An epidemiological study of drug resistance and resistance genes in bovine Escherichia coli isolates in Heilongjiang Province of China

ABSTRACT

Background: To explore the epidemiology of bovine multidrug-resistant Escherichia coli isolates and resistance genes in Heilongjiang province of China. This study examined the prevalence of genes in bovine E. coli isolates, which confer resistance to antibiotics that are commonly used in the clinic, in regions of Baiquan, Shangzhi, and Songbei of Harbin. The purpose of the study was to investigate the epidemiology of the main resistance genes of bovine E. coli isolates in clinical veterinary medicine, and to provide a theoretical basis for preventing the spread of drug-resistant bacteria, as well as for rational drug use.Materials, Methods & Results: The sensitivity of 105 isolates to 22 antibiotics was determined using the KirbyBauer disk diffusion method, and the distribution of 19 kinds of common drug resistance genes was investigated using Polymerase Chain Reaction. The results showed that the resistance rate to nine antibiotics was over 50%, including rifampin (84.76%), ampicillin (73.58%), tetracycline (69.52%), and sulfisoxazole (59.05%). In total, 105 strains of bovine E. coli presented 21 spectra of drug resistance, including eight strains (7.62%, 8/105) that were resistant to one antibiotic and four strains (3.81%, 4/105) that were resistant to 21 antibiotics. The resistance gene detection results showed that the streptomycin-resistance gene strA was found in 73 isolates, accounting for 69.52% of the isolates, followed by the sulfanilamide-resistance genes sul3/sul2 and the aminoglycoside-resistance gene aphA, which accounted for 57.14%, 51.43%, and 50.48%, respectively, of the isolates.[...]