilia. On admission, carbapenems were used in a maximum number of cases (75 %). Furthermore, the median body mass index (BMI) was lower and the median sequential organ failure assessment (SOFA) score on admission was higher in the VAP group than in the non-VAP group. The survival-to-discharge rate in VAP patients was low. Moreover, VAP patients tended to have long ICU stays, low BMI, and high SOFA scores on admission. Unusually, S. maltophilia was the most common isolated bacteria, which may be related to the frequent use of carbapenems. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia is a gram-negative bacterium that can be routinely identified in the aquatic environment, and has become an emergent, multi-drug-resistant life-threatening organism in some circumstances. This bacterium was identified as a presumptive causative agent in cases of polysystemic granulomatous disease in one diamondback terrapin (Malaclemys terrapin) and one mata mata (Chelus fimbriata). Both chelonians presented with lethargy, hyporexia, and multifocal subcutaneous masses diagnosed by physical examination and in one individual on computed tomography (CT). The primary hematologic finding was moderate to severe heterophilic leukocytosis, and both turtles were treated with a combination of supportive care, systemic antibiotics, and/or surgical resection of subcutaneous masses. Medical and surgical management were unsuccessful, and one patient was euthanized and the other found deceased. Necropsies revealed multisystemic granulomas, and cultures identified growth of Stenotrophomonas maltophilia. A postmortem investigation into possible risk factors identified comorbidities including shell disease, repeated administration of injectable antibiotics, low environmental temperature, and aquatic pH changes as possible contributing factors. This bacterium appears to be an emerging organism of concern and should be considered as a potential cause of granulomas in aquatic chelonians. [ABSTRACT FROM AUTHOR]

• Ticagrelor antithrombotic treatment can cause a significant increase in everolimus blood concentration, which can lead to severe immunosuppression, increasing the development of opportunistic infections. • Our case demonstrates that Stenotrophomonas maltophilia hemorrhagic pulmonary infection can occur without leukopenia and is independent of S. maltophilia bloodstream infection. • Rapid onset of thrombocytopenia associated with S. maltophilia infection and concomitant ticagrelor treatment can lead to hemorrhagic pneumonia. • Not only dyspnea and thrombocytopenia but also severe hyperkalemia, elevated concentrations of creatine kinase, lactate dehydrogenase, C-reactive protein, and interleukin-6 may indicate hemorrhagic pneumonia Pneumonia is a common nosocomial complication in transplant patients. Stenotrophomonas maltophilia is recognized as a common cause and is typically seen in immunocompromised and critically ill patients. S. maltophilia , a nonfermenting gram-negative rod, ranks as the third most common nosocomial pathogen, following Pseudomonas aeruginosa and Acinetobacter. The bacteria are frequently found in environmental sources and are prevalent in healthcare facilities, including in tap water faucets, shower outlets, air-cooling systems, intravenous fluids, catheters, dialysis machines, and oxygen humidifiers. This bacterium possesses the ability to rapidly form biofilms, enabling it to colonize new surfaces in less than 24 hours. While S. maltophilia generally exhibits low virulence, there remains uncertainty among many clinicians regarding whether it is merely a colonizer or the primary cause of infection. Although S. maltophilia infections are rare in immunocompetent individuals, the species is increasingly recognized as an opportunistic pathogen in vulnerable populations such as those with cystic fibrosis, cancer, and other conditions leading to immunosuppression. S. maltophilia now recognized as a causative agent in various clinical syndromes, primarily affecting the lungs and bloodstream. We present a case of S. maltophilia -associated lung infection in a kidney transplant recipient, emphasizing the significance of underlying diseases and associated signs and symptoms. [ABSTRACT FROM AUTHOR]

