{"title":"Evaluation of targeted sequencing for pathogen identification in bone and joint infections: a cohort study from China.","authors":"Qiang Zhang, Yonghua Ding, Quanzhong Ren, Feng Zhang, Guoqiang Lyu, Tongxin Lu, Zhen Song, Qing Wang, Yongxiang Cheng, Jing Wang, Hongcang Gu","doi":"10.1186/s12941-024-00733-z","DOIUrl":"10.1186/s12941-024-00733-z","url":null,"abstract":"<p><strong>Purpose: </strong>Bone and joint tuberculosis (BJTB) is a distinct variant of tuberculosis in which clinical diagnosis often leads to relative misdiagnosis and missed diagnoses. This study aimed to evaluate the diagnostic accuracy of the targeted nanopore sequencing (TNPseq) assay for BJTB patients in China.</p><p><strong>Method: </strong>The study enrolled a cohort of 163 patients with suspected BJTB. Diagnostic testing was performed using the TNPseq assay on samples including punctured tissue, pus, and blood. The diagnostic accuracy of the TNPseq assay was then compared with that of the T-SPOT and Xpert MTB/RIF assays.</p><p><strong>Result: </strong>TNPseq exhibited superior performance in terms of accuracy, demonstrating a sensitivity of 76.3% (95% CI: 71.0-81.6%) and a specificity of 98.8% (95% CI: 93.5-100%) in clinical diagnosis. When evaluated against a composite reference standard, TNPseq demonstrated a sensitivity of 74.4% (95% CI: 69.3-79.5%) and a specificity of 98.8% (95% CI: 93.7-100%). These results exceed the performance of both the T-SPOT and Xpert MTB/RIF tests. Notably, TNPseq demonstrated high specificity and accuracy in puncture specimens, with a sensitivity of 75.0% (95% CI: 70.2-79.8%) and a specificity of 98.3% (95% CI: 92.7-100%), as well as in pus samples, with a sensitivity of 83.3% (95% CI: 78.6-88.1%) and a specificity of 100% (95% CI: 100-100%). Additionally, TNPseq facilitated the detection of mixed infection scenarios, identifying 20 cases of bacterial-fungal co-infection, 17 cases of bacterial-viral co-infection, and two cases of simultaneous bacterial-fungal-viral co-infection.</p><p><strong>Conclusion: </strong>TNPseq demonstrated great potential in the diagnosis of BJTB due to its high sensitivity and specificity. The ability of TNPseq to diagnose pathogens and detect drug resistance genes can also guide subsequent treatment. Expanding the application scenarios and scope of TNPseq will enable it to benefit more clinical treatments.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"77"},"PeriodicalIF":4.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11342589/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jing Mao, Xiaoyu Yang, Cheng Yan, Fan Wang, Rui Zheng
{"title":"Proteomic analysis of carbapenem-resistant Klebsiella pneumoniae outer membrane vesicles under the action of phages combined with tigecycline.","authors":"Jing Mao, Xiaoyu Yang, Cheng Yan, Fan Wang, Rui Zheng","doi":"10.1186/s12941-024-00734-y","DOIUrl":"10.1186/s12941-024-00734-y","url":null,"abstract":"<p><strong>Background: </strong>Klebsiella pneumoniae is the most commonly encountered pathogen in clinical practice. Widespread use of broad-spectrum antibiotics has led to the current global dissemination of carbapenem-resistant K. pneumoniae, which poses a significant threat to antibacterial treatment efficacy and public health. Outer membrane vesicles (OMVs) have been identified as carriers capable of facilitating the transfer of virulence and resistance genes. However, the role of OMVs in carbapenem-resistant K. pneumoniae under external pressures such as antibiotic and phage treatments remains unclear.</p><p><strong>Methods: </strong>To isolate and purify OMVs under the pressure of phages and tigecycline, we subjected K. pneumoniae 0692 harboring plasmid-mediated bla<sub>NDM-1</sub> and bla<sub>KPC-2</sub> genes to density gradient separation. The double-layer plate method was used to isolate MJ1, which efficiently lysed K. pneumoniae 0692 cells. Transmission electron microscopy (TEM) was used to characterize the isolated phages and extract OMV groups for relevant morphological identification. Determination of protein content of each OMV group was conducted through bicinchoninic acid assay (BCA) and proteomic analysis.</p><p><strong>Results: </strong>K. pneumoniae 0692 released OMVs in response to different environmental stimuli, which were characterized through TEM as having the typical structure and particle size of OMVs. Phage or tigecycline treatment alone resulted in a slight increase in the mean protein concentration of OMVs secreted by K. pneumoniae 0692 compared to that in the untreated group. However, when phage treatment was combined with tigecycline, there was a significant reduction in the average protein concentration of OMVs compared to tigecycline treatment alone. Proteomics showed that OMVs encapsulated numerous functional proteins and that under different external stresses of phages and tigecycline, the proteins carried by K. pneumoniae 0692-derived OMVs were significantly upregulated or downregulated compared with those in the untreated group.