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Bitkiler çok eski zamanlardan beri hem Türkiye’de hem de dünyada tıbbi amaçlı olarak kullanılmaktadır. Bu bitkilerin çoğu antimikrobiyal özellikleri nedeniyle pek çok hastalığın tedavi sürecine dahil edilmektedir. Benzer şekilde meyveler de geleneksel tedavi amaçlı halk arasında sıklıkla kullanılmaktadır. Bir yabani meyve türü olan Berberis crataegina (karamuk) meyveleri tanen, organik asitler, yüksek oranda C vitamini ve antosiyanin içermekte olup; ateş düşürücü, kaşıntı önleyici ve diüretik etkilerinden dolayı yaygın olarak tüketilmektedir. Bu çalışmada, Berberis crataegina meyvelerinin farklı çözücülerle (etanol, metanol, hekzan, diklorometan) hazırlanan ekstratlarının total antioksidan/oksidan etkileri ve Stenotrophomonas maltophilia bakterisine karşı antibakteriyel etkisinin belirlenmesi amaçlandı. Çalışmada, toplanıp kurutulan meyve tanelerinin farklı çözücülerle hazırlanan ekstraktlarında total antioksidan/oksidan seviyeleri ticari kitler ile spektrofotometrede ölçüldü. Berberis crataegina meyvelerinin Stenotrophomonas maltophilia bakterisine karşı antibakteriyel etkisinin olup olmadığı disk difüzyon yöntemiyle belirlendi. Çalışmaya göre Berberis crataegina meyvelerinin yüksek antioksidan seviyeye sahip olduğu, Stenotrophomonas maltophilia bakterisine karşı antibakteriyel etkisinin olmadığı tespit edildi., Plants have been used for medicinal purposes both in Türkiye and in the world since ancient times. Many of these plants are included in the treatment process of many diseases due to their antimicrobial properties. Similarly, fruits are frequently used among the people for traditional treatment purposes. Berberis crataegina (barberry) fruits, a wild fruit species, contain tannins, organic acids, high levels of vitamin C and anthocyanins; it is widely consumed due to its antipyretic, antipruritic and diuretic effects. In this study, it was aimed to determine the total antioxidant/oxidant effects of Berberis crataegina fruit extracts prepared with different solvents (ethanol, methanol, hexane, dichloromethane) and antibacterial effect against Stenotrophomonas maltophilia bacteria. In the study, the total antioxidant/oxidant levels of the extracts of the collected and dried fruit grains prepared with different solvents were measured in spectrophotometer with commercial kits. The antibacterial effect of Berberis crataegina fruits against Stenotrophomonas maltophilia was determined by disk diffusion method. According to the study, it was determined that Berberis crataegina fruits had high antioxidant level and had no antibacterial effect against Stenotrophomonas maltophilia bacteria.

Background Stenotrophomonas maltophilia causes opportunistic infections in immunocompromised and patients in intensive care units (ICUs). An outbreak of S. maltophilia in ICU is described which highlights the importance of the risk of infection from contaminated medical devices and suction fluids in ventilated patients. Methods The investigation of the outbreak was carried out. Environmental sampling was done. This was followed by MALDI-TOF MS typing and recA gene-based-phylogeny. Results In February, S. maltophilia was reported from the central line blood of six patients from ICU within a span of two weeks. The peripheral line blood cultures were sterile in all patients. Relevant environmental sampling of the high-touch surface and fluids revealed S. maltophilia strains in normal saline used for suction and in the inspiratory circuit of two patients. The isolated strains from patients and environment (inspiratory fluid) showed a minimum of 95.41% recA gene sequence identity between each other. Strict cleaning and disinfection procedures were followed. Continuous surveillance was done and no further case of S. maltophilia was detected. Timely diagnosis and removal of central line prevented development of central-line associated blood stream infection. Conclusion This outbreak report illustrates that environmental sources like suction fluid and normal saline could be the source of S. maltophilia in ICU patients.

Objectives To explore the in vitro antimicrobial susceptibility among clinically important Gram-negative bacteria (GNB) in Taiwan. Methods From 2016 through 2018, a total of 5458 GNB isolates, including Escherichia coli (n = 1545), Klebsiella pneumoniae (n = 1255), Enterobacter species (n = 259), Pseudomonas aeruginosa (n = 1127), Acinetobacter baumannii complex (n = 368), and Stenotrophomonas maltophilia (n = 179), were collected. The susceptibility results were summarized by the breakpoints of minimum inhibitory concentration (MIC) of CLSI 2020, EUCAST 2020 (for colistin), or published articles (for ceftolozane/tazobactam). The resistance genes among multidrug-resistant (MDR) or extensively drug-resistant (XDR)-GNB were investigated by multiplex PCR. Results Significantly higher rates of non-susceptibility (NS) to ertapenem and carbapenemase production, predominantly KPC and OXA-48-like beta-lactamase, were observed in Enterobacterales isolates causing respiratory tract infection than those causing complicated urinary tract or intra-abdominal infection (12.7%/3.44% vs. 5.7%/0.76% or 7.7%/0.97%, respectively). Isolates of Enterobacter species showed higher rates of phenotypic extended-spectrum β-lactamase and NS to ertapenem than E. coli or K. pneumoniae isolates. Although moderate activity (54–83%) was observed against most potential AmpC-producing Enterobacterales isolates, ceftolozane/tazobactam exhibited poor in vitro (44.7–47.4%) activity against phenotypic AmpC Enterobacter cloacae isolates. Additionally, 251 (22.3%) P. aeruginosa isolates exhibited the carbapenem-NS phenotype, and their MDR and XDR rate was 63.3% and 33.5%, respectively. Fifteen (75%) of twenty Burkholderia cenocepacia complex isolates were inhibited by ceftolozane/tazobactam at MICs of ≤4 μg/mL. Conclusions With the increase in antibiotic resistance in Taiwan, it is imperative to periodically monitor the susceptibility profiles of clinically important GNB.

Edible insects, regarded as a potential contributor to food security are currently given wide consideration due to their rich protein and other micronutrients contents. In this study, protease-assisted hydrolysis proposes an economically effective approach to hydrolyse proteins from silkworm (Bombyx mori) pupae to improve its functional properties. The proteolytic activity of a novel neutral protease (265.14 U/ml) with appreciable thermal activities, was identified using 16S rDNA as Stenotrophomonas maltophilia JW20 (SmNP20). The neutral protease with an apparent molecular weight of 28 kDa emerged active at pH 7 and maintained stability in pH range 6.0-8.0. The optimum temperature was 60 °C and stable at 55-60 °C, maintaining over 80% of its initial activity, with a half-life of 78.75, 89, 66.8 and 44 min at 50, 60, 70 and 80 °C. It was purified to 9.98-fold with a specific activity of 455.06 U/mg and 63.73% yield. The Km and Vmax values were 0.70 mg/ml and 9.48 μmol/min/mg, respectively. Enzymolysis with neutral protease enhanced the degree of hydrolysis (97.46±4.87%), increased water solubility over 50%, and a significant protein solubility of 63.44±0.65%. The Km and Vmax of the protein yield were 0.24 mg/ml and 165.63 μmol/min/mg respectively. A total of 17 amino acids have been detected in the hydrolysates obtained from the silkworm pupae protein. In comparison with neutrase and flavorzyme®, the enzyme possesses an elevated hydrolytic and catalytic efficiency. Emulsion activity and foam capacity ranged from 8-48 m2/g and 6-25% respectively. Hence, this study confirms the unique and efficient characteristics of an insect-enzyme correlation that is practically significant with potential improvement in nutritional composition and functional quality of insect proteins.

Stenotrophomonas maltophilia is an important multidrug resistant nosocomial pathogen. Trimethoprim/sulfamethoxazole (TMP/SMX) is considered the drug of choice for treatment of S. maltophilia infections, thus emerging resistance to TMP/SMX poses a serious threat. In the present study we aimed to investigate the frequency of TMP/SMX resistance genes (sul1, sul2, dfrA), and to evaluate their relatedness with integron 1 (int1), and insertion sequence common regions (ISCR) among 100 S. maltophilia from different clinical isolates in Egypt. Isolates were identified biochemically and confirmed by VITEK2. Detection of sul1, sul2, and dfrA genes, int1 and ISCR elements was performed by PCR. Among the 16 TMP/SMX resistant isolates, sul1 gene was detected in all of them, and it was associated with int1 gene presence in all resistant isolates. The sul2 gene was detected in 6 out of 16 resistant isolates (37.5%), and only 2 of the 16 resistant isolates (12.5%) harboured dfrA gene. ISCR was detected in 10 of the resistant isolates (62.5%) and in 4 of them it was associated with the presence of sul2 gene. Among the 84 TMP/SMX sensitive isolates, sul1 gene was detected in 15 (17.8%), int1 in 16 (19%) and ISCR in 6 (7.1%). None of the susceptible isolates had sul2 or dfrA genes. These findings point out an increasing frequency of TMP/SMX resistance genes among S. maltophilia clinical isolates in our region, so the adoption of prudent use of S. maltophilia antimicrobial agents and the establishment of a surveillance system are desperately needed.

