BMC Microbiology最新文献

{"title":"Genomic and molecular characterization of a ceftazidime-avibactam resistant Klebsiella pneumoniae strain isolated from a Chinese tertiary hospital.","authors":"Yanye Tu, Hui Gao, Feng Wang, Rongqing Zhao, Shiyong Chen, Yanzi Chang, Hong Li","doi":"10.1186/s12866-025-03929-1","DOIUrl":"https://doi.org/10.1186/s12866-025-03929-1","url":null,"abstract":"<p><strong>Objective: </strong>This study aims to investigate the molecular biological characteristics of a ceftazidime-avibactam resistant Klebsiella pneumoniae strain isolated from a tertiary care hospital in China.</p><p><strong>Methods: </strong>The K. pneumoniae strain KP217360, isolated from a urine specimen at Li Huili Hospital affiliated with Ningbo University, was analyzed for antimicrobial susceptibility using the VITEK-2 Compact automated system. Antimicrobial susceptibility testing for polymyxin, tigecycline, and ceftazidime-avibactam was performed using broth microdilution according to CLSI guidelines. Whole genome sequencing was conducted using the Illumina platform, followed by comprehensive genomic analysis to characterize resistance determinants and virulence-associated genes. Experiments on conjugation were conducted to evaluate the transmissibility of the resistance plasmids. The virulence potential was evaluated through in vivo experiments using Galleria mellonella larvae as an infection model.</p><p><strong>Results: </strong>The K. pneumoniae KP217360 strain demonstrated extensive antimicrobial resistance, showing non-susceptibility to imipenem, ertapenem and ceftazidime-avibactam. Genomic characterization revealed the strain belonged to capsular type KL16 and harbored multiple resistance determinants, including bla_CTX-M-65, bla_SHV-103 and bla_TEM-1, along with iron acquisition-associated virulence factors (iutA, entABCDEF, and iroN). Plasmid analysis identified three distinct plasmids, among which an IncX3-type plasmid carrying bla_NDM-5 was confirmed, while the functional characteristics of the remaining two plasmids require further investigation. In the Galleria mellonella infection model, the 72-hour post-infection survival rates significantly differed among groups (P < 0.001), with NTUH-K2044, KP217360 and ATCC700603 showing survival rates of 26.7%, 56.7% and 80%, respectively. Subsequent analysis using the Pathogen Host Interactions (PHI) database identified 1,349 genes in the KP217360 strain were expressed for reduced virulence.</p><p><strong>Conclusion: </strong>This study reports the first identification of a ceftazidime-avibactam resistant K. pneumoniae ST685 strain carrying bla_NDM-5 in Ningbo, Zhejiang Province, China. The findings underscore the urgent need for implementing comprehensive antimicrobial resistance surveillance programs and strengthening infection control measures to mitigate the dissemination of IncX3-type plasmids harboring bla_NDM-5 in healthcare settings. Furthermore, our results emphasize the critical importance of establishing rapid enzymatic detection platforms in clinical microbiology laboratories to facilitate timely and precise therapeutic decision-making, thereby optimizing antimicrobial stewardship and improving patient outcomes.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"199"},"PeriodicalIF":4.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143810062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In silico genomic insights into bacteriophages infecting ESBL-producing Escherichia coli from human, animal, and environmental sources.","authors":"Mabel Kamweli Aworh, Opeyemi U Lawal, Beverly Egyir, Rene S Hendriksen","doi":"10.1186/s12866-025-03913-9","DOIUrl":"https://doi.org/10.1186/s12866-025-03913-9","url":null,"abstract":"<p><strong>Background: </strong>The emergence of antimicrobial resistance (AMR) in Escherichia coli, particularly extended-spectrum beta-lactamase-producing E. coli (ESBL-EC), is a global public health concern. Bacteriophages (phages) play a significant role in bacterial evolution and the spread of antibiotic resistance genes (ARGs). This study investigates prophages integrated within ESBL-EC genomes to assess their diversity, gene content, and potential contributions to ESBL-EC persistence across human, animal, and environmental reservoirs. Between May and December 2020, a cross-sectional study was conducted in Abuja and Lagos, collecting 448 stool, cecal, and environmental samples from abattoir workers, slaughtered cattle, and the abattoir environment. ESBL-EC genomes from these samples, obtained in an earlier study, were analyzed for phage regions using PHASTER. Intact prophages were analyzed in silico using computational tools to detect ARGs, ESBL genes, virulence factors, and heavy metal resistance. Their genomic relationships were examined with statistical significance of p < 0.05.