</p><p><strong>Conclusions: </strong>This study confirmed the ability of OMVs to carry abundant proteins and highlighted the important role of OMV-associated proteins in bacterial responses to phages and tigecycline, representing an important advancement in microbial resistance research.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"73"},"PeriodicalIF":4.6,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11337635/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142008177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anna Samarra, Raúl Cabrera-Rubio, Cecilia Martínez-Costa, Maria Carmen Collado
{"title":"Unravelling the evolutionary dynamics of antibiotic resistance genes in the infant gut microbiota during the first four months of life.","authors":"Anna Samarra, Raúl Cabrera-Rubio, Cecilia Martínez-Costa, Maria Carmen Collado","doi":"10.1186/s12941-024-00725-z","DOIUrl":"10.1186/s12941-024-00725-z","url":null,"abstract":"<p><strong>Background: </strong>Alongside microbiota development, the evolution of the resistome is crucial in understanding the early-life acquisition and persistence of Antibiotic Resistance Genes (ARGs). Therefore, the aim of this study is to provide a comprehensive view of the evolution and dynamics of the neonatal resistome from 7 days to 4 months of age using a high-throughput qPCR platform.</p><p><strong>Methods: </strong>In the initial phase, a massive screening of 384 ARGs using a high-throughput qPCR in pooled healthy mother-infant pairs feces from the MAMI cohort was carried out to identify the most abundant and prevalent ARGs in infants and in mothers. This pre-analysis allowed for later targeted profiling in a large number of infants in a longitudinal manner during the first 4 months of life. 16S rRNA V3-V4 amplicon sequencing was performed to asses microbial composition longitudinally. Potential factors influencing the microbiota and ARGs in this period were also considered, such as mode of birth and breastfeeding type.</p><p><strong>Results: </strong>Following the massive screening, the top 45 abundant ARGs and mobile genetic elements were identified and studied in 72 infants during their first months of life (7 days, 1, 2, and 4 months). These genes were associated with resistance to aminoglycosides, beta-lactams and tetracyclines, among others, as well as integrons, and other mobile genetic elements. Changes in both ARG composition and quantity were observed during the first 4 months of life: most ARGs abundance increased over time, but mobile genetic elements decreased significantly. Further exploration of modulating factors highlighted the effect on ARG composition of specific microbial genus, and the impact of mode of birth at 7 days and 4 months. The influence of infant formula feeding was observed at 4-month-old infants, who exhibited a distinctive resistome composition.</p><p><strong>Conclusions: </strong>This study illustrates the ARG evolution and dynamics in the infant gut by use of a targeted, high-throughput, quantitative PCR-based method. An increase in antibiotic resistance over the first months of life were observed with a fundamental role of delivery mode in shaping resistance profiles. Further, we highlighted the influence of feeding methods on the resistome development. These findings offer pivotal insights into dynamics of and factors influencing early-life resistome, with potential avenues for intervention strategies.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"72"},"PeriodicalIF":4.6,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11323388/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaowen Yang, Yan Liu, Na Li, Xiaowei Peng, Yinghui Zhang, Xiaoqian Zhang, Lin Liang, Zengjie Bian, Hui Jiang, Jiabo Ding
{"title":"Analysis of the Brucella melitensis epidemic in Xinjiang: genotyping, polymorphism, antibiotic resistance and tracing.","authors":"Xiaowen Yang, Yan Liu, Na Li, Xiaowei Peng, Yinghui Zhang, Xiaoqian Zhang, Lin Liang, Zengjie Bian, Hui Jiang, Jiabo Ding","doi":"10.1186/s12941-024-00724-0","DOIUrl":"10.1186/s12941-024-00724-0","url":null,"abstract":"<p><p>Brucella spp. are facultative intracellular pathogens that cause zoonosis- brucellosis worldwide. There has been a trend of the re-emergence of brucellosis worldwide in recent years. The epidemic situation of brucellosis is serious in Xinjiang. To analyze the epidemic situation of Brucella spp. in Xinjiang among humans and animals, this study identified 144 Brucella isolates from Xinjiang using classical identification and 16 S rRNA sequencing. MLVA, drug resistance testing, and wgSNP detection were also performed. At the same time, analysis was conducted based on the published data of Brucella isolates