Background To depict ecthyma gangrenosum (EG) clinical presentation and evolution in a large multicenter pediatric retrospective collection of children with malignancies or bone marrow failure syndromes, to facilitate early diagnosis. Methods EG episodes diagnosed in the period 2009-2019 were identified by a retrospective review of clinical charts at centers belonging to the Italian Pediatric Hematology Oncology Association. Results Thirty-eight cases of EG occurring in children (male/female 16/22; median age 5.2 years) with hematologic malignancy (29), allogeneic stem cell transplantation (2) or relapsed/refractory solid tumor (3) were collected. The involved sites were: perineal region (19), limbs (10), trunk (6), head and the iliac crest (3). Bacteremia was present in 22 patients. Overall, the germs isolated were Pseudomonas aeruginosa (30), Stenotrophomonas maltophilia (3) and Escherichia coli (1); 31% of them were multidrug-resistant. All patients received antibacterial treatment, while surgery was performed in 24 patients (63.1%). Predisposing underlying conditions for EG were severe neutropenia (97.3%), corticosteroid treatment (71%) and iatrogenic diabetes (23.7%). All patients recovered, but EG recurred in 5 patients. Nine patients (24%) showed sequelae (deep scars, with muscle atrophy in 2). Four patients (10.5%) died, 1 due to relapse of EG with Carbapenem-resistant Enterobacteriaceae co-infection and 3 due to the progression of the underlying disease. Conclusions EG requires early recognition and a proper and timely treatment to obtain the recovery and to avoid larger necrotic lesions, eventually evolving in scarring sequelae.

Background The emergence of concurrent levofloxacin- and trimethoprim/sulfamethoxazole (TMP/SMX)-resistant Stenotrophomonas maltophilia (LTSRSM) in Taiwan is becoming a serious problem, but clinical data analysis on this has not been reported. Methods A matched case-control-control study was conducted to investigate risk factors for LTSRSM occurrence in hospitalized patients. For patients with LTSRSM infection/colonization (the case group), two matched control groups were used: control group A with levofloxacin- and TMP/SMX-susceptible S. maltophilia (LTSSSM) and control group B without S. maltophilia. Besides, tigecycline, ceftazidime, cefepime, ciprofloxacin, gentamicin, amikacin, and colistin susceptibilities in collected LTSRSM and levofloxacin- and TMP/SMX-susceptible S. maltophilia (LTSSSM) isolates were compared. Results From January 2014 to June 2016, 129 LTSRSM from cultured 1213 S. maltophilia isolates (10.6%) were identified. A total of 107 LTSRSM infected patients paired with 107 LTSSSM-, and 107 non-S. maltophilia-infected ones were included. When compared with control group A, previous fluoroquinolone and TMP/SMX use was found to be independently associated with LTSRSM occurrence. When compared with control group B, mechanical ventilation, cerebrovascular disease, and previous fluoroquinolone use were risk factors for LTSRSM occurrence. Eighty-five LTSRSM and 85 LTSSSM isolates were compared for antibiotic susceptibilities; the resistance rates and minimum inhibitory concentrations of tigecycline and ceftazidime were significantly higher for LTSRSM than for LTSSSM isolates. Conclusion The emergence of LTSRSM showing cross resistance to tigecycline and ceftazidime would further limit current therapeutic options. Cautious fluoroquinolone and TMP/SMX use may be helpful to limit such high-level resistant strains of S. maltophilia occurrence.

Objectives Stenotrophomonas maltophilia MER1, a multidrug resistant (MDR) bacterium was isolated from the wastewater from a hospital, Shandong province, China. We attempted to reveal the genetic determinants related to its striking MDR features for effective treatment to S. maltophilia. Methods Antibiotic susceptibility testing of strain MER1 was performed by using the disk diffusion method on the Mueller-Hinton agar plates, and the minimum inhibitory concentrations (MICs) were determined according to the Clinical Laboratory Standard Institute protocols. The genome of MER1 was sequenced and assembled with a PacBio RS II and a BGISEQ-500 platform. Antibiotic resistance agents together with other transferability or adaptability determinants were identified by comparative genomics. Phylogenetic and contextual assays for these identified elements were conducted to assess the spread risk of MER1. Results Susceptibility testing reveals that strain MER1 is strikingly resistant to nine different antibiotics, including ampicillin, meropenem, amikacin, erythromycin, vancomycin, tetracycline, tigecycline, polymyxin E and ceftazidime. Several genes were identified to encode efflux pumps and inactivation agents accounting for MER1 resistance to above antibiotics, including meropenem, tigecycline and colistin regarded as the last-line therapy for infections caused by multidrug-resistant Gram-negative bacteria. MER1 co-harbors two non-mobile mcr homologs. A novel genomic region of variability was demonstrated to confer bacterial robustness and adaptability upon strain MER1. Conclusion Collective efforts revealed the multiple drug resistance properties and potential genetic determinants of S. maltophilia MER1 isolated from the hospital sewage. Comparative genomic analysis of S. maltophilia MER1 may provide insights into prevention and treatment of its antimicrobial resistance. Our findings would prompt public concern that the MDR genes in the reservoir of S. maltophilia may further spread into various ecological niches or medically high-risk pathogens.

Objectives: The prevalence of Gram-negative bacteria (GNB) demonstrating extensive, multiple antimicrobial resistance is increasing in England, leaving few treatment choices. Cefiderocol is a novel siderophore cephalosporin approved in Europe for the treatment of aerobic GNB infections in adults with limited treatment options. We report pooled data for a clinical isolate set collected in England between 2014–2018. Methods: MICs were determined by broth microdilution according to International Organization for Standardization guidelines. Cefiderocol susceptibility was tested using iron-depleted cation-adjusted Muller–Hinton broth. Susceptibility rates were based on EUCAST breakpoints. In the absence of a species-specific breakpoint, pharmacokinetic/pharmacodynamic breakpoints were used. Results: Of 1886 isolates from England [74.1% Enterobacterales (18.7% Escherichia coli, 17.2% Klebsiella pneumoniae), 25.9% non-fermenters (18.4% Pseudomonas aeruginosa, 3.7% Acinetobacter baumannii)], 98.7% were cefiderocol-susceptible. Cefiderocol susceptibility in Enterobacterales (99.0%) was significantly (P < 0.01) greater than ceftolozane/tazobactam (94.3%), but similar to meropenem (99.3%) and ceftazidime/avibactam (99.4%). Overall, cefiderocol susceptibility (98.0%) in non-fermenters was significantly (P < 0.01) higher than comparators (range, 84.5–92.4%). Susceptibility to cefiderocol was 98.3–99.6% by infection source and was significantly (P < 0.01) greater than comparators for isolates from patients with nosocomial pneumonia (cefiderocol, 98.3%; comparators range, 79.8–93.8%). Excluding intrinsically meropenem-resistant Stenotrophomonas maltophilia, 47/1846 isolates (2.5%) were meropenem-resistant. A high proportion of meropenem-resistant P. aeruginosa were susceptible to cefiderocol (95.0%). All S. maltophilia isolates (40/40) were cefiderocol-susceptible. Conclusion: A substantial proportion of clinical isolates from England, representing a wide range of pathogens across multiple infection sources, was cefiderocol-susceptible. Cefiderocol retained activity against meropenem-resistant strains.

Purpose Stenotrophomonas maltophilia has emerged as a critical opportunistic pathogen associated with significant morbidity and mortality. Tetracycline derivatives have been recognized as alternative treatment options, but they have varied pharmacokinetic properties. An integrated approach to different tetracycline derivatives for formulary decisions is reported. Methods The minimum inhibitory concentration (MIC) data from clonally diverse bloodstream S. maltophilia isolates were examined, along with the pharmacokinetic profiles of 4 tetracycline derivatives, to predict achievable pharmacodynamic exposures with standard intravenous dosing regimens. Antimicrobial therapy was assessed using the ratio of daily drug acquisition cost relative to the ratio of the free-drug area under the time-concentration curve (fAUC) to minimum inhibitory concentration (MIC) for 90% of isolates (fAUC/MIC90). Results In our analysis, minocycline had the greatest fAUC/MIC90. Doxycycline was the most financially preferred agent, as calculated using 2020 average wholesale price for base-case estimates of drug acquisition cost. Conclusion An integrated evaluation for antimicrobial formulary decision-making addressed local susceptibility data, pharmacokinetics, pharmacodynamics, dosing regimens, and drug acquisition costs. This comprehensive method is more objective than the conventional approach and warrants validation.

In this study, we have focused on the lytic phage proteins encoded by the Stenotrophomonas phages. A total of 60 lytic proteins were identified to be encoded by 19 different phages. Those proteins were characterized under eight classes: amidases, muramidases, pectate lyase, peptidases, holins and spanins. The phages encoding these proteins come under the family of Ackermannviridae, Autographiviridae, Myoviridae, Podoviridae and Siphoviridae. All the phages encoding those proteins were found to infect Stenotrophomonas maltophilia. Among the phages, about 50% were found to undergo a lytic lifecycle. The isolated proteins were clustered according to the similarity in the amino acid sequence. These clusters were used to make their phylogenetic tree. The co-occurrence of the amidase, pectate lyase and lipase genes in the phage genome was found using a correlation analysis.