</p><p><strong>Results: </strong>Out of 448 samples, ESBL-EC prevalence was 21.7% (97/448). Among 97 ESBL-EC isolates, 646 prophage regions were detected, with 30% (194/646) classified as intact phages. Among the 158 phages with genus assignments, Punavirus was the most prevalent (60.1%). Escherichia was the most frequent predicted host (308/646), particularly in cattle (n = 143) and human (n = 124) sources. Among ESBL-EC genomes, 83.5% (81/97) with intact phages carried phage-associated ARGs, 76.3% (74/97) carried phage-associated ESBL genes, 18.6% (18/97) harbored phage-associated virulence factors, 15.5% (15/97) contained phage-associated plasmids, and 10.3% (10/97) had heavy metal resistance. The most prevalent phage-associated ARGs detected were qnrS1 (73/81) and bla_CTX-M-15 (72/81). Two isolates recovered from abattoir workers carried two phage-like plasmids, each harboring either tet(A) or bla_CTX-M-55 gene. The predominant phage lifestyles were temperate (n = 182), mainly in the Peduoviridae family, and lytic (n = 12) in the Punavirus genus.</p><p><strong>Conclusion: </strong>This is the first study in Nigeria to characterize phages in ESBL-EC isolates at the One Health interface. The presence of intact phages in humans, animals, and the environment underscores the complex interactions shaping phage ecology. The discovery of ARGs, virulence genes, and heavy metal resistance within prophages suggests a potential role in AMR dissemination. Future research should focus on elucidating mechanisms of ARG transfer mediated by phages in One Health settings.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"200"},"PeriodicalIF":4.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143810074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization and identification of hot pepper-associated endospore-forming bacteria with potential applications as biofertilizers and in biocontrol of pepper wilt pathogens.","authors":"Shiferaw Demissie Tola, Diriba Muleta, Fassil Assefa, Farideh Ghadamgahi, Ramesh Raju Vetukuri, Beira Hailu Meressa","doi":"10.1186/s12866-025-03896-7","DOIUrl":"https://doi.org/10.1186/s12866-025-03896-7","url":null,"abstract":"<p><strong>Background: </strong>Although hot pepper contributes significantly to Ethiopia's national economy, its production is hindered by devastating outbreaks of phytopathogens such as Fusarium wilt and Meloidogyne incognita disease complexes. It is known that bacteria in the pepper rhizosphere can promote plant growth by suppressing soil-borne pathogens and producing growth-promoting substances. Therefore, hot pepper-associated endospore-forming bacteria were evaluated for plant growth-promoting traits and in vitro antagonism to pepper wilt-causing pathogens, revealing some potentially valuable isolates.</p><p><strong>Results: </strong>One hundred and forty-seven heat-resistant endospore-forming rhizobacteria were recovered from 48 rhizosphere samples. Thirty-five of these isolates solubilized phosphate efficiently with solubilization index values of 2.8-10, and produced indole acetic acid (27. 31-59.16 µg/ml). Moreover, 20 isolates hydrolyzed chitin effectively, 21 of them reduced the radial growth of three pathogenic Fusarium oxysporum strains by between 26.7% and 79.2%, and cell-free supernatants of 12 isolates reduced the hatching of M. incognita eggs by 51-96.4% while also increasing juvenile mortality by 45-98.7%. After 16S rRNA gene sequence analysis, 31 of the isolates were identified as Bacillus spp. (B. siamensis, B. velezensis, and B. cereus; n = 26) and Paenibacillus polymyxa (n = 5).</p><p><strong>Conclusions: </strong>The bacterial strains JUBC7 (B. cereus) and JUBC12 (B. siamensis) have multiple phytobeneficial traits that make them promising microbial inoculants for protecting high value crops against phytopathogens.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"198"},"PeriodicalIF":4.