worldwide. The results showed that the dominant species was B. melitensis biovar 3, which belonged to GT42 (MLVA-8 typing) and the East Mediterranean lineage. The correlation among isolates was high both in humans or animals. The isolates in Xinjiang exhibited higher polymorphism compared to other locations in China, with polymorphism increasing each year since 2010. No amikacin/kanamycin-resistant strains were detected, but six rifampicin-intermediate isolates were identified without rpoB gene variation. The NJ tree of the wgSNP results indicated that there were three main complexes of the B. melitensis epidemic in Xinjiang. Based on the results of this study, the prevention and control of brucellosis in Xinjiang should focus on B. melitensis, particularly strains belonging to B. melitensis bv.3 GT42 (MLVA-8 typing) and East Mediterranean lineage. Additionally, the rifampicin- and trimethoprim-sulfamethoxazole- resistance of isolates in Xinjiang should be closely monitored to avoid compromising the therapeutic efficacy and causing greater losses. These results provide essential data for the prevention and control of brucellosis in Xinjiang and China. Although the isolates from Xinjiang have significant characteristics among Chinese isolates and can reflect the epidemiological situation of brucellosis in China to some extent, this study cannot represent the characteristics of isolates from other regions.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"71"},"PeriodicalIF":4.6,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11317003/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141911472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of β-lactam antibiotics on the gut microbiota of term neonates.","authors":"Hongdan Gu, Enfu Tao, Yijia Fan, Gao Long, Xinyi Jia, Tianming Yuan, Lihua Chen, Xiaoli Shu, Wei Zheng, Mizu Jiang","doi":"10.1186/s12941-024-00730-2","DOIUrl":"10.1186/s12941-024-00730-2","url":null,"abstract":"<p><p>β-Lactam antibiotics are a class of antibiotics commonly used to treat bacterial infections. However, the effects of β-lactam antibiotics on term neonatal intestinal flora have not been fully elucidated. Hospitalized full-term newborns receiving β-lactam antibiotics formed the antibiotic group (n = 67), while those without antibiotic treatment comprised the non-antibiotic group (n = 47). A healthy group included healthy full-term newborns (n = 16). Stool samples were collected for 16 S rDNA sequencing to analyze gut microbiota variations. Further investigation was carried out within the β-lactam antibiotic group, exploring the effects of antibiotic use on the newborns' gut microbiota in relation to the duration and type of antibiotic administration, delivery method, and feeding practices. The antibiotic group exhibited significant difference of microbial community composition compared to the other groups. Genera like Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas were enriched, while Escherichia-Shigella, Clostridium sensu stricto 1, Bifidobacterium, and Parabacteroides were reduced. Klebsiella negatively correlated with Escherichia-Shigella, positively with Enterobacter, while Escherichia-Shigella negatively correlated with Enterococcus and Streptococcus. Regardless of neonatal age, β-lactam antibiotics induced an elevated abundance of Klebsiella and Enterococcus. The impact on gut microbiota varied with the duration and type of antibiotic (cefotaxime or ampicillin/sulbactam). Compared to vaginal delivery, cesarean delivery after β-lactam treatment heightened the abundance of Klebsiella, Enterobacteriaceae_Unclassified, Lactobacillales_Unclassified, and Pectobacterium. Feeding patterns minimally influenced β-lactam-induced alterations. In conclusion, β-lactam antibiotic treatment for neonatal pneumonia and sepsis markedly disrupted intestinal microbiota, favoring Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas. The impact of β-lactam varied by duration, type, and delivery method, emphasizing heightened disruptions post-cesarean delivery.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"69"},"PeriodicalIF":4.6,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11308410/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141900752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rapid detection of ceftriaxone-resistant Salmonella by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry combined with the ratio of optical density.","authors":"Chao Fang, Zheng Zhou, Mingming Zhou, Jianping Li","doi":"10.1186/s12941-024-00729-9","DOIUrl":"10.1186/s12941-024-00729-9","url":null,"abstract":"<p><strong>Background: </strong>The increased resistance rate of Salmonella to third-generation cephalosporins represented by ceftriaxone (CRO) may result in the failure of the empirical use of third-generation cephalosporins for the treatment of Salmonella infection in children. The present study was conducted to evaluate a novel method for the rapid detection of CRO-resistant Salmonella (CRS).