BMC Microbiology最新文献

{"title":"Comprehensive molecular epidemiology of Acinetobacter baumannii from diverse sources in Nigeria.","authors":"Samuel O Ajoseh, Abdul-Azeez A Anjorin, Wasiu O Salami, Hanka Brangsch, Heinrich Neubauer, Gamal Wareth, Kabiru O Akinyemi","doi":"10.1186/s12866-025-03917-5","DOIUrl":"10.1186/s12866-025-03917-5","url":null,"abstract":"<p><strong>Background: </strong>Acinetobacter baumannii, a Gram-negative bacterium, is a public health threat due to its role in nosocomial infections and increasing antibiotic resistance. In Nigeria, data on the molecular epidemiology of A. baumannii is scarce. This study investigates the genetic diversity and the presence of antimicrobial resistance determinants and virulence-related genes in whole-genome sequencing data of 189 Nigerian A. baumannii isolates deposited in public repositories. Genotypes were determined in-silico by multilocus sequence typing (MLST) and core genome MLST (cgMLST). Further, antimicrobial resistance (AMR) and virulence-related genes were analyzed.</p><p><strong>Results: </strong>Most isolates (57.67%) originated from South-west Nigeria. Isolates of human origin accounted for 33.86%, while environmental sources comprised 6.87%, and 59.27% lacked information on the source of isolation. The cgMLST analysis revealed a multitude of genomic lineages circulating in Nigeria. The MLST Oxford scheme identified 44 sequence types (STs) in 62.96% of strains, with ST1089 being the most prevalent. The MLST Pasteur could assign 95.77% of strains to 49 STs, with ST2(IC2) and ST85(IC9) being the most dominant. Antimicrobial resistance analysis detected 168 genes encoding resistance to 12 antibiotic classes, with cephalosporin, carbapenem, and aminoglycoside resistance genes being the most prevalent. Notably, bla_ADC-79 (23.81%), bla_OXA-23 (30.69%), and aph(3″)-Ib (30%) were frequent variants encountered. Seventeen multi-efflux system genes conferring resistance to multiple antibiotic classes were identified. Virulence gene analysis revealed 137 genes encoding six mechanisms, with genes for nutritional factors, effector delivery systems, and biofilm production being the most prevalent.</p><p><strong>Conclusion: </strong>This study highlights the diversity in AMR and virulence genes of A. baumannii in Nigeria, emphasizing the need for ongoing genomic surveillance to inform infection control and develop antibiotic resistance management strategies.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"178"},"PeriodicalIF":4.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11956268/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143751372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial and anti-inflammatory effects of antimicrobial peptide Lf-KR against carbapenem-resistant Escherichia coli.","authors":"Jingchun Kong, Yue Wang, Yan Liu, Weijun Chen, Yijia Han, Huijing Zhou, Xiaodong Zhang, Beibei Zhou, Tieli Zhou, Jiayin Zheng","doi":"10.1186/s12866-025-03906-8","DOIUrl":"10.1186/s12866-025-03906-8","url":null,"abstract":"<p><strong>Background: </strong>Carbapenem-resistant Escherichia coli (CREC) is one of the most significant clinical pathogens, primarily emerging owing to the widespread use of broad-spectrum antibiotics. Antimicrobial resistance is a major global health challenge that prolongs treatment duration and increases healthcare costs. This study evaluated the antibacterial and anti-inflammatory effects of the antimicrobial peptide Lf-KR against CREC.</p><p><strong>Methods: </strong>Broth microdilution method, growth curve analysis, and time-kill assays were performed to evaluate the antibacterial activity of Lf-KR against CREC. The working mechanism of Lf-KR was elucidated using N-phenyl-1-naphthylamine, propidium iodide fluorochrome, and lipopolysaccharide-binding assays. qRT-PCR was used to assess the peptide's effects on the expression of pro-inflammatory cytokines expression during infection. Furthermore, the safety and stability of Lf-KR were assessed by testing its cytotoxicity, hemolytic activity, and antibacterial stability under various conditions. The Galleria mellonella infection model was applied to evaluate the in vivo activity of Lf-KR.