ObjectivesComplicated urinary tract infections (cUTIs) are frequently encountered in hospitals and ICUs. Increasingly, the causative pathogens harbour enzymatic resistance mechanisms. Taniborbactam is a novel β-lactamase inhibitor with activity against Ambler class A, B, C and D β-lactamases. Herein, we assessed the efficacy of cefepime alone and the combination cefepime/taniborbactam in a neutropenic murine cUTI model.MethodsEighteen cefepime-resistant clinical isolates (9 Enterobacterales, 3 Pseudomonas aeruginosa and 6 Stenotrophomonas maltophilia; cefepime MIC = 32 to >512 mg/L) were assessed. Cefepime/taniborbactam MICs ranged from 0.06 to 128 mg/L. Human-simulated plasma regimens (HSRs) of cefepime alone and in combination with taniborbactam were developed in the murine cUTI model. The efficacy of cefepime HSR and cefepime/taniborbactam HSR was determined as the change in log10 cfu/kidney at 48 h compared with 48 h controls.ResultsMean ± SD initial bacterial burden was 5.66 ± 0.56 log10 cfu/kidney, which increased to 9.05 ± 0.39 log10 cfu/kidney at 48 h. The cefepime HSR was ineffective, as bacterial burden was similar to untreated controls (−0.14 ± 0.40 change in log10 cfu/kidney). In contrast, cefepime/taniborbactam exhibited substantial killing, with log10 cfu/kidney changes of −5.48 ± 1.3, −4.79 ± 0.3 and −5.04 ± 0.7 for ESBL/AmpC-, KPC- and OXA-48-harbouring Enterobacterales, respectively. Cefepime/taniborbactam also exhibited robust killing of P. aeruginosa (−6.5 ± 0.26) and S. maltophilia (−5.66 ± 0.71).ConclusionsHumanized exposures of cefepime/taniborbactam achieved robust killing of Enterobacterales, P. aeruginosa and S. maltophilia harbouring ESBL, AmpC, KPC and/or OXA-48. These data support the role of cefepime/taniborbactam for cUTI treatment for cefepime/taniborbactam MICs up to 32 mg/L.

Glyphosate-based herbicides are often used for the control of weeds grown on agricultural fields or farms. Different health problems have been reported to be associated with the use of glyphosate-based herbicides mainly due to their toxicity level. Thus, finding glyphosate utilizing microorganisms to remediate the glyphosate-based herbicides in the environment is crucial. The culture conditions for maximum utilization of glyphosate by bacterial isolates, Stenotrophomonas maltophilia, Bacillus cereus and Enterobacter aerogenes previously isolated from Ugini stream close to corn fields treated with glyphosate-based herbicide at Ofagbe, Delta State, Nigeria were optimized using mineral salt medium containing glyphosate as carbon source. The varied culture parameters assessed were temperature (30, 37 and 40 oC), pH (5, 6, 7, 8 and 9), initial glyphosate concentration (1, 3, 5, 7 and 9 g/L) and incubation time (2-14 days). Optical density (OD) at 560 nm of the culture was used to estimate cell growth or cell load of the glyphosate utilizing bacteria strains at every 2 days for 14 days. The following optimal conditions were determined: initial pH 9.0, incubation temperature 30 °C, initial concentration of glyphosate (1g/L) and incubation time of 12 days. Of the isolates on the medium containing the herbicide as sole carbon and energy source, Bacillus cereus showed the highest growth level (OD average, 0.127, pH average, 6.26. This was followed by Stenotrophomonas maltophilia (OD average = 0.114, pH average = 6.44) and Enterobacter aerogenes (OD average = 0.100, pH average, 6.56). At the increased of glyphosate in the medium there was decreased in growth of the bacteria. Bacillus cereus, Stenotrophomonas maltophilia and Enterobacter aerogenes indicated a high capacity to be able to degrade glyphosate. It is therefore concluded that the bacteria employed in this research can be recommended for bioremediation of environments contaminated with this chemical and further research should conducted to ascertain the catabolic genes present in these individual glyphosate degrading bacteria.

Candida utilis and Stenotrophomonas maltophilia co-infections connected to meningitis are uncommon. We describe a patient who developed C. utilis and S. maltophilia after undergoing neurosurgery and received effective nosocomial meningitis treatment. Multiple neurosurgeries were required for a 16-year-old girl due to complications. For probable nosocomial meningitis, she was treated with cefepime with vancomycin. Meropenem and liposomal amphotericin B were prescribed after her seizure and positive CSF culture for Candida utilis. Consequently, S. maltophilia was discovered in the CSF, and ceftazidime and trimethoprim-sulfamethoxazole were prescribed. The patient has been hemodynamically stable for the past two months, and consecutive CSF cultures have been negative. To the best of our knowledge, this is the first case of C. utilis and S. maltophilia co-infection that has been successfully handled.

Stenotrophomonas maltophilia is ubiquitous in diverse environmental habitats. It merits significant concern because of its increasing incidence of nosocomial and community-acquired infection in immunocompromised patients and multiple drug resistance. It is rarely reported as a phytopathogen except in causing white stripe disease of rice in India and postharvest fruit rot of Lanzhou lily. For this study, Dickeya zeae and S. maltophilia strains were simultaneously isolated from soft rot leaves of Clivia miniata in Guangzhou, China, and were both demonstrated to be pathogenic to the host. Compared with the D. zeae strains, S. maltophilia strains propagated faster for greater growth in lysogeny broth medium and produced no cellulases or polygalacturonases, but did produce more proteases and fewer extracellular polysaccharides. Furthermore, S. maltophilia strains swam and swarmed dramatically less on semisolid media, but formed a great many more biofilms. Both D. zeae and S. maltophilia strains isolated from clivia caused rot symptoms on other monocot hosts, but not on dicots. Similar to previously reported S. maltophilia strains isolated from other sources, the strain JZL8 survived under many antibiotic stresses. The complete genome sequence of S. maltophilia strain JZL8 consists of a chromosome of 4,635,432 bp without a plasmid. Pan-genome analysis of JZL8 and 180 other S. maltophilia strains identified 50 genes that are unique to JZL8, seven of which implicate JZL8 as the potential pathogen contributor in plants. JZL8 also contains three copies of Type I Secretion System machinery; this is likely responsible for its greater production of proteases. Findings from this study extend our knowledge on the host range of S. maltophilia and provide insight into the phenotypic and genetic features underlying the plant pathogenicity of JZL8.

Tick-borne viruses and bacteria that can cause diseases of animals and humans have high impact and are of concern as significant threats to human health worldwide. In this research, we screened microorganisms related to those pathogens in ticks from dogs, a cat, and a cow. The techniques used were PCR, DNA sequencing and phylogenetic analysis to detect and classify the microorganisms [Flavivirus, severe fever with thrombocytopenia syndrome virus (SFTSV), Phlebovirus, Coronavirus, Canine Parvovirus, eubacteria, Coxiella and Rickettsia]. A novel virus named Phlebovirus-like-AYUT and Stenotrophomonas maltophilia bacteria were found in one individual tick (Rhipicephalus sanguineus s.l.) from a dog. All tick samples were negative for Rickettsia, while 9/21 (42.9 %) were positive for Coxiella bacteria. The novel virus “Phlebovirus-like-AYUT” (the name derives from Phra Nakhon Si Ayutthaya Province in Thailand) was resolved by phylogenetic analysis of the partial L segment by maximum likelihood (ML) method using MEGA X. The phylogenetic tree also indicated that the virus was related to Phlebovirus in brown dog ticks reported in Trinidad and Tobago. In contrast, Phlebovirus-like-AYUT was in a distinct clade from Lihan tick Phlebovirus-Thailand (LTPV), which was previously found in cow ticks, Rhipicephalus microplus, in Nan Province, Thailand. This study reports the Stenotrophomonas maltophilia bacterium with a novel Phlebovirus-like-AYUT in a brown dog tick. The roles of this bacterium in a virus-positive tick or in viral transmission from animal host requires further investigation.

The aim of the work was to explore the antioxidant potential and antibiofilm activity of the Rosmarinus officinalis essential oil. The DPPH method was used to determine the antioxidant activity. The agar microdilution method was used to determine the minimum biofilm inhibiting concentration (MBIC). The MALDI-TOF MS Biotyper was used to evaluate the antibiofilm activity on the wood and glass surface. Vapor phase antimicrobial analysis was used to determine the effect on the food model. The antioxidant activity was 28.76 % ± 2.68 %. The MBIC for Stenotrophomonas maltophilia was 25 µL.mL-1 and for Bacillus subtilis 12.5 µL.mL-1. Analysis of the mass spectra of S. maltophilia revealed an inhibitory effect from the 5th, which persisted until the end of the experiment. Analysis of the mass spectra of B. subtilis showed an inhibitory effect from the 7th of the experiment. The experiments showed an effect on both tested surfaces. The food model showed a more pronounced effect of the Rosmarinus officinalis essential oil against B. subtilis. We assume that the effect of the essential oil is to disrupt the polysaccharide structure of the biofilm and consequently reduce the resistance of the biofilm. We have established that MALDI-TOF MS Biotyper is a suitable tool for evaluating changes in biofilm structure and could find more significant application for the study of biofilms in food and clinical practice.

