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This article discusses the challenges of developing new antibiotics, particularly for the gram-negative bacteria Pseudomonas aeruginosa. The lack of therapeutic options for this bacteria is concerning, as it is classified as a "serious threat" by the CDC and has high rates of antibiotic resistance. The article presents permeation guidelines for P. aeruginosa, which can help in designing small molecules that can effectively penetrate the bacteria and gain intracellular access. These guidelines differ from those for another gram-negative bacteria, Escherichia coli, and provide insights into the physiological differences between the two bacteria. The article suggests that these permeation guidelines can aid in the development of new antibiotics by enhancing the accumulation of candidate drugs. [Extracted from the article]

Background This study describes the conditions of use of ceftolozane/tazobactam (C/T) and associated outcomes in French hospital settings. Methods This was a prospective, multicenter, French observational study. Patients who received at least 1 dose of C/T were included and followed up as per routine clinical practice, until stop of C/T. Results A total of 260 patients were enrolled between October 2018 and December 2019 in 30 centers across France. Of these, 177 (68.0%) received C/T as per indication of usage following the results of the antibiogram (documented cases). Among documented patients, the mean age was 61.8 years, 73.4% were males, and 93.8% presented with multidrug-resistant (MDR) bacteria at inclusion. C/T was most frequently prescribed for pneumonia (48.6%), bacteremia (14.7%), complicated intra-abdominal infections (13.0%), or complicated urinary tract infections (9.6%). Pseudomonas aeruginosa was the species most frequently isolated with 212 strains from 155 patients, and 96.2% of these strains were susceptible to C/T. The median duration of C/T treatment was 16.1 days (1–115, n = 176). Complete or partial cure was achieved in 71.7% of patients, C/T was discontinued upon adaptation to microbiology results in 11.3% of patients for the following reasons: treatment failure in 2.8%, death in 4.0%, adverse events in 1.7%, and other in 8.5%. Conclusions This is the first prospective observational study of C/T utilization in a health care setting enrolling many patients in France. C/T demonstrated a high rate of clinical effectiveness in MDR infections, confirming it as an effective treatment option for complicated infections in a high-risk population. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa (P. aeruginosa) presents a complex challenge in terms of pathogenicity and antibiotic resistance. This versatile pathogen adeptly colonises various host tissues and evades the immune system through its intricate virulence factors. The review delves into the antimicrobial resistance mechanisms at play, which encompass inherent resistance characteristics and those acquired through genetic mutations and horizontal gene transfer. Notably, efflux pump systems and limited membrane permeability underpin its inherent resistance, rendering many conventional antibiotics ineffective. Multidrug Resistant (MDR) strains are on the rise, posing a substantial threat to patient care and infection control. In response, innovative strategies are being explored, including combination therapies to enhance the effectiveness of existing antibiotics and drug repurposing, redirecting existing medications to target P. aeruginosa. Phage therapy, which leverages bacteriophages to combat P. aeruginosa infections, is gaining attention as a promising solution. Infection prevention and control are pivotal, particularly in healthcare settings, to curtail the spread of P. aeruginosa. Surveillance programs are crucial for monitoring the prevalence and dissemination of antibiotic-resistant strains and guiding response strategies during outbreaks. Comprehending P. aeruginosa's complex virulence and resistance mechanisms is paramount for developing efficient treatments and effective infection control measures. Ongoing research and collaborative efforts are instrumental in mitigating the substantial impact of P. aeruginosa infections on public health, underscoring the need for sustained vigilance and innovation in infectious disease management. [ABSTRACT FROM AUTHOR]

Gut microbiomes profoundly influence insect health and mediate interactions between plant hosts and their environments. Insects, including aphids, harbour diverse obligate symbionts that synthesize essential nutrients and facultative symbionts that enhance host fitness in specific ecological contexts. Sorghum (Sorghum bicolor) is a significant cereal crop cultivated worldwide that has been negatively affected by the presence of an invasive piercing-sucking insect pest, the sugarcane aphid (SCA; Melanaphis sacchari). We previously identified SC265 and SC1345 as the resistant and susceptible sorghum lines, respectively, among the founder nested association mapping (NAM) population. Here, using these resistant and susceptible lines, we explored variations in the SCA gut microbiome when they feed on two different sorghum lines with varied resistance levels. Analyses after excluding the obligate endosymbiont Buchnera aphidicola from the dataset showed a significant difference in microbial diversity and composition between resistant and susceptible sorghum lines 7- and 14 days post aphid infestation. Our results indicate that the SCA fed on susceptible and resistant sorghum lines had Pseudomonadaceae and Rhizobiaceae, respectively, as the most abundant bacterial families. Differences in gut microbial community composition were underscored by alpha diversity metrics and beta diversity compositional analyses. These findings contribute to our understanding of the intricate interplay between plant and aphid microbiomes, shedding light on potential avenues to bolster sorghum resistance to SCA. [ABSTRACT FROM AUTHOR]

The unfolded protein response (UPR) is an evolutionarily conserved pathway that senses and responds to the accumulation of misfolded proteins in the endoplasmic reticulum (ER) lumen during bacterial infection. The IRE-1/XBP-1 pathway is a major branch of the UPRER that has been conserved from yeast to human. Dioscin, a steroidal saponin exhibits a broad spectrum of properties. However, whether dioscin influences the immune response and the underlying molecular mechanisms remain obscure. We find that dioscin increases resistance to Gram-negative pathogen Pseudomonas aeruginosa. Furthermore, dioscin also inhibits the growth of pathogenic bacteria. Meanwhile, dioscin enhances the resistance to pathogens by reducing bacterial burden in the intestine. Through genetic screening, we find that dioscin activates the UPRER to promote innate immunity via IRE-1/XBP-1 pathway. Intriguingly, dioscin requires the neural XBP-1 for immune response. Our findings suggest that dioscin may be a viable candidate for the treatment of infectious diseases. [ABSTRACT FROM AUTHOR]

Background: Acanthamoeba is an environmental host for various microorganisms. Acanthamoeba is also becoming an increasingly important pathogen as a cause of keratitis. In Acanthamoeba keratitis (AK), coinfections involving pathogenic bacteria have been reported, potentially attributed to the carriage of microbes by Acanthamoeba. This study assessed the presence of intracellular bacteria in Acanthamoeba species recovered from domestic tap water and corneas of two different AK patients and examined the impact of naturally occurring intracellular bacteria within Acanthamoeba on the severity of corneal infections in rats. Methodology/Principal findings: Household water and corneal swabs were collected from AK patients. Acanthamoeba strains and genotypes were confirmed by sequencing. Acanthamoeba isolates were assessed for the presence of intracellular bacteria using sequencing, fluorescence in situ hybridization (FISH), and electron microscopy. The viability of the bacteria in Acanthamoeba was assessed by labelling with alkyne–functionalized D–alanine (alkDala). Primary human macrophages were used to compare the intracellular survival and replication of the endosymbiotic Pseudomonas aeruginosa and a wild type strain. Eyes of rats were challenged intrastromally with Acanthamoeba containing or devoid of P. aeruginosa and evaluated for the clinical response. Domestic water and corneal swabs were positive for Acanthamoeba. Both strains belonged to genotype T4F. One of the Acanthamoeba isolates harboured P. aeruginosa which was seen throughout the Acanthamoeba's cytoplasm. It was metabolically active and could be seen undergoing binary fission. This motile strain was able to replicate in macrophage to a greater degree than strain PAO1 (p<0.05). Inoculation of Acanthamoeba containing the intracellular P. aeruginosa in rats eyes resulted in a severe keratitis with increased neutrophil response. Acanthamoeba alone induced milder keratitis. Conclusions/Significance: Our findings indicate the presence of live intracellular bacteria in Acanthamoeba can increase the severity of acute keratitis in vivo. As P. aeruginosa is a common cause of keratitis, this may indicate the potential for these intracellular bacteria in Acanthamoeba to lead to severe polymicrobial keratitis. Author summary: In recent years, Acanthamoeba spp. have become an increasingly important human pathogen, causing serious, debilitating, and sometimes deadly infections. It can cause a rare but severe and potentially blinding corneal infection known as Acanthamoeba keratitis, which is extremely painful, difficult to diagnose, and treat. In a remarkable dual role, Acanthamoeba species act as phagocytic predator, consuming other microbes, but also as environmental hosts for a wide range of bacteria. With the increasing prevalence of coinfections among AK patients, which often lead to the severe outcomes, it is important to identify the intracellular bacteria hosted by Acanthamoeba spp. Using a series of experiments we confirmed the presence of intracellular P. aeruginosa in an Acanthamoeba strain isolated from AK patient domestic tap water. Our study findings showed that amoeba adapted P. aeruginosa exhibited enhanced intracellular survival and replication in human monocyte derived macrophages (hMDMs) compared to the wild–type strain PAO1. Here, for the first time, we investigated the role of naturally acquired viable intracellular P. aeruginosa in the development of Acanthamoeba keratitis in rats. The presence of intracellular bacteria in Acanthamoeba resulted into acute keratitis, highlighting the importance of identifying endosymbionts harbored by Acanthamoeba for accurate differential diagnostics and prognostic evaluations of Acanthamoeba keratitis. [ABSTRACT FROM AUTHOR]

