# Food Safety Threats: Molecular Surveillance, Antibiogram and Virulence Profiling of Biofilm Forming Enterococcus faecalis in Bangladeshi Restaurants

## TL;DR

This study identifies E. faecalis in Bangladeshi restaurants, highlighting its high antibiotic resistance and biofilm-forming ability, which poses a food safety threat.

## Contribution

The study provides novel insights into the prevalence, resistance patterns, virulence, and biofilm-forming capacity of E. faecalis in Bangladesh's restaurant environment.

## Key findings

- E. faecalis was found in 30% of restaurant samples, with higher contamination in crowded areas.
- Most isolates showed resistance to Penicillin, and 18.51% were multidrug-resistant.
- High prevalence of virulence genes and strong biofilm-forming isolates were detected.

## Abstract

Enterococcus faecalis (E. faecalis) is a notable public health bacterium since it can thrive on high‐touch surfaces in restaurants. This study aimed to isolate E. faecalis, conduct antibiogram to determine resistance patterns, explore the virulence profile and observe biofilm‐forming properties. A total of 90 samples were collected from BAU restaurants, including high‐touch surfaces and popular food items. Initial isolation employed culture‐based method followed by Gram's staining technique and biochemical tests. Molecular confirmation was achieved via polymerase chain reaction (PCR) targeting the ddl

E. faecalis
gene specific for E. faecalis. Antibiogram was performed using the Disc Diffusion Test for commonly used antibiotics. Genotypic detection of antibiotic resistance and virulence profile were also explored by PCR. Lastly, the Congo Red (CR) test was done to examine the biofilm‐forming isolates. Results indicated a prevalence (30%) of E. faecalis in both food and surface samples, with higher contamination rates in crowded areas. Antibiogram revealed high resistance to Penicillin (100%) and moderate to low resistance towards Tetracycline, Ciprofloxacin, Erythromycin and Chloramphenicol. Shockingly, bla
TEM gene was found in 81.48% of isolates, and 18.51% were detected as multidrug‐resistant. We found a very high prevalence of the virulence genes fsrA, fsrB, fsrC, gelE, pil, agg, and ace. Finally, the CR test revealed 33.33% and 44.44% isolates as strong and intermediate biofilm formers respectively. This study reinforces the significance of routine surveillance in combating the spread of antimicrobial resistance through the food chain and the prospective use of E. faecalis as a contamination marker.

Nowadays, researchers have found Enterococci in many food items. E. faecalis prevalence, antimicrobial resistance, pathogenicity, and biofilm‐forming capacity in food samples and food outlets in Bangladesh are little known. Microbiological conditions in food preparation sectors must be examined to ensure food safety and meet optimum criteria for high‐quality food production.