</p><p><strong>Results: </strong>In vitro tests showed that Lf-KR exhibited potent antibacterial activity against CREC, with the minimum inhibitory concentrations of ranging from 4-8 µg/mL and minimum bactericidal concentrations 4-16 µg/mL. Mechanistically, Lf-KR induced bacterial cell death by disrupting the bacterial membrane. Furthermore, Lf-KR significantly reduced the expression of pro-inflammatory cytokine genes, including IL-1β, IL-6, and TNF-α, in RAW 264.7 macrophage cells infected with CREC. Lf-KR concentrations < 128 µg/mL showed no significant cytotoxicity or erythrocyte hemolytic activity. Lf-KR antibacterial activity was stable across a wide temperature range (- 80 °C to 65 °C), although it was more susceptible to inhibition by fetal bovine serum. The G. mellonella infection model further demonstrated the robust antimicrobial activity of Lf-KR.</p><p><strong>Conclusions: </strong>This study demonstrated that the antimicrobial peptide Lf-KR is a highly promising antimicrobial and anti-inflammatory agent against CREC, with potential applications in combating multi drug-resistant bacterial infections.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"183"},"PeriodicalIF":4.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11956232/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143751311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of ciprofloxacin and aminoglycoside susceptibility testing for ceftriaxone non-susceptible Enterobacterales by disk diffusion and VITEK 2 vs. broth microdilution using updated Clinical and Laboratory Standards Institute breakpoints.","authors":"Zahra N Sohani, Anthony Lieu, Makeda Semret, Matthew P Cheng, Nancy Simic, Reggie Bamba, Mina Patel, Alexander Lawandi, Todd C Lee","doi":"10.1186/s12866-025-03923-7","DOIUrl":"10.1186/s12866-025-03923-7","url":null,"abstract":"<p><strong>Background: </strong>Fluoroquinolones and aminoglycosides are potential treatment choices in the setting of increasingly multi-drug resistant Enterobacterales. The Clinical & Laboratory Standards Institute (CLSI) breakpoints for fluoroquinolones and aminoglycosides in the Enterobacterales were revised in 2019 and 2022, respectively. However, performance of existing widely used automated systems, such as the VITEK 2 AST-N391 card, has not been extensively tested for MDR isolates at these new breakpoints.</p><p><strong>Objective: </strong>To assess performance of the new breakpoints for ciprofloxacin, gentamicin, and tobramycin on the VITEK 2 system (bioMérieux, France) and disk diffusion by comparing to broth microdilution for ceftriaxone nonsusceptible Enterobacterales.</p><p><strong>Methods: </strong>Ninety-four ceftriaxone non-susceptible Escherichia coli and Klebsiella pneumoniae isolates were identified between January 2021-June 2023. Broth microdilution was used as the reference standard against which disk diffusion and VITEK 2 susceptibility testing were compared. For the Vitek 2, we used the AST-N391 card and interpreted the results according to the updated CLSI breakpoints.</p><p><strong>Results: </strong>Overall, 22.3% of isolates were susceptible to ciprofloxacin by BMD. Compared to BMD, disk diffusion had an overall minor error rate of 7.4% (95%CI 3.0-14.7%) with 0 major or very major errors (97.5% CI 0-3.8%). For the VITEK 2, a minor error rate of 13.8% (95% CI 7.6-22.5%), major error rate 19.0% (95%CI 7.7-40.0%) and very major error rate 0% (97.5%CI 0-3.8%) was noted. By comparison, 69.1% and 56.4% of isolates were susceptible to gentamicin and tobramycin, respectively. Disk diffusion and the VITEK 2 system both correctly categorized 100% of gentamicin susceptible and non-susceptible isolates. For tobramycin, disk diffusion had a 3.2% rate of misclassification (all minor errors) and the VITEK 2 had 2.1% rate of misclassification (all minor errors). There were no major or very major errors.</p><p><strong>Conclusions: </strong>Our findings suggest that both disk diffusion and to a greater extent the AST-N391 card for the VITEK 2 system will overcall non-susceptibility according to current CLSI breakpoints for ciprofloxacin. By contrast, the existing AST-N391 VITEK 2 card can likely be used to correctly infer susceptibility to gentamicin and tobramycin.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"175"},"PeriodicalIF":4.