Thibaud Soumagne, Florence Levesque, Julie Milot, Krystelle Godbout, Yves Lacasse, François Maltais Service de pneumologie, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, CanadaCorrespondence: Thibaud SoumagneService de pneumologie, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, CanadaEmail thibaud_soumagne@live.frIntroduction: Stenotrophomonas maltophilia is an emerging Gram-negative MDR bacteria. In patients with chronic obstructive pulmonary disease (COPD), it is mostly found in those with severe exacerbation of COPD requiring mechanical ventilation. The significance of S. maltophilia when detected in the sputum of ambulatory patients with COPD is uncertain.Objective: To access the prevalence and the risk factors of the presence of S. maltophilia in the sputum of ambulatory patients with COPD and to determine whether it was associated with prognosis.Methods: All consecutive unselected ambulatory patients with GOLD 2– 4 COPD were recruited between January 2017 and September 2019 from the COPD clinic of a tertiary care hospital. Presence of S. maltophilia was defined by a positive sputum culture for S. maltophilia. Demographics, COPD characteristics, comorbidities and known predisposing risk factors associated with S. maltophilia were collected from medical records.Results: S. maltophilia was detected in the sputum of 41/393 (10%) of study participants. Comorbidities, exacerbation, use of oral steroids and carbapenems in the previous year were risk factors for the presence of S. maltophilia. After adjusting on confounding factors associated with mortality including age, Charlson comorbidity index and FEV1, S. maltophilia was significantly associated with mortality (adjusted hazard ratio 2.3; 95% CI 1.1– 4.9).Conclusion: In the current study, we found that 10% of ambulatory patients with GOLD 2– 4 COPD had S. maltophilia detected in their sputum. In addition, S. maltophilia may represent a marker of overall morbidity in patients with COPD.Keywords: Stenotrophomonas maltophilia, pulmonary disease, chronic obstructive, risk factors, prognosis

Aims: To identify the antimicrobial potency of the leaf fractions of Vernonia arborea against selected wound microbes viz., Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Stenotrophomonas maltophilia. Background: Wound healing is often delayed due to the presence of polymicrobial load, that have to be abolished to facilitate the healing process. A major class of antimicrobial phytocompound reported to occur in Vernonia arborea species include sesquiterpenes. Reports on the wound healing potency of V. arborea in wound models of Wistar rats however did not report antimicrobial activity of the aqueous or methanolic extracts. Methodology: The column fractions of the hexane leaf extract were tested against the selected strains by agar well diffusion assay and the zone of inhibition confirmed with TLC bioautography at specific Rf. The minimum inhibitory concentration (MIC) of the bioactive fractions was identified using resazurin microtiter assay (REMA) and the minimum bactericidal concentration (MBC) was determined. HPTLC quantification was also performed. Results: Out of the 30 pooled fractions, six showed antimicrobial potency against all the five tested wound microbes. The minimum inhibitory concentrations of these fractions were determined, ranging from 15.62 µg/mL to 500 µg/mL for the different microbes. Quantitative High-Performance Thin Layer Chromatography (HPTLC) revealed two compounds (a and b) in the bioactive fraction10 with yields of 633 mg (63%) and 97 mg (9.7%) per gram of the extract. Conclusion: The findings suggest the potential use of the bioactive compound in chronic infectious wound management therapy.

Background Antimicrobial resistance (AMR) of non-fermenting Gram-negative bacteria (NFGNB) is increasingly recognized as urgent healthcare threat. Trend data on AMR of NFGNB in Saudi Arabia are either old or limited. The objective was to estimate the prevalence and resistance trends of isolated NFGNB in Saudi Arabia. Methods A retrospective multicenter study involving seven tertiary care hospitals in Saudi Arabia was conducted between 2011 and 2016. Susceptibility testing for non-duplicate isolates was performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines in College of American Pathologists accredited diagnostic microbiology laboratories in the participating hospitals. Results Out of 461,274 isolates, 100,132 (21.7%) were NFGNB which represented 30% of gram-negative pathogens. Pseudomonas aeruginosa was the most common (73.6%), followed by Acinetobacter baumannii (21.0%) and Stenotrophomonas maltophilia (5.3%). Resistance trends of P. aeruginosa were increasing for aztreonam (absolute increase during the study was 17.3%), imipenem (12.3%), and meropenem (11.6%). A. baumannii was fully resistant to several beta lactam drugs, and resistance trends were increasing for potential treatments such as tigecycline (25.1%) and tobramycin (15.5%). S. maltophilia was >90% resistant to trimethoprim/ sulfamethoxazole and ciprofloxacin by the end of the study. Conclusion We are reporting high and/or increasing resistance of NFGNB to common treatment options. The current findings call for urgent actions to combat the increasing resistance of NFGNB. Large scale sharing of AMR data collected at different hospitals with the Saudi AMR committee would be critical to set priorities and monitor progress.

Aim: To focus on the frequency of ICU-acquired infections in Sars Co-V2 Corona Virus disease (COVID 19) patients. Method: A retrospective observational study carried out in two tertiary care hospitals treating COVID 19 cases, Services Institute of Medical Sciences and Bahria International Hospital, Lahore. Data was collected from the medical records of the COVID 19 ICUs of both hospitals from May 1, 2020 to April30, 2021. All charts were reviewed for the evidence of positive cultures. The treatment given prior to positive cultures, after the availability of culture results and outcomes were also recorded. Results: A total of 432 records were reviewed and 400 cases were included while 32 cases were excluded because of incomplete data. The frequency of infections per 1,000 days of ICU stay was calculated in 90 (22.5%) patients. Gram-negative bacteria accounted for 68 cases (75.5%) with Pseudomonas in 44 cases (48.8%), Acinetobacter in 23/90 (25.5%) while 17 cases (18.8%) had gram positive infection with Enterococcus in 14/18 (77.77%) or 14/90 (15.55%), MRSA in 4/18 (22.22%) 4/90 (4.44%), while 5/90 (5.5%) had more than 2 isolates at same time. Among these 3 had both pseudomonas and Acinetobacter while 2 patients had Pseudomonas and Stenotrophomonas Maltophilia. Conclusion: There seems to be an increase in the infection rate among critically sick COVID 19 patients admitted in ICU. Use of steroids and Tocilizumab seems to play a role through their immunomodulatory effects. Keywords: Tocilizumab, Secondary infections

BACKGROUND Stenotrophomonas maltophilia is an opportunistic pathogen and a dreaded cause of bacteraemia with 30-day mortality rates ranging from 14 to 69%. The purpose of this cohort study was to evaluate outcomes of S. maltophilia bacteraemia, at Rigshospitalet, a tertiary hospital in Copenhagen, Denmark. METHODS We included all patients with a blood culture positive for S. maltophilia, from January 1, 2015 to April 1, 2020. We extracted data on antimicrobial susceptibility, treatment, central venous catheter intervention and severe haematological disease. RESULTS Sixty-one cases of S. maltophilia bacteraemia were identified. The overall 90-day mortality was 18%. Sixty percent of patients had a central venous catheter intervention performed. Seventy-nine percent of patients were treated with trimethoprim/sulfamethoxazole (TMP/SMX). Patients with central venous catheter intervention had significantly better survival than those without (HR: 0.16 [95% CI: 0.03-0.73]). Severe haematological disease and patients, who received intensive care unit (ICU) care, were at higher risk of death than other patients (HR: 5.93 [95% CI: 1.18 - 29.94] and HR: 8.37 [95% CI: 1.79 - 39.20], respectively). We found no evidence that any antibiotic regime was superior with regard to 90-day mortality. CONCLUSIONS We did not find evidence to support a change in the current standard-of-care regimen of TMP/SMX and CVC removal. Larger clinical trials are needed to guide such recommendations.

Introduction Tigecycline is a potential alternative to trimethoprim–sulfamethoxazole in treating Stenotrophomonas maltophilia infections due to its potent in vitro antimicrobial activity. Clinical evidence regarding the use of tigecycline in the treatment of S. maltophilia infections is scarce. In this study, we assessed the efficacy of tigecycline treating ventilator-associated pneumonia (VAP) due to S. maltophilia in comparison with fluoroquinolones. Methods This is a multicenter retrospective cohort study of patients admitted between January 2017 and December 2020 with the diagnosis of VAP caused by S. maltophilia receiving either tigecycline or fluoroquinolones as the definitive therapy ≥ 48 h. Clinical outcomes including 28-day mortality, clinical cure and microbiological cure were analyzed. Results Of 82 patients with S. maltophilia VAP included, 46 received tigecycline, and 36 received fluoroquinolones; 70.7% of patients had polymicrobial pneumonia, and the appropriate empiric therapy was applied to only 14.6% of patients. The overall 28-day mortality was 39%. Compared with patients receiving fluoroquinolones, tigecycline therapy resulted in worse clinical cure (32.6% vs. 63.9%, p = 0.009) and microbiological cure (28.6% vs. 59.1%, p = 0.045), while there was no statistical difference between 28-day mortality (47.8% vs. 27.8%, p = 0.105) in the two groups. Similar results were also shown in the inverse probability of treatment weighted univariable regression model and multivariable regression model. Conclusions The standard dose of tigecycline therapy was associated with a lower clinical and microbiological cure rate but not associated with an increased 28-day mortality in patients with S. maltophilia VAP compared with fluoroquinolones. Considering the unfavorable clinical outcomes, we therefore recommend against using the standard dose of tigecycline in treating S. maltophilia VAP unless new clinical evidence emerges. Supplementary Information The online version contains supplementary material available at 10.1007/s40121-021-00516-5.