Two motile, rod-shaped, Gram-stain-negative bacterial strains, TNT11T and TNT19T, were isolated from soil samples collected at Deception Island, Antarctica. According to the 16S rRNA gene sequence similarity, both strains belong to the genus Pseudomonas. Further genomic analyses based on ANI and dDDH suggested that these strains were new species. Growth of strain TNT11T is observed at 0–30 ℃ (optimum, 20 ℃), pH 4.0–9.0 (optimum, pH 6.0) and in the presence of 0–5.0% NaCl (optimum, 1% NaCl), while for TNT19T is observed at 0–30 ℃ (optimum between 15 and 20 ℃), pH 5.0–9.0 (optimum, pH 6.0) and in the presence of 0–5.0% NaCl (optimum between 0 and 1% NaCl). The fatty acid profile consists of the major compounds; C16:0 and C16:1 ω6 for TNT11T, and C16:0 and C12:0 for TNT19T. Based on the draft genome sequences, the DNA G + C content for TNT11T is 60.43 mol% and 58.60 mol% for TNT19T. Based on this polyphasic study, TNT11T and TNT19T represent two novel species of the genus Pseudomonas, for which the proposed names are Pseudomonas violetae sp. nov. and Pseudomonas emilianonis sp. nov., respectively. The type strains are Pseudomonas violetae TNT11T (= RGM 3443T = LMG 32959T) and Pseudomonas emilianonis TNT19T (= RGM 3442T = LMG 32960T). Strains TNT11T and TNT19T were deposited to CChRGM and BCCM/LMG with entry numbers RGM 3443/LMG 32959 and RGM 3442/LMG 32960, respectively. [ABSTRACT FROM AUTHOR]

Introduction This study aimed to examine the effect of commonly used non-antibiotic drugs (dexamethasone and tenoxicam), on treatment of Pseudomonas aeruginosa infections, antibiotic resistance and virulence in this pathogen. Methods Four antibiotics (gentamicin, cefepime, ciprofloxacin and meropenem) were investigated. The proteolysis and hemolysis were selected as virulence factors for investigation. In this work, we selected the following final concentrations: dexamethasone (0.0052 µg/mL) and tenoxicam (2.7 µg/mL) to be used in combination with antibiotics or alone for investigation of their effects on antibiotic resistance and virulence in P. aeruginosa isolates. Results The drugs either increased or decreased antibiotic resistance in only 0-3 isolates, which indicates that the investigated drugs did not significantly affect the antibiotic resistance. Interestingly, our study demonstrated that both dexamethasone and tenoxicam increased the hemolytic activity of the investigated isolates. On the other hand, our results indicated that no overall final increasing or decreasing effect could be observed for dexamethasone on the proteolytic activity, while tenoxicam increased the proteolytic activity of the investigated isolates. Interestingly, by real-time PCR dexamethasone has shown significant down-regulation of virulence genes namely algD, plcH and toxA, apparently, in case of combination with ciprofloxacin and with gentamicin in one isolate. However, a negative influence was observed in another isolate. Unfortunately, in the case of tenoxicam the only positive effect was observed in the combination with gentamicin in one isolate. Conclusions Resistance of P. aeruginosa against gentamicin and ciprofloxacin may be affected by combining these antibiotics with dexamethasone or tenoxicam. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa, an opportunistic bacterium is also an important pathogen in animals, resistant to various antibiotics in different ways. The purpose of the present study was to evaluate 1-8 cineole, a new antimicrobial agent derived from medicinal plants. Four male and female goats about two years of age weighing 45 kg were used. To prepare the P. aeruginosa inoculation site, a 30 cm² area in the right and left flank and thorax region were shaved. The inoculum was injected intradermally at five sites, with 0.4 mL in a concentration of 106 CFU/mL of P. aeruginosa per site. After the induction of cutaneous pseudomoniasis, lesions in the right thoracic area were treated with 1-8 cineole, lesions in the left thoracic area treated with gentamicin ointment as a standard drug and lesions in the right flank were treated with glycerin daily until complete recovery. Daily administration of cineole and gentamicin for nine days improved skin lesions. Same as the untreated group (n=4), glycerin did not affect cutaneous lesions. The results of this study showed that 1,8-cineole, same as gentamicin, healed and improved cutaneous lesions in goats caused by Pseudomonas infection within nine days. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is one of the common pathogens causing serious infections in fish, consequently high economic losses in freshwater aquaculture. This study was carried out to investigate the prevalence, antibiotic sensitivity, and distribution of virulence genes (oprL, toxA, exoS, fliC and pelA) and antibiotic resistance genes (blaTEM and blaCTX-M) related to natural infection of P.aeurginosa among some cultured freshwater fish. A total of 100 Oreochromis niloticus fish were randomly collected from EL-Manzla lake in Port-Said Governorate, Egypt. Clinical and bacteriological examinations were performed on P. aeruginosa, recovered from O. niloticus (32/100; 32%). The PCR results revealed that all isolates harboured 16srRNA conserved gene, oprL virulence gene, whereas only 87.1%, 84.3% were positive for the toxA and pelA gene, respectively. In addition only 37.5% and 15.7% were positive for the fliC and exoS gene, respectively. Depending on the antibiotic sensitivity and molecular analysis of resistance genes, 12.5% of the tested isolates exhibited multi-drug resistance (MDR) to four antimicrobial classes (penicillins, cephalosporins, tetracyclines and sulfonamides) and harboured the blaTEM and blaCTX-M resistance genes as well as oprL, toxA and pelA virulence genes. MDR to three antimicrobial classes (penicillins, cephalosporins and fluroquinolones) was demonstrated by 9.4% of the tested isolates which harboured the blaTEM and blaCTX-M resistance genes as well as oprL, toxA and pelA virulence genes. Of tested isolates, 12.5% exhibited extensive drug resistance (XDR) to five antimicrobial classes (penicillins, cephalosporins, tetracyclines, aminoglycosides and sulfonamides) harbouring the blaTEM and blaCTX-M resistance genes as well as oprL, toxA, exoS and pelA virulence genes. The emergence of MDR and XDR strains is regarded as a public health issue and indicates improper treatment and a bad prognosis of infections caused by P. aeruginosa [ABSTRACT FROM AUTHOR]

Background: The spread of antibiotic resistance and the emergence of MDR strains, especially in gram-negative bacteria, has led to combining antibiotics to treat infections caused by these bacteria. The study aimed to evaluate some antibiotics' synergistic effect on multidrug-resistant Pseudomonas aeruginosa isolates isolated from clinical samples between thyroid dysfunction and asymptomatic bacteriuria in women of reproductive and postmenopausal age. Materials and Methods: P. aeruginosa was isolated from Rasht city hospitals (North of Iran) clinical specimens with multiple antibiotic resistance. The antibiotic resistance of isolates was determined by the disk diffusion method. The screening checklist evaluated the synergistic effects of ciprofloxacin, colistin, meropenem, and gentamicin. Results: The combination of meropenem and colistin in four isolates was additive, and in two isolates was indifferent. The combined effect of ciprofloxacin and colistin was also incremental in 4 isolates and indifferent in 2 isolates. The combined effect of gentamicin and colistin was indifferent in all selected strains. Conclusion: Results of this study showed that combinations of colistin with ciprofloxacin and colistin with meropenem were successful against resistant isolates, while a combination of gentamicin and colistin showed no synergistic effect. Since the characteristics of each clinical isolate differ from the other isolates, more study with more isolates is recommended to make any precise and definite recommendation. [ABSTRACT FROM AUTHOR]

Background: Pseudomonas aeruginosa is a nosocomial bacterium responsible for variety of infections. Inappropriate use of antibiotics could lead to emergence of multidrug-resistant (MDR) P. aeruginosa strains. Herein, a virulent phage; vB_PaeM_PS3 was isolated and tested for its application as alternative to antibiotics for controlling P. aeruginosa infections. Methods: Phage morphology was observed using transmission electron microscopy (TEM). The phage host range and efficiency of plating (EOP) in addition to phage stability were analyzed. One-step growth curve was performed to detect phage growth kinetics. The impact of isolated phage on planktonic cells and biofilms was assessed. The phage genome was sequenced. Finally, the therapeutic potential of vB_PaeM_PS3 was determined in vivo. Results: Isolated phage has an icosahedral head and a contractile tail and was assigned to the family Myoviridae. The phage vB_PaeM_PS3 displayed a broad host range, strong bacteriolytic ability, and higher environmental stability. Isolated phage showed a short latent period and large burst size. Importantly, the phage vB_PaeM_PS3 effectively eradicated bacterial biofilms. The genome of vB_PaeM_PS3 consists of 93,922 bp of dsDNA with 49.39% G + C content. It contains 171 predicted open reading frames (ORFs) and 14 genes as tRNA. Interestingly, the phage vB_PaeM_PS3 significantly attenuated P. aeruginosa virulence in host where the survival of bacteria-infected mice was markedly enhanced following phage treatment. Moreover, the colonizing capability of P. aeruginosa was markedly impaired in phage-treated mice as compared to untreated infected mice. Conclusion: Based on these findings, isolated phage vB_PaeM_PS3 could be potentially considered for treating of P. aeruginosa infections. [ABSTRACT FROM AUTHOR]