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11956328/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143751326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling organohalide respiration potential in River Nile sediments via 16S rRNA gene amplicon sequencing of endogenous bacterial communities.","authors":"Hwayda Soliman, Mohamed Ismaeil, Hoda Soussa, Wael S El-Sayed","doi":"10.1186/s12866-025-03864-1","DOIUrl":"10.1186/s12866-025-03864-1","url":null,"abstract":"<p><strong>Background: </strong>Industrial waste, agricultural runoff and untreated sewage contaminate the Nile, leaving a toxic legacy in its sediments. Organohalides-polluted sediment in particular poses serious public health risks and detrimental effects on aquatic life. Sediment microbiomes may harbor bacterial strains that could be utilized in bioremediation of such toxic pollutants.</p><p><strong>Material and methods: </strong>Two microbiomes from polluted River Nile sediments were analyzed by using 16S rRNA gene amplicon sequencing. In addition, PICRUSt analysis based on 16S rRNA data was used to explore the organohalide respiring bacteria (OHRB) genera and their corresponding organohalide respiration (OHR) activity. Microcosm studies were performed to validate the potential for dechlorination activity of River Nile sediment. Dechlorination of the parent chloroethenes into daughter end product were detected by gas chromatography coupled with flame ionization detection analysis.</p><p><strong>Results: </strong>Analysis of 16S rRNA gene amplicon sequences using the EZ-biocloud server identified Proteobacteria as the dominant phylum in both microbiomes, with Bacteroidetes and Chloroflexi prevalent in RNS1 sediment and Chlorobi in RNS2 sediment. EZ-biocloud and PCR analyses detected several potential OHRB genera, including Dehalococcoides, Dehalogenimonas, Desulfomonile, Desulfovibrio, and Geobacter, suggesting potential OHR activity. Further evidence for potential OHR activity was provided by PICRUSt functional prediction analysis, which suggested the presence of reductive dehalogenases as functional biomarkers associated with OHR in the sediment samples. Specifically, PICRUSt analysis predicted the presence of potential genes of tetrachloroethene reductive dehalogenase and 3-chloro-4-hydroxyphenylacetate reductive dehalogenase, previously linked to OHR. Microcosm studies confirmed the dechlorination potential of tetrachloroethene to dichloroethene.</p><p><strong>Conclusion: </strong>This study demonstrates that River Nile sediment in industrialized area harbors distinct microbiomes enclosing various OHRB genera, providing substantial evidence for potential reductive dechlorination activity. It also provides potential functional biomarkers for OHR activity.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"186"},"PeriodicalIF":4.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11956321/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143751154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of different fiber levels of energy feeds on rumen fermentation and the microbial community structure of grazing sheep.","authors":"Xiaoyun Zhang, Xulei Liu, Kaili Xie, Yueting Pan, Fuyao Liu, Fujiang Hou","doi":"10.1186/s12866-024-03644-3","DOIUrl":"10.1186/s12866-024-03644-3","url":null,"abstract":"<p><strong>Background: </strong>Rumen microbial community structure and stability are very important for ruminant health, growth and development, and livestock product yield. Dietary composition and nutritional structure affect microbial diversity and richness. The purpose of this study was to evaluate the effects of different fiber levels of energy feed on the rumen microflora and fermentation function of grazing sheep in salinized sown pasture, to reveal the response of the main microflora of sheep rumen at the phylum and genus levels to different fiber levels of energy feed and to analyze the internal mechanism to provide a reference for the selection of energy feed and the improvement of the production performance of grazing livestock.