Bacterial endophthalmitis is a rare intraocular infection, and prompt administration of intravitreal antibiotics is crucial for preventing severe vision loss. The retrospective study is to investigate the in vitro susceptibility to the antibiotics vancomycin, amikacin, and ceftazidime of bacterial endophthalmitis isolates in specimens at a tertiary referral center from January 1996 to April 2019 in Taiwan. Overall, 450 (49.9%) isolates were gram positive, 447 (49.6%) were gram negative, and 4 (0.4%) were gram variable. In gram-positive isolates, coagulase-negative staphylococci were the most commonly cultured bacteria (158, 35.1%), followed by streptococci (100, 22.2%), enterococci (75, 16.7%), and Staphylococcus aureus (70, 15.6%). In gram-negative isolates, they were Klebsiella pneumoniae (166, 37.1%) and Pseudomonas aeruginosa (131, 29.3%). All gram-positive organisms were susceptible to vancomycin, with the exception of one Enterococcus faecium isolate (1/450, 0.2%). Of the gram-negative isolates, 96.9% and 93.7% were susceptible to ceftazidime and amikacin, respectively. Nine isolates (9/447, 2.0%) were multidrug-resistant gram-negative bacteria, comprising Klebsiella pneumoniae (4/164, 2.4%), Acinetobacter baumannii (2/3, 67%), and Stenotrophomonas maltophilia (3/18, 17%). In conclusion, in vitro susceptibility testing revealed that vancomycin remains the suitable antibiotic treatment for gram-positive endophthalmitis. Ceftazidime and amikacin provide approximately the same degree of gram-negative coverage. Multidrug-resistant bacterial endophthalmitis was uncommon.

Bioremediation is becoming an increasingly popular approach for the remediation of sites contaminated with the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Multiple lines of evidence are often needed to assess the success of such approaches, with molecular studies frequently providing important information on the abundance of key biodegrading species. Towards this goal, the current study utilized shotgun sequencing to determine the abundance and diversity of functional genes (xenA, xenB, xplA, diaA, pnrB, nfsI) and species previously associated with RDX biodegradation in groundwater before and after biostimulation at an RDX-contaminated Navy Site. For this, DNA was extracted from four and seven groundwater wells pre- and post-biostimulation, respectively. From a set of 65 previously identified RDX degraders, 31 were found within the groundwater samples, with the most abundant species being Variovorax sp. JS1663, Pseudomonas fluorescens, Pseudomonas putida, and Stenotrophomonas maltophilia. Further, 9 RDX-degrading species significantly (p30 RDX-degrading species were detected. • Nine RDX-degrading species increased following biostimulation. • Sequencing and high-throughput qPCR indicated that xenA and xenB were most abundant.

Background. Since 2020 COVID-19 pandemic became an emergent public sanitary incident. The epidemiology data and the impact on prognosis of secondary infection in severe and critical COVID-19 patients in China remained largely unclear.Methods. We retrospectively reviewed medical records of all adult patients with laboratory-confirmed COVID-19 who were admitted to ICUs from January 18th 2020 to April 26th 2020 at two hospitals in Wuhan, China and one hospital in Guangzhou, China. We measured the frequency of bacteria and fungi cultured from respiratory tract, blood and other body fluid specimens. The risk factors for and impact of secondary infection on clinical outcomes were also assessed. Results. Secondary infections were very common (86.6%) when patients were admitted to ICU for >72 hours. The majority of infections were respiratory, with the most common organisms being Klebsiella pneumoniae (24.5%), Acinetobacter baumannii (21.8%), Stenotrophomonas maltophilia (9.9%), Candida albicans (6.8%), and Pseudomonas spp. (4.8%). Furthermore, the proportions of multidrug resistant (MDR) bacteria and carbapenem resistant Enterobacteriaceae (CRE) were high. We also found that age ≥60 years and mechanical ventilation ≥13days independently increased the likelihood of secondary infection. Finally, patients with positive cultures had reduced ventilator free days in 28 days and patients with CRE and/or MDR bacteria positivity showed lower 28 day survival rate.Conclusions. In a retrospective cohort of severe and critical COVID-19 patients admitted to ICUs in China, the prevalence of secondary infection was high, especially with CRE and MDR bacteria, resulting in poor clinical outcomes.

Bacteria have long been considered drivers in the development of cutaneous lymphoma, as bacterial antigens may encourage reactive, dysregulated lymphocytic proliferation.1,2 For example, Staphylococcus aureus infection has been implicated in the pathogenesis of mycosis fungoides and Sezary syndrome, whereas Borrelia burgdorferi is clinically associated with primary cutaneous B-cell lymphoma.3, 4, 5, 6, 7 Stenotrophomonas maltophilia is an opportunist gram-negative bacterium, primarily recognized as a cause of nosocomial infection among immunocompromised individuals.8 Ste maltophilia, specifically, has been associated with breast implant–associated anaplastic large-cell lymphoma (BIA-ALCL),9,10 and it has also been reported to be an antigenic driver in cutaneous pseudolymphoma.11 We report a new association of primary cutaneous anaplastic large-cell lymphoma (PC-ALCL) with Ste maltophilia in otherwise immunocompetent men.

O objetivo deste estudo foi avaliar os dados in silico de cepas de S. maltophilia (n=974) caracterizadas por Multilocus Sequence Typing (MLST) disponíveis no banco PubMLST isoladas entre 1958 e 2020. As cepas com perfil alélico completo (n=972) foram analisadas utilizando a árvore filogenética neighbor-joining, a ferramenta minimum spanning tree e o algoritmo eBURST. O índice de Simpson foi aplicado para calcular o poder de resolução do MLST para tipificação. A maioria das cepas depositadas são de origem clínica (87,6%) e oriundas da Ásia (47,1%). As cepas de S. maltophilia apresentaram alta diversidade genética quando avaliadas, sendo identificadas em 679 ST distintos, uma taxa de ~1,4 cepa/ST. O índice de Simpson calculado foi de 0,99. O Brasil possui 10 cepas depositadas classificadas em sete ST distintos, sendo quatro isolados de infecções em humanos. Em conclusão, o MLST apresentou-se como uma ferramenta poderosa para investigações epidemiológicas de cepas de S. maltophilia.

Background Fatal hemorrhagic pneumonia is one of the most severe manifestations of Stenotrophomonas maltophilia (SM) infections. Here, we aimed to investigate the clinical characteristics of SM bacteremia and to identify the risk factors of hemorrhagic pneumonia caused by SM in patients with hematologic diseases. Methods The clinical records of 55 patients diagnosed with hematologic diseases and SM bacteremia were retrospectively reviewed. We compared patients’ clinical characteristics and outcomes between the hemorrhagic pneumonia group and non-hemorrhagic pneumonia group. Results Twenty-seven (49.1%) patients developed hemorrhagic pneumonia. The overall mortality rate of SM bacteremia was 67.3%. Hemorrhagic pneumonia (adjusted HR 2.316, 95% CI 1.140–4.705; P = 0.020) was an independent risk factor of 30-day mortality in hematological patients with SM bacteremia. Compared with the non-hemorrhagic pneumonia group, patients in the hemorrhagic pneumonia group were older and showed clinical manifestations as higher proportions of isolated SM in sputum culture, neutropenia and elevated procalcitonin (PCT). Multivariate analysis showed that neutropenia, high levels of PCT, prior tigecycline therapy within 1 month were independent risk factors associated with hemorrhagic pneumonia. Conclusions Neutropenia, high level of PCT and prior tigecycline therapy within 1 month were significant independent predictors of hemorrhagic pneumonia in hematologic patients with SM bacteremia. Due to no effective antibiotics to prevent hemorrhagic pneumonia, prophylaxis of SM infection and its progression to hemorrhagic pneumonia is particularly important.

Background Trimodality therapy is a treatment option for patients with locally advanced non-small cell lung cancer (LA-NSCLC). Thoracic radiation has both early (radiation pneumonitis) and late (chronic lung injury [CLI]) adverse effects on the lung. While CLI is expected to result in various problems in long-term survivors, these manifestations have not been precisely investigated. Methods We enrolled 112 LA-NSCLC patients who had received induction chemoradiotherapy followed by surgery, and then undergone follow-up computed tomography (CT) every 6 months for greater than 1 year. All chest CT images were reviewed to evaluate any injury of the pulmonary parenchyma. Results CLI at 1 year after surgery and its progression were observed in 94 (84%) and 38 (34%) patients, respectively. Progressive lung fibrosis as the first manifestation of CLI progression was most frequent after right middle and lower lobectomy. Cavity formation was the subsequent manifestation after progressive lung fibrosis , and chronic infection was the final stage of CLI. The cumulative rate of chronic infection was 76.4% at 10 years in patients with cavity formation. Ten patients with chronic infection included 7 cases of pulmonary aspergillosis and 2 cases of cavity infections with methicillin-resistant Staphylococcus aureus or Stenotrophomonas maltophilia. Among them, 4 patients required surgical interventions including completion pneumonectomy or fenestration. Conclusions CLI is a common incidence after trimodality therapy for LA-NSCLC. CLI frequently results in cavity formation, which is a precursor of highly refractory chronic infections requiring surgical intervention. Appropriate management needs to be established for CLI developing after trimodality therapy.

