目的了解产气肠杆菌携带bla_(NDM-1)质粒的转移性、复制子分型及周围环境。方法产气肠杆菌HNNDM0711为实验菌株,利用接合实验研究其质粒的转移性,对接合子进行稳定性试验,采用质粒复制子分型法对质粒进行分型,利用染色体步移技术对基因b...目的了解产气肠杆菌携带bla_(NDM-1)质粒的转移性、复制子分型及周围环境。方法产气肠杆菌HNNDM0711为实验菌株,利用接合实验研究其质粒的转移性,对接合子进行稳定性试验,采用质粒复制子分型法对质粒进行分型,利用染色体步移技术对基因bla_(NDM-1)上下游进行测序,使用BLASTN和BLASTP对基因组序列进行比对,使用Vector NTI 11.5.1注释并生成序列管道图,序列通过软件Banklt递交至Genbank。结果产气肠杆菌HN-NDM0711接合实验阳性,阳性接合子稳定传代4 d后,所有克隆株对亚胺培南和美罗培南的最低抑菌浓度(MIC)均未发生变化,基因bla_(NDM-1)均为阳性。质粒复制子为IncA/C型;基因bla_(NDM-1)位于不常见的插入序列ISAba14和IS91之间,在bla_(NDM-1)的上游出现一个Tn3转座子和I型整合子,整合子上含有一个由庞大镶嵌序列构成的少见耐药基因盒。结论 IncA/C型质粒pHN-NDM0711携带基因bla_(NDM-1)及耐药基因盒,可能源于不同抗菌药物选择压力下的基因重组,建议严格控制临床、工业和农业抗菌药物的使用,从源头上减少此类细菌的产生。展开更多
Salmonella enterica serovar 1,4,[5],12:i:-(S.1,4,[5],12:i:-)has been recognized as an emerging foodborne pathogen in recent years.It can cause human salmonellosis predominated by the contamination of animal-derived fo...Salmonella enterica serovar 1,4,[5],12:i:-(S.1,4,[5],12:i:-)has been recognized as an emerging foodborne pathogen in recent years.It can cause human salmonellosis predominated by the contamination of animal-derived foods such as raw poultry and pork.This study aimed to characterize the genetic diversity,plasmid replicon types,and antibiotic resistance of 15 S.1,4,[5],12:i:-environmental isolates collected from two poultry farms using pulsed-field gel electrophoresis(PFGE),multilocus sequence typing(MLST),polymerase chain reaction-based replicon typing,and minimum inhibitory concentration approach.Ten different PFGE genotypes were detected,indicating a high diversity among these S.1,4,[5],12:i:-isolates.Three sequence types(ST19,ST1544,ST34)were identified by MLST.Among them,ST1544 was first detected in S.1,4,[5],12:i:-environmental isolates from poultry farms.All isolates were resistant to cefazolin,cefotetan,tobramycin,amikacin,and gentamicin,but susceptible to piperacillin-tazobactam,aztreonam,ceftazidime,cefepime,and ertapenem.Five incompatibility groups(Inc)of plasmids were identified,including IncFIIs(66.7%),IncHI2(20%),IncI1(6.7%),IncN(6.7%),and IncQ(6.7%).Among these isolates,80%carried at least one plasmid replicon type,and 20%carried multiple plasmid replicon types.Interestingly,the multidrug-resistant isolate 263 carried numerous resistance genes(i.e.qnrS,aac(6ʹ)-Ib-cr,bla_(TEM),bla_(CTX-M-9),bla_(OXA-1),sul1,sul2,sul3,floR,and mcr-1)and class I integronase gene intI1,which possessed both IncHI2 and IncQ plasmids,suggesting that resistance genes may be horizontally transferred by the combination of IncHI2 and IncQ plasmids.Collectively,antibiotic-resistant S.1,4,[5],12:i:-isolates were first found in poultry farm environments in China,and surveillance should be strengthened to prevent their further spread from poultry farms to foods.展开更多
文摘目的了解产气肠杆菌携带bla_(NDM-1)质粒的转移性、复制子分型及周围环境。方法产气肠杆菌HNNDM0711为实验菌株,利用接合实验研究其质粒的转移性,对接合子进行稳定性试验,采用质粒复制子分型法对质粒进行分型,利用染色体步移技术对基因bla_(NDM-1)上下游进行测序,使用BLASTN和BLASTP对基因组序列进行比对,使用Vector NTI 11.5.1注释并生成序列管道图,序列通过软件Banklt递交至Genbank。结果产气肠杆菌HN-NDM0711接合实验阳性,阳性接合子稳定传代4 d后,所有克隆株对亚胺培南和美罗培南的最低抑菌浓度(MIC)均未发生变化,基因bla_(NDM-1)均为阳性。质粒复制子为IncA/C型;基因bla_(NDM-1)位于不常见的插入序列ISAba14和IS91之间,在bla_(NDM-1)的上游出现一个Tn3转座子和I型整合子,整合子上含有一个由庞大镶嵌序列构成的少见耐药基因盒。结论 IncA/C型质粒pHN-NDM0711携带基因bla_(NDM-1)及耐药基因盒,可能源于不同抗菌药物选择压力下的基因重组,建议严格控制临床、工业和农业抗菌药物的使用,从源头上减少此类细菌的产生。
基金supported by the National Natural Science Foundation of China(No.32102111)the Project was funded by the China Postdoctoral Science Foundation(2021M702194).
文摘Salmonella enterica serovar 1,4,[5],12:i:-(S.1,4,[5],12:i:-)has been recognized as an emerging foodborne pathogen in recent years.It can cause human salmonellosis predominated by the contamination of animal-derived foods such as raw poultry and pork.This study aimed to characterize the genetic diversity,plasmid replicon types,and antibiotic resistance of 15 S.1,4,[5],12:i:-environmental isolates collected from two poultry farms using pulsed-field gel electrophoresis(PFGE),multilocus sequence typing(MLST),polymerase chain reaction-based replicon typing,and minimum inhibitory concentration approach.Ten different PFGE genotypes were detected,indicating a high diversity among these S.1,4,[5],12:i:-isolates.Three sequence types(ST19,ST1544,ST34)were identified by MLST.Among them,ST1544 was first detected in S.1,4,[5],12:i:-environmental isolates from poultry farms.All isolates were resistant to cefazolin,cefotetan,tobramycin,amikacin,and gentamicin,but susceptible to piperacillin-tazobactam,aztreonam,ceftazidime,cefepime,and ertapenem.Five incompatibility groups(Inc)of plasmids were identified,including IncFIIs(66.7%),IncHI2(20%),IncI1(6.7%),IncN(6.7%),and IncQ(6.7%).Among these isolates,80%carried at least one plasmid replicon type,and 20%carried multiple plasmid replicon types.Interestingly,the multidrug-resistant isolate 263 carried numerous resistance genes(i.e.qnrS,aac(6ʹ)-Ib-cr,bla_(TEM),bla_(CTX-M-9),bla_(OXA-1),sul1,sul2,sul3,floR,and mcr-1)and class I integronase gene intI1,which possessed both IncHI2 and IncQ plasmids,suggesting that resistance genes may be horizontally transferred by the combination of IncHI2 and IncQ plasmids.Collectively,antibiotic-resistant S.1,4,[5],12:i:-isolates were first found in poultry farm environments in China,and surveillance should be strengthened to prevent their further spread from poultry farms to foods.
