Polish journal of microbiology最新文献

{"title":"Influence of Drying Condition and Other Aspects on Recovery of <i>Pseudomonas aeruginosa</i> in the PN-EN 14561 Carrier Test.","authors":"Agnieszka Chojecka","doi":"10.33073/pjm-2025-034","DOIUrl":"10.33073/pjm-2025-034","url":null,"abstract":"<p><p><i>Pseudomonas aeruginosa</i> is a bacterium sensitive to desiccation. Its use in disinfectant testing methods is important given its association with hospital-acquired infections. According to PNEN 14561:2008, obtaining a sufficient number of <i>P. aeruginosa</i> cells on a glass test surface under clean conditions after the drying process is essential for evaluating the bactericidal effectiveness of disinfectants. Does reducing the drying temperature of glass carriers contaminated with <i>P. aeruginosa</i> under clean conditions from the standard-recommended 37°C ± 1°C to 24°C ± 1°C improve bacterial recovery after drying? The recovery of <i>P. aeruginosa</i> from glass surfaces after drying was performed by the procedure specified for the water control, as outlined in PN-EN 14561:2008. Additionally, in the 24°C ± 1°C, the glass carriers were inoculated onto TSA medium, whereas at 37 °C ± 1°C the number of <i>P. aeruginosa</i> was determined in hard water following the contact time. The mean recovery of <i>P. aeruginosa</i> (6.37 log ± 0.12 log) was significantly higher in the 24°C ± 1°C variant compared to the 37°C ± 1°C variant (5.60 log ± 0.24 log). At 24°C ± 1°C, <i>P. aeruginosa</i> remained on the glass carrier after recovery, whereas at 37°C ± 1°C, the bacteria were detected in hard water. Lowering the drying temperature did not allow recovery of <i>P. aeruginosa</i> at the level required by PN-EN 14561:2008. The reduction in <i>P. aeruginosa</i> recovery resulted from bacterial detachment into hard water and retention on the carrier surface.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 3","pages":"401-406"},"PeriodicalIF":1.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445979/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Clinical Characteristics and Antimicrobial Resistance in 249 Isolates of <i>Streptococcus mitis</i>: a Single-Centre Study.","authors":"Jingjing Kuai, Jianwei Ji, Ling Xiao, Ping Wang, Yonglan Shan, Dongmei Yan","doi":"10.33073/pjm-2025-028","DOIUrl":"10.33073/pjm-2025-028","url":null,"abstract":"<p><p>Cases of invasive infection caused by <i>Streptococcus mitis</i> have been gradually increasing, but less attention has been paid to its clinical characteristics and drug resistance. This study conducted a single-center retrospective analysis of patients with <i>S. mitis</i>-positive results admitted to a tertiary hospital in Yancheng between January 2020 and December 2024. Data were extracted from case notes and electronic medical records. There were 249 cases of <i>S. mitis</i> detected, with community-acquired infections (44.98%), colonization (46.59%) and hospital-acquired infections (8.43%). Of these, the three departments with the highest detection rates were pediatrics (22.09%), urology (19.68%), and stomatology (11.65%). Primary specimen sources included secretions (23.30%), bronchoalveolar lavage fluid (23.30%), urine (20.48%), and blood (17.67%). In terms of years, the detection rate of <i>S. mitis</i> infection showed an annual increase, while antimicrobial resistance remained stable with a decrease in the year 2024. Our analysis identified associations between patient ages and infection type, specimen source, and antimicrobial resistance profile. Furthermore, we observed distinct resistance patterns across different infection types. These findings underscore the need for enhanced hospital surveillance measures to monitor antimicrobial resistance trends and nosocomial infection patterns associated with <i>S. mitis</i>.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 3","pages":"329-337"},"PeriodicalIF":1.