Analysis on distribution and characterization of drug-resistant determinants in clinical bacteria

Objective To investigate the distribution and characterization of integrons in clinical strains.Methods The presence and genetic content of 3 classes integrons among 55 clinical strains were examined by multiple PCR and sequencing.Results 55(100%)strains were positive for intI1 gene.Furthermore,intI1-positive strains were amplified with primers of in-F and in-B which were set for amplifying the region of antibiotics resistance genes.Among 55 strains,an amplicon of 1?913?bp was yielded in 49 isolates,an amplicon of 1?664?bp was yielded in 6 isolates.Sequencing analysis revealed that amplicon 1?913?bp harbored genes of dhfr,orfF and aadA?2,amplicon 1?664?bp harbored genes of aadA5 and dfr?17,adA?2 and aadA?5 showing aminoglycoside resistance;dhfr and dfr?17 conferring resistance to trimethoprim,orfF encoding unknown function.Conclusion Resistance gene(s)mediated by class 1 integron was extensively existed in clinical isolates of both gram-negative and gram-positive bacteria.The result stressed the need for continued surveillance of antibiotic resistance gene(s) horizontal transference among bacteria genus.