In recent years,the mobile metallo-β-lactamase(MBL)genes have been found to correspond to one of the most important resistance characters identified in Gramnegative bacteria,severely affecting clinical chemotherapy a...In recent years,the mobile metallo-β-lactamase(MBL)genes have been found to correspond to one of the most important resistance characters identified in Gramnegative bacteria,severely affecting clinical chemotherapy and threatening public health.The prevalence of mobile MBL genes and their flanking regions in Gram-negative bacteria from diseased pigs in China was investigated.A total of 334 lung samples from diseased pigs were screened for Gram-negative bacteria classified as non-susceptible to meropenem(MIC≥4mg·L^(–1)).Six isolates,including three Escherichia coli,two Acinetobacter baumanii and one A.calcoaeticus,exhibitedMBL production and carried the blaNDM-1 gene.S1-PFGE and Southern blot analysis showed that the blaNDM-1 gene was located on the chromosome of one A.baumanii isolate and on plasmids of various sizes in the other five isolates.MIC testing using broth microdilution revealed that all blaNDM-1-carrying isolates and some of their transconjugants exhibited resistance to almost allβ-lactams tested.Whole genome sequencing revealed that the flanking region of the blaNDM-1 gene from all porcine isolates had high levels of similarity with the corresponding regions in human isolates.One porcine E.coli isolate carrying blaNDM-1 was typed as ST48,a common sequence type in human E.coli isolates.These results suggest the possibility of human-tofood animal transfer of blaNDM-1-producing E.coli,highlighting the need for surveillance of carbapenemase producers among bacteria from food animals.In addition,the prudent use of antimicrobial agents to decrease the opportunities for co-selection of carbapenemase genes in food animals is also urgently needed.展开更多
The co-occurrence of plasmid-mediated multidrug resistance and hypervirulence in epidemic carbapenem-resistant Klebsiella pneumoniae has emerged as a global public health issue.In this study,an ST23 carbapenem-resista...The co-occurrence of plasmid-mediated multidrug resistance and hypervirulence in epidemic carbapenem-resistant Klebsiella pneumoniae has emerged as a global public health issue.In this study,an ST23 carbapenem-resistant hyper-virulent K.pneumoniae(CR-HvKP)strain VH1-2 was identified from cucumber in China and harbored a novel hybrid plasmid pVH1-2-VIR.The plasmid pVH1-2-VIR carrying both virulence and multidrug-resistance(MDR)genes was likely generated through the recombination of a virulence plasmid and an IncFIIK conjugative MDR plasmid in clinical ST2318622 isolated from a sputum sample.The plasmid pVH1-2-VIR exhibited the capacity for transfer to the clinical ST11 carbapenem-resistant K.pneumoniae(CRKP)strain via conjugation assay.Acquisition of pVH1-2-VIR plasmid directly converted a CRKP into CR-HvKP strain characterized by hypermucoviscosity,heightened virulence for Galleria mellonella larvae,and increased colonization ability in the mouse intestine.The emergence of such a hybrid plasmid may expedite the spread of CR-HvKP strains,posing a significant risk to human health.展开更多
基金grants from the National Basic Research Program of China(2013CB127200)the National Natural Science Foundation of China(31422055).
文摘In recent years,the mobile metallo-β-lactamase(MBL)genes have been found to correspond to one of the most important resistance characters identified in Gramnegative bacteria,severely affecting clinical chemotherapy and threatening public health.The prevalence of mobile MBL genes and their flanking regions in Gram-negative bacteria from diseased pigs in China was investigated.A total of 334 lung samples from diseased pigs were screened for Gram-negative bacteria classified as non-susceptible to meropenem(MIC≥4mg·L^(–1)).Six isolates,including three Escherichia coli,two Acinetobacter baumanii and one A.calcoaeticus,exhibitedMBL production and carried the blaNDM-1 gene.S1-PFGE and Southern blot analysis showed that the blaNDM-1 gene was located on the chromosome of one A.baumanii isolate and on plasmids of various sizes in the other five isolates.MIC testing using broth microdilution revealed that all blaNDM-1-carrying isolates and some of their transconjugants exhibited resistance to almost allβ-lactams tested.Whole genome sequencing revealed that the flanking region of the blaNDM-1 gene from all porcine isolates had high levels of similarity with the corresponding regions in human isolates.One porcine E.coli isolate carrying blaNDM-1 was typed as ST48,a common sequence type in human E.coli isolates.These results suggest the possibility of human-tofood animal transfer of blaNDM-1-producing E.coli,highlighting the need for surveillance of carbapenemase producers among bacteria from food animals.In addition,the prudent use of antimicrobial agents to decrease the opportunities for co-selection of carbapenemase genes in food animals is also urgently needed.
基金supported in part by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(32121004)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2019BT02N054)+4 种基金Laboratory of Lingnan Modern Agriculture Project(NT2021006)Guangdong Major Project of Basic and Applied Basic Research(grant 2020B0301030007)Innovation Team Project of Guangdong University(2019KCXTD001),the 111 Project(grant D20008)Natural Science Foundation of Shandong Province of China(ZR2022MC001)the Scientific and Technological Projects of Qingdao(19‐6‐1‐94‐nsh).
文摘The co-occurrence of plasmid-mediated multidrug resistance and hypervirulence in epidemic carbapenem-resistant Klebsiella pneumoniae has emerged as a global public health issue.In this study,an ST23 carbapenem-resistant hyper-virulent K.pneumoniae(CR-HvKP)strain VH1-2 was identified from cucumber in China and harbored a novel hybrid plasmid pVH1-2-VIR.The plasmid pVH1-2-VIR carrying both virulence and multidrug-resistance(MDR)genes was likely generated through the recombination of a virulence plasmid and an IncFIIK conjugative MDR plasmid in clinical ST2318622 isolated from a sputum sample.The plasmid pVH1-2-VIR exhibited the capacity for transfer to the clinical ST11 carbapenem-resistant K.pneumoniae(CRKP)strain via conjugation assay.Acquisition of pVH1-2-VIR plasmid directly converted a CRKP into CR-HvKP strain characterized by hypermucoviscosity,heightened virulence for Galleria mellonella larvae,and increased colonization ability in the mouse intestine.The emergence of such a hybrid plasmid may expedite the spread of CR-HvKP strains,posing a significant risk to human health.
