Molecular screening of oxacillinases beta-lactamase among gentamicin-resistant Escherichia coli isolates

Abstract

Expansion of β-lactamases in Gram-negative rods has been documented as most severe threat to the management of infectious diseases. The ever-increasing use of antibiotics with the evolution of intrinsic and acquired resistance has led to the development of resistance mechanism in Gram-negative rods contributing to the expansion of several multi-drug resistance epidemics in hospital environment. So this study aimed to investigate genes responsible for Oxacillinases production among gentamicin- resistant Escherichia coli isolates. The results showed that out of 573 specimens, 270 (56.13%) showed bacterial growth versus 264(46.07%) showed no bacterial growth 309(53.92%), among 573 clinical specimens 102(17.80%) were male patients while 471(82.19%) were female patients. According to result of the vitek-2 system recorded 110 isolates as E. coli. However result of gentamicin susceptibility demonstrated that 29 (26.36%) E. coli isolates were resistance to gentamicin compared with 39 (35.45%) and 42 (38.18%) of isolates were intermediate and sensitive to this antibiotic respectively. Results of antibiotic susceptibility showed that the highest bacterial resistance was Tobramycin 27(93.1%) and Ciprofloxacin 29(100 %),while Nitrofurantoin 3(10.3%) had the least resistance. Results of polymerase chain reaction (PCR ) amplification showed that OXA, OXA-1 and OXA-9,OXA-10 were 29(100%),26/(89.65%),29(100%) and 20(68.96%) respectively While OXA-2 did not detect.