Molecular determination of van genes among clinical isolates of enterococci at a hospital setting

Vancomycin-resistant enterococci (VRE) poses a formidable challenge to public health due to its inherent resistance to multiple antibiotics coupled with the ability to transfer genetic determinants to dangerous pathogens like Methicillin-resistant Staphylococcus aureus (MRSA). The purpose of this study was to investigate the incidence of vancomycin resistance in enterococci among clinical isolates at a tertiary care military hospital in the eastern region of Saudi Arabia and to detect van genes using multiplex-PCR. Overall, 246 isolates of enterococci were collected from various clinical specimens. The isolates were identified, and antimicrobial susceptibility testing was done using the Vitek 2 system. Multiplex PCR was performed on the VRE isolates, thus identified to determine the van genes harbored. A total of 15 VRE were identified, of which 14 (93.3%) were Enterococcus faecium, and 1(6.7%) was Enterococcus casseliflavus with intrinsic vanC resistance. Of the 14 vancomycin-resistant Enterococcus faecium, 8 (57.1%) harbored vanB genes, while 6 (42.8%) harbored vanA genes. All the VRE were susceptible to linezolid and tigecycline. Our study detected a low prevalence (6.1%) of VRE among clinical isolates of enterococci and that the vanB gene predominates in such strains. Susceptibility profiles indicated that linezolid and tigecycline are still effective against these multidrug-resistant pathogens. Pus specimens yielded the highest percentage (53.3%) of isolates from which VRE was obtained, and this finding is novel among studies done in Saudi Arabia. ? 2021 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study investigated the incidence of vancomycin resistance in enterococci clinical isolates at a military hospital in Saudi Arabia and found a low prevalence (6.1%) of VRE. The study also showed that the vanB gene predominates in these strains, and that linezolid and tigecycline are effective against these multidrug-resistant pathogens.