Background: Stenotrophomonas maltophilia is a gram-negative bacterium that can cause hospital infections and outbreaks within hospitals. This study aimed to evaluate an outbreak of Stenotrophomonas maltophilia, caused by ready-to-use commercial syringes containing liquid lithium and heparin for arterial blood gas collection in a university hospital. Methods: Upon detecting an increase in Stenotrophomonas maltophilia growth in blood cultures between 15.09.2021 and 19.11.2021, an outbreak analysis and a case-control study (52 patients for the case group, 56 patients for the control group) were performed considering risk factors for bacteremia. Samples from possible foci for bacteremia were also cultured. Growing bacteria were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The genetic linkage and clonal relationship isolates were investigated with pulsed-field gel electrophoresis (PFGE) in the reference laboratory. Results: In the case-control study, the odds ratio for the central venous catheter [3.38 (95% confidence interval [CI]: 1.444, 8.705 ; p = 0.006)], for surgery [3.387 (95% confidence interval [CI]: 1.370, 8.373 ; p = 0.008)] and for arterial blood gas collection history [18.584 (95% confidence interval [CI]:4.086, 84.197; p < 0.001)] were identified as significant risk factors. Stenotrophomonas maltophilia growth was found in ready-to-use commercial syringes used for arterial blood gas collection. Molecular analysis showed that the growths in the samples taken from commercial syringes and the growths from blood cultures were the same. It was decided that the epidemic occurred because the method for sterilization of heparinized liquid preparations were not suitable. After discontinuing the use of the kits with this lot number, the outbreak was brought under control. Conclusions: According to our results, disposable or sterile medical equipment should be included as a risk factor in outbreak analyses. The method by which injectors containing liquids, such as heparin, are sterilized should be reviewed. Our study also revealed the importance of the cooperation of the infection control team with the microbiology laboratory. [ABSTRACT FROM AUTHOR]

L-asparaginase is an important therapeutic enzyme that is frequently utilized in the chemotherapy regimens of adults as well as pediatric patients with acute lymphoblastic leukemia. However, a high rate of hypersensitivity with prolonged use has limited its utilization. Stenotrophomonas maltophilia (S. maltophilia) EMCC2297 isolate was reported as a novel and promising source for L- asparaginase. The present study aimed at the production, purification, and characterization of L- asparaginase from S. maltophilia EMCC2297 isolate. The microbial production of L-asparaginase by the test isolate could be increased by pre-exposure to chloramphenicol at 200 µg/ml concentration. S. maltophilia EMCC2297 L-asparaginase could be purified to homogeneity by ammonium sulphate precipitation and the purified form obtained by gel exclusion chromatography showed total activity of 96.4375 IU/ml and specific activity of 36.251 IU/mg protein. SDS-PAGE analysis revealed that the purified form of the enzyme is separated at an apparent molecular weight of 17 KDa. Michaelis-Menten constant analysis showed a Km value of 4.16 × 10− 2 M with L-asparagine as substrate and Vmax of 10.67 IU/ml. The antitumor activity of the purified enzyme was evaluated on different cell lines and revealed low IC50 of 2.2 IU/ml and 2.83 IU/ml for Hepatocellular cancer cell line (HepG-2), human leukemia cancer cell line (K-562), respectively whereas no cytotoxic effect could be detected on normal human lung fibroblast cells (MRC-5). However, mice treated with native L-asparaginase showed lower IgG titre compared to commercial L-asparaginase. This study highlights the promising characteristics of this enzyme making it a valuable candidate for further research and development to be an adduct in cancer chemotherapy. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia (S. maltophilia) is a nosocomial pathogen causing life-threatening invasive infections with a high mortality rate in some patient populations, especially those who are severely ill or immunocompromised. There is a need for data on mortality in patients with S. maltophilia bacteremia. In this meta-analysis, we aimed to investigate risk factors for mortality in S. maltophilia bacteremia. Studies comparing patients who died from S. maltophilia bacteremia with patients who survived were considered for inclusion. Studies were included if they reported one or more risk factors for mortality. Mortality risk factors included clinical predisposing factors, predisposing comorbidities and appropriateness of antibiotic therapy. Nineteen studies with 1248 patients were included in the meta-analysis. Five hundred and six (40.5%) patients died. The following risk factors for mortality were identified: ICU admission, septic shock, need for mechanical ventilation, indwelling central venous catheter, neutropenia, comorbid hematological malignancies, chronic kidney disease, inappropriate antimicrobial therapy and prior antibiotic use. Appropriate antimicrobial therapy had a protective effect against mortality in S. maltophilia bacteremia. Indwelling central venous catheter, neutropenia, hematological malignancies and chronic kidney disease were also risk factors for mortality. [ABSTRACT FROM AUTHOR]