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445984/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of a Novel Haloarchaeal Species <i>Halorubellus amylolyticus</i> sp. nov., Isolated from Salt Crystals of Salted Seaweed Knots and Genomic Insights into Genus <i>Halorubellus</i>.","authors":"Yawen Liu, Aodi Zhang, Cunlong Lu, Shilong Shao, Yue Ding, Yuling Hao, Y U Jin, Jingfang Liu, Liang Shen, Shaoxing Chen","doi":"10.33073/pjm-2025-032","DOIUrl":"10.33073/pjm-2025-032","url":null,"abstract":"<p><p>An extremely halophilic archaeon named strain PRR65^T was isolated from a salt crystal of salted seaweed knots which were purchased from a supermarket in Wuhu, China. It exhibited an ability to hydrolyze starch. Strain PRR65^T is a coccus. Its growth range and optimum concentration for NaCl are 2.0-5.1 M and 3.4 M, respectively, and it requires magnesium ions (with an optimum concentration of 0.01 M). Homology search of the 16S rRNA gene sequence indicated that strain PRR65^T shows the highest sequence similarities with <i>Halorubellus salinus</i> GX3^T (96.97%). The basic growth conditions and many other physicochemical characteristics of strain PRR65^T are distinct from those of other species within its genus. The average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (dDDH) values between strain PRR65^T and its close relatives were 88.97%, 86.47% and 39.2%, respectively. The DNA G + C content (mol%) for strain PRR65^T is 67.2%. Based on a polyphasic taxonomic approach integrating phenotypic characteristics, chemotaxonomic markers, and comprehensive phylogenetic and genomic analyses, strain PRR65^T represents a novel species within the genus <i>Halorubellus</i>. The name <i>Halorubellus amylolyticus</i> sp. nov. is proposed, with the specific epithet reflecting the organism's notable amylolytic activity. The type strain is PRR65^T (= MCCC 4K00175 = KCTC 4323).</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 3","pages":"374-384"},"PeriodicalIF":1.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445982/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trend Analysis of Fungal Infections Based on Culture among Inpatients in Henan Province from 2018 to 2023.","authors":"Xiaolong Li, Fang Han, Lifang Ban, Hongzhi Li, Yuling Li, Alaa A Alnahari, Chaohong Fu","doi":"10.33073/pjm-2025-026","DOIUrl":"10.33073/pjm-2025-026","url":null,"abstract":"<p><p>With the increasing number of immunocompromised hosts, the epidemiological characteristics of fungal infections have undergone enormous changes worldwide, including in China. The epidemiology of fungal infections is diverse and varies worldwide depending on geography, host immune status, and infection site. Fungal infections continue to be associated with significant morbidity and death rates and with increased financial burdens on the health care system. Therefore, understanding the contemporary epidemiology of fungal infections is important. The medical records of 75,001 inpatients from January 2018 to December 2023 at Henan Provincial Infectious Disease Hospital were analyzed in this retrospective study. A total of 3,550/75001 (4.73%) patients presented increasing fungal infections, predominantly <i>Candida albicans</i> (3.12%), <i>Aspergillus fumigatus</i> (0.59%), and <i>Aspergillus flavus</i> (0.50%) over the years. The detection rate of fungal infections varied across departments in the following order: AIDS (19.26%), ICU (19.04%), Tuberculosis (4.41%), and other non-infectious departments, such as Surgery and Oncology (1.42%) and Hepatology (0.71%). Compared with urban patients, rural patients (6.79%) had a significantly greater fungal detection rate (3.48%) (χ² = 429.89, <i>p</i> < 0.001), primarily <i>C. albicans, Talaromyces marneffei, Cryptococcus neoformans</i>, and <i>A. flavus</i>. The fungal detection rate among patients with infectious diseases has been increasing annually, with variations in the pathogenic spectra. Therefore, clinical attention is essential for pathogen detection to achieve prompt diagnosis and targeted antifungal treatment.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 3","pages":"306-317"},"PeriodicalIF":1.