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143810060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Age-related dynamics of predominant methanogenic archaea in the human gut microbiome.","authors":"Rokhsareh Mohammadzadeh, Alexander Mahnert, Tejus Shinde, Christina Kumpitsch, Viktoria Weinberger, Helena Schmidt, Christine Moissl-Eichinger","doi":"10.1186/s12866-025-03921-9","DOIUrl":"10.1186/s12866-025-03921-9","url":null,"abstract":"<p><strong>Background: </strong>The reciprocal relationship between aging and alterations in the gut microbiota is a subject of ongoing research. While the role of bacteria in the gut microbiome is well-documented, specific changes in the composition of methanogens during extreme aging and the impact of high methane production in general on health remain unclear. This study was designed to explore the association of predominant methanogenic archaea within the human gut and aging.</p><p><strong>Methods: </strong>Shotgun metagenomic data from the stool samples of young adults (n = 127, Age: 19-59 y), older adults (n = 86, Age: 60-99 y), and centenarians (n = 34, age: 100-109 years) were analyzed.</p><p><strong>Results: </strong>Our findings reveal a compelling link between age and the prevalence of high methanogen phenotype, while overall archaeal diversity diminishes. Surprisingly, the archaeal composition of methanogens in the microbiome of centenarians appears more akin to that of younger adults, showing an increase in Methanobrevibacter smithii, rather than Candidatus Methanobrevibacter intestini. Remarkably, Ca. M. intestini emerged as a central player in the stability of the archaea-bacteria network in adults, paving the way for M. smithii in older adults and centenarians. Notably, centenarians exhibit a highly complex and stable network of these two methanogens with other bacteria. The mutual exclusion between Lachnospiraceae and these methanogens throughout all age groups suggests that these archaeal communities may compensate for the age-related drop in Lachnospiraceae by co-occurring with Oscillospiraceae.</p><p><strong>Conclusions: </strong>This study underscores the dynamics of archaeal microbiome in human physiology and aging. It highlights age-related shifts in methanogen composition, emphasizing the significance of both M. smithii and Ca. M. intestini and their partnership with butyrate-producing bacteria for potential enhanced health.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"193"},"PeriodicalIF":4.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11969853/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779242","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":"Shifts in dominant tree species modulate phyllosphere microbial diversity and function in successional forests.","authors":"Zi-Wen Gao, Zheng-Ning Xu, Yi-Lin Li, Lin Chang, Ning Li, Yang-Chun-Zi Liao, Wen-Jing Meng, Hui Sun, Lin Huang","doi":"10.1186/s12866-025-03905-9","DOIUrl":"10.1186/s12866-025-03905-9","url":null,"abstract":"<p><strong>Background: </strong>Phyllosphere microbiome plays a crucial role in maintaining plant fitness. However, its response to changes in dominant tree species during forest succession still remains poorly understood.</p><p><strong>Methods: </strong>In this study, microbial isolation and high-throughput sequencing techniques were used to analyze the community structure and diversity of phyllosphere microbes in pure Pinus massoniana forests, mixed P. massoniana and Liquidambar formosana forests, and pure L. formosana forests.</p><p><strong>Results: </strong>The results showed that the isolation rates of key plant fungal pathogens varied significantly in phyllosphere across forest types. In pure pine forest, Fusarium was most prevalent in pine needles, while in the mixed forest, Alternaria was dominant. For Liquidambar leaves, Phyllosticta dominated in pure forests, while Colletotrichum was prevalent in the mixed forests. Alpha diversity analysis revealed that higher microbial richness and diversity in the mixed forest compared to the pure forest. The bacterial community structure in Liquidambar leaves differed between the pure forest and the mixed forest. Co-occurrence networks confirmed more complex and stable microbial compositions and interactions in the mixed forest. Bacterial communities in pine needles exhibited higher functional capacity for methanotrophy and nitrogen fixation in the mixed forests.</p><p><strong>Conclusions: </strong>The results demonstrate that the mixed forests foster greater microbial diversity, complexity, and functional potential in the phyllosphere compared to the pure forests, highlighting the importance of forest composition in shaping phyllosphere microbial communities.