Objetive/Background. The aim of this was to assess the diversity and antibiotic resistance of bacteria isolated from 19 crops with bacterial infection symptoms. Material and Methods: This collection was identified using 16S rRNA gene sequencing and the Biolog system. Susceptibility and minimum inhibitory concentration (MIC) for streptomycin, tetracycline, and gentamicin were determined using disk diffusion and E-test methods, respectively. Results: A total of 55 species belonging to 20 bacterial genera were identified, with Pseudomonas, Serratia, Pantoea, and Stenotrophomonas being the most abundant. Approximately 27% of the isolates were categorized as pathogenic through the hypersensitivity reaction test, including phytopathogenic species like Pseudomonas syringae, P. cichorii, Pantoea anthophila, P. stewartii, Stenotrophomonas maltophilia, Dickeya oryzae, Erwinia billingiae, Pectobacterium aroidearum, and Enterobacter cloacae subsp. dissolvens. Resistance to at least one antibiotic was detected in 60% of isolates from 17 crops, with tomatoes, heart of palm, and lettuce exhibited the highest proportion of resistant bacteria (>80%). Streptomycin resistance was most common (35%), followed by tetracycline (28%) and gentamicin (9%). Conclusions: The findings indicate the presence of antibiotic resistance in saprophytic and pathogenic bacteria associated with 17 out of 19 assessed crops, posing risks to the environment, phytosanitary conditions, and public health. [ABSTRACT FROM AUTHOR]

Objective This study aimed to contribute to the literature by evaluating the clinical characteristics of children with Stenotrophomonas maltophilia infection, predisposing factors, and implementation of additional measures for disease control, with the goal of improving survival and reducing mortality in pediatric patients. Methods Clinical data and microbiological test results of patients with S. maltophilia growth in cultures of samples from any biological site and clinical symptoms of systemic infection referred to the pediatric clinic of a tertiary university hospital between January 2021 and August 2023 were reviewed. Results The study included 40 patients with a median age of 2.5 years (range 1–16 years). Medical devices were present in 26 patients (65%). Polymicrobial growth occurred in 16 patients (40%). Prior to the detection of S. maltophilia infection, 35 patients (87.5%) received broad-spectrum antimicrobial therapy. Death occurred in 11 patients (27.5%). In 2022, there were 23 cases of S. maltophilia infection, with the highest number occurring in March 2022 (9 cases per month). After that date, various nonpharmacological measures were implemented for all patients with confirmed infection, including strict contact isolation in single-occupancy, high-efficiency particulate air-filtered rooms. Conclusion There were multiple risk factors for increased mortality in our study population. Despite these unfavorable factors, the mortality rate was low. Disease control was achieved through nonpharmacological interventions implemented alongside antimicrobial therapy, resulting in effective prevention of potential outbreaks. Implementation of nonpharmacological interventions alongside medical treatment can reduce mortality and improve survival in pediatric patients with S. maltophilia infection. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia (SM) bloodstream infections (BSIs) contribute to significant mortality in hematologic malignancy (HM) and hematopoietic stem cell transplantation (HSCT) patients. A risk score to predict SM BSI could reduce time to appropriate antimicrobial therapy (TTAT) and improve patient outcomes. A single center cohort study of hospitalized adults with HM/HSCT was conducted. Patients had ≥ 1 blood culture with a Gram-negative (GN) organism. A StenoSCORE was calculated for each patient. The StenoSCORE2 was developed using risk factors for SM BSI identified via logistic regression. Receiver operating characteristic (ROC) curves were plotted. Sensitivity and specificity for the StenoSCORE and StenoSCORE2 were calculated. Thirty-six SM patients and 534 non-SM patients were assessed. A StenoSCORE ≥ 33 points was 80% sensitive, 68% specific, and accurately classified 69% of GN BSIs. StenoSCORE2 variables included acute leukemia, prolonged neutropenia, mucositis, ICU admission, recent meropenem and/or cefepime exposure. The StenoSCORE2 performed better than the StenoSCORE (ROC AUC 0.84 vs. 0.77). A StenoSCORE2 ≥ 4 points was 86% sensitive, 76% specific, and accurately classified 77% of GN BSIs. TTAT was significantly longer for patients with SM BSI compared with non-SM BSI (45.16 h vs. 0.57 h; p < 0.0001). In-hospital and 28-day mortality were significantly higher for patients with SM BSI compared to non-SM BSI (58.3% vs. 18.5% and 66.7% vs. 26.4%; p-value < 0.0001). The StenoSCORE and StenoSCORE2 performed well in predicting SM BSIs in patients with HM/HSCT and GN BSI. Clinical studies evaluating whether StenoSCORE and/or StenoSCORE2 implementation improves TTAT and clinical outcomes are warranted. [ABSTRACT FROM AUTHOR]

