Linezolid Susceptibility and Virulence Factors in Vancomycin Resistant Enterococcus faecalis and Enterococcus faecium among Hospitalized Burn Patients

Background: Enterococci are the 3rd cause of HAIs. E. faecalis and E. faecium are the commonest enterococcal species, showed resistance to vancomycin due to resistance genes (vanA, vanB and vanC). Linezolid is considered a good substitute . The virulence factors like asa1, gelE, cylA, esp, and hyl may interfere with antibiotic susceptibility. Objectives: Determine linezolid resistance in VR E. faecalis and E. faecium in relation to virulence factors. Methodology: Enterococcus spp. identified by colony morphology, Gram stain, biochemical reactions and by the VITEK 2 system. Antibiotic susceptibility was done through VITEK 2 system, AST-GP72 card. Vancomycin and linezolid MIC were done according to CLSI. Multiplex PCR for ddl E. faecalis , ddl E. faecium . vanA and vanB detection. Other for asa1, gelE, cylA, esp, and hyl virulence genes determination then conventional PCR for cfr and optrA genes were done. Results: A total of 65 enterococci CIs. (45 E. faecalis & 20 E. faecium) were isolated from different samples. E. faecalis and E. faecium were resistant to vancomycin by 11,1% and 35% and to linezolid by 4.4% and 10% respectively. The vanA, vanB, cfr and optrA genes were present in 100% of VR E. faecalis like E. faecium except that, the cfr was not detected. The gelE was frequently detected in E. faecalis followed by asa1, esp, hyl and finally cylA. And for E. faecium, the most frequent one was asa1followed by gelE. esp, and finally cylA and hyl. Conclusions: LZD resistant enterococci were increasingly detected, with no significant relation between linezolid resistance and vancomycin resistance. And with different impact of virulence genes.