Phenotypes and genotypes of Aminoglycosides resistance in Klebsiella pneumonia isolated from Borujerd hospitals

Introduction: Aminoglycosides with Beta-lactams are generally used to treat serious bacterial infections. These antibiotics interfere with protein synthesis in bacteria via binding to the A site of 30S ribosomal subunits of 16SrRNA of prokaryotic. Inactivation by aminoglycoside-modifying enzymes (AMEs) has known as the main mechanism of aminoglycoside resistance in bacteria. In the present study, we investigated prevalence resistance to gentamicin and amikacin as aminoglycoside antibiotics and aac(6')-Ib and aac(3)-II genes encoding AMEs in Klebsiella pneumoniae strains isolated from Broujerd hospitals, Iran. Materials and methods: A total of 100 of K. pneumonia were collected from Boroujerd hospitals from April to September 2015. K. pneumonia isolates were identified by conventional microbiologic methods. Resistance to gentamicin, amikacin, gentamicin MICs were detected by disk diffusion and micro broth dilution methods, respectively. Duplex PCR assay were used to investigate the presence of aac(6')-Ib and aac(3)-II genes. Results: Among 100 isolates of Klebsiella pneumonia, 34% and 21% of isolates showed resistance to gentamicin and amikacin, respectively. Simultaneously resistance to gentamicin and Amikacin observed in 18% of cases. Most of isolates (95%) showed resistant to ampicillin. Multi Drug Resistant (MDR) patterns were detected in 71% of cases. Gentamicin MICs ranges were from 256-1024 mg/L. 70% (24) of aminoglycoside resistant isolates, harbored aac(6')-Ib and aac(3)-II genes. Conclusion: In conclusion, our data showed high frequency distribution of aac(3)-IIin aminoglycosides resistant K. pneumonia. Simultaneous resistant to aminoglycosides and beta-lactams is the cause of concern in hospitals.

Keywords:

Klebsiella pneumonia , Aminoglycoside , aac(6')-Ib , aac(3)-II