Biofilm Formation, Virulence Traits, and Antimicrobial Resistance Profiles of Enterococcus faecalis in Layer Parent Stock in Bangladesh

Sep 30, 2026

Opportunistic infection threats from Enterococcus faecalis are rising in both human and veterinary contexts due to virulence, biofilm formation, and resistance to multiple antibiotics. This study assessed the occurrence of E. faecalis in Bangladesh layer parent stock, evaluated virulence genes, quantified biofilm production, and determined antimicrobial resistance profiles. Cloacal swabs and liver tissues from healthy and dead birds were analyzed using PCR, Congo red agar, and disc diffusion, revealing high detection, frequent biofilm producers, widespread virulence genes, and substantial multidrug resistance.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages11

Reading Time28 min

AccessFree to download

Introduction

Methods

Results

Occurrence and biofilm formation

Virulence genes distribution

Antimicrobial resistance and multidrug resistance

Conclusion

Wiley International Journal of Microbiology Volume 2026, Article ID 4082070, 11 pages [https://doi.org/10.1155/ijm/4082070](https://doi.org/10.1155/ijm/4082070) Research Article Biofilm Formation, Virulence Traits, and Antimicrobial Resistance Profiles of Enterococcus faecalis in Layer Parent Stock in Bangladesh Nirab Chakroborty , 1 Naeem Ahammed Ibrahim Fahim , 1 Md Saiful Islam , 1,2 Md. Liton Rana , 1,3,4 Farhana Binte Ferdous , 1 Md. Nowshad Atiq , 1 Md. Abdus Sobur , 1 MahfuzAhammed , 1 Sukumar Saha , 1 and Md. Tanvir Rahman 1 1Department of Microbiology and Hygiene, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh 2Department of Animal Science, University of California–Davis, Davis, California, USA 3 University of Chinese Academy of Sciences, Beijing, China 4National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Research Center for EcoEnvironmental Sciences, Chinese Academy of Sciences, Beijing, China Correspondence should be addressed to Md. Tanvir Rahman; [tanvirahman@bau.edu.bd](tanvirahman@bau.edu.bd) Received 10 September 2025; Revised 15 November 2025; Accepted 4 December 2025 Academic Editor: Todd R. Callaway Copyright © 2026 Nirab Chakroborty et al. International Journal of Microbiology published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Enterococcus faecalis is an opportunistic pathogen of growing concern in both human and veterinary medicine due to its virulence traits, bioﬁlm-forming ability, and resistance to multiple antibiotics. This study was aimed at investigating the occurrence, virulence factors, bioﬁlm formation, and antimicrobial resistance (AMR) of E. faecalis in layer parent stock birds in Bangladesh. Samples (n =80) were collected from healthy (cloacal swabs, n =60) and dead (liver tissues, n =20) birds. PCR was used for E. faecalis conﬁrmation and detection of virulence genes. Bioﬁlm formation was assessed using Congo red agar, and antimicrobial susceptibility was determined by disc diﬀusion. E. faecalis was detected in 76.3% of samples, with higher detection in live birds (80%) than in dead birds (65%) . Bioﬁlm production was found in 75.4% of isolates, with a higher rate in dead birds (84.6%) than live birds (72.9%) . Strong and intermediate bioﬁlm-forming capacities were more prevalent in isolates from dead birds. All eight tested virulence genes were commonly distributed, particularly pil (95.8%), ace (93.4%), and agg (91.8%), with no signiﬁcant diﬀerences between live and dead bird isolates. High resistance was observed against ampicillin (93.4%), ciproﬂoxacin (80.3%), erythromycin (78.7%), and tetracycline (72.1%) . Multidrug resistance (MDR) was found in 79.2% of isolates from live birds and 69.2% from dead birds, with multiple antibiotic resistance indices ranging from 0.27 to 0.72. To the best of our knowledge, this is the ﬁrst study in Bangladesh determining MDR and virulence determinants in E. faecalis isolates from layer parent stock. These ﬁndings highlight E. faecalis as a prevalent, multidrug-resistant, and virulent bacterium in breeder ﬂocks, emphasizing the need for routine AMR monitoring in parent stock farms. Keywords: antimicrobial resistance; Bangladesh; bioﬁlm formation; Enterococcus faecalis; layer parent stock; multidrug resistance; virulence genes 1. Introduction Enterococcus faecalis is a Gram-positive, facultative anaerobic bacterium that constitutes a natural component of the gastrointestinal ﬂora of humans and animals [1] . Although typically commensal, E. faecalis can become opportunistic, causing a broad spectrum of infections, including urinary tract infections, endocarditis, intra-abdominal infections, and bacteremia, particularly in healthcare settings [2, 3] . I

FAQs

What is the study's main objective regarding Enterococcus faecalis?

To investigate the occurrence of E. faecalis in layer parent stock birds in Bangladesh, and to characterize its virulence factors, biofilm formation, and antimicrobial resistance profiles.

How were E. faecalis and virulence genes detected?

E. faecalis was confirmed using PCR, and virulence genes were detected via PCR as well.

Which antimicrobial resistance and multidrug resistance patterns were observed?

High resistance was reported against ampicillin, ciprofloxacin, erythromycin, and tetracycline, and multidrug resistance was common, with MDR rates differing between live and dead birds.

Sep 30, 2026

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