Aim of this study was to investigate the genotypic distribution of extended-spectrum β-lactamases (ESBLs) and AmpC enzymes among Escherichia coli isolated from farm animals in Chongqing City. 326 E.coli isolates were...Aim of this study was to investigate the genotypic distribution of extended-spectrum β-lactamases (ESBLs) and AmpC enzymes among Escherichia coli isolated from farm animals in Chongqing City. 326 E.coli isolates were obtained from piglets,cattle and chickens.In these isolates,19 ESBLs and 6 AmpC-producing E.coli isolates were detected by preliminary screening and phenotypic identification, and polymerase chain reaction and sequence analysis methods were used to detect ESBLs and AmpCβ-lactamases genes.The results showed that the frequencies of TEM,CTX-M,DHA-1 and CMY-2 genes were 2.15%,5.21%,0.61%and 0.61%,respectively,in E.coli of animal origin in the Chongqing area,and 5 E.coli isolates were found to carry two kinds of genotype.The DHA-1 gene was detected for the first time in a veterinary clinic in China;its GenBank accession number is FJ386455.This study indicated that TEM and CTX-M genes were the predominant genotypes in Chongqing,and the majority of ESBLs and AmpC-producing E.coli isolates were multi-resistant to antibiotics,so they deserve particular attention in veterinary clinics.展开更多
CTX-M-producing bacteria are known as a resistant source against oxyimino-cephalosporin such as cefotaxime and ceftazidime;although laboratory diagnosis of this gene has not been properly defined. The aims of this stu...CTX-M-producing bacteria are known as a resistant source against oxyimino-cephalosporin such as cefotaxime and ceftazidime;although laboratory diagnosis of this gene has not been properly defined. The aims of this study are determining the rates of prevalence of CTX-M and CTX-M group 1 in the Escherichia coli (E. coli) obtained from urinary tract infections (UTI), and also determining their genetic relationship in the city of Sanandaj. In current study, 180 E. coli strains isolated from urinary tract infections were used. Sensitivity to common antibiotics was studied by the disc diffusion method. Phenotypic detection of isolated ESBL-producing starins was done by the combination disc test. CTX-M and CTX-M1 genes were detected using the PCR method and finally, the possible clonal relationship between isolates was determined using the REP-PCR method. 89 samples were ESBL-positive. The PCR assay used for detecting the CTX-M gene, showed that 48 samples out of 180 samples (26.66%) contained that gene;also among these 48 samples, 23 (12.77%) had CTX-M group 1. Based on the REP-PCR assay, 48 genotypes among 48 samples were CTX-M-positive. Results from the REP-PCR assay indicated that the clonal propagation theory of one epidemic strain of Escherichia coli is not apply, i.e. all CTX-M-producing species are not originated from one single strain and the gene is spread between different isolates. Therefore, hospitals and their employees must be more hygiene and, proper disposal of hospital waste can help to prevent the spread of different resistances.展开更多
基金supported by Chongqing Natural Science Foundation(CSTC,2007BB0002)
文摘Aim of this study was to investigate the genotypic distribution of extended-spectrum β-lactamases (ESBLs) and AmpC enzymes among Escherichia coli isolated from farm animals in Chongqing City. 326 E.coli isolates were obtained from piglets,cattle and chickens.In these isolates,19 ESBLs and 6 AmpC-producing E.coli isolates were detected by preliminary screening and phenotypic identification, and polymerase chain reaction and sequence analysis methods were used to detect ESBLs and AmpCβ-lactamases genes.The results showed that the frequencies of TEM,CTX-M,DHA-1 and CMY-2 genes were 2.15%,5.21%,0.61%and 0.61%,respectively,in E.coli of animal origin in the Chongqing area,and 5 E.coli isolates were found to carry two kinds of genotype.The DHA-1 gene was detected for the first time in a veterinary clinic in China;its GenBank accession number is FJ386455.This study indicated that TEM and CTX-M genes were the predominant genotypes in Chongqing,and the majority of ESBLs and AmpC-producing E.coli isolates were multi-resistant to antibiotics,so they deserve particular attention in veterinary clinics.
文摘CTX-M-producing bacteria are known as a resistant source against oxyimino-cephalosporin such as cefotaxime and ceftazidime;although laboratory diagnosis of this gene has not been properly defined. The aims of this study are determining the rates of prevalence of CTX-M and CTX-M group 1 in the Escherichia coli (E. coli) obtained from urinary tract infections (UTI), and also determining their genetic relationship in the city of Sanandaj. In current study, 180 E. coli strains isolated from urinary tract infections were used. Sensitivity to common antibiotics was studied by the disc diffusion method. Phenotypic detection of isolated ESBL-producing starins was done by the combination disc test. CTX-M and CTX-M1 genes were detected using the PCR method and finally, the possible clonal relationship between isolates was determined using the REP-PCR method. 89 samples were ESBL-positive. The PCR assay used for detecting the CTX-M gene, showed that 48 samples out of 180 samples (26.66%) contained that gene;also among these 48 samples, 23 (12.77%) had CTX-M group 1. Based on the REP-PCR assay, 48 genotypes among 48 samples were CTX-M-positive. Results from the REP-PCR assay indicated that the clonal propagation theory of one epidemic strain of Escherichia coli is not apply, i.e. all CTX-M-producing species are not originated from one single strain and the gene is spread between different isolates. Therefore, hospitals and their employees must be more hygiene and, proper disposal of hospital waste can help to prevent the spread of different resistances.