In April 2021, the South Eastern Sydney Local Health District Public Health Unit (Sydney, New South Wales, Australia) was notified of 3 patients with Pseudomonas aeruginosa infections secondary to skin piercings performed at the same salon. Active case finding through laboratories, clinician alerts, and monitoring hospital visits for piercing-related infections identified additional cases across New South Wales, and consumers were alerted. We identified 13 confirmed and 40 probable case-patients and linked clinical isolates by genomic sequencing. Ten confirmed case-patients had used the same brand and batch of aftercare solution. We isolated P. aeruginosa from opened and unopened bottles of this solution batch that matched the outbreak strain identified by genomic sequencing. Piercing-related infections returned to baseline levels after this solution batch was recalled. Early outbreak detection and source attribution via genomic sequencing are crucial for controlling outbreaks linked to contaminated products. Manufacturing standards for nonsterile cosmetic products and guidance for piercing aftercare warrant review. [ABSTRACT FROM AUTHOR]

Objective Bacterial biofilm formation is a multistep process involving bacterial adhesion to inorganic or mucosal surfaces. We aimed to identify Staphylococcus aureus and Pseudomonas aeruginosa strains colonizing the respiratory tracts of cystic fibrosis (CF) patients and to gauge the antibiofilm potential of streptomycin and ozone solutions against them. Methods Bacteria were obtained from CF patients' sputum samples processed in our microbiology laboratory over 1 year (2021–2022). A total of 26 nonduplicate strains (13 S. aureus and 13 P. aeruginosa) were included in this study. Results Both ozone and streptomycin solutions showed significant inhibitory activity. However, when faced with mature biofilm, the streptomycin solution had a significantly more substantial impact than the ozone solution. Furthermore, the ozone solution had no inhibitory effect on mature P. aeruginosa biofilm. Conclusion Ozone and streptomycin solutions might be used as nasal irrigation to eliminate the biofilms in patients with CF in acute respiratory infections. However, our in vitro observations would need to be confirmed in vivo. In chronic inflammation, ozone solution cannot degrade the mature biofilm of P. aeruginosa , whereas streptomycin solution can degrade such biofilms. This result is promising in lessening the biofilms associated with these bacteria that colonize patients with CF. [ABSTRACT FROM AUTHOR]

• Pseudomonas aeruginosa UK strain prevalence assessed. • 51% of patients harboured either common clusters or transmissible strains. • LES prevalence remains stable (9.5%) on comparison with 2013 data. • Cross-infection with hospital-specific strains was found, but was mainly historical. We aimed to describe the UK Pseudomonas aeruginosa population structure amongst people with cystic fibrosis (PWCF), and to examine evidence for cross-infection. Variable Number Tandem Repeat (VNTR) typing was performed on 4640 isolates from 2619 PWCF received from 55 hospital laboratories between 2017 and 2019. A combination of whole genome sequence (WGS)-based analysis of four clusters from one hospital, and epidemiological analysis of shared strains in twelve hospitals evaluated cross-infection. Of 2619 PWCF, 1324 (51%) harboured common clusters or known transmissible strains, while 1295 carried unique strains/those shared among small numbers of patients. Of the former, 9.5% (250 patients) harboured the Liverpool epidemic strain (LES), followed in prevalence by clone C (7.8%; 205 patients), cluster A (5%;130 patients), and cluster D (3.6%; 94 patients). WGS analysis of 10 LES isolates, 9 of cluster D and 6 isolates each of cluster A and clone C from one hospital revealed LES formed the tightest cluster (between 7 and 205 SNPs), and cluster D the loosest (between 53 and 1531 SNPs). Hospital-specific shared strains were found in some centres, although cross-infection was largely historical, with few new acquisitions. Fifty-nine PWCF (2.3%) harboured "high-risk" clones; one ST235 isolate carried a bla IMP-1 allele. Of 2619 PWCF who had P. aeruginosa isolates submitted for VNTR, 51% harboured either common clusters or known transmissible strains, of which LES was the most common. Limited evidence of recent patient-to-patient strain transmission was found, suggesting cross-infection prevention measures and surveillance effectively reduce transmission. [ABSTRACT FROM AUTHOR]

Objective: Molecular detection and co-presence of carbapenem-resistant genes in the isolates of Pseudomonas aeruginosa are less commonly reported from Quetta. In the present study, we determined to highlight the antibiotic sensitivity profile and genetic mechanism of carbapenem resistance. Methods: The cross-sectional study was conducted from May to September 2018 at the Hi-tech laboratory, Centre for Advance Studies in Vaccinology and Biotechnology, University of Baluchistan, Quetta. Biochemical and molecular methods were ascertained for the recognition of the isolates and minimum inhibitory concentration was performed using E-test and broth microdilution methods. The molecular basis of carbapenemase activity was determined by identifying carbapenemase genes in the isolates. Results: Of the (n=23) P. aeruginosa isolated from pus aspirates obtained from surgical/burn units, we have detected blaIMP (n=7/8) 87.5%, blaNDM-1 (n=5/8) 62.5%, and blaSHV (n=4/8) 50%. The co-existence of multiple antibiotic-resistant genes, blaIMP, blaNDM-1 and blaSHV was found in (n=2/8) 25% isolates. These isolates displayed resistance against a range of antimicrobials from β-lactams, tetracyclines, cephalosporins, quinolones, monobactams, aminoglycosides, sulphonamides, phosphoric acid, macrolides, and polypeptide groups, suggesting extensive-drug resistance. Conclusion: The emergence of MBL and ESBL producers is an alarming threat in the region. It is of great importance to determine the resistance mechanism of bacterial bugs. The lack of new antimicrobials particularly against gramnegative bacteria is quite alarming worldwide. [ABSTRACT FROM AUTHOR]

Background: Multidrug-resistant Pseudomonas aeruginosa has become a major cause of severe infections. Due to the lack of approved vaccines, this study has presented putative vaccine candidates against it. Methods: P. aeruginosa 24Pae112 as a reference strain was retrieved from GenBank database. The surface-exposed, antigenic, non-allergenic, and non-homologous human proteins were selected. The conserved domains of selected proteins were evaluated, and the prevalence of proteins was assessed among 395 genomes. Next, linear and conformational B-cell epitopes, and human MHC II binding sites were determined. Finally, five conserved and highly antigenic B-cell epitopes from OMPs were implanted on the three platforms as multi-epitope vaccines, including FliC, the bacteriophage T7 tail, and the cell wall-associated transporter proteins. The immunoreactivity was investigated using molecular docking and immune simulation. Furthermore, molecular dynamics simulation was done to refine the chimeric cell-wall-associated transporter-TLR4 complex as the best interaction. Results: Among 6494 total proteins of P. aeruginosa 24Pae112, 16 proteins (seven OMPs and nine secreted) were ideal according to the defined criteria. These proteins had a molecular weight of 110 kDa and were prevalent in ≥ 75% of P. aeruginosa genomes. Among the presented multi-epitope vaccines, the chimeric cell-wall-associated transporter had the strongest interaction with TLR4. Moreover, the immune simulation response revealed that the bacteriophage T7 tail chimeric protein had the strongest ability to stimulate the immune system. In addition, molecular docking and molecular dynamic simulation indicated the proper and stable interactions between the chimeric cell-wall-associated transporter and TLR4. Conclusion: This study proposed 16 shortlisted proteins as promising immunogenic targets. Two novel platforms (e.g. cell-wall-associated transporter and bacteriophage T7 tail proteins) for designing of multi-epitope vaccines (MEVs), showed the better performance compared to FliC. In our future studies, these two MEVs will receive more scrutiny to evaluate their immunoreactivity. [ABSTRACT FROM AUTHOR]

Objective(s): Virulent strains of Pseudomonas aeruginosa exhibit multidrug resistance by intrinsic and extrinsic mechanisms which are regulated by quorum sensing signalling systems. This includes the production of auto-inducers and their transcriptional activators to activate various virulence factors resulting in host infections. The present study is thus aimed to detect the virulence factor production, quorum sensing activity, and susceptibility pattern of P. aeruginosa to antibiotics from clinical specimens. Materials and Methods: A total of 122 isolates of P. aeruginosa were phenotypically characterized by standard protocols and were categorized into MDR and non-MDR based on the antibiotic susceptibility profiles. Pyocyanin, alkaline protease and elastase production were assessed by qualitative and quantitative methods. Crystal violet assay was carried out for the quantification of biofilms. The genetic determinants of virulence were detected by PCR. Results: Out of the 122 isolates, 80.3% of isolates were MDR and the production of virulence factors was in positive correlation with the presence of genetic determinants and 19.6% were non-MDR, but still showed the production of virulence factors, as confirmed by both phenotypic and genotypic methods. Few carbapenem-resistant strains were detected which did not show the production of virulence factors by both methods. Conclusion: The study concludes, though the strains were non-MDR, they were still capable of producing the virulence factors which may be responsible for the dissemination and chronicity of the infection caused by P. aeruginosa. [ABSTRACT FROM AUTHOR]

