Polish journal of microbiology最新文献

{"title":"Optimization and Mechanism of Ca²⁺ Biosorption by <i>Virgibacillus pantothenticus</i> Isolated from Gelatine Wastewater.","authors":"Haiwei Ren, Yumeng Xiang, Aili Zhang, Hongyuan Zhao, Hui Tian, Xiaopeng Guo, Yi Zheng, Bingyun Zhang","doi":"10.33073/pjm-2025-002","DOIUrl":"10.33073/pjm-2025-002","url":null,"abstract":"<p><p>Gelatine-processing wastewater contains much residual sludge due to its high calcium ion concentration and chemical oxygen demand. In this study, N3-4, a microbial strain with excellent calcium tolerance capacity, was screened and identified as <i>Virgibacillus pantothenticus</i> using morphological observation, physiological and biochemical testing, and 16S rRNA sequence analysis. Its growth characteristics were investigated, and the maximum adsorption of calcium reached 572.43 μg/g under the optimal conditions (contact time, 72.68 min; biomass dosage, 1.3 g/l; initial calcium concentration, 142.01 mg/l). Conditions were optimized using response surface methodology and structural characterization. The structure of the bacterial pellets was altered from flat to rough, accompanied by bulges and sediments after Ca²⁺ treatment, according to structural characterization. Energy-dispersive X-ray spectroscopy of the bacterial precipitates under calcium(II) treatment revealed the immobilization of Ca²⁺ species on the bacterial cell surface. The results indicate that -OH, -NH₂, C≡C, C=O, -CH₂, -C-O-, and -C-N groups play a significant role in calcium dispersion on the surface of <i>V. pantothenticus</i>.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 1","pages":"19-32"},"PeriodicalIF":0.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949390/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143733789","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":"Purification and Biochemical Characterization of α-Amylase from Newly Isolated <i>Bacillus Cereus</i> Strain and its Application as an Additive in Breadmaking.","authors":"Lina S Alhazmi, Wafa A Alshehri","doi":"10.33073/pjm-2025-004","DOIUrl":"10.33073/pjm-2025-004","url":null,"abstract":"<p><p>Amylase has numerous applications in the processing food sector, including brewing, animal feed, baking, fruit juice manufacturing, starch syrups, and starch liquefaction. Practical applications have been the primary focus of recent research on novel properties of bacterial α-amylases. Many amylolytic-active bacterial isolates were obtained from samples of organic-rich, salinity-rich soil. Morphological and 16S rRNA gene sequence studies clearly revealed that the organism belongs to <i>Bacillus</i> sp. and was named <i>Bacillus cereus</i> strain GL2 (PP463909.1 (When pH 6.0, 45°C, and 12 hours of incubation were met the optimal growth conditions for the strain produced the highest amount of α-amylase activity. <i>B. cereus</i> strain GL2 α-amylase isoenzyme was purified to homogeneity using Sephacryl™ S-200 chromatography and ammonium sulfate precipitation. The electrophoretic molecular weight of <i>B. cereus</i> α-amylase was 58 kDa. The optimal pH and temperature for measuring α-amylase activity were 50°C and 6.0, respectively. α-Amylase did not change at 50°C. The purified enzyme improves bread texture by reducing stiffness while improving cohesiveness and flexibility. Purified α-amylase was added to the flour, which improved the rheological properties and overall bread quality. As a result, the α-amylase from <i>B. cereus</i> strain GL2 can be used to promote bread-making.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 1","pages":"48-59"},"PeriodicalIF":0.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949385/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143733794","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":"Characterization of OXA232-Producing Carbapenem-Resistant <i>Klebsiella pneumoniae</i>: Genomic Analysis and Virulence Assessment.","authors":"Zhouxun Li, Chunyan Wu, Xuemei Cai, Yongli Song, Xingping Zheng, Yuan He, Guibo Song","doi":"10.33073/pjm-2025-007","DOIUrl":"10.33073/pjm-2025-007","url":null,"abstract":"<p><p>Globally, the infection rate of carbapenem-resistant <i>Klebsiella pneumoniae</i> (CRKP) producing OXA-48-like carbapenemase is increasing, posing a significant public health threat due to its high antibiotic resistance. Between December 2019 and April 2023, ten CRKP strains carrying the OXA-48-like carbapenemase were isolated from inpatients at the First Affiliated