Detection On Antibiotic Resistance And PMQR Determinants Of E. Coli From Swine In Xinjiang

In order to study the porcine resistance of E. coli from a farming enterprises on widely used antibioticals and their carrying case PMQR determinants, anal swab samples were collected in different region(Changji, Hutubi and Manasi) of Xinjiang, and in different growth stages. Minimum inhibitory concentration of E. coli isolated was measured by broth microdilution method. Resistance results were analyzed by chi-square test. To survey the epidemic characteristics of PMQR determinants, and to analysis their contribution to resistant strains phenotype, PMQR determinants of drug-resistant strains were detected by PCR method.Different region results showed that resistance rates of E. coli from Hutubi were significantly higher than those from Changji and Manas(P<0.05) for apramycin, amikacin, amoxicillin / clavulanic acid and ceftiofur. Resistance rates of E. coli from Manas were significantly higher than Hutubi and Changji for ciprofloxacin and norfloxacin(P<0.05). Resistance rates of E. coli from Changji was significantly higher than Hutubi for norfloxacin(P<0.05). Resistance rates of E. coli from Changji were significantly higher than Manas for amoxicillin / clavulanic acid ceftiofur. Percentage of 3~7-resistant strains was 80.7%, 89.5% and 81.0% in Hutubi, Manas, Changji, respectively. Different region of 3~7-resistant strains is not significantly different(P>0.05).Different growth stages results showed that resistance rates from nursery pigs were significantly higher than sucklings, and sucklings were significantly higher than pregnant for ciprofloxacin and enrofloxacin(P<0.05). Resistance rate from sucklings were significantly higher than nursery and pregnant pigs for amikacin, gentamicin, ampicillin, ceftiofur(P<0.05).Resistance rate from nurserys were significantly higher than pregnant pigs for apramycin, amikacin and gentamicin(P<0.05). Percentage of 5~9-resistant strains was 77.5%, 78.5% and 49.3% in suckling, nursery, pregnant pigs, respectively. The rate of 7-resistant strains and 8-resistant strains in sucklings were significantly higher than pregnant and nursery pigs(P<0.05).Moreover, the qnrS and aac(6’)-Ib-cr of PMQR determinants were the main gene in suckling and pregnant pigs; the oqxB and qnrS were the main gene in nursery pigs. Detection rates of qnrS and aac(6’)-Ib-cr in pregnant pigs were significantly higher than suckling and nursery pigs(P<0.05). Detection rate of aac(6’)-Ib-cr in sulkings was significantly higher than nursery pigs(P<0.05). The qnrA, qnrB, qnrC, qnr D and qepA were not been detected in the present study.Under the same raising pattern, resistance of E. coli and PMQR determinants of resistant isolates from the swine farm are affected by the region and growth stages. Resistance of E. coli, especially multi-drug resistance is serious and the resistance type showed multifarious. The main determinantss of PMQR are qnrS, aac(6′)-Ib-cr, oqxA and oqxB indicating that PMQR determinants should be monitored in the swine farm.