During a 2018 antimicrobial resistance surveillance of Escherichia coli isolates from diarrheal calves in Xinjiang Province,China,an unexpectedly high prevalence(48.5%)of fosfomycin resistance was observed.This study ...During a 2018 antimicrobial resistance surveillance of Escherichia coli isolates from diarrheal calves in Xinjiang Province,China,an unexpectedly high prevalence(48.5%)of fosfomycin resistance was observed.This study aimed to reveal the determinants of fosfomycin resistance and the underlying transmission mechanism.Polymerase chain reaction(PCR)screening showed that all fosfomycin-resistant E.coli carried the fosA3 gene.Pulsed-field gel electrophoresis(PFGE)and southern blot hybridization revealed that the 16 fosA3-positive isolates belonged to four different PFGE patterns(i.e.,A,B,C,D).The fosA3 genes of 11 clonally related strains(pattern D)were located on the chromosome,while others were carried by plasmids.Whole-genome and long-read sequencing indicated that the pattern D strains were E.coli O101:H9-ST10,and the pattern C,B,and A strains were O101:H9-ST167,O8:H30-ST1431,and O101:H9 with unknown ST,respectively.Among the pattern C strains,the blaCTX-M-14 gene was co-localized with the fosA3 gene on the F18:A-:B1 plasmids.Interestingly,phylogenetic analysis based on core genome single nucleotide polymorphisms(cgSNPs)showed that the O101:H9-ST10 strains were closely related to a Australian-isolated Chroicocephalus-origin E.coli O101:H9-ST10 strain producing CTX-M-14 and FosA3,with a difference of only 11 SNPs.These results indicate possible international dissemination of the high-risk E.coli clone O101:H9-ST10 by migratory birds.展开更多
The rapid spread of mobile tigecycline resistance presents a significant public health threat,particularly with the increasing prevalence of tet(X4)-positive Enterobacterales across various species.This study aimed to...The rapid spread of mobile tigecycline resistance presents a significant public health threat,particularly with the increasing prevalence of tet(X4)-positive Enterobacterales across various species.This study aimed to inves-tigate the epidemic features and transmission dynamics of tet(X4)-positive Klebsiella pneumoniae(K.pneumo-niae)through the analysis of 206 raw meats,including pork(n=182),beef(n=16),duck(n=5),and chicken(n=3).These samples were collected from schools,markets,and restaurants in Chengdu City,China.A total of 25 isolates were obtained from 13 administrative regions.All isolates exhibited resistance to tetracycline,tigecycline,ampicillin,chloramphenicol,and florfenicol.Over half of the isolates also demon-strated resistance to streptomycin(80%),sulfamethoxazole/trimethoprim(72%),ciprofloxacin(64%),and ampicillin/sulbactam(56%).Among these strains,14 distinct sequence types(STs)were identified,revealing evidence of inter-regional clonal spread,notably among 9 K.pneumoniae ST3393.Phylogenetic analysis revealed the presence of two K.pneumoniae ST5 closely resembling hypervirulent K.pneumoniae from Jiangsu.Importantly,12 isolates were capable of transferring tigecycline resistance to Escherichia coli J53.Further plasmid analysis showed that the tet(X4)-harboring plasmids in K.pneumoniae could be classified into four types,primarily belonging to the IncFIA(HI1)/HI1A/HI1B hybrid plasmid(n=16)and IncFII plasmid(n=7),which significantly contributed to the cross-species dissemination of tet(X4).In summary,this study highlights the prevalence of MDR tet(X4)-positive K.pneumoniae in Chengdu,driven predominantly by clonal expansion and plasmid-mediated horizontal gene transfer.These findings emphasize the importance of contin-uous surveillance of tet(X4)-positive K.pneumoniae in raw meat and the implementation of effective measures to control their spread.展开更多