Hospital of Kunming Medical University. Wholegenome sequencing (WGS) revealed that all strains carried the OXA-232 gene, a variant of OXA-48-like, located on the non-conjugative ColKP3 plasmid. Sequence typing identified nine strains as ST231 and one as ST11. The ST231 strains carried common virulence genes, including yersiniabactin (ybtA, fyuA, irp2) and aerobactin (iucABCD, iutA), while the ST11 strain carried high-virulence genes (rmpA, rmpA2, peg-344) as well as KPC-2 and OXA-232 carbapenemase genes on separate plasmids, suggesting that CRKP can harbor multiple plasmids with carbapenemase genes. Sequence typing of 264 global ST231 CRKP isolates (n = 264) showed a distinct clonal relationship between our strains and Indian CRKP isolates, indicating potential cross-border transmission. The virulence potential and immune response of the ST231 strains were assessed using a mouse respiratory infection model. The concentrations of inflammatory factors CCL2/MCP-1, IL-6, and TNF-α in the alveolar lavage fluid and blood of the model mice were detected. Combined with the pathological analysis of lung and liver tissues, it reveals variability in virulence and immune response despite carrying identical resistance and virulence genes. This underscores the urgent need for monitoring and tailored public health strategies to combat the global spread of drug-resistant strains.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 1","pages":"82-94"},"PeriodicalIF":0.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949386/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143733771","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 and Characterization of Highly Active Uricase from <i>Alcaligenes</i> spp. Strain UR1.","authors":"Atheer Alshareef, Mahmoud Z El-Readi, Leena A Neyaz, Hussein H Abulreesh, Ahmad A Alsaigh, Ashjan F Khalel, Wafaa A Alshehri, Khaled Elbanna","doi":"10.33073/pjm-2025-009","DOIUrl":"10.33073/pjm-2025-009","url":null,"abstract":"<p><p>For the first time, this study reports extracellular uricase enzyme isolation and characterization from strain UR1 of <i>Alcaligenes</i> spp. from Western Saudi Arabia. The strain efficiently produced highly active extracellular uricase for therapeutic applications. It offers a simplified enzyme purification approach rather than complicated intracellular enzyme purification from other microbes. Strain UR1 exhibited significantly higher uricase synthesis potential [916 U/mg (specific activities) and 275 U/ml (volume)]. The study optimized the conditions (37°C and pH 7.4) for 10% enhanced uricase production in the BT medium where sucrose served as the carbon source. Uricase enzyme remained stable at various pH levels (5-9) up to 50°C, however, the optimal activity was noted at 40°C and pH 7.5. The strain was sensitive to EDTA-like inhibitors. Ca²⁺ improved the strain activity, which could yield potent formulations for clinical and industrial applications. This novel aspect presents <i>Alcaligenes</i> spp. strain UR1 as a promising candidate for the treatment of hyperuricemia and gout. It offers an efficient and inexpensive alternative for uricase synthesis at the industrial scale. These findings encourage further investigations regarding genetic aspects of uricase for improved bioprocessing and therapeutic applications.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 1","pages":"106-129"},"PeriodicalIF":0.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949387/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143733784","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":"Hyperoside Alleviates <i>Helicobacter pylori</i>-Induced Gastric Epithelial Cell Injury by Regulating Nrf2/HO-1 Signaling.","authors":"Yanfen Wang, Yuxue Liu, Xiuhua Zheng","doi":"10.33073/pjm-2025-005","DOIUrl":"10.33073/pjm-2025-005","url":null,"abstract":"<p><p>Infection with <i>Helicobacter pylori</i> is the major causative factor of chronic gastritis, peptic ulcer, gastric cancer, and other diseases. Gastric mucosal epithelial injury characterized by abnormal apoptosis, oxidative stress, and inflammation is a crucial mechanism of <i>H. pylori</i> infection. Hyperoside (HYP) is a flavonol glycoside derived from many herbal plants, which exhibits potent anti-apoptotic, antioxidant, and anti-inflammatory properties. Our research explored whether it exerts protective effects on <i>H. pylori</i>-infected human gastric epithelial cells. GES-1 cells were first treated for 24 h with HYP (0, 10, 20, 