Purpose: To describe the bacterial findings by a targeted sequencing approach from corneal samples of patients with microbial keratitis and factors influencing culture outcome of indirectly inoculated corneal specimen. Methods: Prospective inclusion of patients fulfilling predefined criteria of microbial keratitis. Samples from the corneal lesion were collected and dispensed in liquid transport medium, from which both culture and targeted amplification and sequencing of the V3-V4 region of the 16S rRNA gene were carried out. Additional standard corneal culture from the corneal lesions was also performed. Factors influencing culture outcome of indirectly inoculated corneal samples were identified by a multivariate regression model incorporating quantitative data from sequencing. Results: Among the 94 included patients with microbial keratitis, contact lens wear (n = 69; 73%) was the most common risk factor. Contact lens wearers displayed significant differences in the bacterial community composition of the corneal lesion compared to no lens wearers, with higher abundance of Staphylococcus spp., Corynebacterium spp., and Stenotrophomonas maltophilia. Targeted sequencing detected a potential corneal pathogen in the highest proportional abundance among 9 of the 24 (38%) culture-negative patients with microbial keratitis. Age, bacterial density in the sample, and prior antibiotic treatment significantly influenced culture outcome of indirectly inoculated corneal samples. Conclusion: Targeted sequencing may provide insights on pathogens in both culture negative episodes of microbial keratitis and among subgroups of patients with microbial keratitis as well as factors influencing culture outcome of indirectly inoculated corneal samples. [ABSTRACT FROM AUTHOR]