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445985/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Dynamic Changes of Nutrient and Microbial Succession in Nanomembrane Aerobic Composting of Tomato Straw.","authors":"Rongjiao Wang, P O Pu, Dan Huang, Xuanyan DU, Rui Xiang, Guizhen Li, Latie Jiaka","doi":"10.33073/pjm-2025-030","DOIUrl":"10.33073/pjm-2025-030","url":null,"abstract":"<p><p>As the demand for sustainable agriculture grows, the use of agricultural by-products for organic fertilizer production has garnered substantial attention. This study investigates the nutrient dynamics and microbial diversity during the composting of tomato straw using nanomembrane aerobic composting and conventional composting methods. Over 28 days, we measured temperature, pH, moisture, electrical conductivity, and nutrient levels. The results indicate that nanomembrane aerobic composting achieved a higher initial temperature, thereby accelerating the decomposition of organic matter and promoting nutrient conversion. The nanomembrane treatment maintained higher organic carbon content and increased total nitrogen, phosphorus, and potassium relative to conventional composting. Microbial profiling revealed marked differences in fungal diversity between treatments. Key fungal phyla were more abundant in nanomembrane compost, suggesting enhanced microbial activity. In contrast, bacteria were undetectable on the third day of fermentation, raising questions about their role in the middle and late stages of composting. This study demonstrates that nanomembrane aerobic composting can enhance composting efficiency and organic fertilizer quality by optimizing environmental conditions and promoting microbial activity. Nanomembrane aerobic composting promotes a more controlled succession of fungal communities, which may play a crucial role in the fermentation process. It is noteworthy that during the composting process, bacteria gradually became undetectable as fermentation progressed, whereas fungi were consistently present throughout the experiment. It might suggest to the researchers that fungi, rather than bacteria, may play a more significant role in the fermentation process of organic fertilizers.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 3","pages":"347-362"},"PeriodicalIF":1.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445980/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation, Identification, and Comprehensive Genomic Characterization of a Bovine Rotavirus G10P[11] Strain in China.","authors":"Jian Liu, Xianchao Yang, Yaping Gui, Qiqi Xia, Guidan Feng, Dequan Yang, Ping Xu, Jun Tao, Yuling Ma, Jun Ma, Wenwei Sheng, Jian Wang, Weidong Qian, Shixin Huang","doi":"10.33073/pjm-2025-027","DOIUrl":"10.33073/pjm-2025-027","url":null,"abstract":"<p><p>Rotavirus is a principal infectious agent of diarrhea in both animals and humans, causing acute gastroenteritis with symptoms such as abdominal pain, fever, nausea, and vomiting. Bovine rotavirus (BRVA) not only causes illness in cattle but also poses a risk to human health through direct transmission or reassortment among different virus strains. Here, quantitative RT-PCR for the NSP5 gene was applied to pinpoint BRVA in six fecal specimens from calves. A positive sample was identified and further examined using MA104 cells to isolate the virus. The isolate was then identified through RT-PCR, indirect immunofluorescence assays, and transmission electron microscopy. Genotyping and phylogenetic examination of the entire genome were performed via standard bioinformatics methods. A unique G10P[11] rotavirus strain, named SHH2023001, was identified in a fecal sample from a calf suffering from severe diarrhea in Shanghai, China. Whole genome sequencing revealed a unique genomic configuration of G10-P[11]-I2-R2-C2-M2-A11-N2-T6-E2-H3 for the 11 segments. Notably, these segments likely result from reassortment events involving rotavirus strains from humans, cattle, sheep, and horses. This study is the first to report the G10P[11] genotype constellation in Shanghai, highlighting the genetic diversity and potential for interspecies transmission of calf rotavirus.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 3","pages":"318-328"},"PeriodicalIF":1.