40, 80, 100, or 120 μM) to determine the cytotoxicity of HYP. Subsequently, GES-1 cells were pre-treated for 4 h with HYP (80 μM), followed by exposure to <i>H. pylori</i> for 24 h. CCK-8 assay, flow cytometry assay, ELISA, RT-qPCR, DCFH-DA staining, the commercial assay kits, immunofluorescence staining, and western blotting were used to assess cell viability, cell apoptosis, pro-inflammatory cytokine levels, oxidative stress marker levels, and Nrf2/HO-1 signaling-related molecule levels. The Nrf2 inhibitor ML385 was employed to verify the beneficial role of Nrf2 activation in HYP-mediated GES-1 cell injury induced by <i>H. pylori</i>. The results showed that HYP pre-treatment reversed <i>H. pylori</i>-induced cell apoptosis, inflammation, and oxidative stress in GES-1 cells. Furthermore, HYP downregulated Nrf2, HO-1, and NQO1 protein levels in <i>H. pylori</i>-infected GES-1 cells. ML385 overturned the protective effects of HYP against <i>H. pylori</i>-induced GES-1 cell apoptosis, inflammation, and oxidative stress. In conclusion, HYP protects gastric epithelial cells against <i>H. pylori</i>-induced cell injury by activating the Nrf2/HO-1 pathway.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 1","pages":"60-70"},"PeriodicalIF":0.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949383/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143733781","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, Molecular, and Metabolic Profiling of Benzene-Remediating Bacteria Inhabiting the Tannery Industry Soil.","authors":"Nadia Hussain, Farhan Mohiuddin, Fatima Muccee, Saboor Muarij Bunny, Amal H I Al Haddad","doi":"10.33073/pjm-2025-003","DOIUrl":"10.33073/pjm-2025-003","url":null,"abstract":"<p><p>Benzene is a pervasive contaminant and human carcinogen. Its remediation from environmental resources using conventional procedures has always been challenging due to high cost and incomplete benzene degradation. The present study was designed to explore highly efficient bacteria with benzene degrading potential from tannery industry soil, which might be used as an alternative to these conventional benzene removal remedies. Bacterial isolation was performed using benzene (80 μl/1,000 ml) supplemented with minimal salt media (MSM). Characterization of isolates was carried out by performing growth curve analysis, Gram staining, biochemical characterization via Remel RapID<b>™</b> NF PLUS System (Thermo Scientific™, Thermo Fisher Scientific, Inc., USA), antibiotic sensitivity profiling, 16S rRNA gene sequencing, benzene removal efficiency estimation assay, FTIR, and GC-MS profiling. Five bacteria isolated in the present study were identified as <i>Paracoccus aestuarii</i> PUB1, <i>Bacillus tropicus</i> PUB2, <i>Bacillus albus</i> PUB3, <i>Bacillus subtilis</i> PUB4, and <i>Bacillus cereus</i> PUB6. All of these fast-growing bacteria were Gram-positive except <i>P. aestuarii</i> PUB1. Maximum benzene removal efficiency (30 mg/l per 25 h) was found in <i>B. tropicus</i> PUB2. Comparing the FTIR spectra of bacterial culture supernatant versus control revealed the peaks shifting corresponding to benzene ring bonds breaking. GC-MS analysis identified the metabolic intermediates from benzoate methylation and benzaldehyde pathways. These bacteria can be employed for benzene degradation via enzyme-based nanoparticle synthesis or cloning of relevant genes in eco-friendly expression systems.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 1","pages":"33-47"},"PeriodicalIF":0.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949388/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143733787","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":"Comparative Analysis of Microbiological Profiles and Antibiotic Resistance Genes in Subjects with Colorectal Cancer and Healthy Individuals.","authors":"Jun Li, Yanyun Zhu, Qing Chang, Yuan Gong, Jun Wan, Shiping Xu","doi":"10.33073/pjm-2025-006","DOIUrl":"10.33073/pjm-2025-006","url":null,"abstract":"<p><p>Alteration of the gut microbiota (GM) is associated with various diseases, including colorectal cancer (CRC). With the development of next-generation sequencing techniques, metagenomic sequencing, along with metabolic function and antibiotic-resistant gene analyses, has been used to investigate differences in GM between CRC patients and healthy controls. Fecal samples were obtained from seven CRC patients and six healthy subjects, and the sequencing data were analyzed for