Annals of Clinical Microbiology and Antimicrobials最新文献

{"title":"Differences in clinical outcomes of bloodstream infections caused by Klebsiella aerogenes, Klebsiella pneumoniae and Enterobacter cloacae: a multicentre cohort study.","authors":"Mariana Guedes, David Gathara, Inmaculada López-Hernández, Pedro María Martínez Pérez-Crespo, María Teresa Pérez-Rodríguez, Adrian Sousa, Antonio Plata, Jose María Reguera-Iglesias, Lucía Boix-Palop, Beatriz Dietl, Juan Sevilla Blanco, Carlos Armiñanzas Castillo, Fátima Galán-Sánchez, Clara Natera Kindelán, Alfredo Jover-Saenz, Josune Goikoetxea Aguirre, Ana Alemán Alemán, Teresa Marrodán Ciordia, Alfonso Del Arco Jiménez, Jonathan Fernandez-Suarez, Luis Eduardo Lopez-Cortes, Jesús Rodríguez-Baño","doi":"10.1186/s12941-024-00700-8","DOIUrl":"10.1186/s12941-024-00700-8","url":null,"abstract":"<p><strong>Background: </strong>Klebsiella aerogenes has been reclassified from Enterobacter to Klebsiella genus due to its phenotypic and genotypic similarities with Klebsiella pneumoniae. It is unclear if clinical outcomes are also more similar. This study aims to assess clinical outcomes of bloodstreams infections (BSI) caused by K. aerogenes, K. pneumoniae and Enterobacter cloacae, through secondary data analysis, nested in PRO-BAC cohort study.</p><p><strong>Methods: </strong>Hospitalized patients between October 2016 and March 2017 with monomicrobial BSI due to K. aerogenes, K. pneumoniae or E. cloacae were included. Primary outcome was a composite clinical outcome including all-cause mortality or recurrence until 30 days follow-up. Secondary outcomes were fever ≥ 72 h, persistent bacteraemia, and secondary device infection. Multilevel mixed-effect Poisson regression was used to estimate the association between microorganisms and outcome.</p><p><strong>Results: </strong>Overall, 29 K. aerogenes, 77 E. cloacae and 337 K. pneumoniae BSI episodes were included. Mortality or recurrence was less frequent in K. aerogenes (6.9%) than in E. cloacae (20.8%) or K. pneumoniae (19.0%), but statistical difference was not observed (rate ratio (RR) 0.35, 95% CI 0.08 to 1.55; RR 0.42, 95% CI 0.10 to 1.71, respectively). Fever ≥ 72 h and device infection were more common in K. aerogenes group. In the multivariate analysis, adjusted for confounders (age, sex, BSI source, hospital ward, Charlson score and active antibiotic therapy), the estimates and direction of effect were similar to crude results.</p><p><strong>Conclusions: </strong>Results suggest that BSI caused by K. aerogenes may have a better prognosis than E. cloacae or K. pneumoniae BSI.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"42"},"PeriodicalIF":5.7,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11071190/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140849588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genomic epidemiology reveals multiple mechanisms of linezolid resistance in clinical enterococci in China","authors":"Ziran Wang, Danping Liu, Jingjia Zhang, Lingli Liu, Zeming Zhang, Chang Liu, Songnian Hu, Linhuan Wu, Zilong He, Hongli Sun","doi":"10.1186/s12941-024-00689-0","DOIUrl":"https://doi.org/10.1186/s12941-024-00689-0","url":null,"abstract":"Infections caused by linezolid-resistant enterococci (LRE) are clinically difficult to treat and threaten patient health. However, there is a lack of studies on long time-span LRE strains in China. For this reason, our study comprehensively revealed the resistance mechanisms of LRE strains collected in a Chinese tertiary care hospital from 2011 to 2022. Enterococcal strains were screened and verified after retrospective analysis of microbial data. Subsequently, 65 LRE strains (61 Enterococcus faecalis and 4 Enterococcus faecium, MIC ≥ 8 µg/ml), 1 linezolid-intermediate Enterococcus faecium (MIC = 4 µg/ml) and 1 linezolid-susceptible Enterococcus faecium (MIC = 1.5 µg/ml) were submitted for whole-genome sequencing (WGS) analysis and bioinformatics analysis. The optrA gene was found to be the most common linezolid resistance mechanism in our study. We identified the wild-type OptrA and various OptrA variants in 98.5% of LRE strains (61 Enterococcus faecalis and 3 Enterococcus faecium). We also found one linezolid-resistant Enterococcus faecium strain carried both optrA and cfr(D) gene, while one linezolid-resistant Enterococcus faecium only harbored the poxtA gene. Most optrA genes (55/64) were located on plasmids, with impB-fexA-optrA, impB-fexA-optrA-erm(A), fexA-optrA-erm(A), and fexA-optrA segments. A minority of optrA genes (9/64) were found on chromosomes with the Tn6674-like platform. Besides, other possible linezolid resistance-associated mechanisms (mutations in the rplC and rplD genes) were also found in 26 enterococcal strains. Our study suggested that multiple mechanisms of linezolid resistance exist among clinical LRE strains in China.