</p><p><strong>Results: </strong>The fiber level of energy feed affects the rumen fermentation and rumen microbial community structure of grazing sheep. Low-fiber-energy feeds significantly increased the relative abundance of Actinobacteria, while the relative abundances of Cyanobacteria, Ruminococcaceae_UCG_010, Ruminococcaceae_NK4A214_group, and Elusimicrobium significantly decreased, adjusting the relationship between the flora toward cooperation. High-fiber-energy feeds significantly increased the concentration of VFAs, significantly decreased the relative abundances of Proteobacteria, Ruminococcaceae_NK4A214_group and Rikenellaceae_RC9_gut_group, adjusted the relationship between the flora to compete, and promoted the enrichment of metabolic pathways such as \"Protein Digestion and Absorption,\" \"Nitrogen Metabolism,\" \"Starch and Sucrose Metabolism,\" and \"Degradation of Other Sugars.\"</p><p><strong>Conclusions: </strong>Supplementary feeding of high and low fiber energy feeds reduced the pH value of rumen fluid and the richness and diversity of microorganisms in grazing sheep, reduced the relative abundance of some harmful microorganisms, affected the metabolic activities of some fiber-digesting bacteria, regulated the interaction and competition between bacteria, increased the content of volatile fatty acids (VFAs) and the relative abundance of metabolic-related microorganisms in the supplementary feeding group, and enriched the metabolic-related pathways. However, further understand the mechanism of the effect of fiber level on the rumen of sheep, it is necessary to conduct in-depth analysis using research methods such as transcriptomics, proteomics and metabolomics.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"180"},"PeriodicalIF":4.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11956436/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143751376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luteolin loaded PEGylated cerosomes: a novel treatment for MRSA skin infections.","authors":"Sally A Mohamed, Walaa A Eraqi, Paris E Georghiou, Mohamed Y Zakaria","doi":"10.1186/s12866-025-03873-0","DOIUrl":"10.1186/s12866-025-03873-0","url":null,"abstract":"<p><strong>Background: </strong>Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of skin and soft tissue infections which, due to the spread of antimicrobial resistance, have become increasingly serious. Bacterial skin infection affects the barrier function of skin causing depletion of the ceramide content in the stratum corneum (SC) of the epidermis. In the study reported herein, luteolin (LUT) a naturally-occurring flavonoid was incorporated in PEGylated cerosomes (PCs) to boost its antibacterial action as a topical application. The opimal formulation of the surface-modified lipidic vesicles was chosen with the aid of a 2³ full factorial design. The effectiveness of the optimal LUT formulation which was developed was evaluated using several MRSA strains both in vitro and in vivo studies.</p><p><strong>Results: </strong>A 2³ full factorial design was employed for the preparation of the optimum PC formulation, designated herein as F5. A comparative in vitro release study revealed the superiority of F5 over a LUT suspension in solubilizing and releasing after 24 h, a higher percentage 78.1 ± 1.8% of luteolin compared with only 18.3 ± 2.1% for the luteolin suspension. When tested against MRSA strains, F5 showed antimicrobial activity that was higher than that of the luteolin suspension, having a MIC value of 187.5 µg/mL versus 1500 µg/mL. In addition to having enhanced anti-virulence activity than the luteolin suspension in terms of antibiofilm formation (with % inhibition ranging from 45 to 99% with the tested strains at 0.5 × and 0.25 × MICs, where the luteolin suspension only had a range from 1 to 45%), enhanced anti-pigment production, and anti-α-hemolysin activity were also observed. Moreover, F5 affected the cell wall integrity as confirmed by transmission electron microscopy (TEM). Scanning electron microscopy (SEM) verified the effect of F5 on bacterial biofilm formation, showing reduction of cellular adhesion and disruption of biofilm, factors which greatly contribute to bacterial pathogenesis and antibiotic resistance. When compared to the negative control and the luteolin suspension groups, the F5 formulation also resulted in reducing the bacterial load in the murine skin infection model.</p><p><strong>Conclusions: </strong>F5 PEGylated cerosomes are potential new potent defense agents against MRSA infections, demonstrating promising therapeutic capabilities.