similarity, a-diversity, principal component analysis (PCA), and linear discriminant analyses (LDA). Regarding Actinobacteria, 3 orders, 5 families, 9 genera, and 19 species were identified with no differences between the CRC and control groups, while the levels of <i>Bifidobacterium bifidum</i> and <i>Bifidobacterium dentium</i> were higher, and the level of <i>Bifidobacterium breve</i> was lower in the CRC group compared to the healthy controls (<i>p</i> = 0.053). Otherwise, 2 genera (<i>Leuco-nostoc</i> and <i>Salmonella</i>) and 7 species of bacteria (<i>Parabacteroides merdae, Alistipes shahii, Alistipes finegoldii, Clostridium nexile, Salmonella enterica</i>, unclassified <i>Salmonella, Enterobacter cloacae</i>) were found to be significantly differently distributed between CRC patients and healthy controls. PCA-LDA successfully classified these 2 groups with satisfactory accuracy (84.52% for metabolic function and 77.38% for resistant genes). These findings underscore the potential of GM as a diagnostic tool for CRC, offering a promising avenue for non-invasive screening and risk assessment. The identification of specific microbial signatures, particularly those linked to metabolic functions and resistance traits, could open new doors for understanding the role of the microbiome in CRC progression and treatment resistance.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 1","pages":"71-81"},"PeriodicalIF":0.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949384/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143733774","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":"Dynamics of Antimicrobial Susceptibility and Risk Factors Associated with Infections Caused by Colistin-Resistant Bacteria: A Study from the Northern Region of Haryana, India.","authors":"Shubham Chauhan, Pottathil Shinu, Narinder Kaur, Adesh K Saini, Rosy Bala, Anroop B Nair, Aminur Rahman, Mohamed A Morsy","doi":"10.33073/pjm-2025-008","DOIUrl":"10.33073/pjm-2025-008","url":null,"abstract":"<p><p>Antimicrobial resistance poses a significant threat to global health, with colistin as a last-resort antibiotic against multidrug-resistant (MDR) microorganisms. The present study aimed to investigate the dynamics of antimicrobial susceptibility patterns and risk factors associated with infections caused by colistin-resistant bacteria in the Northern region of Haryana, India. Clinical samples (n = 12,652) collected from a single hospital in Haryana were subjected to microbiological analysis for five months. Among the total samples (n = 12,652) processed, 24% (n = 3,061) showed growth of pathogenic bacteria. Within the Gram-negative isolates, 56% (n = 1,242) were non-MDR, while 44% (n = 995) were MDR. Among MDR isolates (n = 995), 6% (n = 57) showed resistance to colistin. Notably, <i>Pseudomonas</i> spp. (12%, n = 19) and <i>Acinetobacter</i> spp. (11%, n = 8) demonstrated the highest resistance to colistin, followed by <i>Klebsiella</i> spp. (5%, n = 13), <i>Escherichia coli</i> (3%, n = 16), and <i>Citrobacter freundii</i> (1%, n = 1), respectively. The study revealed significant associations between the level of education (demographic variable) and the occurrence of colistin resistance. Prolonged hospital stays (> 5 days) and specific comorbidities, including diabetes (<i>p</i> < 0.01) and chronic obstructive pulmonary disease (<i>p</i> < 0.01), were identified as risk factors for colistin-resistant infections. Importantly, none of the colistin-resistant bacteria harbored <i>mcr</i> genes, suggesting alternative resistance mechanisms. Antibiotic sensitivity analysis indicated promising efficacy of antibiotics such as amikacin and gentamicin against colistin-resistant strains, though with variations across bacterial species. In summary, the study emphasizes the urgent need for enhanced surveillance, infection control protocols, and antimicrobial stewardship programs in healthcare settings to minimize the dissemination of MDR and colistin-resistant bacteria.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"74 1","pages":"95-105"},"PeriodicalIF":0.