Detection of Acra and Acrb Genes in Locally Isolated Carbapenems Sensitive Enterobacter Aerogenes

Abstract

Urinary Tract Infections (UTIs) are serious bacterial infections. In this study, which was extended from July/2018 to February/2019, 50 urine samples of confirmed urinary tract infection cases were collected. Of which, 24 cases were caused by Enterobacter aerogenes. The results show that 24 samples of them were caused by Enterobacter aerogenes, while the rest were caused by E.coli, Acinetobacter spp. The identification of the isolated bacteria was achieved using Vitek system, which was also used to do antibiotic sensitivity test. The results showed that the isolated Enterobacter aerogenes isolates were sensitive to carbapenems antibiotics, e.g imipenem and meropenem. Polymerase chain reaction (PCR) was used to detect some of the genes that are known to contribute in carbapenems resistance mechanism such as acriflavine (Acr) Efflux System. Surprisingly, the results showed that isolated Enterobacter aerogenes have some of acriflavine efflux genes, AcrA and AcrB, and these genes are important architectural genes of  acriflavine (Acr) Efflux System. The obtained results clearly indicated that these sensitive strains have the capabilities to shift to resistance ones when these genes start expressing themselves under certain environmental conditions.  The results are also prime importance and can explain the increasing frequency of the UTIs that can resist carbapenems treatment.