Background: Ruminant mastitis continues to be a cause of economic losses in the dairy industry and remains a major public health hazard globally. Objectives: This cross‐sectional study was carried out in Mukurweini Sub‐County of Nyeri County, Kenya, to investigate the prevalence of bacteria causing mastitis, risk factors associated with goat mastitis and the antibiotic resistance profiles of bacteria isolated from the goat milk. Methods: Farm level data on risk factors for mastitis was obtained from 56 farmers using a semi structured questionnaire. A total of 189 goat milk samples were collected. The goat's udder was observed for signs of clinical mastitis and the California Mastitis Test (CMT) used to test the milk for sub‐clinical mastitis. All samples were then cultured for morphological identification of bacteria and strain typing by Matrix Assisted Laser Desorption/Ionization (MALDI)‐Time of Flight (ToF) technique. Antimicrobial susceptibility of the isolated Staphylococcus aureus, coagulase‐negative Staphylococcus (CoNS), Escherichia coli, Klebsiella oxytoca, Pseudomonas spp., Enterobacter spp., Proteus vulgaris and Escherichia vulneris to eight commonly used antibiotics was done by the disc diffusion method and validated by determining the presence of antibiotic resistance genes (mecA and blaTEM) using polymerase chain reaction method. Results: The prevalence of clinical mastitis was 1.1% (2/189) while that of sub‐clinical mastitis was 84.7% (160/189). Higher (p < 0.05) prevalence of mastitis was observed in goats whose houses were cleaned fortnightly and in cases where farmers used same towel to dry different does' udders during the milking process. Thirteen different bacterial species were isolated from the milk samples and identified by MALDI‐ToF, and these included S. aureus (22.0%), CoNS (20.3%), E. coli (18.1%), Pseudomonas spp. (14.3%), Enterobacter spp. (10.4%), K. oxytoca (6.0%), E. vulneris (1.7%), P. vulgaris (1.7%), Raoutella ornithinolytica (1.7%), Stenotrophomonas maltophilia (1.1%), Pantoea agglomerans (1.1%), Serratia marcescens (1.1%) and Cedeceas spp. (0.6%). One hundred pathogenic bacterial isolates were randomly selected and tested for antibiotic sensitivity to eight antibiotics out of which S. aureus were 97.5% resistant to Oxacillin and 100% sensitive to Ciprofloxacin. The CoNSs were 100% resistant to Oxacillin and 100% sensitive to Ciprofloxacin. E. coli were 93.9% resistant to Oxacillin, 69.7% sensitive to Ciprofloxacin and 87.9% sensitive to both Amoxicillin/Clavulanic acid and Meropenem. The antimicrobial resistant genes detected in S. aureus and E. coli were mecA [66.7%, 0%], and blaTEM [20% and 78.3%], respectively. Conclusion: In conclusion, the study showed that most of the does were affected by subclinical mastitis with the main causative bacteria being Staphylococci spp. and coliforms. Farmers need to be trained on improved control of mastitis by adoption of good milking practices and use of CMT kit for early detection of mastitis. Occurrence of multidrug resistance by key mastitis causing pathogens was shown to be prevalent and therefore there is need for development of intervention strategies. [ABSTRACT FROM AUTHOR]

Background: Infections caused by Stenotrophomonas maltophilia and related species are increasing worldwide. Unfortunately, treatment options are limited, whereas the antimicrobial resistance is increasing. Methods: We included clinical isolates identified as S. maltophilia by VITEK 2 Compact. Ceftazidime/avibactam, meropenem/vaborbactam, imipenem/relebactam, cefiderocol, quinolones, and tetracycline family members were evaluated by broth microdilution method and compared with first-line treatment drugs. Minimum inhibitory concentrations (MICs) were reported for all antibiotics. We sequenced the Whole Genome of cefiderocol resistant strains (CRSs) and annotated their genes associated with cefiderocol resistance (GACR). Presumptive phylogenetic identification employing the 16S marker was performed. Results: One hundred and one clinical strains were evaluated, sulfamethoxazole and trimethoprim, levofloxacin and minocycline showed susceptibilities of 99.01%, 95.04% and 100% respectively. Ceftazidime was the antibiotic with the highest percentage of resistance in all samples (77.22%). Five strains were resistant to cefiderocol exhibiting MIC values ≥ 2 μg/mL (4.95%). The β-lactamase inhibitors meropenem/vaborbactam and imipenem/relebactam, failed to inhibit S. maltophilia, preserving both MIC50 and MIC90 ≥64 μg/mL. Ceftazidime/avibactam restored the activity of ceftazidime decreasing the MIC range. Tigecycline had the lowest MIC range, MIC50 and MIC90. Phylogeny based on 16S rRNA allowed to identify to cefiderocol resistant strains as putative species clustered into Stenotrophomonas maltophilia complex (Smc). In these strains, we detected GARCs such as Mutiple Drug Resistance (MDR) efflux pumps, L1-type β-lactamases, iron transporters and type-1 fimbriae. Conclusion: Antimicrobial resistance to first-line treatment is low. The in vitro activity of new β-lactamase inhibitors against S. maltophilia is poor, but avibactam may be a potential option. Cefiderocol could be considered as a potential new option for multidrug resistant infections. Tetracyclines had the best in vitro activity of all antibiotics evaluated. [ABSTRACT FROM AUTHOR]

