Prevalence of aminoglycoside and tetracycline resistance genes and their association with virulence factors in clinical isolates of Acinetobacter baumannii

摘要

High prevalence of antibiotic resistance in Acinetobacter baumannii ( A. baumannii ) is a serious threat to modern health care system due to its inherent and acquired resistance mechanism.It is difficult to treat and becoming resistant to various classes of antibiotics. The aim of the study was to investigate aminoglycoside and tetracyclineantibiotic resistancegenes in A. baumannii and their correlation with virulence factors. A total of 240 clinical A. baumannii isolates collected from Pakistan Institute of Medical Sciences (PIMS) were preceded for the present study. Initially isolates were identified by using standard microbiologicaltechniques. Antibiotic susceptibility assay was performed using Kirby Bauer disk diffusion method. Polymerase chain reaction (PCR) was done for screening of antibiotic resistance genesand virulence factors. PCR results showed that among aminoglycoside resistance genes20%, 8%, 1% and 0.42% of isolates were found positive for aaC1 , aadA1 , aadB and aphA6 genes respectively. In case of tetracycline resistance genes, 13% isolates were positive for tetB and 1% for tetA . Among virulence factors, only one isolate harbored csgA gene and none of the isolates were positive for iutA , cnf1 and cvaC. It was concluded that due to residing on same genetic elements antibiotic resistance genes suppress the effect of virulence factors.