Analysis of Antibiotic Resistance Gene Expression in Clinical Escherichia coli Isolates from Al-Diwaniyah, Iraq

Abstract

Globally, antibiotic resistance in Escherichia coli is major health problem. In Iraq, it has become a real issue because many people use antibiotics without proper medical guidance. This resistance comes from bacterial genes that can break the drug or push it out of the cell. Studying these genes at the molecular level is important for understanding how resistance develops and for improving treatment.

This work underline the expression of important resistance genes in clinical E. coli isolates and how gene action is linked to antibiotic resistance. The specimen were obtain from hospitalized patients and confirm as E. coli by standard lab tests. Antibiotic susceptbility analysis was accomplished, as well as three genes—bla_TEM, aac(3)-IV, and tetA—related to β-lactam, aminoglycoside, and tetracycline resistanse, were measured by real-time PCR.

The results showed β-lactam-resistant isolates had larger bla_TEM expression. Also, aac(3)-IV and tetA were more expressed in strains resistant to aminoglycosides and tetracycline. A very strong link originated between gene overexpression and resistance paterns. These result show that molecular testing is very useful to detect resistance early and to help choose better antibiotics in clinics. This can reduce treatment failure and slow the spread of resistant E. coli strains.