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"195"},"PeriodicalIF":4.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11969814/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779246","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":"Multilocus sequence typing of clinical and colonizing isolates of Acinetobacter baumannii and comparison with the world isolates.","authors":"Jyoti Choudhary, Malini Shariff","doi":"10.1186/s12866-025-03804-z","DOIUrl":"10.1186/s12866-025-03804-z","url":null,"abstract":"<p><strong>Objectives: </strong>To establish the epidemiological correlation between the study isolates, Indian and World isolates of Acinetobacter baumannii by performing Multilocus Sequence typing.</p><p><strong>Materials and methods: </strong>A total of 181 isolates (Sputum (n = 116), lower respiratory tract other than sputum (n = 36), upper respiratory tract (n = 20), Environment (medical) (n = 4), and Blood (n = 5) of Acinetobacter baumannii were retrieved from our repository. DNA was isolated and Multilocus Sequence Typing was performed according to the Pasteur scheme. The amplified fragments were sequenced by outsourcing, and the locus and the sequence types were determined as given in the PUBMLST site. The clonal complexes were assigned using eBURST.</p><p><strong>Results and conclusion: </strong>Of the 181 isolates, 20 were colonizers and 4 were from hospital environments. All the study isolates were multidrug-resistant (MDR) and 4 of them were extensively drug-resistant (XDR). 23 sequence types were unique and were assigned new sequence types. Among them, 2125 (n = 12), an SLV (Single Locus Variant) of 2, was the commonest followed by 2126 (n = 2) which was a DLV (Double Locus Variant) of 2 and an SLV of 2125. Others were singletons. Among the known STs, 149 (n = 72) was the commonest followed by ST 2 (n = 62) & 415 (n = 5), ST 10 (n = 4), ST 15, ST622 and ST1482 (3 each). ST149 had 1SLV ST1482 (n = 3). ST 2 has 5 SLVs (415, 1555, 2125, 2128, & 2131, and 2 DLVs (2130 & 2126). eBURST analysis of the study isolates showed three groups: Group I (86 isolates) with ST 2 as the primary founder, group II (6 isolates) and group III (79 isolates) with ST 149 as the primary founder. All the other 11 isolates were singletons. There was no difference in antimicrobial sensitivity or sequence types of clinical and colonizing isolates. The sequence types of study isolates were compared to the world isolates in the PUBMLST database. To conclude, MLST is an important tool for establishing isolates' phylogenetic relationships. Acinetobacter baumannii being an important nosocomial pathogen should be routinely screened for the frequent changes in the sequence types to demonstrate the emerging resistance patterns and other changes.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"196"},"PeriodicalIF":4.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11969935/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787787","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":"Potential interactions between vancomycin and meropenem in culture-negative periprosthetic joint infection: an in vitro study.","authors":"Liqin Yao, Youcai Ma, Rui Liu, Yicheng Li, Xuebin Sun, Tuerhongjiang Wahafu, Li Cao, Wenbo Mu","doi":"10.1186/s12866-025-03918-4","DOIUrl":"10.1186/s12866-025-03918-4","url":null,"abstract":"<p><strong>Background: </strong>Culture-negative periprosthetic joint infections (CN-PJIs) represent a critical subtype of PJI, and their high prevalence poses substantial challenges for treatment. CN-PJI is commonly managed utilizing antibiotic combinations, however, the interactions between these antibiotics have not been investigated. The aim of study was to investigate the synergistic and antagonistic effects of vancomycin (VAN) and meropenem (MEM), in an in vitro model of CN-PJI.</p><p><strong>Methods: </strong>Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), Minimum Biofilm Inhibitory Concentration (MBIC), and Minimum Biofilm Eradication Concentration (MBEC) were determined for VAN and MEM. Fractional Inhibitory Concentration (FIC) and Fractional Biofilm Eradication Concentration (FBEC) indices were calculated to assess the synergistic or antagonistic effects of VAN in combination with MEM on Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), and Escherichia coli (E. coli) incubated alone or in combination.