: Pyogenic infections are frequently caused by bacteria and fungi. In a prospective study of 335 aerobically cultured purulent samples from inpatients or outpatients during the year 2022, 257 aerobic microbial growths were obtained. The first 3 most frequently isolated species were Staphylococcus aureus (31.13%), Escherichia coli (15.56%) and Pseudomonas aeruginosa (8.95%). Regarding the percentage of strains resistant to antibiotics, the situation is as follows: Staphylococcus aureus 43.75%, Escherichia coli 75% and Pseudomonas aeruginosa 4.35%. A percentage of 3.72% of the strains identified have multiple resistance (MDR), 32.5% of Staphylococcus aureus strains are resistant to methicillin (MRSA) and ESBL are 29.26% of Enterobacteriaceae. The means to control pyogenic infections with resistant bacteria are continuous monitoring of the antimicrobial susceptibility pattern, good practices for hospital hygiene and the application of a clear policy regarding the administration of antibiotics. [ABSTRACT FROM AUTHOR]

Bats play an important ecological role all over the world, and their presence is thought to be an indicator of a healthy ecosystem. Microorganisms play an important role in maintaining the delicate ecological balance of the earth. But frequently, they have a negative public image as a vector of disease-causing microbes. Megaderma lyra, a common carnivorous bat, was chosen to study the impact of their microbial flora. The oral cavity and intestinal bacterial florawas collected. Nutrient agar, Blood agar, MacConkeyagar, and Salmonella shigella agar culture medium were prepared to identify the aerobic organisms. Bacterial species isolated from M.lyra harboured twelve species belonging to three different families; ten from Enterobacteriaceae, one from Streptococcaceae and one from Pseudomonadaceae. Studies on the oral aerobic flora of this bat species revealed, that they have the same microbial flora as any mammal, including humans. Dietary items of carnivorous bats are also a major influencing factor on bacterial oral cavity bacterial floral composition. This work made an attempt of focus the bacterial flora of M.lyra. [ABSTRACT FROM AUTHOR]

Introduction: Pseudomonas aeruginosa, a nosocomial pathogen, causes respiratory infections, particularly in individuals with cystic fibrosis (CF); it poses a significant challenge due to escalating antibiotic resistance. Phage therapy is emerging as a potential alternative approach to treating antibioticresistant bacteria. This study aimed to isolate and identify a highly efficacious bacteriophage targeting P. aeruginosa. Methods: Sewage samples from Mofid Children's Hospital were collected and titrated using a double-layer plaque assay. After plaque detection, the phage was isolated, and then the host range, adsorption rate, and stability were evaluated through spot tests and double-layer plaque assays. Phage morphology was determined using transmission electron microscopy (TEM). Results: Of the three sewage samples collected, one contained phage. We isolated a lytic bacteriophage that exhibited clear plaque formation and induced lysis in planktonic P. aeruginosa. TEM analysis revealed that the phage belonged to the Myoviridae family. The phage had a broad host range and demonstrated optimal stability at 37 °C and pH 7. Conclusion: The isolated phage can potentially be used for treating P. aeruginosa lung infections, offering an alternative approach to address drug-resistant isolates. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa (PA) has emerged as a significant cause of Gram-negative infections, particularly in patients with impaired host defenses. It is one of the six ESKAPE pathogens that majorly cause severe nosocomial infections. In addition to biofilm formation, PA possesses various virulence factors. It can be life-threatening due to his remarkable capacity to resist antibiotics, either intrinsically, developing adaptative resistance, or following the acquisition of resistance genes. The situation worsens when these mechanisms co-exist, conferring worrying multiresistant phenotypes. Therapeutic options are becoming limited, which has led to the development of new antibiotics and novel alternative therapeutic strategies that require the exploration of other therapeutic avenues. Although mostly at the preclinical stages, many recent studies have reported several innovative therapeutic technologies that have demonstrated pronounced effectiveness in fighting against drug-resistant Pa strains. This literature review aims to discuss the mechanism of pyocyanic bacillus resistance to antibiotics, highlight the current state of some novel antibiotics and combination therapies, and the new alternative therapeutic approaches for treating PA infections. [ABSTRACT FROM AUTHOR]

Introduction: Cystic fibrosis is a life-shortening disease of young children but it has been present in adults in recent days. Studies on epidemiology and microbiota of cystic fibrosis from the southern part of India are very few. So we tried to project the data of bacteria responsible for pulmonary exacerbations in cystic fibrosis patients and their antibiotic sensitivity. Materials and Methods: A total of 75 samples were collected from confirmed cystic fibrosis patients attending outpatient clinical departments and were processed for culture and sensitivity according to CLSI protocols. ESBL and MBL production among non fermenters were detected using antibiotic discs using modified Kirby bauer method. Results: Out of all isolated pathogens Pseudomonas aeruginosa isolates were 29 (40.8%), 15 (21.1%) isolates were Klebsiella pneumoniae, 12 (16.9%) Staphylococcus aureus, 7 (9.8%) Candida albicans, 4 (5.6%) Enterobacter cloacae, 2 (2.8%) Burkholderia cepacia, and 2 (2.8%) Burkholderia species. Out of 29 Pseudomonas aeruginosa isolates 68.9% showed ESBL production and 17.2% showed MBL production. All the Burkholderia cepacia tested were ESBL and MBL producers. 100% and 50% of Burkholderia species expressed ESBL and MBL enzymes respectively. Conclusion: Coexistence of S.aureus and P.aeruginosa in cystic fibrosis patients is still a matter of debate. Many hypotheses including the present study concluded that microorganisms are antagonistic invitro after a prolonged co-existence. [ABSTRACT FROM AUTHOR]

Background: Primary infection has been questioned as the pathogenetic cause of acute appendicitis. We attempted to identify the bacteria involved and to investigate if their species, types, or combinations affected the severity of acute appendicitis in children. Methods: Samples from both the appendiceal lumen and the peritoneal cavity of 72 children who underwent appendectomy were collected to perform bacterial culture analysis. The outcomes were studied to identify if and how they were associated with the severity of the disease. Regression analysis was performed to identify any risk factors associated with complicated appendicitis. Results: Escherichia coli, Pseudomonas aeruginosa, and Streptococcus species were the most common pathogens found in the study population. The same microorganisms, either combined or separate, were the most common in the appendiceal lumen and the peritoneal cavity of patients with complicated appendicitis. Gram-negative bacteria and polymicrobial cultures in the peritoneal fluid and in the appendiceal lumen were associated with complicated appendicitis. Polymicrobial cultures in the peritoneal cavity presented a four times higher risk of complicated appendicitis. Conclusions: Polymicrobial presentation and Gram-negative bacteria are associated with complicated appendicitis. Antibiotic regimens should target the combinations of the most frequently identified pathogens, speculating the value of early antipseudomonal intervention. [ABSTRACT FROM AUTHOR]

Objective: Lung cystic fibrosis (CF) is characterized by chronic infections and hyperinflammatory response of neutrophils and macrophages. P. aeruginosa (PA) and S. aureus (MSSA, MRSA) are major pathogens of advanced CF. The main goal of this study was to compare the inflammatory phenotype of murine C57BL/6 macrophages exposed to PA57 with that exposed to MSSA60, both strains isolated from the same patient with severe CF. In the present study, we used C57BL/6 mice sensitive to lung infection with P. aeruginosa. Methods: We measured the release of cytokines and the expression of phenotypic markers of murine neutrophils and macrophages exposed to bacterial cells and biofilm components (i.e., EPS) of the selected bacteria. In addition, a quantitative proteomic approach was used for the characterization of proteome-wide changes in macrophages. Results: Neutrophils stimulated with PA57 and MSSA60 strains produced hyperinflammatory pattern of cytokines. The pro-inflammatory impact of PA57 was significantly higher than that of MSSA60 (IL-6/IL-10 ratio: PA57 = 9.3 vs. MSSA60 = 1.7). Macrophages produced significantly lower amount of cytokines, but showed classical pattern of M1 markers (iNOS-High; arginase-1 and mannose receptor MRC1-Low). Importantly, as evidenced by proteomic analysis, PA57 and PA57-EPS were stronger inducers of M1 macrophage polarization than the MSSA60 counterparts. Conclusions: Our study demonstrated that strong biofilm P. aeruginosa strains, CF isolates, are dominant inducers of M1 macrophages, termed biofilm-associated macrophages (BAMs). We suggest that repolarization of detrimental BAMs might be a new therapeutic strategy to ameliorate the airway damage in CF. [ABSTRACT FROM AUTHOR]

