Kraiyot Saelim, Sireewan Kaewsuwan, Akio Tani and Suppasil Maneerat

pp. 299 - 307

Abstract

Enterocin CE5-1 produced by Enterococcus faecium CE5-1 isolated from the chicken gastrointestinal tract was active
in the wide range of pH 2-10 and temperature 30-100°C and sensitive to proteolytic enzymes and -amylase. It remained active
after storage at -20°C for 2 months. Moreover, enterocin CE5-1 showed antibacterial activity against lactobacilli, bacilli,
listeria, staphylococci and enterococci, especially antibiotic-resistant enterococci. In vitro study of enterocin CE5-1 decreased
the population of Ent. faecalis VanB from 6.03 to 4.03 log CFU/ml. The lethal mode of action of enterocin CE5-1 appeared
to be pore and filament formation in the cell wall. PCR sequencing analysis revealed the presence of two open reading frames
(ORFs), containing enterocin CE5-1 (entCE5-1) and enterocin immunity (entI) gene. Therefore, enterocin CE5-1 from Ent.
faecium CE5-1 could possibly be used as an antimicrobial agent to control foodborne pathogen, spoilage bacteria and antibiotic-resistant enterococci in foods, feeds and the environments.

Keywords

• enterocin
• Enterococcus faecium
• chicken
• antibiotic-resistant enterococci