</p><p><strong>Results: </strong>In the planktonic bacterial phase, MEM showed higher activity than VAN. Resistance increased when the bacteria were cultured together. The combination of VAN and MEM exhibited an indifferent effect against individual Staphylococci but an antagonistic effect against polymicrobial cultures. In biofilm, MEM demonstrated better antibiofilm activity than VAN, especially against E. coli biofilms. The combination of VAN and MEM showed an indifferent effect against E. coli and S. epidermidis-E. coli biofilms, but an antagonistic effect against S. aureus, S. epidermidis, S. aureus-S. epidermidis, and S. aureus-E. coli biofilms.</p><p><strong>Conclusion: </strong>This study provides valuable insights into the effectiveness of VAN and MEM combinations in treating CN-PJIs, highlighting the need for careful consideration when selecting antibiotic treatments for these infections.</p><p><strong>Clinical trial number: </strong>Not applicable.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"197"},"PeriodicalIF":4.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11969832/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787853","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":"Genomic features, antimicrobial resistance and pathogenicity assessment of Escherichia coli serotype O177:H51 strain JS01 isolated from a diseased chicken.","authors":"Lunbin Xia, Guanglei Wang, Naidong Chen, Deliang Qiao, Jianwen Cao, Shaoshuai Bi","doi":"10.1186/s12866-025-03925-5","DOIUrl":"10.1186/s12866-025-03925-5","url":null,"abstract":"<p><strong>Background: </strong>Avian colibacillosis, caused by avian pathogenic Escherichia coli (APEC), remains one of the most significant bacterial diseases threatening global poultry production and causing substantial economic losses. The dominant serotypes of APEC regional diversity, complicating prevention and control efforts. Given the pathogen's importance, this study focused on the microbiological identification of an E. coli strain (JS01) isolated from diseased chickens on a poultry farm in China. Further analyses were conducted to characterize its antimicrobial resistance (AMR) phenotype and pathogenicity. To elucidate its multi-drug resistance and pathogenic mechanisms, whole-genome sequencing (WGS) of JS01 was performed, followed by functional gene annotation, sequence typing, and serotype analysis. Additionally, the genetic evolutionary characteristics of JS01 were investigated through comparative genomics and phylogenetic tree analysis.</p><p><strong>Results: </strong>Strain JS01 was identified as an ST155 E. coli of O177:H51 serotype, exhibiting multi-drug resistant and strong virulence. WGS revealed that JS01's genome consists of one chromosome and three plasmids, comprising 4,670 coding DNA sequences with a total length 5,089,394 bp. The genome harbored 64 AMR genes and 177 virulence factor (VF) genes. The AMR genes were primarily associated with defense mechanisms conferring antibiotic resistance, while the VF genes were linked to adhesins, motility, and effector systems. Comparative genomic analysis indicated that JS01 is closely related to GCA_900636075.1, ASM1038v1 and ASM3229062v1, which were isolated from different hosts.</p><p><strong>Conclusion: </strong>This study isolated and identified the O177: H51 serotype E. coli strain JS01 from chickens. The findings of this study provide valuable insights into the serotype distribution, antibiotic resistance patterns, and virulence characteristics of APEC isolates from diseased chickens in China. These results lay a foundation for future research to more accurately assess the impact of colibacillosis on the poultry industry and to develop targeted control strategies.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"194"},"PeriodicalIF":4.