</p><p><strong>Methods: </strong>We introduced the concept of the ratio of optical density (ROD) with and without CRO and combined it with matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) to establish a new protocol for the rapid detection of CRS.</p><p><strong>Results: </strong>The optimal incubation time and CRO concentration determined by the model strain test were 2 h and 8 µg/ml, respectively. We then conducted confirmatory tests on 120 clinical strains. According to the receiver operating characteristic curve analysis, the ROD cutoff value for distinguishing CRS and non-CRS strains was 0.818 [area under the curve: 1.000; 95% confidence interval: 0.970-1.000; sensitivity: 100.00%; specificity: 100%; P < 10<sup>- 3</sup>].</p><p><strong>Conclusions: </strong>In conclusion, the protocol for the combined ROD and MALDI-TOF MS represents a rapid, accurate, and economical method for the detection of CRS.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"70"},"PeriodicalIF":4.6,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11308677/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141900753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Angelo Roberto Raccagni, Giovanni Mori, Valeria Poletti de Chaurand, Raffaele Dell’Acqua, Daniela Maria Cirillo, Chiara Oltolini, Benedetta Mazzi, Francesco Scomazzoni, Antonella Castagna, Monica Guffanti
{"title":"Long-term successfull management of recurrent episodes of nontuberculous mycobacterial infection in an apparently healthy Chinese woman","authors":"Angelo Roberto Raccagni, Giovanni Mori, Valeria Poletti de Chaurand, Raffaele Dell’Acqua, Daniela Maria Cirillo, Chiara Oltolini, Benedetta Mazzi, Francesco Scomazzoni, Antonella Castagna, Monica Guffanti","doi":"10.1186/s12941-024-00732-0","DOIUrl":"https://doi.org/10.1186/s12941-024-00732-0","url":null,"abstract":"Disseminated non-tuberculous mycobacteria (dNTM) infections are mostly reported among individuals with an underlying congenital or acquired immunodeficiency or receiving immunosuppressive treatment, but are rarely documented in otherwise healthy subjects. We describe a case of recurrent disseminated mycobacterial infection in an apparently immunocompetent Chinese woman. Mycobacterium szulgai and Mycobacterium avium-complex were identified in distinct episodes. Long-term antimycobacterial therapy was administered given the occurrence of recurrent events when off-treatment. Successful management over more than 10 years and immunologic data are reported. This case-report highlights that dNTM should be suspected also among apparently immunocompetent hosts and that thorough assessment of underling immune-impairments is helpful to define patients’ management. Long-term antimycobacterial therapy and close monitoring is required to grant successful outcomes in case of recurrent dNTM infections.","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"42 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wang Zhang, Caihua Ma, Linghui Hu, Ling Wang, Falin Xu
{"title":"Late-onset sepsis in newborns caused by Bacillus Cereus: a case report and literature review.","authors":"Wang Zhang, Caihua Ma, Linghui Hu, Ling Wang, Falin Xu","doi":"10.1186/s12941-024-00712-4","DOIUrl":"10.1186/s12941-024-00712-4","url":null,"abstract":"<p><p>Bacillus cereus is a bacterium capable of causing late-onset neonatal sepsis. By analyzing 11 cases, this study investigates the diagnosis, treatment, and prognosis of Bacillus cereus infections, aiming to provide insights into clinical diagnosis and therapy. The study scrutinized 11 instances of late-onset neonatal sepsis, including two fatalities attributable to Bacillus cereus, one accompanied by cerebral hemorrhage. An examination and analysis of these cases' symptoms, signs, laboratory tests, and treatment processes, along with a review of related literature from 2010 to 2020, revealed a high mortality rate of 41.38% in non-gastrointestinal infections caused by Bacillus cereus. Our findings underscore the critical importance of rapid diagnosis and effective antimicrobial therapy in reducing mortality rates. Once the source of infection is identified, implementing effective infection control measures is essential.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"66"},"PeriodicalIF":4.6,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11282708/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141764924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaofen Mo, Hui Zhang, Junfeng Fan, Linna Xu, Hao Fu, Junpeng Yue, Kaixuan Dong, Qixia Luo, Fen Wan