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"13 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140839381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence and genetic basis of Mycobacterium tuberculosis resistance to pretomanid in China","authors":"Bing Zhao, Huiwen Zheng, Juliano Timm, Zexuan Song, Shaojun Pei, Ruida Xing, Yajie Guo, Ling Ma, Feina Li, Qing Li, Yan Li, Lin Huang, Chong Teng, Ni Wang, Aastha Gupta, Sandeep Juneja, Fei Huang, Yanlin Zhao, Xichao Ou","doi":"10.1186/s12941-024-00697-0","DOIUrl":"https://doi.org/10.1186/s12941-024-00697-0","url":null,"abstract":"Pretomanid is a key component of new regimens for the treatment of drug-resistant tuberculosis (TB) which are being rolled out globally. However, there is limited information on the prevalence of pre-existing resistance to the drug. To investigate pretomanid resistance rates in China and its underlying genetic basis, as well as to generate additional minimum inhibitory concentration (MIC) data for epidemiological cutoff (ECOFF)/breakpoint setting, we performed MIC determinations in the Mycobacterial Growth Indicator Tube™ (MGIT) system, followed by WGS analysis, on 475 Mycobacterium tuberculosis (MTB) isolated from Chinese TB patients between 2013 and 2020. We observed a pretomanid MIC distribution with a 99% ECOFF equal to 0.5 mg/L. Of the 15 isolates with MIC values > 0.5 mg/L, one (MIC = 1 mg/L) was identified as MTB lineage 1 (L1), a genotype previously reported to be intrinsically less susceptible to pretomanid, two were borderline resistant (MIC = 2–4 mg/L) and the remaining 12 isolates were highly resistant (MIC ≥ 16 mg/L) to the drug. Five resistant isolates did not harbor mutations in the known pretomanid resistant genes. Our results further support a breakpoint of 0.5 mg/L for a non-L1 MTB population, which is characteristic of China. Further, our data point to an unexpected high (14/475, 3%) pre-existing pretomanid resistance rate in the country, as well as to the existence of yet-to-be-discovered pretomanid resistance genes.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"45 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140839385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct metagenomics investigation of non-surgical hard-to-heal wounds: a review","authors":"Madjid Morsli, Florian Salipante, Chloé Magnan, Catherine Dunyach-Remy, Albert Sotto, Jean-Philippe Lavigne","doi":"10.1186/s12941-024-00698-z","DOIUrl":"https://doi.org/10.1186/s12941-024-00698-z","url":null,"abstract":"Non-surgical chronic wounds, including diabetes-related foot diseases (DRFD), pressure injuries (PIs) and venous leg ulcers (VLU), are common hard-to-heal wounds. Wound evolution partly depends on microbial colonisation or infection, which is often confused by clinicians, thereby hampering proper management. Current routine microbiology investigation of these wounds is based on in vitro culture, focusing only on a limited panel of the most frequently isolated bacteria, leaving a large part of the wound microbiome undocumented. A literature search was conducted on original studies published through October 2022 reporting metagenomic next generation sequencing (mNGS) of chronic wound samples. Studies were eligible for inclusion if they applied 16 S rRNA metagenomics or shotgun metagenomics for microbiome analysis or diagnosis. Case reports, prospective, or retrospective studies were included. However, review articles, animal studies, in vitro model optimisation, benchmarking, treatment optimisation studies, and non-clinical studies were excluded. Articles were identified in PubMed, Google Scholar, Web of Science, Microsoft Academic, Crossref and Semantic Scholar databases. Of the 3,202 articles found in the initial search, 2,336 articles were removed after deduplication and 834 articles following title and abstract screening. A further 14 were removed after full text reading, with 18 articles finally included. Data were provided for 3,628 patients, including 1,535 DRFDs, 956 VLUs, and 791 PIs, with 164 microbial genera and 116 species identified using mNGS approaches. A high microbial diversity was observed depending on the geographical location and wound evolution. Clinically infected wounds were the most diverse, possibly due to a widespread colonisation by pathogenic bacteria from body and environmental microbiota. mNGS data identified the presence of virus (EBV) and fungi (Candida and Aspergillus species), as well as Staphylococcus and Pseudomonas bacteriophages. This study highlighted the benefit of mNGS for time-effective pathogen genome detection. Despite the majority of the included studies investigating only 16 S rDNA, ignoring a part of viral, fungal and parasite colonisation, mNGS detected a large number of bacteria through the included studies. Such technology could be implemented in routine microbiology for hard-to-heal wound microbiota investigation and post-treatment wound colonisation surveillance.