Abstract:

【Objective】 To investigate the prevalence of the plasmid-mediated quinolone resistance PMQR genes and their molecule epidemiological relationship with class 1 integrons of nursing sow origin Enterobacteria in Guangdong Province. 【Method】 Seventy-four Escherichia coli, 20 Salmonella were screened for the PMQR(qnrA, qnrB, qnrS, aac(6')-Ib-cr, qepA) genes by PCR and then conformed with sequencing. intIⅠ was screened from the PMQR positive strains. Antimicrobial susceptibility tests for the PMQR positive strains were performed by the agar dilution method. 【Result】 PMQR genes were detected in 14 (14.9%) of 94 strains, including 2 strains carried qnrB,11 strains carried qnrS, and 4 strains carried aac(6')-Ib-cr gene. The strain Salmonella 14 harboured 3 PMQR genes (qnrB, qnrS and aac(6')-Ib-cr), and one E. coli 2 harboured qnrB and qnrS. qnrA and qepA were not detected. intI1 was detected in all the 14 PMQR positive strains and they showed high rate of resistance to antimicrobial agents widely used in veterinary medicine. 【Conclusion】 The prevalence of PMQR genes existed from strains of Enterobacteria in nursing sow in Guangdong Province. And had a highest prevalence of qnrS was detected among Enterobacteria strains from the farms. The co-exist of class Ⅰintegron and PMQR genes played an important role in multi antimicrobial resistance in Enterobacteria.

Key words: nursing sow')">nursing sow, enterobacteria, quinolone, resistance