{"title":"Co-existence of two plasmids harboring transferable resistance-nodulation-division pump gene cluster, tmexCD1-toprJ1, and colistin resistance gene mcr-8 in Klebsiella pneumoniae.","authors":"Xiaofen Mo, Hui Zhang, Junfeng Fan, Linna Xu, Hao Fu, Junpeng Yue, Kaixuan Dong, Qixia Luo, Fen Wan","doi":"10.1186/s12941-024-00727-x","DOIUrl":"10.1186/s12941-024-00727-x","url":null,"abstract":"<p><strong>Background: </strong>The emergence of plasmid-mediated mobile colistin resistance (mcr) gene poses a great challenge to the clinical application of polymyxins. To date, mcr-1 to mcr-10 have been found in animals, humans, and the environment. Among them, mcr-8 was first identified in Klebsiella pneumoniae (K. pneumoniae) of swine origin, and then mcr-8.1 to mcr-8.5 were successively identified. Notably, K. pneumoniae is the major host of the mcr-8 gene in both animals and humans. This study aims to explore the characteristics of K. pneumoniae strains carrying the mcr-8 gene and tmexCD1-toprJ1 gene cluster and investigate the correlation between these two antibiotic resistance genes.</p><p><strong>Methods: </strong>The isolates from the poultry farms and the surrounding villages were identified by mass spectrometer, and the strains positive for mcr-1 to mcr-10 were screened by polymerase chain reaction (PCR). The size of the plasmid and the antimicrobial resistance genes carried were confirmed by S1-nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern hybridization, and the transferability of the plasmid was verified by conjugation experiments. Antimicrobial susceptibility testing (AST) and whole genome sequencing (WGS) were used to characterize the strains.</p><p><strong>Results: </strong>Two K. pneumoniae isolates (KP26 and KP29) displaying polymyxin resistance were identified as mcr-8 gene carriers. Besides that, tigecycline-resistant gene cluster tmexCD1-toprJ1 was also found on the other plasmid which conferred strain resistance to tigecycline. Through epidemiological analysis, we found that the mcr-8 gene has dispersed globally, circulating in the human, animals, and the environment. Furthermore, our analysis suggests that the coexistence of mcr-8 and tmexCD1-toprJ1 on a single plasmid might evolved through plasmid recombination.</p><p><strong>Conclusions: </strong>Although the mcr-8 and tmexCD1-toprJ1 gene clusters in the two strains of K. pneumoniae in this study were on two different plasmids, they still pose a potential threat to public health, requiring close monitoring and further study.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"67"},"PeriodicalIF":4.6,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11282740/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141765002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"To evaluate the performance of simultaneous amplification and testing assay for group B Streptococcus detection: comparison with real-time PCR and ddPCR assays.","authors":"Loukaiyi Lu, Yisheng Chen, Qiang Wang, Jing Gao, Chunmei Ying","doi":"10.1186/s12941-024-00726-y","DOIUrl":"10.1186/s12941-024-00726-y","url":null,"abstract":"<p><strong>Background: </strong>To evaluate the performance of simultaneous amplification and testing (SAT) assay for the detection of group B Streptococcus (GBS) in maternal vaginal and perianal swabs compared with real-time polymerase chain reaction (RT-PCR).</p><p><strong>Methods: </strong>We obtained vaginal and perianal swabs from 1474 pregnant women at the Obstetrics and Gynecology Hospital of Fudan University (Shanghai, China) between April 2023 and June 2023. Vaginal and perianal swabs were collected at 35-37 weeks of gestation. Swabs were tested for GBS simultaneously by using the SAT assay and RT-PCR, and a comparative analysis (kappa coefficient) was performed. Furthermore, we conducted additional droplet digital PCR (ddPCR) tests to confirm the results when there were controversial results between SAT and RT-PCR. In addition, we compared the limit of detection, technical specificity, repeatability and reproducibility of SAT-GBS with those of routine RT-PCR assays.</p><p><strong>Results: </strong>In our study, the detection rate of clinical GBS according to the SAT assay was 11.5% (169/1471). The SAT assay showed a sensitivity of 91.8%, a specificity of 99.9%, a diagnostic accuracy of 98.9%, a positive predictive value (PPV) of 99.4% and a negative predictive value (NPV) of 98.8%. The kappa value between RT-PCR and SAT was 0.917.</p><p><strong>Conclusions: </strong>This SAT assay for the detection of group B Streptococcus is not only easy to perform but can also detect GBS sensitively and specifically and may be used in the regular molecular diagnosis of GBS infection among pregnancies.</p>","PeriodicalId":8052,"journal":{"name":"Annals of Clinical Microbiology and Antimicrobials","volume":"23 1","pages":"65"},"PeriodicalIF":4.6,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11264765/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141722839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}