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"32 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140839515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Whole-genome sequencing of clinical isolates of Citrobacter Europaeus in China carrying blaOXA−48 and blaNDM−1","authors":"Jie Ma, Ranran Xu, Wanxiang Li, Mi Liu, Xiaomei Ding","doi":"10.1186/s12941-024-00699-y","DOIUrl":"https://doi.org/10.1186/s12941-024-00699-y","url":null,"abstract":"To analyze the clinical infection characteristics and genetic environments of resistance genes in carbapenem-resistant Citrobacter europaeus using whole-genome sequencing. The susceptibility of two clinical isolates of C. europaeus (WF0003 and WF1643) to 24 antimicrobial agents was assessed using the BD Phoenix™ M50 System and Kirby-Bauer (K-B) disk-diffusion method. Whole-genome sequencing was performed on the Illumina and Nanopore platforms, and ABRicate software was used to predict resistance and virulence genes of carbapenem-resistant C. europaeus. The characteristics of plasmids carrying carbapenem-resistance genes and their genetic environments were analyzed. Single nucleotide polymorphisms were used to construct a phylogenetic tree to analyze the homology of these two C. europaeus strains with ten strains of C. europaeus in the NCBI database. The two strains of carbapenem-resistant C. europaeus are resistant to various antimicrobial agents, particularly carbapenems and β-lactams. WF0003 carries blaNDM− 1, which is located on an IncX3 plasmid that has high homology to the pNDM-HN380 plasmid. blaNDM− 1 is located on a truncated Tn125. It differs from Tn125 by the insertion of IS5 in the upstream ISAba125 and the deletion of the downstream ISAba125, which is replaced by IS26. WF1643 carries blaOXA− 48 in a Tn1999 transposon on the IncL/M plasmid, carrying only that single drug resistance gene. Homology analysis of these two strains of C. europaeus with ten C. europaeus strains in the NCBI database revealed that the 12 strains can be classified into three clades, with both WF0003 and WF1643 in the B clade. To the best of our knowledge, this is the first study to report an IncX3 plasmid carrying blaNDM− 1 in C. europaeus in China. C. europaeus strains harboring carbapenem-resistance genes are concerning in relation to the spread of antimicrobial resistance, and the presence of carbapenem-resistance genes in C. europaeus should be continuously monitored.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"60 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140839378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performances of two rapid LAMP-based techniques for the intrapartum detection of Group B Streptococcus vaginal colonization","authors":"Rym Charfi, Cécile Guyonnet, Meiggie Untrau, Gaëlle Giacometti, Thierry Paper, Claire Poyart, Céline Plainvert, Asmaa Tazi","doi":"10.1186/s12941-024-00695-2","DOIUrl":"https://doi.org/10.1186/s12941-024-00695-2","url":null,"abstract":"Group B Streptococcus (GBS) is the leading cause of invasive infections in newborns. The prevention of GBS neonatal disease relies on the administration of an intrapartum antibiotic prophylaxis to GBS-colonized women. In recent years, rapid intrapartum detection of GBS vaginal colonization using real-time nucleic acid amplification tests (NAATs) emerged as an alternative to antenatal culture screening methods. We compared the performances of two loop-mediated isothermal amplification (LAMP) tests, the Ampliflash® GBS and the PlusLife® GBS tests, to standard culture for GBS detection in vaginal specimens from pregnant women. The study was conducted from April to July 2023 in a French hospital of the Paris area. A total of 303 samples were analyzed, including 85 culture-positive samples (28.1%). The Ampliflash® GBS test and the PlusLife® GBS tests gave a result for 100% and 96.3% tests, respectively. The performances of the tests were as follows: sensitivity 87.1% (95% confidence interval (CI) 78.3–92.6) and 98.7% (95% CI 93.0-99.8), specificity 99.1% (95% CI 96.7–99.8), and 91.9% (95% CI 87.3–95.0), respectively. False negative results of the Ampliflash® GBS test correlated with low-density GBS cultures. Time-to-results correlated with GBS culture density only for the PlusLife® GBS test (p < 0.001). Both techniques provide excellent analytical performances with high sensitivity and specificity together with a short turnaround time and results available in 10 to 35 min. Their potential to further reduce the burden of GBS neonatal disease compared with antenatal culture screening needs to be assessed in future clinical studies.