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11969786/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779244","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":"Transcriptional response study of auto inducer-2 regulatory system in Escherichia coli harboring bla_NDM.","authors":"Chandrayee Deshamukhya, Sabnam Ahmed, Bhaskar Jyoti Das, Debadatta Dhar Chanda, Amitabha Bhattacharjee","doi":"10.1186/s12866-025-03911-x","DOIUrl":"10.1186/s12866-025-03911-x","url":null,"abstract":"<p><strong>Background: </strong>The emergence of carbapenem resistance in gram-negative bacteria such as Escherichia coli is one of the world's most urgent public health problems. E. coli, which encounter a diverse range of niches in host can rapidly adapt to the changes in surrounding environment by coordinating their behavior via production, release and detection of signal molecules called autoinducers through a cell density dependent communication system known as quorum sensing. Here, in this study we investigated whether imipenem, and acyl homoserine lactone quorum sensing signal molecules influence the transcriptional response within lsr and lsrRK operon which are associated with auto inducer-2 mediated quorum sensing in E. coli. Two E. coli isolates carrying bla_NDM were treated with 10% SDS for 20 consecutive days, resulting in the successful elimination of the bla_NDM encoding plasmid from one isolate. Plasmid was extracted from the isolate and was transformed into recipient E. coli DH5α by electroporation. The native type, plasmid-cured type, transformant, and E. coli DH5α were allowed to grow under eight different inducing conditions and the transcriptional responses of lsr and lsrRK operons were studied by quantitative real-time PCR method.</p><p><strong>Results: </strong>The findings of this study highlight the distinct effects of imipenem and AHL on the transcriptional responses of the lsrB,lsrR, and lsrK genes in native type, plasmid cured type, transformant, and E. coli DH5α.</p><p><strong>Conclusion: </strong>This study provides a basis for further research to elucidate different inducing conditions including antibiotics and autoinducers that could switch on the quorum sensing circuit in carbapenem non-susceptible E. coli, one of the world's most urgent public health threats.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"192"},"PeriodicalIF":4.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11967149/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143778909","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":"The expression profile of inflammatory microRNAs in Leishmania major infected human macrophages; mining the effects of Leishmania RNA virus.","authors":"Zahra Mirabedini, Mehdi Mohebali, Hamed Mirjalali, Homa Hajjaran, Fatemeh Goudarzi, Hanieh Mohammad Rahimi","doi":"10.1186/s12866-025-03901-z","DOIUrl":"10.1186/s12866-025-03901-z","url":null,"abstract":"<p><strong>Background: </strong>Leishmaniasis is a disease caused by the Leishmania parasite. Recent studies suggest a critical role for double-stranded RNA virus (LRV) in the disease outcome. MicroRNAs (miRs) are small, non-coding RNA molecules that may also contribute to the outcome of infection and the pattern of disease. This study aimed to investigate the influence of L. major infected with LRV2 + on the expression profile of microRNAs compared to LRV2-.</p><p><strong>Methods: </strong>Samples were collected from cutaneous leishmaniasis (CL) patients in a leishmaniasis-endemic area of Iran. Leishmania species were determined using PCR (kDNA gene), and the presence of LRV2 was identified with semi-nested PCR (RdRp gene). The expression of miRs (miR-155, miR-146b, and miR-133a) was determined through quantitative real-time PCR analysis in human monocytes cell line (THP-1) infected with both LRV2 + and LRV2- isolates of L. major during 0, 12, 24, and 36 h post-co-infection.</p><p><strong>Results: </strong>The expression of miR-155 showed a significant decrease in the LRV2 + isolate compared to LRV2- at zero hours, but exhibited upregulation at 12, 24, and 36 h post-infection for both LRV2 + and LRV2- isolates compared to the control group. The expression of miR-146b was upregulated in both LRV2 + and LRV2- isolates compared to the control group at zero, 24, and 36 h post-infection. Conversely, miR-133a showed significant increases at zero and 12 h in both LRV2 + and LRV2- isolates compared to the control group, but it was downregulated in LRV2 + at 24 and 36 h compared to LRV2-.</p><p><strong>Conclusion: </strong>In this study, significant differences were observed in the expression profiles of miR-155, miR-146b, and miR-133a about the presence of LRV2. Our data suggest a potential determinative role for these miRs in the pathogenesis of CL.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"187"},"PeriodicalIF":4.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11963528/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143762888","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}