High Incidence of Virulence Factors among Clinical Enterococcus faecalis Isolates in Southwestern Iran

다국어 초록 (Multilingual Abstract)

Background: Over the past two decades, enterococci have emerged as an important agent responsible for hospital acquiredinfection. Several virulence factors contribute to the adherence, colonization, evasion of the host immune response, and pathogenicityand severity of the infection. Enterococcus faecalis is the most common and virulent species causing infections in hospitalizedpatients. The aim of the present study was to examine the prevalence of genes encoding virulence factors and antimicrobialresistance patterns of E. faecalis strains isolated from hospitalized patients in Shiraz, south west of Iran.
Materials and Methods: A 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 phenotypicand genotypic methods. Antimicrobial sensitivity tests and detection of virulence factors were performed using standardmethods.
Results: The 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.
Conclusion: Our 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.

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