Humans interact constantly with surfaces and associated microbial communities in the environment. The factors shaping the composition of these communities are poorly understood: some proposed explanations emphasize the influence of local habitat conditions (niche‐based explanations), while others point to geographic structure and the distance among sampled locations (dispersal‐based explanations). However, the relative roles of these different drivers for microbial community assembly on human‐associated surfaces are not clear. Here, we used a combination of sampling, sequencing (16S rRNA) and culturing to show that the composition of banknote‐associated bacterial communities varies depending on the local collection environment. Using banknotes collected from various locations and types of shops across Switzerland, we found taxonomic diversity dominated by families such as Pseudomonadaceae and Staphylococcaceae, but with banknote samples from particular types of shops (especially butcher shops) having distinct community structure. By contrast, we found no evidence of geographic structure: similarity of community composition did not decrease with increasing distance among sampled locations. These results show that microbial communities associated with banknotes, one of the most commonly encountered and exchanged human‐associated surfaces, can reflect the local environmental conditions (in this case, the type of shop), and the signal for this type of variation was stronger than that for geographic structure among the locations sampled here. [ABSTRACT FROM AUTHOR]

Objective: By analyzing the distribution and drug resistance of common pathogen in different sites in plastic surgery to provide reference for clinicians to choose the best antibacterial treatment plan. Methods: Pathogens of postoperative infection in plastic surgery from January 2011 to December 2021 were retrospectively analyzed to determine the species and quantity, and to access the trend of each pathogen's detection rate. The antibiotic sensitivity and distribution characteristics of common pathogens were studied in conjunction with the site of infection. Results: A total of 1709 bacterial strains were detected, including 1244 gram‐positive bacterial strains and 465 gram‐negative bacterial strains. The main pathogen of perineum was Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa), while Staphylococcus aureus (S. aureus) was the most common pathogen in the other infected sites. The detection rate of methicillin‐resistant S. aureus (MRSA) and methicillin‐resistant coagulase‐negative staphylococcus (MRCNS) was on the rise from 2011 to 2021. No S. aureus and coagulase‐negative staphylococcus (CoNS) strains were resistant to vancomycin. The sensitive rate of S. aureus from all parts and CoNS from all sites except lower limbs and mandible was higher than 80% to linezolid. The resistance rate of S. aureus and CoNS in all parts to penicillin, clindamycin, and erythromycin was high. The susceptibility rate of CoNS in lower mandible was high to gentamicin. Conclusions: Staphylococcus aureus was the primary pathogen of gram‐positive bacteria in all site of plastic surgery except perineum, followed by CoNS. The distribution and drug resistance of pathogen in different infection sites were different. We should formulate more accurate and reasonable antibacterial programs according to drug resistance results of various parts to reduce the emergence of resistant strains and effectively prevent and control infection. [ABSTRACT FROM AUTHOR]

The difficulty of degrading lignin is the main factor limiting the high-value conversion process of lignocellulosic biomass. The biodegradation of lignin has attracted much attention because of its strong environmental friendliness, but it still faces some dilemmas such as slow degradation rate and poor adaptability. The microbial consortia with high lignin degradation efficiency and strong environmental adaptability were obtained in our previous research. To further increase the lignin degradation efficiency, this paper proposes a composite treatment technology of steam explosion combined with microbial consortium degradation to treat three kinds of biomass. We measured the lignin degradation efficiency, selectivity value (SV) and enzymatic saccharification efficiency. The structural changes of the biomass materials and microbial consortium structure were also investigated. The experimental results showed that after 1.6 MPa steam explosion treatment, the lignin degradation efficiency of the eucalyptus root reached 35.35% on the 7th days by microbial consortium. At the same time, the lignin degradation efficiency of the bagasse and corn straw treated by steam explosion followed by microbial biotreatment was 37.61–44.24%, respectively, after only 7 days of biotreatment. The microbial consortium also showed strong selectivity degradation to lignin. The composite treatment technology can significantly improve the enzymatic saccharification efficiency. Saccharomycetales, Ralstonia and Pseudomonadaceae were the dominant microorganisms in the biomass degradation systems. It was proved that the combined treatment technology of steam explosion and microbial consortium degradation could overcome the drawbacks of traditional microbial pretreatment technology, and can facilitate the subsequent high-value conversion of lignocellulose. [ABSTRACT FROM AUTHOR]

• Pseudomonas/Aspergillus co-positive cultures are less common than expected in CF airway samples. • Increasing Pseudomonas culture density is associated with decreasing Aspergillus frequency. • Af-sequencing positive, culture negative samples were more common with Pseudomonas present. • Interpretation of negative Aspergillus culture in Pa-positive samples should be cautious. Aspergillus fumigatus (Af) infection is associated with poor lung health in chronic suppurative lung diseases but often goes undetected. We hypothesised that inhibition of Af growth by Pseudomonas aeruginosa (Pa) increases the frequency of false-negative Af culture in co-infected people. Using a substantial group of cystic fibrosis (CF) airway samples, we assessed the relationship between Af and bacterial pathogens, additionally comparing fungal culture with next-generation sequencing. Frequency of co-culture was assessed for 44,554 sputum/BAL cultures, from 1,367 CF patients between the years 2010–2020. In a subgroup, Internal Transcribed Spacer-2 (ITS2) fungal sequencing was used to determine sequencing-positive, culture-negative (S+/C-) rates. Pa+ samples were nearly 40% less likely (P <0.0001) than Pa- samples to culture Af, an effect that was also seen with some other Gram-negative isolates. This impact varied with Pa density and appeared to be moderated by Staphylococcus aureus co-infection. Sequencing identified Af-S+/C- for 40.1% of tested sputa. Samples with Pa had higher rates of Af-S+/C- (49.3%) than those without (35.7%; RR 1.38 [1.02–1.93], P <0.05). Af-S+/C- rate was not changed by other common bacterial infections. Pa did not affect the S+/C- rates of Candida, Exophiala or Scedosporium. Pa/ Af co-positive cultures are less common than expected in CF. Our findings suggest an Af-positive culture is less likely in the presence of Pa. Interpretation of negative cultures should be cautious, particularly in Pa-positive samples, and a companion molecular diagnostic could be useful. Further work investigating mechanisms, alternative detection techniques and other chronic suppurative lung diseases is needed. [ABSTRACT FROM AUTHOR]

Background: Pseudomonas aeruginosa intestinal carriage rates are significantly higher in immunosuppressed individuals and hospitalized patients who therefore have increased risk of infections and antibiotic-associated diarrhea. To combat intestinal dysbiosis and decolonize P. aeruginosa from gastrointestinal tract, we investigated the anti-adherence and gut microbiota modulation properties of marine prebiotic fucoidans. Methods: Proteomic analysis of culture supernatant was performed by LC–MS/MS. Using lectin-based enzyme-linked immunosorbent assay, hemagglutinin domain interaction and inhibition with biomolecules were studied. We investigated the role of nutritional grade fucoidans in a mouse model and used 16S ribosomal RNA sequencing to examine fecal microbiota composition. Results: Analysis of culture supernatant proteins indicated the secretion of two-partner secretion (TPS) family proteins, including TpsA1/CdiA2 and TpsA2/CdiA1. Lectin like activity at the N-terminal of TpsA due to a conserved hemagglutinin domain (Pfam identifier [ID] PF05860) mediates binding to mucins that carry multiple fucosylated glycans. Fucose-rich sulfated polysaccharides (fucoidans) and sulfated dextrans were found to be potent inhibitors of the recombinant N-terminal hemagglutinin domain of TpsA (TpsA-NT-HAD) binding to mucins. In a mouse model, antibiotic-induced dysbiosis was essential for P. aeruginosa gastrointestinal colonization. After prophylactic oral fucoidans supplementation, a higher proportion (60%) of the mice were decolonized over time and resisted re-colonization, this was associated with remarkable expansion of Bacteroides (post-infection day-3 abundance, 29–50%) and consequential reductions in bloom of Enterobacteriaceae and Enterococcaceae populations. In the non-supplemented group, Parabacteroides mediated recovery from dysbiosis but failed to decolonize P. aeruginosa. Conclusions: Supplementing diet with marine prebiotic fucoidans can mediate earlier recovery from dysbiosis and decolonization of P. aeruginosa from gut by inhibiting secreted virulence factor (TpsA/CdiA) interaction with mucins and promoting the growth of beneficial Bacteroides population. We suggest the prophylactic use of nutritional grade fucoidans to decolonize P. aeruginosa from gastrointestinal tract of at-risk individuals to prevent infection and transmission of colonizing P. aeruginosa. [ABSTRACT FROM AUTHOR]