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949382/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143733777","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":"Harnessing Monoterpenes and Monoterpenoids as Weapons against Antimicrobial Resistance.","authors":"Amanda Shen-Yee Kong, Swee-Hua Erin Lim, Wan-Hee Cheng, Mohd Hafis Yuswan, Ngai-Paing Tan, Kok-Song Lai","doi":"10.33073/pjm-2025-010","DOIUrl":"10.33073/pjm-2025-010","url":null,"abstract":"<p><p>Antimicrobial resistance (AMR) poses a formidable challenge in global healthcare, driving the exploration of natural products for novel antimicrobials. Among these, essential oils (EOs) derived from medicinal plants are rich sources of diverse bioactive compounds. Monoterpenes and monoterpenoids, critical constituents of EOs, have emerged as promising agents in combating multidrugresistant (MDR) pathogens. This review analyzed recent literature on the efficacy of monoterpenes against AMR, highlighting their broad-spectrum activity and potential as alternative therapeutic options for MDR infections. Mechanistic insights reveal their ability to disrupt cell membranes, inhibit biofilm formation, and modulate gene expression linked to virulence and resistance, thereby reducing microbial viability through alterations in membrane potential, enzymatic activity, and genetic regulation. Synergistic interactions between monoterpenes and conventional antibiotics are also elucidated. Innovative approaches in monoterpene research are explored, although challenges such as resistance, limited solubility, volatility, and potential toxicity are acknowledged, emphasizing the need for advanced formulation strategies and interdisciplinary research. The synergy observed with conventional antibiotics, coupled with their ability to target specific microbial resistance mechanisms, underscores the potential of monoterpenes in combating antibioticresistant infections. Future investigations should prioritize optimizing monoterpenes' therapeutic properties and assessing their safety profiles to fully exploit their potential in addressing AMR.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":" ","pages":"1-18"},"PeriodicalIF":0.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949389/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143574787","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":"Antibiotic Resistance and Serotypes Distribution in <i>Streptococcus agalactiae</i> Bulgarian Clinical Isolates During the Years of 2021-2024.","authors":"Vasil S Boyanov, Alexandra S Alexandrova, Preslava M Hristova, Hristina Y Hitkova, Raina T Gergova","doi":"10.33073/pjm-2024-042","DOIUrl":"10.33073/pjm-2024-042","url":null,"abstract":"<p><p><i>Streptococcus agalactiae (</i>group B <i>Streptococcus</i>, GBS) is an important human and animal pathogen. In recent years, the number of streptococcal isolates resistant to antimicrobial agents has increased in many parts of the world. Various mechanisms of antimicrobial resistance and capsular serotypes of GBS with different geographical distributions can be found. A prospective cross-sectional study was conducted from September 2021 to May 2024. The survey included 257 GBS isolates from Bulgarian inpatients and outpatients with streptococcal infections. Antibiotic resistance genes and capsular serotypes were detected and evaluated using polymerase chain reaction (PCR). We classified GBS isolates into groups according to their source as vaginal samples (191) and extra-vaginal samples (66), subdivided as invasive (36) and non-invasive specimens (30). The most common serotypes were Ia (26.5%), III (20.2%), and V (19.8%). Antimicrobial susceptibility testing revealed that all examined isolates were susceptible to penicillin and vancomycin. Resistance to macrolides, lincosamides, and tetracyclines was observed in 60.3%, 24.9%, and 89.1% of the isolates. The distribution of phenotypes was cMLSb 47.4%, iMLSb 30.8%, M-type 21.2%, and L-type 0.6%. PCR analysis revealed nine genes associated with macrolide and lincosamide resistance: <i>ermB</i> (54.2%), <i>ermA</i>/<i>TR</i> (30.3%), <i>mefA</i> (20.7%), <i>ermC</i> (18.1%), <i>msrD</i> (14.8%), <i>mefE</i> (8.4%), <i>IsaC</i> (8.4%), <i>InuB</i> (7.7%), and <i>IsaE</i> (6.5%). Two genes linked to tetracycline resistance <i>tetM</i> (89.1%) and <i>tetO</i> (14.4%) were detected. Compared to the previous period, we observed increased antibiotic resistance. There was no statistical significance between the distribution of serotypes and antimicrobial non-susceptibility depending on the sample source.</p>","PeriodicalId":94173,"journal":{"name":"Polish journal of microbiology","volume":"73 4","pages":"505-514"},"PeriodicalIF":0.0,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11639287/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142820393","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}