Prevalence and molecular typing of Metallo-β-lactamase-producing Pseudomonas aeruginosa with adhesion factors: A descriptive analysis of burn wounds isolates from Iran

Abstract

Pseudomonas aeruginosa produces a wide range of adhesion factors involved in pathogenicity and antibiotic resistance. The aim of this study was to determine the prevalence of Metallo-β-lactamase (MBL) enzymes and virulence factors among Pseudomonas aeruginosa clinical isolates. In this Descriptive-analytical study, 73 samples collected from post-burn infection patients. MBL-producing strains were detected by phenotypic methods. All isolates were investigated for the presence of β-lactamase-producing and virulence factor genes. The phenotypic identification for MBL enzyme present was revealed in 20 isolates (27.39%) by the modified Hodge test (MHT) and Carba-NP methods, 21 isolates (28.76%) by the Carbapenem Inactivation Method and 19 isolates (26.02%) by the modified Carbapenem Inactivation Method (mCIM) method. Moreover, 21(28.76%) isolates were considered as strong biofilms, and five isolates (6.84%) were considered as medium biofilms. The presence of β-lactamase genes in P. aeruginosa were as follows: blaSMP (9.58%), blaVIM (21.91%), blaIMP (16.43%), blaKPC (23.28%), blaSIM (12.32%), blaNDM (6.84%), and blaGIM (9.58%). In addition, the presence of virulence factors in P. aeruginosa isolates were as follows: pclN (49.31%), toxA (79.45%), exoS (72.6%), phzM (39.72%), pclH (39.72%), lasB (50.68%), apr (30.13%), lasA (56.16%), nanL (23.28%) and algD (54.79%). However, a significant statistical relationship was reported between the β-lactamase enzyme, extracellular virulence factor genes, and biofilm production. The results of this study showed that adhesion factors in P. aeruginosa isolated from post-burn infection plays an important role in increasing antibiotic resistance. Likewise, plasmids carrying genes are diverse and stable in multidrug resistance (MDR) and extensively drug-resistant (XDR) isolates.