基金supported by the National Natural Science Foundation of China(31625026)International Science and Technology Cooperation Project of Xinjiang Production and Construction Corps(XPCC)(2019BC004)Innovation Team Project of Guangdong University(2019KCXTD001)。
文摘During a 2018 antimicrobial resistance surveillance of Escherichia coli isolates from diarrheal calves in Xinjiang Province,China,an unexpectedly high prevalence(48.5%)of fosfomycin resistance was observed.This study aimed to reveal the determinants of fosfomycin resistance and the underlying transmission mechanism.Polymerase chain reaction(PCR)screening showed that all fosfomycin-resistant E.coli carried the fosA3 gene.Pulsed-field gel electrophoresis(PFGE)and southern blot hybridization revealed that the 16 fosA3-positive isolates belonged to four different PFGE patterns(i.e.,A,B,C,D).The fosA3 genes of 11 clonally related strains(pattern D)were located on the chromosome,while others were carried by plasmids.Whole-genome and long-read sequencing indicated that the pattern D strains were E.coli O101:H9-ST10,and the pattern C,B,and A strains were O101:H9-ST167,O8:H30-ST1431,and O101:H9 with unknown ST,respectively.Among the pattern C strains,the blaCTX-M-14 gene was co-localized with the fosA3 gene on the F18:A-:B1 plasmids.Interestingly,phylogenetic analysis based on core genome single nucleotide polymorphisms(cgSNPs)showed that the O101:H9-ST10 strains were closely related to a Australian-isolated Chroicocephalus-origin E.coli O101:H9-ST10 strain producing CTX-M-14 and FosA3,with a difference of only 11 SNPs.These results indicate possible international dissemination of the high-risk E.coli clone O101:H9-ST10 by migratory birds.
基金supported by the National Key Research and Development Program of China(No.2022YFD1800400)National Natural Science Foundation of China(No.81991531)+1 种基金Natural Science Foundation of Shandong Province(No.ZR2020MC188)The sequence data of 25 K.pneumoniae isolates have been submitted to NCBI under BioProject accession number PRJNA1011004.
文摘The rapid spread of mobile tigecycline resistance presents a significant public health threat,particularly with the increasing prevalence of tet(X4)-positive Enterobacterales across various species.This study aimed to inves-tigate the epidemic features and transmission dynamics of tet(X4)-positive Klebsiella pneumoniae(K.pneumo-niae)through the analysis of 206 raw meats,including pork(n=182),beef(n=16),duck(n=5),and chicken(n=3).These samples were collected from schools,markets,and restaurants in Chengdu City,China.A total of 25 isolates were obtained from 13 administrative regions.All isolates exhibited resistance to tetracycline,tigecycline,ampicillin,chloramphenicol,and florfenicol.Over half of the isolates also demon-strated resistance to streptomycin(80%),sulfamethoxazole/trimethoprim(72%),ciprofloxacin(64%),and ampicillin/sulbactam(56%).Among these strains,14 distinct sequence types(STs)were identified,revealing evidence of inter-regional clonal spread,notably among 9 K.pneumoniae ST3393.Phylogenetic analysis revealed the presence of two K.pneumoniae ST5 closely resembling hypervirulent K.pneumoniae from Jiangsu.Importantly,12 isolates were capable of transferring tigecycline resistance to Escherichia coli J53.Further plasmid analysis showed that the tet(X4)-harboring plasmids in K.pneumoniae could be classified into four types,primarily belonging to the IncFIA(HI1)/HI1A/HI1B hybrid plasmid(n=16)and IncFII plasmid(n=7),which significantly contributed to the cross-species dissemination of tet(X4).In summary,this study highlights the prevalence of MDR tet(X4)-positive K.pneumoniae in Chengdu,driven predominantly by clonal expansion and plasmid-mediated horizontal gene transfer.These findings emphasize the importance of contin-uous surveillance of tet(X4)-positive K.pneumoniae in raw meat and the implementation of effective measures to control their spread.