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445978/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Age-Related Dynamics of Fecal Microbiota in the Captive Chimpanzee (<i>Pan troglodytes</i>).","authors":"Liu Juan, Haili Wu, Yaohua Yuan, Yingdi Zhu, Kangning Huang, Nina Yan, Y I Lou, Yalan Zhang, Weiyi Zhang, Shen Cheng, Jianmin Zhan, Shuke Ye, Yuyan You, Hongjie Pan","doi":"10.33073/pjm-2025-031","DOIUrl":"10.33073/pjm-2025-031","url":null,"abstract":"<p><p>Understanding gut microbiome diversity in endangered chimpanzees (<i>Pan troglodytes</i>) is crucial for their effective <i>ex situ</i> conservation. This study characterized the age-related dynamics of the fecal microbiota in captive juvenile (< 5 years), adolescent (5-10 years), and adult (> 15 years) chimpanzees reared in Shanghai and Hangzhou Zoos using 16S rRNA sequencing and demonstrated significant ontogenetic shifts in the microbiota composition. Alpha diversity peaked in adolescents (significantly higher Ace/Chao1/Observed Species; <i>p</i> < 0.05), with the greatest number of unique OTUs (1,139). Community structures significantly differed between the age groups (ANOSIM <i>R</i> = 0.121). Furthermore, the captive diets drove the fundamental restructuring of the core phyla. The Firmicutes/Bacteroidetes ratio was considerably lower in captive individuals than in wild conspecifics. The discriminative taxa were also analyzed. Notably, the abundance of <i>Lactobacillus</i> increased significantly in adults (5.44% ± 4.43%) compared to younger groups (< 1.26%), whereas that of <i>Prevotella</i> decreased with age. These findings demonstrate the regulatory role of age in determining gut microbiome in captivity, which is potentially attributed to physiological transitions and dietary adaptations, which present a basis for microbiome-informed health monitoring and age-specific dietary management for the welfare of captive chimpanzees.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 3","pages":"363-373"},"PeriodicalIF":1.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445987/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oral Microbiota and Pharyngeal-Laryngeal Cancer Risk: Evidence from Mendelian Randomization in East Asian Populations.","authors":"Jingfeng Fu","doi":"10.33073/pjm-2025-029","DOIUrl":"10.33073/pjm-2025-029","url":null,"abstract":"<p><p>Pharyngeal and laryngeal cancer (PLC) encompasses a range of aggressive malignancies associated with substantial clinical impact, underscoring the need for novel preventive and therapeutic measures. Mendelian randomization (MR) serves as an effective methodology for assessing causal associations based on genetic variants as instrumental tools. It reduces biases such as confounding and reverse causation prevalent in traditional observational studies. This research sought to investigate the causal relationships between oral microbial taxa and PLC using a two-sample MR approach. The goal was to identify specific oral microbiota that may directly contribute to the development of PLC and could serve as potential biomarkers or targets for therapeutic intervention. A two-sample MR analysis was conducted to assess the causal impact of 3,117 oral microbial taxa on the risk of PLC. Instrumental variables (IVs) were selected based on genome-wide significance (<i>p</i> < 1 × 10^-5), minimal linkage disequilibrium (r² < 0.001), and robust strength (F > 10). The primary evaluation employed the inverse-variance weighted (IVW) approach, complemented by sensitivity analyses (including weighted median, weighted mode, simple mode, MR-Egger regression, and MR-PRESSO) to account for pleiotropy and heterogeneity. Bidirectional MR was performed to examine possible reverse causation. The forward MR analysis identified 14 oral microbial taxa that are casually linked to PLC risk (<i>p</i> < 0.01). Seven taxa were associated with elevated PLC risk, with odds ratios spanning 2.51 to 3.23, whereas seven taxa demonstrated protective effects, with odds ratios ranging from 0.36 to 0.52. Sensitivity analyses, encompassing Cochran's <i>Q</i> test, MR-Egger intercept, and MR-PRESSO, validated the reliability of these results, indicating no notable heterogeneity or pleiotropy. Bidirectional MR analyses detected no evidence of reverse causation, suggesting that these oral microbiotas likely act as upstream contributors to PLC development rather than downstream outcomes. This MR analysis identifies 14 oral microbial taxa causally linked to PLC, with seven increasing risk and seven conferring protections. These findings underscore the role of oral microbiota in PLC pathogenesis and highlight potential microbial mechanisms. Further research is needed to elucidate their roles and explore their use as biomarkers or therapeutic targets.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 3","pages":"338-346"},"PeriodicalIF":1.