A Survey of Plasmid-Mediated Fluoroquinolone Resistance Genes from Escherichia coli Isolates and Their Dissemination in Shandong, China
| Autor: | Jianzhong Shen, Lei Dai, Lin Li, Yuqing Liu, Li-Ning Xia, Li-Ming Lu, Xiao-Qi Tao, Yong-Hua Qi, Congming Wu |
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| Rok vydání: | 2010 |
| Předmět: |
China
Swine medicine.drug_class Colony Count Microbial Microbial Sensitivity Tests Drug resistance Biology medicine.disease_cause Polymerase Chain Reaction Applied Microbiology and Biotechnology Microbiology beta-Lactam Resistance law.invention Plasmid Antibiotic resistance Bacterial Proteins law Drug Resistance Bacterial Genotype Escherichia coli Prevalence medicine Animals Humans Escherichia coli Infections Polymerase chain reaction Dose-Response Relationship Drug Molecular epidemiology Escherichia coli Proteins Genetic Variation Quinolone Anti-Bacterial Agents Electrophoresis Gel Pulsed-Field Aminoglycosides Food Microbiology Animal Science and Zoology Chickens Fluoroquinolones Plasmids Food Science |
| Zdroj: | Foodborne Pathogens and Disease. 7:207-215 |
| ISSN: | 1556-7125 1535-3141 |
| DOI: | 10.1089/fpd.2009.0378 |
| Popis: | Bacterial resistance to fluoroquinolones result from mutations in the quinolone resistance-determining regions of the drug targets, overexpression of efflux pumps, and/or the more recently identified plasmid-mediated low-level resistance mechanisms. We investigated the prevalence of and characterized plasmid-mediated fluoroquinolone resistance genes (qnrA, qnrB, qnrS, aac(6')-Ib-cr, and qepA) by polymerase chain reaction in fluoroquinolone-resistant Escherichia coli (n = 530) isolated from a chicken farm, a pig farm, and hospitalized patients in Shandong, China, in 2007. The aac(6')-Ib-cr gene was the most prevalent resistance gene that was detected in bacteria isolated from all sources. Next was the qnrS gene, which was predominantly present in isolates from the pig farm. Only eight (5.8%) isolates from hospital patients were found to possess the qepA gene, and these isolates were first reported in qepA-carrying E. coli from humans in China. The qnrA and qnrB genes were not detected in any of the isolates. Further, most of the isolates were also resistant to beta-lactams and aminoglycosides as determined by the broth microdilution method. Pulsed-field gel electrophoresis analysis of the E. coli isolates with similar resistance patterns that also carried resistance genes showed great genomic diversity among these bacteria, suggesting that the multiresistant E. coli isolates carrying the qnr, aac(6')-Ib-cr, or qepA genes were not derived from a specific clone, but represented a wide variety of different genotypes. The results of Southern hybridization revealed that qepA, qnrS, and parts of aac(6')-Ib-cr genes were localized on plasmids and/or chromosome. qepA and aac(6')-Ib-cr genes were colocalized with aac(6')-Ib-cr and qnrS genes, respectively, on the same plasmids. Our study demonstrated that two different genes (qepA and aac(6')-Ib-cr) were identified on the same plasmid in E. coli strains derived from patients and qnrS and aac(6')-lb-cr genes on the same plasmid in an E. coli strain of animal origin. |
| Databáze: | OpenAIRE |
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