High Incidence of Virulence Factors Among ClinicalEnterococcus faecalisIsolates in Southwestern Iran

Abstract

BackgroundOver the past two decades, enterococci have emerged as an important agent responsible for hospital acquired infection. Several virulence factors contribute to the adherence, colonization, evasion of the host immune response, and pathogenicity and severity of the infection. Enterococcus faecalis is the most common and virulent species causing infections in hospitalized patients. The aim of the present study was to examine the prevalence of genes encoding virulence factors and antimicrobial resistance patterns of E. faecalis strains isolated from hospitalized patients in Shiraz, south west of Iran.Materials and MethodsA total of 51 E. faecalis isolates from the urine, blood, pleural fluid, peritoneal fluid, eye discharge, endotracheal tube (ETT) and transjugular intrahepatic portosystemic shunt (TIPS) specimens of patients were identified by phenotypic and genotypic methods. Antimicrobial sensitivity tests and detection of virulence factors were performed using standard methods.ResultsThe efa and asa1 were the most frequently detected gene (100%) among the isolates, followed by esp (94.1%), ace (90.2%), gelE (80.4%), cylA (64.7%), and hyl (51%). More than half of the isolates (52.9%) were high level gentamicin resistant (HLGR). Vancomycin resistance was observed among 23 (45.1%) isolates. The lowest antimicrobial activity was related to erythromycin (3.9%), tetracycline (5.9%) and ciprofloxacin (9.8%). No isolate was found resistant to fosfomycin and linezolid.ConclusionOur data indicated a high incidence of virulence factors among E. faecalis strains isolated from clinical samples. Colonization of drug resistant virulent isolates in hospital environment may lead to life threatening infection in hospitalized patients. Therefore, infection control procedures should be performed.

Emergence of High-level Gentamicin Resistance among Enterococci Clinical Isolates from Burn Patients in South-west of Iran: Vancomycin Still Working

“…Like in this study, the HLGR was reported high in other similar studies from Iran, (Emaneini et al 2016;Heidari et al 2017). The studies conducted in other countries have also been reported a high rate of the HLGR phenotype.…”

Improved detection of esp, hyl, asa1, gelE, cylA virulence genes among clinical isolates of Enterococci

“…As reported earlier, hyl was detected only in E. faecium [33]. Nevertheless, a few studies have reported the incidence of hyl in both species [29,[34][35][36][37][38][39]. Significant difference was observed in the VF score between species.…”

“…Nevertheless, the presence of virulence determinants in the clinical isolates might contribute to increased severity as they could be expressed under optimum conditions in vivo. Metadata of the previous studies on the detection of virulence genes of enterococci by multiplex/duplex/simplex PCR is depicted in Additional file 1: Table S1 [18,27,29,[33][34][35][36][37][38][39][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59].…”

Genetic relatedness of the Enterococcus faecalis isolates in stool and urine samples of patients with community-acquired urinary tract infection

“…E. faecalis, likely through multiple virulence factors that may involve in its colonization, survival, and pathogenicity, promote disease in the urinary tract. Heidari and et al investigated the incidence of genetic virulence markers among clinical E. faecalis and found that occurrence of multiple virulence factors was common in the urinary tract isolates, while most of the strains carried predominantly four, ve and seven virulence determinants in HA-UTIs [33]. Aberna and Prabakaran investigated the presence of genetic virulence markers in E. faecalis and found that the occurrence of multiple virulence factors was common in the urinary tract isolates, while most of the strains carried predominantly two and three virulence determinants in HA-UTIs [24].…”