The aim of the current study was to analyse the distribution of antimicrobial drug resistance (AMR) among Pseudomonas aeruginosa (P. aeruginosa, PA) isolates from Guangdong Provincial People's Hospital (GDPH) from 2017 to 2021, and the impact of the COVID-19 outbreak on changes in the clinical distribution and drug resistance rate of P. aeruginosa to establish guidelines for empiric therapy. Electronic clinical data registry records from 2017 to 2021 were retrospectively analysed to study the AMR among P. aeruginosa strains from GDPH. The strains were identified by VITEK 2 Compact and MALDI-TOF MS, MIC method or Kirby–Bauer method for antibiotic susceptibility testing. The results were interpreted according to the CLSI 2020 standard, and the data were analysed using WHONET 5.6 and SPSS 23.0 software. A total of 3036 P. aeruginosa strains were detected in the hospital from 2017 to 2021, and they were primarily distributed in the ICU (n = 1207, 39.8%). The most frequent specimens were respiratory tract samples (59.6%). The detection rate for P. aeruginosa in 5 years was highest in September, and the population distribution was primarily male(68.2%). For the trend in the drug resistance rate, the 5-year drug resistance rate of imipenem (22.4%), aztreonam (21.5%) and meropenem (19.3%) remained at high levels. The resistance rate of cefepime decreased from 9.4% to 4.8%, showing a decreasing trend year by year (p < 0.001). The antibiotics with low resistance rates were aminoglycoside antibiotics, which were gentamicin (4.4%), tobramycin (4.3%), and amikacin (1.4%), but amikacin showed an increasing trend year by year (p = 0.008). Our analysis indicated that the detection rate of clinically resistant P. aeruginosa strains showed an upwards trend, and the number of multidrug-resistant (MDR) strains increased year by year, which will lead to stronger pathogenicity and mortality. However, after the outbreak of COVID-19 in 2020, the growth trend in the number of MDR bacteria slowed, presumably due to the strict epidemic prevention and control measures in China. This observation suggests that we should reasonably use antibiotics and treatment programs in the prevention and control of P. aeruginosa infection. Additionally, health prevention and control after the outbreak of the COVID-19 epidemic (such as wearing masks, washing hands with disinfectant, etc., which reduced the prevalence of drug resistance) led to a slowdown in the growth of the drug resistance rate of P. aeruginosa in hospitals, effectively reducing the occurrence and development of drug resistance, and saving patient's treatment costs and time. [ABSTRACT FROM AUTHOR]

Introduction: Antimicrobial resistance (AMR) is a serious global threat. Identification of novel antibacterial targets is urgently warranted to help antimicrobial drug discovery programs. This study attempted identification of potential targets in two important pathogens Pseudomonas aeruginosa and Staphylococcus aureus. Methods: Transcriptomes of P. aeruginosa and S. aureus exposed to two different quorum-modulatory polyherbal formulations were subjected to network analysis to identify the most highly networked differentially expressed genes (hubs) as potential anti-virulence targets. Results: Genes associated with denitrification and sulfur metabolism emerged as the most important targets in P. aeruginosa. Increased buildup of nitrite (NO2) in P. aeruginosa culture exposed to the polyherbal formulation Panchvalkal was confirmed through in vitro assay too. Generation of nitrosative stress and inducing sulfur starvation seemed to be effective anti-pathogenic strategies against this notorious gram-negative pathogen. Important targets identified in S. aureus were the transcriptional regulator sarA, immunoglobulin-binding protein Sbi, serine protease SplA, the saeR/S response regulator system, and gamma-hemolysin components hlgB and hlgC. Conclusion: Further validation of the potential targets identified in this study is warranted through appropriate in vitro and in vivo assays in model hosts. Such validated targets can prove vital to many antibacterial drug discovery programs globally. [ABSTRACT FROM AUTHOR]

Introduction: The use of hydrocarbons and their derivatives, have generated a problem of environmental contamination. The most current studies suggest a solution to this situation, based on microbiological degradation or biotransformation, using axenic microbial cultures. Objective: To develop a systematic mapping of the scientific literature on research on bacteria and fungi in the biodegradation of hydrocarbons. Methodology: The exploration, classification, verification and study of the documents with the respective research guidelines in relation to the purpose of this research was carried out. The documents obtained from WoS and Scopus were merged and replicas were eliminated, using the R studio software. Subsequently, a study of origin, theoretical reference, bibliometric and network study on bacteria and fungi in the biodegradation of hydrocarbons was developed. Results: The search yielded a total of 424 records. It was evidenced that the subject has had a significant increase over the years, mainly from 2015, with an increase of 51.9% and an annual increase rate of 10.41%. The country with the highest scientific production is China with 67 publications. According to the scientific papers reviewed until 2021, this is the first systemic review study on BHBH, which has used the R studio application to analyze the bibliographic productivity on this topic. Conclusion: Some of the native bacteria that biodegrade hydrocarbons are Gordonia, Brevibacterium, Dietzia, Burkholderia, Pseudomonas aeruginosa. For fungi they are Aspergillus, Penicillium, Fusarium. For yeasts they are Candida, Yarrowia, Pichia. [ABSTRACT FROM AUTHOR]

Background: Pseudomonas aeruginosa is a commonly known opportunistic bacteria that can produce a wide range of biologically active compounds. The ability of certain strains to generate extra pigments such as yellow pyoverdin, dark red pyorubin, and pyomelanin (dark black), as well as the two primary dyes, were pyocyanin (blue-green) and fluorescein (yellow-green). Aims: To investigate the frequency of some virulence factors genes (phz M, phz S), of carbapenem resistance P. aeruginosa local isolates. Methods: Clinical samples were taken from wounds, burns, urine, nose, and ear swabs, and 110 isolates of Pseudomonas aeruginosa were obtained from two hundred and ten samples gathered from affected patients, and diffusion method was utilized to assess the resistance of the bacterial isolates. Also was used molecular detection of (Phz M, Phz S) genes by using PCR technique. Results: Most of the isolates (40) % were found in burn samples whereas in wounds samples (16.3)%, urine (23.7)%, and ear swabs (20)%. In the present study, a prevalent large percentage of P. aeruginosa isolates exhibited high levels of resistance to meropenem (20)% and the lowest level to Imipenem (5.5)%. Molecular analysis showed the phz M and phz S genes identified in all of the carbapenem resistance P.aeruginosa. Conclusions: Large percentage of P. aeruginosa isolates exhibited high levels of resistance to meropenem (20%) and the lowest percentage to Imipenem (5.5%). The results showed that al l isolates have phenazine genes (Phz S, Phz M). [ABSTRACT FROM AUTHOR]

Sorghum is a major staple crop in sub-Saharan Africa with yields severely impacted by biotic and abiotic factors. Here, we analysed the taxonomic diversity and biogeographical distribution of bacterial taxa of 48 agricultural fields along a transect of approximately 2000 km across the Ethiopian sorghum belt, the centre of origin of sorghum. The ultimate goal is to identify—yet-unexplored—beneficial plant–microbe associations. Based on bulk soil bacterial communities and DArT-SNP analyses of 59 sorghum accessions, we selected three microbiologically distinct field soils and 12 sorghum genotypes, including commercial varieties, wild relatives, and farmer-preferred landraces. The results showed a core rhizosphere microbiome of 2125 amplicon sequence variants (ASVs), belonging to eight bacterial families consistently found across the three soil types and the 12 sorghum genotypes. Integration of the rhizosphere bacterial community analysis with DArT-SNP sorghum genotyping revealed the association of differentially abundant ASVs with sorghum genotypic traits, including the distinct recruitment of Pseudomonadaceae by the stay-green, drought-tolerant, and wild sorghum genotypes. Collectively, these results provide new insights into the core and accessory bacterial taxa in the sorghum rhizosphere in the centre of origin, setting a baseline for targeted isolation and functional characterization of putative beneficial rhizobacteria. [ABSTRACT FROM AUTHOR]