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"182"},"PeriodicalIF":4.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11956497/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143750408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of temperate bacteriophage vB_SauS_S1 on the adaptability and pathogenicity of Staphylococcus aureus ST398.","authors":"Hui Liu, Craig Billington, Xing Ji, Haichang Sun, Xiang Hou, Abbas Soleimani-Delfan, Ran Wang, Heye Wang, Lili Zhang","doi":"10.1186/s12866-025-03900-0","DOIUrl":"10.1186/s12866-025-03900-0","url":null,"abstract":"<p><p>Livestock-associated Staphylococcus aureus ST398 is a highly pathogenic species that causes infections in a wide variety of animals, including humans. The bacteriophage (phage) vB_SauS_S1 was isolated originally using a ST398 strain as its \"isolating host\", then the spot tests showed it was able to infect 73.33% (22/30) ST398 isolates. Phage S1 was assigned as a temperate phage based on genome analysis and phenotypic validation. Phylogenetic analysis showed that S1 was closely related to temperate phages tp310-2 and SA137ruMSSAST121PVL. Following infection of ST398 by phage S1, the lysogenic strain showed enhanced biofilm forming ability compared to the wildtype strain, and the invasion rate of MAC-T cells increased by 10.39%. The minimum inhibitory concentration showed that phage S1 did not change the antibiotic sensitivity of the lysogen strain, and the virulence of the lysogen strain did not change significantly in the injection models of Galleria mellonella (G. mellonella) and mice. The lysogen demonstrated superinfection immunity and reduced sensitivity to virulent phage infection. Thus, this study contributes to understanding the co-evolutionary relationships between temperate phages and the multi-host zoonotic pathogen S. aureus ST398.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"184"},"PeriodicalIF":4.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11956185/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143751374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validation of mNGS results using extensive lab and clinical data.","authors":"Zhen Zhang, Lei Tian","doi":"10.1186/s12866-025-03908-6","DOIUrl":"https://doi.org/10.1186/s12866-025-03908-6","url":null,"abstract":"<p><strong>Purpose: </strong>Interpreting the results of metagenomic next-generation sequencing (mNGS) presents a significant challenge in both clinical and laboratory contexts.</p><p><strong>Methods: </strong>A retrospective analysis was conducted to validate mNGS findings, with a particular emphasis on Mycobacterium tuberculosis, Mycoplasma pneumoniae, and Pneumocystis jirovecii as representative pathogens, examined from both clinical and laboratory perspectives.</p><p><strong>Results: </strong>Based on a comprehensive clinical analysis, the mNGS demonstrated detection accuracies for M. tuberculosis, M. pneumoniae, and P. jirovecii of 87.0% (60 out of 69; 95% confidence interval [CI], 77.04%-92.99%), 97.6% (81 out of 83; 95% CI, 91.63%-99.34%), and 78.9% (45 out of 57; 95% CI, 66.72%-87.53%), respectively. Conversely, when incorporating laboratory confirmation from a variety of detection methodologies, the accuracy rates for mNGS in identifying M. tuberculosis, M. pneumoniae, and P. jirovecii were 92.7% (51 out of 55; 95% CI, 82.74%-97.14%), 82.3% (51 out of 62; 95% CI, 70.96%-89.80%), and 83.9% (26 out of 31; 95% CI, 67.36%-92.91%), respectively. Additionally, our analysis revealed no statistically significant difference in read counts and relative abundances between mNGS results deemed clinically as false positives and those considered true positives (P < 0.05).</p><p><strong>Conclusion: </strong>In contemporary clinical practice, the detection of positive results from mNGS is notably high from both laboratory and clinical standpoints. Nonetheless, the interpretation of results with low read counts presents significant challenges for both clinical and laboratory environments under current conditions.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"173"},"PeriodicalIF":4.