QRT-PCR profiling of adhesion genes in Acinetobacter baumannii

Acinetobacter baumannii is a multidrug-resistant opportunistic pathogen that causes significant hospital-acquired infections. The ability of A. baumannii to adhere to surfaces and form biofilms is mostly due to the mediation of certain genes related to adhesion, namely OmpA, CsuC, and CsuE. The present study intended to assess the molecular prevalence and expression of these genes using conventional PCR and quantitative real-time PCR (qRT-PCR). Twenty clinical isolates of A. baumannii were obtained from infection sources and identified using a combination of morphological, biochemical and molecular methods. PCR screening showed that there was a high prevalence of adhesion genes OmpA (100%), CsuC (100%), and CsuE (95%). qRT-PCR analysis indicated that gene expression for OmpA remained stable and expression for CsuC and CsuE was variable and downregulated with the isolates. Collectively, these results confirm that A. baumannii is equipped with a conserved genetic system for adhesion and that differential gene regulation is likely influenced by environmental conditions. The study demonstrates that qRT-PCR is a sensitive molecular technique with the potential to assess virulence-associated genes and characterization of the adaptive mechanisms of this clinically relevant pathogen.