BACKGROUND Stenotrophomonas maltophilia is a gram-negative bacillus, multidrug resistant (MDR) opportunistic pathogen, which is normally present in hospital surroundings. It has been one of the leading causes of nosocomial infections due to risk factors such as extended intensive care unit (ICU) stays and multiple invasive procedures. In this study we wanted to assess the antibiotic sensitivity pattern with various antimicrobial agents i.e. levofloxacin, minocycline, ceftazidime, chloramphenicol, & ticarcillin-clavulanic acid with special focus on trimethoprim-sulfamethoxazole (TMP-SMX). METHODS In vitro analysis was conducted on 164 Stenotrophomonas maltophilia strains isolated from blood and respiratory tract from January 2016 to November 2020. Antibiotic susceptibility and minimum inhibitory concentration (MIC) testing for trimethoprim-sulfamethoxazole (TMP-SMX), levofloxacin (LVX), ticarcillin - clavulanic acid (TIM), and minocycline (MIN) were performed using Vitek 2, as per clinical and laboratory standards institute (CLSI) guideline. RESULTS A total of 164 S. maltophilia were isolated. Out of the 164 S. maltophilia isolates, 26 (16 %) were isolated from blood, 114 (70 %) were isolated from respiratory samples, 20 (12 %) from pus & tissue, and 4 (2 %) from urine. Out of the 164 patients, 130 (80 %) were males and 32 (20 %) were females. Maximum patients were above 50 years of age 93 (56 %) followed by 20 - 50 years 55 (34 %). Out of the 164 patients, 67 (40 %) were admitted to wards, 92 (56 %) were in ICU and 5 (3 %) were seen in out-patient department (OPD). A total of 90 % strains were sensitive to trimethoprim-sulfamethoxazole (TMP-SMX). Total 91 % strains were sensitive to levofloxacin. CONCLUSIONS S. maltophilia is emerging as a significant nosocomial pathogen, with a growing rate of isolation. Trimethoprim- sulfamethoxazole (TMP-SMX) is still the drug of choice, but resistance to it has been reported. KEYWORDS Minimum Inhibitory Concentration, Trimethoprim-Sulfamethoxazole (TMP-SMX), Levofloxacin

Background The SmeVWX efflux pump of Stenotrophomonas maltophilia contributes to menadione (MD) tolerance and resistance to chloramphenicol, quinolones and tetracycline. The components of the SmeVWX efflux pump are encoded by a five-gene operon, smeU1VWU2X. We have previously demonstrated that the smeU1VWU2X operon is intrinsically unexpressed and inducibly expressed by MD via a SoxR- and SmeRv-involved regulatory circuit in S. maltophilia KJ. We also inferred that there should be other regulator(s) involved in MD-mediated smeU1VWU2X expression in addition to SoxR and SmeRv. Objectives To identify novel regulator(s) involved in the regulation of MD-mediated smeU1VWU2X expression and elucidate the regulatory circuit. Methods A possible regulator candidate involved in the regulation of MD-mediated smeU1VWU2X expression was identified by a homologue search using the helix-turn-helix domain of SmeRv as a query. Gene expression was assessed using the promoter-xylE transcriptional fusion assay and quantitative RT–PCR. The impact of the regulator on SmeVWX pump-mediated functions was investigated via mutant construction and functional tests (antibiotic susceptibility and MD tolerance). Results AzoR (Smlt3089), a LysR-type transcriptional regulator, was investigated. In unstressed logarithmically grown cells, AzoR was abundantly expressed and functioned as a repressor, inhibiting the expression of the smeU1VWU2X operon. MD challenge attenuated azoR expression, thus derepressing the expression of the smeU1VWU2X operon in S. maltophilia KJ. AzoR down-regulation-mediated smeU1VWU2X expression was observed in quinolone-resistant and SmeVWX-overexpressing S. maltophilia clinical isolates. Conclusions AzoR negatively regulates the expression of the smeU1VWU2X operon and SmeVWX pump-mediated antibiotic resistance in S. maltophilia.

The persistence of Stenotrophomonas maltophilia, especially in hospital environments where disinfectants are used intensively, is one of the important factors that allow this opportunistic pathogen to establish nosocomial infections. In the present study, we illustrated that S. maltophilia possesses adaptive resistance to the disinfectant benzalkonium chloride (BAC). This BAC adaptation was abolished in the ΔmfsQ mutant, in which a gene encoding an efflux transporter belonging to the major facilitator superfamily (MFS) was deleted. The ΔmfsQ mutant also showed increased susceptibility to BAC and chlorhexidine gluconate compared with a parental wild type. The expression of mfsQ increased upon exposure to quaternary ammonium compounds, including BAC. Thus, the results of this study suggest that mfsQ plays a role in both adaptive and nonadaptive protection of S. maltophilia from the toxicity of the disinfectant BAC.

Stenotrophomonas maltophilia has plant growth-promoting potential, and interaction with Arachis hypogaea changes host-plant physiology, biochemistry, and metabolomics, which provides tolerance under the N2 starvation conditions. About 226 suppression subtractive hybridization clones were obtained from plant-microbe interaction, of which, about 62% of gene sequences were uncharacterized, whereas 23% of sequences were involved in photosynthesis. An uncharacterized SSH clone, SM409 (full-length sequence showed resemblance with Cytb6), showed about 4-fold upregulation during the interaction was transformed to tobacco for functional validation. Overexpression of the AhCytb6 gene enhanced the seed germination efficiency and plant growth under N2 deficit and salt stress conditions compared to wild-type and vector control plants. Results confirmed that transgenic lines maintained high photosynthesis and protected plants from reactive oxygen species buildup during stress conditions. Microarray-based whole-transcript expression of host plants showed that out of 272,410 genes, 8704 and 24,409 genes were significantly (p 2 up or down-regulated) under N2 starvation and salt stress conditions, respectively. The differentially expressed genes belonged to different regulatory pathways. Overall, results suggested that overexpression of AhCytb6 regulates the expression of various genes to enhance plant growth under N2 deficit and abiotic stress conditions by modulating plant physiology.

SIGNIFICANCE A multipurpose disinfecting solution (MPDS), which contains povidone-iodine (PI) as a disinfectant, has high disinfecting efficacy not only on planktonic bacterium but also on the case biofilms. The addition of case hygiene practice removed more bacteria from cases than MPDS alone. PURPOSE This study compared the ability of two MPDSs, one containing PI and another containing polyaminopropyl biguanide and polyquaternium, to reduce bacterial numbers in solution or adhered to the cases following case hygiene procedures. METHODS Bacterial strains (Delftia acidovorans, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Serratia marcescens, Staphylococcus aureus, and Staphylococcus epidermidis) were exposed to the MPDSs for the recommended disinfection times, and the viable number evaluated according to ISO 14729. Cases were inoculated with bacterial strains and incubated for 24 hours to allow for biofilm formation. Cases were disinfected with both disinfecting solutions for 4 hours and rinsed, followed by recapping or air-drying, or tissue-wiping and air-drying for 18 hours. The number of survivors was counted using standard culture techniques. RESULTS Both products exceeded the recommended 3-log reduction against planktonic bacteria. Regarding biofilm, after rinsing and recapping wet, the numbers of D. acidovorans (mean difference [95% confidence interval] log10 colony-forming units per case, -2.9 [0.8 to -4.6], P < .01), P. aeruginosa (-2.0 [0.5 to -3.1], P < .01), S. marcescens (-1.7 [0.8 to -3.5], P < .05), and S. epidermidis (-2.1 [0.6 to -3.5], P < .05) in PI cases were significantly lower than in the dual-disinfectant MPDS storage cases. After air-drying, the PI storage cases had significantly lower numbers of S. maltophilia (-2.6 [0.6 to -4.0], P < .01), D. acidovorans (-1.6 [0.7 to -3.3], P < .05), and S. aureus (-1.6 [0.7 to -3.1], P < .05). The addition of tissue-wiping reduced the bacterial numbers in the MPDS storage cases to levels in the PI storage cases. CONCLUSIONS Contact lens users should be recommended to tissue-wipe and air-dry their lens storage cases after disinfection with regular MPDS.