Objective(s): Numerous studies have confirmed sumac's ability to inhibit pathogens and even eradicate chronic drug-resistant infections. Current research was conducted to demonstrate the action of various sumac extracts at sub-inhibitory concentrations in modulating pathogen-related characteristics instead of killing them. Materials and Methods: The influence of sumac extracts on the quorum sensing dependent virulence of multidrug-resistant isolates of Pseudomonas aeruginosa recovered from burn wounds was considered by detecting the effect on biofilm development, various virulence factors, and expression of bacterial exotoxin A and quorum sensing related genes. Results: Experiments to characterize and measure sumac extract's impact on the P. aeruginosa growth, biofilm, exoproteases, pyocyanin, motility, and the quorum sensing networks revealed that all studied characteristics were reduced by concentrations below inhibition without affecting bacterial growth. Furthermore, the expression of exotoxin A, rhl, and las glucons was declined or even inhibited by lower levels of sumac fruit fractions. Conclusion: The findings revealed that sumac fights infections either by its inhibitory effect on the bacterial cells or by reducing bacterial signaling and virulence by disruption of the bacterial signal system. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa pathogen is opportunistic. Several virulence factors and biofilms can cause its pathogenicity. Furthermore, infections triggered via multidrug-resistant P. aeruginosa among hospitalized patients are a public health concern. The primary antimicrobial agents in treating Gram-negative infection include Meropenem and Imipenem. Moreover, the spread of Carbapenem-resistant P. aeruginosa is a focal concern worldwide. The present research aims to determine the spread of Carbapenem-resistant P. aeruginosa, and the distribution of the Alginate and Metallo-beta-lactamase encoding gene in clinical isolates. In the present cross-sectional descriptive research, 50 wound and sputum clinical specimens were obtained. Isolates were all identified by applying cultural characteristics and biochemical tests. The Polymerase Chain Reaction (PCR) was conducted to distinguish algD, BLA-VIM, BLA-IMP, and 16SrRNA genes. Moreover, the phenotypic method was used to detect hemolysin. The disk diffusion technique was applied to screen clinical isolates for eight antimicrobial agents. The PCR results showed all isolates to be positive for algD and negative for BLA-VIM and BLA-IMP genes. Hemolysin and multidrug resistance prevalence was 100% and 76%, respectively. Furthermore, Meropenem proved to be the most efficient antibiotic against clinical isolates. Alginate and hemolysin are considered significant virulence factors for P. aeruginosa, playing a key role in triggering diseases and tissue or skin lesions. The emergence of Multidrug Resistant (MDR) isolates indicates that developing antibiotic stewardship in our regional community hospital is a top priority. Infection control measures could help control the distribution of virulence genes in P. aeruginosa isolates. Moreover, regular observation is needed to decrease public health threats, distributing virulence factors and Imipenem-resistance patterns in clinical isolates of P. aeruginosa. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is a significant pathogen responsible for severe multisite infections with high morbidity and mortality rates. This study analyzed carbapenem-resistant Pseudomonas aeruginosa (CRPA) at a tertiary hospital in Shandong, China, using whole-genome sequencing (WGS). The objective was to explore the mechanisms and molecular characteristics of carbapenem resistance. A retrospective analysis of 91 isolates from January 2022 to March 2023 was performed, which included strain identification and antimicrobial susceptibility testing. WGS was utilized to determine the genome sequences of these CRPA strains, and the species were precisely identified using average nucleotide identification (ANI), with further analysis on multilocus sequence typing and strain relatedness. Some strains were found to carry the ampD and oprD genes, while only a few harbored carbapenemase genes or related genes. Notably, all strains possessed the mexA , mexE , and mexX genes. The major lineage identified was ST244, followed by ST235. The study revealed a diverse array of carbapenem resistance mechanisms among hospital isolates, differing from previous studies in mainland China. It highlighted that carbapenem resistance is not due to a single mechanism but rather a combination of enzyme-mediated resistance, AmpC overexpression, OprD dysfunction, and efflux pump overexpression. This research provides valuable insights into the evolutionary mechanisms and molecular features of CRPA resistance in this region, aiding in the national prevention and control of CRPA, and offering references for targeting and developing new drugs. • Hospital isolates had carbapenem resistance through diverse and complex mechanisms. • The β-lactamase genes blaoxa and blapdc were detected. • The genes mexa, mexe, and mexx caused resistance through the efflux pump mechanism. • The Oprd gene caused resistance due to decreased outer membrane permeability. • Vigilant monitoring of high-risk clones is important. [ABSTRACT FROM AUTHOR]

The global rise of antibiotic resistance poses a substantial risk to mankind, underscoring the necessity for alternative antimicrobial options. Developing novel drugs has become challenging in matching the pace at which microbial resistance is evolving. Recently, nanotechnology, coupled with natural compounds, has emerged as a promising solution to combat multidrug-resistant bacteria. In the present study, silver nanoparticles were green-synthesized using aqueous extract of Phoenix dactylifera (variety Ajwa) fruits and characterized by UV–vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) coupled with Energy dispersive X-ray analysis (EDX), Transmission electron microscopy (TEM) and Thermogravimetric-differential thermal analysis (TGA-DTA). The in-vitro synergy of green synthesized P. dactylifera silver nanoparticle (PD-AgNPs) with selected antibiotics and bioactive extract of Punica granatum, i.e., ethyl acetate fraction (PGEF), was investigated using checkerboard assays. The most effective synergistic combination was evaluated against the QS-regulated virulence factors production and biofilm of Pseudomonas aeruginosa PAO1 by spectroscopic assays and electron microscopy. In-vivo anti-infective efficacy was examined in Caenorhabditis elegans N2 worms. PD-AgNPs were characterized as spherical in shape with an average diameter of 28.9 nm. FTIR analysis revealed the presence of functional groups responsible for the decrease and stabilization of PD-AgNPs. The signals produced by TGA-DTA analysis indicated the generation of thermally stable and pure crystallite AgNPs. Key phytocompounds detected in bioactive fractions include gulonic acid, dihydrocaffeic acid 3-O-glucuronide, and various fatty acids. The MIC of PD-AgNPs and PGEF ranged from 32 to 128 μg/mL and 250–500 μg/mL, respectively, against test bacterial strains. In-vitro , PD-AgNPs showed additive interaction with selected antibiotics (FICI 0.625–0.75) and synergy with PGEF (FICI 0.25–0.375). This combination inhibited virulence factors by up to 75 % and biofilm formation by 84.87 % in P. aeruginosa PAO1. Infected C. elegans worms with P. aeruginosa PAO1 had a 92.55 % survival rate when treated with PD-AgNPs and PGEF. The combination also reduced the reactive oxygen species (ROS) level in C. elegans N2 compared to the untreated control. Overall, these findings highlight that biosynthesized PD-AgNPs and bioactive P. granatum extract may be used as a potential therapeutic formulation against MDR bacteria. • Silver nanoparticles from aqueous extract of P. dactylifera (PD-AgNPs) were well-dispersed and spherical, with an average diameter of 28.9 nm. • PD-AgNPs and bioactive extract of P. granatum (PGEF) showed synergy in vitro with FICI of 0.25–0.375. • Synergistic formulation inhibited QS-regulated virulence factors in P. aeruginosa PAO1 more than 75 %.. • The anti-infective efficacy of synergistic formulations against P. aeruginosa PAO1-infected C. elegans N2 worms highlights in vivo therapeutic potential.. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa causes life-threatening diseases and is resistant to almost all conventional antibiotics. The quorum sensing (QS) system of P. aeruginosa contributes to many pathogenic factors some of which are pigment production, motility, and biofilm. The disruption of quorum sensing system may be an impactful strategy to deal with infections. The present study investigates the anti-quorum sensing property of a bioactive molecule extracted from marine epibiotic bacteria present on the surface of seaweeds. Among all the isolates tested against monitor strain Chromobacterium violaceum (MTCC 2656), the one with the highest activity was identified as Bacillus zhangzhouensis SK4. The culture supernatant was extracted with chloroform which was then partially purified by TLC and column chromatography. The probable anti-QS compound was identified as 1,2-benzenedicarboxylic acid, bis (2-methylpropyl ester) by GC-MS and NMR analysis. The treatment of P. aeruginosa MCC 3457 with the lead compound resulted in the reduced production of pyocyanin, rhamnolipids, exopolysaccharide, biofilm, and motility. The observations of light and scanning electron microscopy also supported the biofilm inhibition. The lead compound showed synergism with the meropenem antibiotic and significantly reduced MIC. The molecular docking and pharmacokinetics study predicted 1, 2-benzenedicarboxylic acid, bis (2-methylpropyl ester), a phthalate derivative as a good drug candidate. The molecular dynamics study was also performed to check the stability of the lead compound and LasR complex. Further, lead compounds did not exhibit any cytotoxicity when tested on human embryonic kidney cells. As per our knowledge, this is the first report on the anti-QS activity of B. zhangzhouensis SK4, indicating that epibiotic bacteria can be a possible source of novel compounds to deal with the multidrug resistance phenomenon. [Display omitted] • First report of anti-QS activity of B. zhangzhouensis SK4, a marine epibiotic bacterium. • 1,2-benzenedicarboxylic acid, bis (2-methylpropyl ester), a phthalate derivative was identified as QS inhibitor. • A phthalate derivate effectively inhibited virulence factors clinical strain of P. aeruginosa MCC3457. • A phthalate derivate showed synergism with antibtiotics and no cytotoxicity against cell line • Molecular docking, molecular dynamic simulation and ADMET analysis were satisfactory. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is often identified as the causative agent in nosocomial infections. Their adapted resistance makes them strong towards antimicrobial treatments. They protect and empower their survival behind strong biofilm architecture that works as their armor toward antimicrobial therapy. Additionally, P. aeruginosa generates virulence factors, contributing to chronic infection and recalcitrant phenotypic characteristics. The current study utilizes the benevolence of nanotechnology to develop an alternate technique to control the spreading of P. aeruginosa by limiting its biofilm and virulence development. This study used a natural compound, tetramethylpyrazine, to generate gold nanoparticles. Tetramethylpyrazine-gold nanoparticles (Tet-AuNPs) were presented in spherical shapes, with an average size of 168 ± 52.49 nm and a zeta potential of −12.22 ± 2.06 mV. The minimum inhibition concentration (MIC) of Tet-AuNPs that proved more than 90 % effective in inhibiting P. aeruginosa was 256 μg/mL. Additionally, it also shows antibacterial activities against Staphylococcus aureus (MIC, 256 μg/mL), Streptococcus mutans (MIC, 128 μg/mL), Klebsiella pneumoniae (MIC, 128 μg/mL), Listeria monocytogenes (MIC, 256 μg/mL), and Escherichia coli (MIC, 256 μg/mL). The sub-MIC values of Tet-AuNPs significantly inhibited the early-stage biofilm formation of P. aeruginosa. Moreover, this concentration strongly affected hemolysis, protease activity, and different forms of motilities in P. aeruginosa. Additionally, Tet-AuNPs destroyed the well-established mature biofilm of P. aeruginosa. The expression of genes linked with the biofilm formation and virulence in P. aeruginosa treated with sub-MIC doses of Tet-AuNPs was shown to be significantly suppressed. Gene expression studies support biofilm- and virulence-suppressing effects of Tet-AuNPs at the phenotypic level. • Tet-AuNPs was synthesized using tetramethylpyrazine as a reducing agent. • Tet-AuNPs had antibacterial efficacy against Gram-negative and Gram-positive pathogens. • The sub-MIC value of Tet-AuNPs inhibited P. aeruginosa biofilm and virulence properties. • Tet-AuNPs suppressed the expression of biofilm and virulence-associated genes in P. aeruginosa. [ABSTRACT FROM AUTHOR]