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11951646/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143742490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence, antibiotic resistance, virulence and antimicrobial resistance gene profiles of Salmonella species recovered from retail beef and poultry processing environments.","authors":"Zahra Osivand, Ebrahim Rahimi, Amir Shakerian, Faham Khamesipour","doi":"10.1186/s12866-025-03871-2","DOIUrl":"https://doi.org/10.1186/s12866-025-03871-2","url":null,"abstract":"<p><strong>Background: </strong>This study investigates the prevalence, antimicrobial resistance, genotypic resistance profiles, and virulence gene distribution of Salmonella isolates from poultry and beef processing environments in Shahrekord, Iran.</p><p><strong>Method: </strong>A total of 680 samples were collected from poultry (n = 300) and beef (n = 380) products between January and December 2023.</p><p><strong>Results: </strong>Salmonella was detected in 21% (63/300) of poultry samples and 15.8% (60/380) of beef samples, with non-typhoidal Salmonella (NTS) being the predominant serovar. High antimicrobial resistance (AMR) rates were observed across both food types, with the most common resistances found in ciprofloxacin (48%), tetracycline (44%), and ampicillin (39%). Genotypic analysis revealed the presence of key resistance genes, including bla_TEM (35%), tetA (29%), and sul1 (23%). Virulence gene analysis identified invA (92%), agfA (80%), and hilA (76%) as the most prevalent genes. Comparative analysis of resistance patterns between poultry and beef samples revealed higher resistance in poultry isolates to ciprofloxacin and tetracycline.</p><p><strong>Conclusion: </strong>This study highlights significant antimicrobial resistance and the presence of virulence factors in Salmonella isolates from retail beef and poultry, suggesting a potential risk to public health and the need for enhanced surveillance and control measures in food processing environments.</p><p><strong>Clinical trial number: </strong>Not applicable.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"174"},"PeriodicalIF":4.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11951776/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143742486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Total darkness activated intestinal clock system and improved intestinal barrier function in growing rabbits.","authors":"Yao Li, Jiali Chen, Fuchang Li, Lei Liu","doi":"10.1186/s12866-025-03916-6","DOIUrl":"10.1186/s12866-025-03916-6","url":null,"abstract":"<p><p>The aim of study was to investigate the effects of dark environment on production performance, intestinal barrier function and clock-related gene expression in rabbits. Forty weaned rabbits with similar body weight (35-day-old) were randomly divided into 2 treatments (20 replicates per treatment, 1 rabbit per replicate: normal light group (12 L and 12 D) or total dark group (24 D). The experimental period lasted for 10 days, with an adaptation period of 3 days and a subsequent formal experimental period of 7 days. The results showed that feed-to-weight ratio of rabbits in total dark group was significantly decreased compared with normal light group. Dark treatment significantly increased gene expression of claudin-1, mucin1 in duodenum, occludin-1, claudin-1, zona occludens 1 (ZO1), junctional adhesion molecule 2 (JAM2) and interleukin 10 (IL10) in jejunum, claudin-1, mucin1, ZO1 and IL10 in ileum and clock, melatonin 1 A, melatonin 1B, and period1 in cecum compared with normal light group. Total dark treatment increased alpha diversity via increasing chao1 index, observed species index and faith_pd index of cecal flora. Total dark treatment significantly reduced percentage of Deferobacterium at phylum level in cecum, but significantly increased percentage of Rumenococci at genus level. There is an insignificant increasing tendency of acetic acid and propionic acid content of soft feces in total dark group. In conclusion, total dark treatment improves feed conversion efficiency in rabbits and activates cecum clock system, which increased diversity of bacterial flora and production of short-chain fatty acids, then increases intestinal barrier function.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"172"},"PeriodicalIF":4.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11948808/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143717795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}