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"15 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140798776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chromobacterium sp. septicemia in Sweden. A clinical case report","authors":"Oscar Backrud, Erik Engberg, Kristina Nyberg, Peter Wieslander, Edward R. B. Moore","doi":"10.1186/s12941-024-00692-5","DOIUrl":"https://doi.org/10.1186/s12941-024-00692-5","url":null,"abstract":"Chromobacterium is a genus of fourteen species with validly published names, most often found in soil and waters in tropical and subtropical regions around the world. The most well-known species of the genus, C. violaceum, occasionally causes clinically relevant infections; cases of soft tissue infections with septicemia and fatal outcomes have been described. Here, we present a clinical case report of a 79-year-old man from Sweden with a soft-tissue infection and septicemia. The pathogen was identified as a strain of Chromobacterium species, but not C. violaceum. The patient was treated with clindamycin and ciprofloxacin and recovered well. This case report demonstrates the potential of Chromobacterium species as infectious agents in immunocompetent patients. It also indicates the existence of a novel species.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"13 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140625007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial resistance prediction by clinical metagenomics in pediatric severe pneumonia patients","authors":"Mingyu Gan, Yanyan Zhang, Gangfeng Yan, Yixue Wang, Guoping Lu, Bingbing Wu, Weiming Chen, Wenhao Zhou","doi":"10.1186/s12941-024-00690-7","DOIUrl":"https://doi.org/10.1186/s12941-024-00690-7","url":null,"abstract":"Antimicrobial resistance (AMR) is a major threat to children’s health, particularly in respiratory infections. Accurate identification of pathogens and AMR is crucial for targeted antibiotic treatment. Metagenomic next-generation sequencing (mNGS) shows promise in directly detecting microorganisms and resistance genes in clinical samples. However, the accuracy of AMR prediction through mNGS testing needs further investigation for practical clinical decision-making. We aimed to evaluate the performance of mNGS in predicting AMR for severe pneumonia in pediatric patients. We conducted a retrospective analysis at a tertiary hospital from May 2022 to May 2023. Simultaneous mNGS and culture were performed on bronchoalveolar lavage fluid samples obtained from pediatric patients with severe pneumonia. By comparing the results of mNGS detection of microorganisms and antibiotic resistance genes with those of culture, sensitivity, specificity, positive predictive value, and negative predictive value were calculated. mNGS detected bacterial in 71.7% cases (86/120), significantly higher than culture (58/120, 48.3%). Compared to culture, mNGS demonstrated a sensitivity of 96.6% and a specificity of 51.6% in detecting pathogenic microorganisms. Phenotypic susceptibility testing (PST) of 19 antibiotics revealed significant variations in antibiotics resistance rates among different bacteria. Sensitivity prediction of mNGS for carbapenem resistance was higher than penicillins and cephalosporin (67.74% vs. 28.57%, 46.15%), while specificity showed no significant difference (85.71%, 75.00%, 75.00%). mNGS also showed a high sensitivity of 94.74% in predicting carbapenem resistance in Acinetobacter baumannii. mNGS exhibits variable predictive performance among different pathogens and antibiotics, indicating its potential as a supplementary tool to conventional PST. However, mNGS currently cannot replace conventional PST.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"19 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140594543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical manifestations, antimicrobial resistance and genomic feature analysis of multidrug-resistant Elizabethkingia strains","authors":"Chongyang Wu, Li Xiong, Quanfeng Liao, Weili Zhang, Yuling Xiao, Yi Xie","doi":"10.1186/s12941-024-00691-6","DOIUrl":"https://doi.org/10.1186/s12941-024-00691-6","url":null,"abstract":"Elizabethkingia is emerging as an opportunistic pathogen in humans. The aim of this study was to investigate the clinical epidemiology, antimicrobial susceptibility, virulence factors, and genome features of Elizabethkingia spp. Clinical data from 71 patients who were diagnosed with Elizabethkingia-induced pneumonia and bacteremia between August 2019 and September 2021 were analyzed. Whole-genome sequencing was performed on seven isolates, and the results were compared with a dataset of 83 available Elizabethkingia genomes. Genomic features, Kyoto Encyclopedia of Genes and Genomes (KEGG) results and clusters of orthologous groups (COGs) were analyzed. The mean age of the patients was 56.9 ± 20.7 years, and the in-hospital mortality rate was 29.6% (21/71). Elizabethkingia strains