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445983/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comparison of the Intestinal Fungal Community in Wild and Captive Himalayan Vultures (<i>Gyps himalayensis</i>).","authors":"Feng Li, Quanchao Cui, Sitong Fan, Huiwen Li, Wen Wang","doi":"10.33073/pjm-2025-033","DOIUrl":"10.33073/pjm-2025-033","url":null,"abstract":"<p><p>In this study, we systematically analyzed the ecological response mechanism of the intestinal fungal community of the endangered species, the Himalayan vultures (<i>Gyps himalayensis</i>), concerning the survival differences between wild and captive environments. Based on its high-throughput sequencing technology, the key features such as species composition analysis, α/β diversity assessment, principal coordinate analysis, and correlation network analysis revealed that the captive environment led to the complexity of the fungal community structure, the turnover of the core flora, and the increase in the complexity of the intergeneric interactions network. It was further shown by FUNGuild functional annotation that the relative abundance of undefined saprotroph functional taxa in the wild population was significantly higher than that in the captive population, corroborating the adaptive advantage of its intestinal fungal community to the scavenging ecological niche. This study reveals for the first time the potential effects of captive stress on Himalayan vultures from the perspective of gut fungi, providing key microbiomic evidence for optimizing the conservation strategy of endangered raptors, and at the same time expanding the functional cognitive system of gut fungi in highland carrion-feeding birds.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 3","pages":"385-400"},"PeriodicalIF":1.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445988/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial Resistance Mechanisms in Carbapenem-Resistant <i>Pseudomonas aeruginosa</i> Clinical Strains Isolated in Shanghai, China.","authors":"Keying Zhu, Suting Li, Ziyan Guo, Chengchao Xiao, Quhao Wei","doi":"10.33073/pjm-2025-022","DOIUrl":"10.33073/pjm-2025-022","url":null,"abstract":"<p><p>Carbapenems, as the preferred treatment for multidrug-resistant <i>Pseudomonas aeruginosa</i>, are increasingly facing issues of insufficient therapeutic efficacy. This study aims to investigate the antimicrobial resistance mechanisms of clinical <i>P. aeruginosa</i> isolates to carbapenems. The whole genome sequencing revealed various β-lactamase genes, including the intrinsic genes <i>bla</i> _PAO and <i>bla</i> _OXA-50-like, as well as the acquired <i>bla</i> _GES-5 (n = 6), and <i>bla</i> _OXA-101 (n = 10) in 40 carbapenem-resistant <i>P. aeruginosa</i> (CRPA) isolates. These isolates were categorized into 18 different sequence types, with ST235 (n = 6) and ST270 (n = 10) being the most prevalent. Single nucleotide polymorphism (SNP) analysis revealed that the collected isolates can be divided into two evolutionary branches, with some exhibiting high homogeneity. Isolates belonging to ST207, ST235, ST270, and ST277 may have contributed to small-scale outbreaks of infection in the hospital. A total of 5 different class 1 integrons, including a new gene cassette array <i>bla</i> _GES-5 -<i>gcuE15-aph(3')-XV-ISPa21e</i>, were detected in this study. All 40 CRPAs were found to have mutations in the outer membrane porin OprD. The efflux pump gene <i>mexY</i> showed the highest overexpression frequency at 55.00% (22/40). The CRPAs that overexpress <i>mexY</i> showed a higher resistance rate to various antimicrobial agents than those with normal levels of <i>mexY</i> expression (<i>p</i> < 0.05). Of 40 CRPAs, four isolates carried four antimicrobial resistance mechanisms simultaneously (<i>bla</i> _GES-5, OprD mutation, high expression of efflux pump, and biofilm formation). To the best of our knowledge, a new gene cassette array of class 1 integron, <i>bla</i> _GES-5-<i>gcuE15</i>-<i>aph(3'</i>)-<i>XV</i>-<i>lSPa21e</i>, was reported for the first time in this study.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":" ","pages":"275-288"},"PeriodicalIF":1.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12506996/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144984102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}