Antibiotic resistance-related genes were determined by polymerase chain reaction (PCR) combined with sequencing.  PCR screening for PMQR genes of 62 quinolone-nonsusceptible isolates revealed the presence of qnrS, qnrD, aac(6')-Ib-cr, and oqxAB in 3 (4.8%), 2 (3.2%), 1 (1.6%), and 10 (16.1%) isolates, respectively. 
PCR
Southern blotting, conjugation tests, and transformation tests were used to characterize plasmid-mediated quinolone resistance (PMQR) determinants.



Southern blotting
Southern blotting, conjugation tests, and transformation tests were used to characterize plasmid-mediated quinolone resistance (PMQR) determinants.



conjugation tests
Southern blotting, conjugation tests, and transformation tests were used to characterize plasmid-mediated quinolone resistance (PMQR) determinants.



transformation tests