were obtained mainly from intensive care units (36.6%, 26/71) and emergency departments (32.4%, 23/71). The majority of the strains were isolated from respiratory tract specimens (85.9%, 61/71). All patients had a history of broad-spectrum antimicrobial exposure. Hospitalization for invasive mechanical ventilation or catheter insertion was found to be a risk factor for infection. The isolates displayed a high rate of resistance to cephalosporins and carbapenems, but all were susceptible to minocycline and colistin. Genomic analysis identified five β-lactamase genes (blaGOB, blaBlaB, blaCME, blaOXA, and blaTEM) responsible for β-lactam resistance and virulence genes involved in stress adaptation (ureB/G, katA/B, and clpP), adherence (groEL, tufA, and htpB) and immune modulation (gmd, tviB, cps4J, wbtIL, cap8E/D/G, and rfbC). Functional analysis of the COGs revealed that “metabolism” constituted the largest category within the core genome, while “information storage and processing” was predominant in both the accessory and unique genomes. The unique genes in our 7 strains were mostly enriched in KEGG pathways related to microRNAs in cancer, drug resistance (β-lactam and vancomycin), ABC transporters, biological metabolism and biosynthesis, and nucleotide excision repair mechanisms. The Elizabethkingia genus exhibits multidrug resistance and carries carbapenemase genes. This study presents a comparative genomic analysis of Elizabethkingia, providing knowledge that facilitates a better understanding of this microorganism.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"12 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140594535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quenching of quorum sensing in multi-drug resistant Pseudomonas aeruginosa: insights on halo-bacterial metabolites and gamma irradiation as channels inhibitors","authors":"Reham Talaat, Mohamed N. Abu El-naga, Heba Abd Alla El-Bialy, Mohie Z. El-Fouly, Mohamed A. Abouzeid","doi":"10.1186/s12941-024-00684-5","DOIUrl":"https://doi.org/10.1186/s12941-024-00684-5","url":null,"abstract":"Anti-virulence therapy is a promising strategy to treat multi-drug resistant (MDR) pathogens. Pseudomonas aeruginosa is a potent opportunistic pathogen because of an array of virulence factors that are regulated by quorum sensing systems. The virulence features of four multi-drug resistant P. aeruginosa strains were investigated upon exposure to the sub-lethal dose of gamma rays (1 kGy), and sub-inhibitory concentrations of bioactive metabolites recovered from local halophilic strains in comparison to control. Then, the gene expression of AHL-mediated quorum sensing systems (las/rhl) was quantitatively determined in treated and untreated groups by real-time PCR. The bioactive metabolites recovered from halophilic strains previously isolated from saline ecosystems were identified as Halomonas cupida (Halo-Rt1), H. elongate (Halo-Rt2), Vigibacillus natechei (Halo-Rt3), Sediminibacillus terrae (Halo-Rt4) and H. almeriensis (Halo-Rt5). Results revealed that both gamma irradiation and bioactive metabolites significantly reduced the virulence factors of the tested MDR strains. The bioactive metabolites showed a maximum efficiency for inhibiting biofilm formation and rhamnolipids production whereas the gamma irradiation succeeded in decreasing other virulence factors to lower levels in comparison to control. Quantitative-PCR results showed that AHL-mediated quorum sensing systems (las/rhl) in P. aeruginosa strains were downregulated either by halo-bacterial metabolites or gamma irradiation in all treatments except the upregulation of both lasI internal gene and rhlR intact gene in P. aeruginosa NCR-RT3 and both rhlI internal gene and rhlR intact gene in P. aeruginosa U3 by nearly two folds or more upon exposure to gamma irradiation. The most potent result was observed in the expression of lasI internal gene that was downregulated by more than ninety folds in P. aeruginosa NCR-RT2 after treatment with metabolites of S. terrae (Halo-Rt4). Analyzing metabolites recovered from H. cupida (Halo-Rt1) and H. elongate (Halo-Rt2) using LC–ESI–MS/MS revealed many chemical compounds that have quorum quenching properties including glabrol, 5,8-dimethoxyquinoline-2-carbaldehyde, linoleoyl ethanolamide, agelasine, penigequinolones derivatives, berberine, tetracosanoic acid, and liquidambaric lactone in the former halophile and phloretin, lycoctonine, fucoxanthin, and crassicauline A in the latter one. QS inhibitors can significantly reduce the pathogenicity of MDR P. aeruginosa strains; and thus can be an effective and successful strategy for treating antibiotic resistant traits.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"102 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140594533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}