Introduction Stenotrophomonas maltophilia keratitis is an uncommon infectious disease of the cornea. The clinical features, antibiotic susceptibility, and clinical outcomes of S. maltophilia keratitis were investigated in this study. Methods Between January 2015 and February 2020, the medical records of 16 patients with culture-proven S. maltophilia-associated infectious keratitis were retrospectively reviewed. Clinical data were analyzed regarding risk factors, clinical presentation, antibiotic susceptibility, and clinical outcomes. Results The average age of the patients was 56.24 ± 24.84 years. The most common risk factors for S. maltophilia keratitis were trauma (6/16, 37.5%), use of contact lenses (6/16, 37.5%), and herpes simplex virus keratitis (3/16, 18.8%), which caused ocular instability. Regarding the antibiotic sensitivities, most isolates (15/16, 93.8%) were susceptible to fluoroquinolones, 87.5% (14/16) of them to aminoglycosides, and 81.3% (13/16) of them to beta-lactams. Patients were classified into two groups according to the initial antibiotic eye drops, and there were significant differences in the final visual acuity between two groups: mixed fluoroquinolone, beta-lactam, aminoglycoside group, and mixed beta-lactam and aminoglycoside groups (p = 0.039). Conclusion Ocular infection due to S. maltophilia is an opportunistic infection followed by instability of the ocular surface. In cases of S. maltophilia infection, mixed use of fluoroquinolone, beta-lactam, and aminoglycoside should be considered for treatment of choice.

Objective. Because there are few studies on the clinical implications of colonization by carbapenem-resistant gram-negative bacteria (CRB) this was analyzed in rectal smears (RS) and pharyngeals (PS) and its ability to predict infection/colonization. Methodology. A cross-sectional, retrospective study from adult inpatients between January 2016 and December 2019 was conducted. The isolates were characterized by MicroScan and spectrometry of masses applying EUCAST 2018 cutoff points. The detection of carbapenemases was performed by PCR and Sanger sequencing; sequencies was assigned by MLST. The genetic relationship between the clinical isolates was made by pulsed field electrophoresis using the enzymes Xbal, Spel or Apal. Results. A total of 308 (86.03%) RS and 50 (13.97%) positive PS were detected, the RS had a 85% sensibility, 100% specificity, 100% positive predictive value and 97% negative predictive value. In RS, the following were isolated: 44% (n=135) Acinetobacter baumannii, 26% (n =80) Enterobacterales (20 KPC, 29 OXA-48, 22 VIM, 2 IMP, 7 NDM), 17% (n=53) Pseudomonas aeruginosa and 13% (n=40) Stenotrophomonas maltophilia. In the PS were isolated 44% (n=22) S. maltophilia, 40% (n = 20) A. baumannii, 8% (n=4) P. aeruginosa and 8% (n=4) Enterobacterales (3 VIM, 1 OXA). From the patients with simultaneous RS and PS, 41 (40.6%) had positivity in both smears, 45 (44.6%) only in RS and 15 (14.9%) only in PS. Colonization preceded infection in 81.3% (n=13) of the isolates; association between infection and colonization was found (p

Introduction: Non-fermentative Gram-negative bacterias (NFGNBs) are a major cause of life threatening infections in hospitalized children. in this study, we aimed to evaluate the demographic and clinical characteristics of NFGNBs infections and identify the risk factors and outcomes of bloodstream infections (BSIs) caused by carbapenem-resistant (CR) NFGNBs infections. Methods: A retrospective cohort was designed to evaluate the patients with a BSI caused by NFGNBs between in January 2014 and December 2017. Results: A total of 131 episodes from 115 patients were evaluated. The mean age of the patients was 4.79 +/-(4.74) year. The most commonly isolated NFGNBs species was Acinetobacter spp. (35.9%), Pseudomonas spp. (34.4%), and Stenotrophomonas maltophilia (13%). The rate of carbapenem-resistance was 38.2% in Acinetobacter spp. and 26.6% in Pseudomonas spp. The comparison of CR group with carbapenem-susceptible (CS) group showed statistical significance for the length of hospital stay prior to onset of infection and total hospital stay (P values were 0.001, 0.008). Based on the univariate analysis, requirement of mechanical ventilation, central venous catheter, nasogastric tube, Foley catheter, severe neutropenia (14 days), prior intensive care unit admission and prior antimicrobial treatment (carbapenems, colistin, glycopeptide) were more common in carbapenemresistant NFGNBs infections (P values are 0.001, 0.012, 0.000, 0.005, 0.042, 0.027, 0.007, 0.007). in patients with NFGNBs infections 14-day and 30-day mortality rates were %16.8 and 21.4%. Conclusion: CR infections were more common in children with prolonged and severe neutropenia. Prior antimicrobial use and intensive care unit admission were more common in CR infections. (c) 2021 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Stenotrophomonas maltophilia is a nosocomial, multidrug-resistant pathogen that causes significant economic losses in milk production and deterioration of dairy product quality. This study investig...

Background: Stenotrophomonas maltophilia is an aerobic, non-fermentative, gram negative, multidrug resistant and opportunistic nosocomial pathogen. It is associated with high morbidity and mortality in severely immunocompromised paediatric patients, including neonates. Immunoinformatic analysis paved a new way to design epitope-based vaccines which resulted in a potential immunogen with advantages such as lower cost, specific immunity, ease of production, devoid of side effects, and less time consumption than conventional vaccines. Till date, there is no development in the vaccines or antibody-based treatments for S. maltophilia-associated infections. Introduction: Currently, epitope-based peptide vaccines against pathogenic bacteria have grasped more attention. In our present study, we have utilized various immunoinformatic tools to find a prominent epitope that interacts with the maximum number of HLA alleles and also with the maximum population coverage for developing a vaccine against Stenotrophomonas maltophilia. Methods: This study has incorporated an immunoinformatic based screening approach to explore potential epitope-based vaccine candidates in Stenotrophomonas maltophilia proteome. In this study, 4365 proteins of the Stenotrophomonas maltophilia K279a proteome were screened to identify potential antigens that could be used as a good candidate for the vaccine. Various immunoinformatic tools were used to predict the binding of the promiscuous epitopes with Major Histocompatibility Complex (MHC) class I molecules. Other properties such as allergenicity, physiochemical properties, adhesion properties, antigenicity, population coverage, epitope conservancy and toxicity were analysed for the predicted epitope. Results: This study helps in finding the prominent epitope in Stenotrophomonas infections. Hence, the main objective in this research was to screen complete Stenotrophomonas maltophilia proteome to recognize putative epitope candidates for vaccine design. Using computational vaccinology and immunoinformatic tools approach, several aspects are obligatory to be fulfilled by an epitope to be considered as a vaccine candidate. Our findings were promising and showed that the predicted epitopes were non-allergenic and fulfilled other parameters required for being a suitable candidate based on certain physio-chemical, antigenic and adhesion properties. Conclusion: The epitopes LLFVLCWPL and KSGEGKCGA have shown the highest binding score of −103 and −78.1 kcal/mol with HLA-A*0201 and HLA-B*0702 MHC class I allele, respectively. They were also predicted to be immunogenic and non-allergenic. Further various immunological tests, both in vivo and in vitro methods, should be performed for finding the efficiency of the predicted epitope in the development of a targeted vaccine against Stenotrophomonas maltophilia infection.

Relevance. Infectious septic complications caused by polyresistant gram-negative micro-organisms are a pressing issue in the treatment of patients after polychemotherapy (PCT) and hematopoietic stem cell transplantation at the high risk of the fulminant current and high lethality against the background of hematopoesis aplasia. One of the therapeutic strategies of antimicrobial treatment is the systematic use of 0.5 % hydroxymethylquinoxaline dioxide (dioxidine) solution in the complex antibacterial therapy of patients with severe infectious-septic complications. The preparation has a bactericidal type of action, a wide spectrum of antibacterial activity. Experience in adult clinical practice has demonstrated the effectiveness of dioxidine in the treatment of the most severe forms of aerobic and anaerobic infection. Strict dose enforcement and injection technique to avoid the appearance of side effects. Data on the intravenous use of dioxin in children are presented in a limited number of scientific literature.The aim of the study was to demonstrate the efficacy of systemic use of hydroxymethylquinoxaline dioxide (0.5 % dioxidine solution) in children with infectious complications progressing against the background of aplasia of hematopoiesis caused by multidrug-resistant pathogens Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Stenotrophomonas maltophilia.Materials and methods. 16 patients with a verified gram-negative infection were prescribed 0.5 % hydroxymethylquinoxaline dioxide solution as part of a combination antimicrobial therapy were included in the retrospective study. The median age of patients was 5 years (6 months – 16 years), 11 (69 %) were boys and 5 (31 %) girls.All children included in the study has infectious-septic complications at the PCT-induced hematopoietic aplasia, obtained according to the protocols of the main disease: severe combined immune deficiency (n = 2), idiopathic aplastic anaemia (n = 3), solid tumor (n = 2), acute myeloblastic leukemia (n = 7), acute lymphoblastic leukemia (n = 2). The main criterion for adding to the study was the existence at the least one site with a verified gram-negative infection (Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Stenotrophomonas maltophilia): bacteriemia (n = 11), oral mucosa (n = 6), ulcerative necrotic damage of perineum (n = 6), enterocolite (n = 6), infectionseptic compartments in the subcutaneous fat (n = 4), pleuropneumonia (n = 4), abscesses and inflammatory infiltration of the liver, spleen, pancreas, kidneys, lymph nodes (n = 1), infection of soft tissues in the area of the ventricular bypass with inflammatory changes of the brain membranes (n = 1).All patients received 0.5 % of the solution of dioxin by injection according of vital importance, as they had pathogens with confirmed laboratory resistance or clinical progression of the infectious process against the background of combined antibacterial therapy.Discussion. There is a complete control of fulminant developing infectious-septic processes caused by polyresistant micro-organisms against the background of hydroxymethylquinoxaline dioxide therapy in all 16 patients. The eradication of the pathogen, according to the microbiological study, has been confirmed in almost all observed patients, the efficacy of the drug has been preserved throughout the period of treatment, and the resistance of micro-organisms has not been observed. Strict adherence to the dosing and infusion technique of hydroxymethylquinoxaline dioxide has helped to achieve the full resolution of the infection process in all children without side-effects.Conclusion. On the basis of the experience presented, in immunocomputed patients of young age, 0.5 % dioxidine solution can be used as a necessary reserve preparation for the treatment of the most severe forms of infections of different localization, caused by polyresistant strains of gram-negative micro-organisms.