Background: The clinical outcomes of usual doses of Trimethoprim–sulfamethoxazole (TMP/SMZ) for treating S. maltophilia in critically ill patients on renal replacement therapies (RRT) have not been established. We sought to assess the clinical outcomes of TMP/SMZ in patients with sepsis utilizing RRT. Methods: A retrospective study was performed on all critically ill adult patients with S. maltophilia infections who received RRT between May 2015 and January 2022. The primary endpoint was clinical cure while the secondary endpoints were microbiologic cure, 30-day infection recurrence, and mortality. Results: Forty-five subjects met the inclusion criteria. The median age was 70.0 [interquartile range (IQR): 63.5–77] years, 57.8% were males, and the median body mass index was 25.7 [IQR: 22–30.2] kg/m2. Clinical success and failure were reported in 18 (40%) and 27 (60%) cases, respectively. There was no significant difference between the 30-day reinfection rates of both groups; however, mortality was significantly higher in the clinical failure group, involving 12 patients (44.4%), versus none in the clinical success group (p = 0.001). The median daily dose of TMP/SMZ upon continuous veno-venous hemofiltration was 1064 [IQR: 776–1380] mg in the clinical cure group vs. 768 [IQR:540–1200] mg in the clinical failure group (p = 0.035). Meanwhile, the median dose for those who received intermittent hemodialysis was 500 [IQR: 320–928] mg in the clinical success group compared to 640 [IQR: 360–1005] mg in the clinical failure group (p = 0.372). A total of 55% experienced thrombocytopenia, 42% hyperkalemia, and 2.2% neutropenia. The multivariable logistic regression analysis showed that the total daily dose at therapy initiation was the only independent factor associated with clinical success after adjusting for different variables including the body mass index [Odds ratio 1.004; 95% confidence interval: (1–1.007), p = 0.044]. Conclusions: Although the S. maltophilia isolates were reported as susceptible, TMP/SMZ with conventional doses to treat bacteremia and pneumonia in critically ill patients utilizing RRT was associated with high rates of clinical and microbiologic failure as well as with mortality. Larger outcomes and pharmacokinetics studies are needed to confirm our findings. [ABSTRACT FROM AUTHOR]

In order to improve the extraction rate of active components in fig leaves, the fermentation of fig leaves by bacterial enzyme was studied. A strain of Stenotrophomonas maltophilia was isolated from fresh, frozen, and dried fig leaves using fig leaves as the sole carbon source. It was found that the coumarin content of fermented fig leaves was higher than that of unfermented fig leaves. Therefore, this bacterium strain was selected as the fermentation strain in this experiment. After fermentation for two days, the coumarin and terpenes contents in the fermentation broth were determined by colorimetry, and the culture conditions were optimized by single factor and orthogonal experiments. The results showed that the optimal fermentation mode was bacterial-enzyme co-fermentation, the optimal precursor was 8 mg/L of L-phenylalanine, the additional carbon source was 2 g/L maltose, the optimum nitrogen source was ammonium sulfate + peptone mixture of 3 g/L, and the optimum ratio of cellulase and pectinase was 1: 2. At the optimization condition, the contents of coumarins, terpenoids, flavonoids, and polysaccharides in the fermentation broth of fig leaves were increased by 92.66%, 59.40%, 44.68%, and 42.84% respectively. The content of polyphenols was 4.24 times higher than that before optimization. The study indicates that fig leaves fermentation can increase the content of its active components, and the study provides a basis for the development and utilization of fig leaves as a new feed additive. [ABSTRACT FROM AUTHOR]