Despite several campaigns aimed at antibiotic stewardship, antibiotic use continues unabated. Most disturbing is the seemingly unstoppable use of antibiotic agents in animal feed and consumable plants.[[5], [7]] Researchers and industry have responded to the growing concern of antibiotic resistance by proposing the further development of more powerful and broader antibiotic agents.[8] Antibiotic agents that seem to "kill everything" has been the most popular approach. "It Is Not Necessary to Kill Them in Order to Make Them Relatively Harmless": Molecular Diplomacy in the Pathogen-Host Interaction In 1899, before the discovery of antibiotics and before the discovery of DNA, I. Burney Yeo, MD, FRCP, Senior Physician, King's College Hospital and Professor of Medicine stated, "We are still very much in the dark as to the precise mode of action of pathogenic microbes, but we do know that their activities and their virulence vary greatly according to their environment, and that it is not necessary to kill them in order to make them relatively harmless."[1] As we reach the dawn of a potential pandemic of antibiotic resistance, it is important to understand how we can contain or distance ourselves from our microbial foes without waging an all-out war against them. [Extracted from the article]

Eusocial corbiculate bees, including bumble bees and honey bees, maintain a socially transmitted core gut microbiome that contributes to digestion and pathogen defense. In contrast, solitary bees, which have fewer opportunities for direct interhost transmission, typically have less consistent microbiomes dominated by bacteria associated with pollen and food reserves. Carpenter bees (genus Xylocopa) are long-lived bees that are not eusocial but that often live in shared nesting sites. We characterized gut microbiomes for Xylocopa micans, X. mexicanorum, X. tabaniformis parkinsoniae, and X. virginica and for five solitary bee species from other genera (Andrena, Habropoda, Megachile, and Svastra), sampled in the same localities in central Texas. Unexpectedly, all four Xylocopa species had microbiomes dominated by bacterial lineages previously known only from social bees or other insect groups. Microbiomes were similar across three Xylocopa species and included lineages in the families Bifidobacteriaceae, Orbaceae, Lactobacillaceae, Pseudomonadaceae, and Enterobacteriaceae. In contrast, X. virginica had a distinct microbiome dominated by the genus Bombilactobacillus, a group abundant in guts of eusocial bees. Phylogenetic analyses support a past transfer of bacterial lineages into Xylocopa from bumble bees or honey bees. Gut microbiome compositions of Xylocopa species were distinct from those of other co-occurring solitary bees that had variable gut microbiomes dominated by bacteria from environmental sources. [ABSTRACT FROM AUTHOR]

Cutibacterium acnes (C. acnes) is an organism implicated in the pathogenesis of acne. Despite regular immersion in antimicrobial chlorine, adolescent swimmers suffer from acne and tend to be resistant to standard therapies. Given the presence of Pseudomonas within swimming facilities, we hypothesized that "swimmer acne" is potentially driven by a different microbial mechanism. In this study, we aimed to examine the microbial dynamics of C. acnes and Pseudomonadaceae, a family of gram‐negative bacteria (includes Pseudomonas aeruginosa), in swimmers and its potential contribution to the pathogenesis of acne in this population. Using fluorescence photography that measures the Coproporphyrin III (CPIII), we quantitated an absolute abundance of C. acnes present on the face of each participant pre‐ and post‐swimming. In addition, 16S rRNA gene sequencing was utilized to assess relative abundance of the skin microbiota on each participant pre‐ and post‐swimming. 16 swimmers (8 girls and 8 boys) completed the study. Seven had acne on the face. The CPIII fluorescence levels decreased for all swimmers after 1 h of swimming (p‐value <0.001). In contrast, the relative abundance of C. acnes remained unchanged, while that of Pseudomonadaceae increased after swimming (p‐value =0.027). Comparing the relative abundances of Pseudomonadaceae before swimming, there was a significant increase in variance from the mean in acne group as compared to no acne group (p‐value <0.001). Taken together, we conclude that the skin dysbiosis resulting from repeated decolonization and colonization of C. acnes and Pseudomonadaceae, respectively, can potentially be associated with the pathogenesis of acne in swimmers. [ABSTRACT FROM AUTHOR]

Background Antibiotic resistant bacteria and various infections caused by them especially extensive drug resistance (XDR) strains and worrying statistics of mortality due to these strains and also the lack of a clear vision for development and production of new effective antibiotics have made the necessity of using alternative therapies more apparent. Materials and Methods In this study, specific phages affecting the Pseudomonas aeruginosa XDR strain were extracted from hospital wastewater and their laboratory characteristics along with lysis effect on 40 XDR strains of P. aeruginosa were investigated. Results The results indicated that three isolated phages (PaB1, PaBa2 and PaBa3) belonged to the Myoviridae and Pododoviridae families and were specific to Pseudomonas aeruginosa strains. More than 98% of phages absorbed their host in less than 10 minutes (Adsorption time <10 min) and completed their lytic cycle after 40 minutes (latent time = 40 min). Burst size of PaBa1, PaBa2 and PaBa3 was 240, 250 and 220 pfu/cell, respectively. PaBa1 lysed 62.5% of the XDR strains with the highest efficiency. The three Phage cocktail was effective against 67.5% of the studied strains. Conclusion The results of this study indicate the significant potential of these phages for therapeutic use and prophylaxis of infections caused by this bacterium. [ABSTRACT FROM AUTHOR]

Objective(s): Antimicrobial resistance emerged as a global challenge owing to limited therapeutic options to control infections. Pseudomonas aeruginosa, an MDR pathogen already developed resistance against many conventional antibiotics. An "anti-virulence strategy" that targets bacterial virulence rather than growth proves effective against drug-resistant pathogens. Materials and Methods: Here, we used a structure-based drug design approach to identify lead molecules using the LasR receptor protein of P. aeruginosa as a target responsible for virulence production in this bacterium. From the identified hits, we developed lead-based nanoformulation and investigated its effectiveness for treating the P. aeruginosa associated surface-infection in-vivo. First, TC-based nanoemulsions were fabricated by high-pressure homogenization and evaluated for various in vitro parameters. The optimized nanoemulsions were thereby utilized to prepare NEG. Results: The nanoemulsion (F3) exhibited low droplet size (51.04±1.88 nm), PDI (0.065±1.14), and negative zeta potential (-33.65±0.82 mV). In animals, topical application of NEG-3 demonstrated significant improvement on skin permeability (459±10.17 μg), drug influx (18.99±0.76 μg/cm2 hr), and repressed the CFU of P. aeruginosa induced-surface infection (P≤ 0.001). The histology of rat skin demonstrated a significant effect for groups treated with TC-based NEGs as compared with a negative control group, whereas no significant effect was seen on rat liver indicating low systemic exposure to the drug. Also, NEG3 showed no significant changes under different stability conditions after 3 months. Conclusion: TC-based NEGs open up the possibility of a more effective way to combat serious surface infections caused by P. aeruginosa. [ABSTRACT FROM AUTHOR]

The emergence of multidrug resistance and increased pathogenicity in microorganisms is conferred by the presence of highly synchronized cell density dependent signalling pathway known as quorum sensing (QS). The QS hierarchy is accountable for the secretion of virulence phenotypes, biofilm formation and drug resistance. Hence, targeting the QS phenomenon could be a promising strategy to counteract the bacterial virulence and drug resistance. In the present study, artocarpesin (ACN), a 6-prenylated flavone was investigated for its capability to quench the synthesis of QS regulated virulence factors. From the results, ACN showed significant inhibition of secreted virulence phenotypes such as pyocyanin (80%), rhamnolipid (79%), protease (69%), elastase (84%), alginate (88%) and biofilm formation (88%) in opportunistic pathogen, Pseudomonas aeruginosa PAO1. Further, microscopic observation of biofilm confirmed a significant reduction in biofilm matrix when P. aeruginosa PAO1 was supplemented with ACN at its sub-MIC concentration. Quantitative gene expression studies showed the promising aspects of ACN in down regulation of several QS regulatory genes associated with production of virulence phenotypes. Upon treatment with sub-MIC of ACN, the bacterial colonization in the gut of Caenorhabditis elegans was potentially reduced and the survival rate was greatly improved. The promising QS inhibition activities were further validated through in silico studies, which put an insight into the mechanism of QS inhibition. Thus, ACN could be considered as possible drug candidate targeting chronic microbial infections. [Display omitted] • Anti-Quorum Sensing potential of ACN against P. aeruginosa was studied. • A significant reduction in biofilm formation was observed at sub-MIC concentration. • ACN downregulated the expression of QS regulatory genes and other genes. • ACN improved the survival rate of infected C. elegans. • In silico studies provide an insight into mechanism of QS inhibition. [ABSTRACT FROM AUTHOR]