High Level of Biofilm Formation and Virulence Factors in Enterococci Species Isolated From Clinical and Normal Flora Samples Publisher



Esmaeili Z¹ ; Sadeghi J² ; Razavi S¹ ; Oshaghi M³ ; Sayyahfar S⁴ ; Rahbar M⁵ ; Talebi M¹ Show Affiliations
Source: Infectious Diseases in Clinical Practice Published:2018

Abstract

Enterococci are gram-positive bacteria, and they are members of normal intestinal microflora of humans as well as animals. However, recently, they evolved from common avirulent commensal bacteria into a multidrug-resistant health care-associated pathogen. In this study, 147 isolates were collected from clinical and healthy people. The presence of 7 genes including ace, ebp, efaA, ebrB, ecbA, fsrB, and sgrA were investigated by polymerase chain reaction method. Finally, for detection of biofilm formation, Congo red agar and microliter plate methods were used. Our results showed that ace (94.6%), efaA (94.6%), and ebp (92.5%) were present almost in all of the isolates, followed by fsrB (53.7%), sgrA (36%), ecbA (33.3%), and ebrB (13.6%). By Congo red method, 38% of our isolates formed black colonies on Congo red agar (biofilm producer), whereas others (62%) had red colonies (nonbiofilm producer). Finally, by using microliter plate method, 23.8% of isolates were able to form biofilm. These results indicate that normal flora isolates can constitute as a reservoir for virulent Enterococcus isolates. © 2017 Wolters Kluwer Health, Inc. All rights reserved.