Ornamental birds: hidden carriers of potentially virulent and antimicrobial-resistant Enterococcus faecalis in Bangladesh.

Enterococcus faecalis, a nosocomial pathogen adept at acquiring virulence and resistance genes, may be silently carried by ornamental birds in proximity to humans, posing a health risk. Two hundred ornamental bird samples (feces = 120, cage feed = 60, and store feed = 20) were collected and processed to detect E. faecalis isolates and determine their biofilm-forming capabilities, virulence, and antimicrobial resistance profiles. In PCR, 44 (22%) samples were found positive for E. faecalis, with the highest occurrence in cage feed samples (18/60), followed by feces (25/120) and stored feed (1/20) samples. Among them, nine E. faecalis isolates were determined as strong, 23 were intermediate, and 12 were non-biofilm formers in the Congo Red Agar test. Most isolates carried the following tested virulence genes: gelE (95.5%), fsrC (93.2%), ace (90.9%), sprE (88.6%), fsrB (88.64%), fsrA (81.8%), pil (79.5%), agg (72.7%), and cyl (31.8%). Thirteen E. faecalis isolates (29.54%) were phenotypically multidrug-resistant (MDR), including resistance to the reserve group (fosfomycin, 4.5% and linezolid, 11.4%), watch group (vancomycin, 2.3%; ciprofloxacin, 4.5%; and rifampicin, 29.5%), and active group (ampicillin, 100%, erythromycin, 29.5%, and tetracycline, 27.3%). Moreover, all the ampicillin-resistant E. faecalis isolates harbored blaTEM, and 81.8% of tetracycline-resistant isolates contained tetA resistance genes. The multiple antibiotic resistance indices of MDR isolates ranged from 0.27 to 0.64. Our findings indicate that ornamental birds and their associated feed can harbor E. faecalis with virulence and resistance genes, highlighting the urgent need for strict monitoring, responsible antibiotic use, and improved hygiene to minimize antimicrobial resistance.IMPORTANCEOrnamental birds are increasingly popular as pets and companions; however, their role in the spread of antibiotic-resistant and virulent bacteria remains poorly understood. This study reveals that Enterococcus faecalis, a bacterium commonly associated with hospital-acquired infections, can be found in ornamental birds and their feed in Bangladesh. Many of the detected strains carried genes that make them more harmful to humans and resistant to multiple antibiotics, including those considered last-resort treatments. These findings are significant because ornamental birds often live in close contact with humans, creating potential pathways for bacterial transmission. The results underscore the need for improved hygiene, responsible antibiotic use in animal husbandry, and regular monitoring of antimicrobial resistance in non-traditional animal species. This research provides crucial insights for public health, particularly in regions where ornamental bird keeping is prevalent but often lacks regulation for microbial safety.