Regular monitoring of bacterial susceptibility to antibiotics in clinical settings is key for ascertaining the current trends as well as re-establish empirical therapy. This study aimed to determine bacterial contaminants and their antimicrobial susceptibility patterns from medical equipment, inanimate surfaces and clinical samples obtained from Thika Level V Hospital (TLVH), Thika, in Central Kenya. Three hundred and five samples were collected between the period of March 2021 to November 2021 and comprised urine, pus swabs, catheter swabs, stool, and environmental samples. Bacterial identification and antimicrobial susceptibility were performed using VITEK 2 and disc diffusion respectively. We observed that Coagulase-negative Staphylococci (28 /160, 17.5%) were the most commonly isolated species from clinical samples followed by E. coli (22 /160 13.8%) and S. aureus (22/160, 13.8%). The bed rails were the mostly contaminated surface with S. aureus accounting for 14.2% (6/42). Among the clinical samples, pus swabs yielded the highest number of pathogens was pus (92/160). Trauma patients had the highest proportion of isolates (67/160, 41.8%). High level of antimicrobial resistance to key antimicrobials, particularly among Enterobacterales was observed. Extended Spectrum Beta Lactamase (ESBL) phenotype was noted in 65.9% (29/44) of enteric isolates. While further ESBL genetic confirmatory studies are needed, this study highlights the urgent need for actions that mitigate the spread of antibiotic-resistant bacteria. [ABSTRACT FROM AUTHOR]

Little is known about the relationships between human genetics and the airway microbiome. Deeply sequenced airway metagenomics, by simultaneously characterizing the microbiome and host genetics, provide a unique opportunity to assess the microbiome-host genetic associations. Here we performed a co-profiling of microbiome and host genetics with the identification of over 5 million single nucleotide polymorphisms (SNPs) through deep metagenomic sequencing in sputum of 99 chronic obstructive pulmonary disease (COPD) and 36 healthy individuals. Host genetic variation was the most significant factor associated with the microbiome except for geography and disease status, with its top 5 principal components accounting for 12.11% of the microbiome variability. Within COPD individuals, 113 SNPs mapped to candidate genes reported as genetically associated with COPD exhibited associations with 29 microbial species and 48 functional modules (P < 1 × 10−5), where Streptococcus salivarius exhibits the strongest association to SNP rs6917641 in TBC1D32 (P = 9.54 × 10−8). Integration of concurrent host transcriptomic data identified correlations between the expression of host genes and their genetically-linked microbiome features, including NUDT1, MAD1L1 and Veillonella parvula, TTLL9 and Stenotrophomonas maltophilia, and LTA4H and Haemophilus influenzae. Mendelian randomization analyses revealed a potential causal link between PARK7 expression and microbial type III secretion system, and a genetically-mediated association between COPD and increased relative abundance of airway Streptococcus intermedius. These results suggest a previously underappreciated role of host genetics in shaping the airway microbiome and provide fresh hypotheses for genetic-based host-microbiome interactions in COPD. [ABSTRACT FROM AUTHOR]

Rice is a major cereal crop which ensure food security to more than half of the global population. Several biotic factors impact rice grain quality and its final production. White stripe disease, caused by pathogen Stenotrophomonas maltophilia is considered among the major limiting factor for reducing rice yields and quality. Present study was performed to understand the white stripe disease, which has been frequently misdiagnosed as bacterial leaf blight (BLB) due to similar symptoms. A survey was carried out based on accessibility and farmer participation to monitor incidence and sample collection. The survey was conducted in districts Faisalabad, Gujranwala, Sialkot, Sheikhupura, and Hafizabad, these districts were selected for their importance for rice cultivation in Pakistan. The total sample size was around 500 leaves distributed evenly throughout each study area. The results of study indicated presence of new pathogen of rice. These isolates were biochemically identified and confirmed by gram staining negative, 3% KOH positive, 5% salt tolerance positive, oxidase test negative, catalase test positive, starch hydrolysis test negative, nitrate reductase test positive, indole test negative, lactose test positive, maltose test positive, methyl red test negative, Vogesprokauer test negative and urea hydrolysis test negative. The pathogenicity test was confirmed that pathogen and the Sialkot isolate were the most aggressive isolate among the five isolates collected form the studied areas. The molecular characterization was accomplished by PCR and sequencing. The results of the phylogenetic study indicate that this pathogen belongs to a distinct group, as it is distantly related to Xanthomonas oryzae pv. oryzae (Xoo). This study provides important findings into a novel clade of pathogen causing white stripe disease in rice. [ABSTRACT FROM AUTHOR]

