Outer membrane protein D gene mutations and carbapenem resistance in Pseudomonas Aeruginosa isolated from burns infection in Al-Najaf/Iraq

Abstract

The Most common mechanism used by P. aeruginosa for carbapenem resistance is the decrease of OM permeability, via accumulating mutations cause loss/reduce in the OprD gene expression. This study was designed to detect and determine the OprD gene mutations in carbapenem-resistant isolates of clinical P. aeruginosa isolated from burn wound infections. A 12/20 isolates were sequenced by Sanger method and the results were compared with wildtype (POA1) OprD gene sequence. The PCR products of 12/20 isolates were labeled as A and B, A for F1 forward primer and B for F2 forward primer, packed and sent to the Macrogen company for sequencing. All carbapenem-resistant isolates (10/12) contain mutations in their OprD genes, most of mutations are frameshift mutations, 1/12 still carbapenem-sensitive despite containing 40 mutations. All resistant sequenced isolates contain OprD mutations this might be the main cause and most related to carbapenem-resistance trait in the mutant strains, also despite the OprD mutations in isolate 21A it still carbapenem-sensitive indicates that the OprD mutation isn’t definitive factor for carbapenems resistance trait.