Background The release of triphenylmethane dyes, like malachite green (MG) and crystal violet (CV), into the environment is a cause of concern due to its toxicity, mutagenicity and carcinogenicity. Result A bacterial strain that is capable of decolorizing both dyes was isolated from the composted neem oil-seed cake. The strain was characterized as Stenotrophomonas maltophilia based on the 16S rRNA gene sequence and designated as isolate TPMD-1. The kinetic study of the dye degradation revealed the efficiency of the above isolate to degrade MG. The effect of substrate concentration, pH, temperature, and agitation on the decolorization of MG by the isolate was also studied. The MG degradation rate was slightly more in neutral pH at 28–30 °C and 150 rpm. The UV-spectroscopy, HPLC, and FTIR analyses of the dye sample before and after bacterial treatment revealed the high ability of S. maltophilia TPDM-1 in the removal of MG from the media. The genetic snapshot of the isolate by PCR amplification and sequencing showed the presence of genes 'lac’ and ‘tmr’ that codes for laccase and triphenylmethane reductase. Conclusion This study presented the first report of Stenotrophomonas maltophilia in the degradation and detoxification of MG dye by oxidoreduction, which could be used for the bioremediation of aquatic environments contaminated by MG.

Objective The purpose of the present study was to investigate the antimicrobial susceptibility pattern, biofilm production, and the presence of biofilm genes among the S. maltophilia clinical isolates. A total of 85 clinical isolates of S. maltophilia were collected from patients referred to several hospitals. Susceptibility to antibiotics was investigated by disc diffusion method according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI). By the crystal violet staining method, the capability of biofilm formation was examined. The genes associated with biofilm production were investigated by the PCR-sequencing techniques. Results All isolates were resistant to doripenem, imipenem, and meropenem. Minocycline, trimethoprim/sulfamethoxazole and levofloxacin exhibited the highest susceptibility of 100%, 97.65%, and 95.29%, respectively. The results of crystal violet staining assay showed that all isolates (100%) form biofilm. Moreover, 24 (28.23%), 32 (37.65%), and 29 (34.12%) of isolates were categorized as weak, moderate, and strong biofilm producers, respectively. Biofilm genes including rpfF, spgM and rmlA had an overall prevalence of 89.41% (76/85), 100% (85/85) and 84.71% (72/85), respectively. Rational prescribing of antibiotics and implementation of infection control protocols are necessary to prevent further infection and development of antimicrobial resistance. Combination strategies based on the appropriate antibiotics along with anti-biofilm agents can also be selected to eliminate biofilm-associated infections.

Background Stenotrophomonas maltophilia, an opportunistic pathogen, is intrinsically resistant to most β-lactams except ceftazidime and ticarcillin/clavulanate, due to the inducibly expressed L1 and L2 β-lactamases. A two-component regulatory system (TCS) allows organisms to sense and respond to changes in different environmental conditions. The PhoPQ TCS of S. maltophilia plays regulatory roles in antibiotic susceptibility, physiology, stress adaption and virulence. Inactivation of S. maltophilia phoPQ increases β-lactam susceptibility. Objectives To elucidate the PhoPQ-regulating mechanism for β-lactam resistance. Methods The candidate genes responsible for the ΔphoPQ-mediated β-lactam resistance compromise were identified by transcriptome analysis and verified by quantitative RT–PCR and complementation assay. Etest was used to assess β-lactam susceptibility. The phosphorylation level of the PhoP protein was determined by Phos-tag SDS-PAGE and western blotting. A β-lactam influx assay was used to investigate the influx efficiency of a β-lactam. Results PhoPQ deletion down-regulated the expression of mltD1 and slt, attenuated the induced β-lactamase activity and then compromised the β-lactam resistance. Complementation of mutant phoPQ with mltD1 or slt genes partially reverted the induced β-lactamase activity and β-lactam resistance. The PhoPQ TCS was activated in logarithmically grown KJ cells and was further activated by low magnesium, but not by a β-lactam. However, low-magnesium-mediated PhoPQ activation hardly made an impact on β-lactam resistance enhancement. Furthermore, PhoPQ inactivation altered the outer membrane permeability and increased the influx of a β-lactam. Conclusions The PhoPQ TCS is activated to some extent in physiologically grown S. maltophilia. Inactivation of phoPQ attenuates the expression of mltD1 and slt, and increases β-lactam influx, both synergically contributing to β-lactam resistance compromise.

A consortium of already isolated strains has been applied to degrade endosulfan. These were identified by 16S rRNA technique as Stenotrophomonas maltophilia EN-1, Pseudomonas sp. TAH and Enterobact...

Objectives: Stenotrophomonas maltophilia, a Gram-negative non-fermentative bacillus, has emerged as an important nosocomial pathogen in recent years. It is intrinsically resistant to many antibiotics and has the ability to acquire antibiotic resistance by multiple mechanisms. Treating Stenotrophomonas infections, therefore, is a serious challenge for physicians. This study aimed to investigate the antibiotic susceptibility patterns and risk factors contributing to S. maltophilia infections. Methods: A retrospective cross-sectional study was conducted at Sohar Hospital in Sohar, Oman. The demographic, clinical and microbiological data of individuals from whom S. maltophilia was isolated between September 2016 and August 2019 were reviewed. Descriptive statistics were presented as frequencies and percentages. Results: A total of 41 S. maltophilia isolates from clinical specimens of 41 patients were studied. Infection occurred predominantly in males (73%) and the majority of patients (88%) were either ≤5 years old or >60 years old. All inpatients had at least one comorbidity while 50% had more than one. All inpatients were exposed to various medical interventions such as intensive care (44%), mechanical ventilation (41%), haemodialysis (25%), Foley’s catheterisation (13%) and central venous lines (6%). Most patients (81%) were in hospital longer than two weeks. The susceptibility rates of S. maltophilia to minocycline (97%), trimethoprimsulfamethoxazole (93%) and levofloxacin (92%) were high; the rate was lowest for ceftazidime (50%). Conclusion: S. maltophilia was found to be an important nosocomial opportunistic pathogen. Prolonged hospital stay and exposure to various medical interventions were key factors contributing to the development of infection. Minocycline and ceftazidime were found to be the most and least susceptible drugs, respectively. KEYWORDS Nosocomial Infection; Opportunistic Infections; Fluoroquinolones; Hemodialysis; Ventilation; Oman.

Background The incidence of secondary pulmonary infections is not well described in hospitalized COVID-19 patients. Understanding the incidence of secondary pulmonary infections and the associated bacterial and fungal microorganisms identified can improve patient outcomes. Objective This narrative review aims to determine the incidence of secondary bacterial and fungal pulmonary infections in hospitalized COVID-19 patients, and describe the bacterial and fungal microorganisms identified. Method We perform a literature search and select articles with confirmed diagnoses of secondary bacterial and fungal pulmonary infections that occur 48 h after admission, using respiratory tract cultures in hospitalized adult COVID-19 patients. We exclude articles involving co-infections defined as infections diagnosed at the time of admission by non-SARS-CoV-2 viruses, bacteria, and fungal microorganisms. Results The incidence of secondary pulmonary infections is low at 16% (4.8–42.8%) for bacterial infections and lower for fungal infections at 6.3% (0.9–33.3%) in hospitalized COVID-19 patients. Secondary pulmonary infections are predominantly seen in critically ill hospitalized COVID-19 patients. The most common bacterial microorganisms identified in the respiratory tract cultures are Pseudomonas aeruginosa, Klebsiella species, Staphylococcus aureus, Escherichia coli, and Stenotrophomonas maltophilia. Aspergillus fumigatus is the most common microorganism identified to cause secondary fungal pulmonary infections. Other rare opportunistic infection reported such as PJP is mostly confined to small case series and case reports. The overall time to diagnose secondary bacterial and fungal pulmonary infections is 10 days (2–21 days) from initial hospitalization and 9 days (4–18 days) after ICU admission. The use of antibiotics is high at 60–100% involving the studies included in our review. Conclusion The widespread use of empirical antibiotics during the current pandemic may contribute to the development of multidrug-resistant microorganisms, and antimicrobial stewardship programs are required for minimizing and de-escalating antibiotics. Due to the variation in definition across most studies, a large, well-designed study is required to determine the incidence, risk factors, and outcomes of secondary pulmonary infections in hospitalized COVID-19 patients.