Virulence Potential and Characteristics of Multidrug-Resistant Corynebacterium amycolatum Strains Isolated from Nosocomial Infections

Abstract

The present study demonstrated Corynebacterium amycolatum as an emerging MDR nosocomial pathogen with emphasis on recognition of the class A β-lactamase encoding gene. Analysis of phenotypic and genotypic features of virulence mechanisms including C. elegans survival response to infection to C. amycolatum (imipenem - resistant and susceptible) strains were also investigated. Antimicrobial resistance genes were detected by polymerase chain reaction. We also evaluated the ability of Corynebacterium amycolatum in its ability to colonize and kill or host in a C. elegans infection model system and we investigated the adherence and invasion persistence of C. amycolatum within HEp-2 and U-937 cells. This study identified two C. amycolatum strains penicillin resistant and were positive for the blagene, encoding a class A betalactamase. The ability to C. amycolatum to kill the nematode C. elegans was verified. All strains of C. amycolatum caused a decline in the survival curve of C. elegans. The interaction of nematode and C. amycolatum results in morphological changes: Dar formation and “bag of worms” in all tested strains. About U-937 macrophages assay, the data indicate that the samples of Corynebacterium amycolatum studied had greater ability to adhere to the surface in the first 3 hours of infection of the monolayers (p <0.05). According to current knowledge, this is the first identification of C. amycolatumbla gene positive. So, we suggest that medical surveillance programs should include control strategies in order to decrease potential risk factors of nosocomial infections due to C. amycolatum.