Occurrence, Safety Assessment and Enterocinogenic Potential of Enterococcus Species Recovered from Retail Kilishi, a Traditional Ready-to-Eat Meat Product in Nigeria
DOI:
https://doi.org/10.33003/fjs-2026-1018-5638Keywords:
Enterococcus faecium, Kilishi, Enterocin, Antimicrobial Resistance, Virulence Determinants, Listeria monocytogenesAbstract
This study investigated the occurrence, safety characteristics and enterocinogenic potential of Enterococcus faecium isolated from retail Kilishi, a traditional Nigerian ready-to-eat dried meat product. A total of 201 retail Kilishi samples were homogenized in buffered peptone water, cultured on De Man, Rogosa, and Sharpe (MRS) agar, and phenotypically characterized isolates via Gram staining, catalase testing, and bile-esculin hydrolysis. Species specific PCR assays targeting E. faecium confirmed 54 distinct enterococci isolates. These confirmed isolates were systematically screened for phenotypic virulence traits (haemolysin, gelatinase, and aggregation substance) alongside critical virulence genes (gelE, esp and asa1) and antimicrobial resistance genes (ermB, vanA and vanB) via multiplex PCR. Antibiotic susceptibility profiles were found using the Kirby-Bauer disc diffusion method against CLSI guidelines. Isolates exhibiting ideal safety characteristics were subsequently screened for production of enterocin-like substances against Listeria monocytogenes. E. faecium predominated, accounting for 72.2% of the confirmed isolates, while E. faecalis constituted 27.8%. Most isolates exhibited low virulence potential, and four E. faecium isolates lacked the tested virulence genes and major antimicrobial resistance genes. Although resistance to some clinically important antibiotics was observed among a proportion of isolates, E. faecium KEC79 remained susceptible to all antibiotics evaluated and demonstrated the highest enterocin-like substance production (5120 AU mL⁻¹) together with the strongest inhibitory activity against Listeria monocytogenes. Retail kilishi therefore, harbours safe enterocin-producing E. faecium strains. Following comprehensive safety assessment, KEC79 in particular is found to be a promising candidate for biopreservation applications.
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Copyright (c) 2026 Adamu Idris, Abdulkadir Magaji Magashi, Usman Aliyu Dutsinma
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