Several biologically active compounds involved in the green synthesis of silver and gold nanoparticles have been isolated from snail mucus and characterized. This paper presents a successful method for the application of snail mucus from Cornu aspersum as a bioreducing agent of copper sulfate and as a biostabilizer of the copper oxide nanoparticles (CuONPs-Muc) obtained. The synthesis at room temperature and neutral pH yielded nanoparticles with a spherical shape and an average diameter of 150 nm. The structure and properties of CuONPs-Muc were characterized using various methods and techniques, such as ultraviolet–visible spectroscopy (UV–vis), high-performance liquid chromatography (HPLC), one-dimensional polyacrylamide gel electrophoresis (1D-PAGE), up-conversion infrared spectroscopy Fourier transform (FTIR), scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS), Raman spectroscopy and imaging, thermogravimetric analysis (TG-DSC), etc. Mucus proteins with molecular weights of 30.691 kDa and 26.549 kDa were identified, which are involved in the biogenic production of CuONPs-Muc. The macromolecular shell of proteins formed around the copper ions contributes to a higher efficiency of the synthesized CuONPs-Muc in inhibiting the bacterial growth of several Gram-positive (Bacillus subtilis NBIMCC2353, Bacillus spizizenii ATCC 6633, Staphylococcus aureus ATCC 6538, Listeria innocua NBIMCC8755) and Gram-negative (Escherichia coli ATCC8739, Salmonella enteitidis NBIMCC8691, Salmonella typhimurium ATCC 14028, Stenotrophomonas maltophilia ATCC 17666) bacteria compared to baseline mucus. The bioorganic synthesis of snail mucus presented here provides CuONPs-Muc with a highly pronounced antimicrobial effect. These results will expand knowledge in the field of natural nanomaterials and their role in emerging dosage forms. [ABSTRACT FROM AUTHOR]

Background and Objectives: Stenotrophomonas maltophilia is an opportunistic pathogen causing nosocomial infections. Diclofenac is an anti-inflammatory drug that is considered a non-antibiotic drug. This study assessed the antibacterial and antibiofilm effects of diclofenac and levofloxacin/diclofenac combination against levofloxacin resistant isolates. Materials and Methods: Minimum inhibitory concentration was determined using broth microdilution method for levofloxacin, diclofenac, and levofloxacin/diclofenac combination. Biofilm forming capacity and biofilm inhibition assay were determined. Relative gene expression was measured for efflux pump genes; smeB, and smeF genes and biofilm related genes rmlA, spgM, and rpfF without and with diclofenac and the combination. Results: Diclofenac demonstrated MIC of 1 mg/ml. The combination-with ½ MIC diclofenac-showed synergism where levofloxacin MIC undergone 16-32 fold decrease. All the isolates that overexpressed smeB and smeF showed a significant decrease in gene expression in presence of diclofenac or the combination. The mean percentage inhibition of biofilm formation with diclofenac and the combination was 40.59% and 46.49%, respectively. This agreed with biofilm related genes expression investigations. Conclusion: Diclofenac showed an antibacterial effect against Stenotrophomonas maltophilia. The combination showed in-vitro synergism, significant reduction in biofilm formation and in the relative level of gene expression. Furthermore, it can potentiate the levofloxacin activity or revert its resistance. [ABSTRACT FROM AUTHOR]