Characterization of the genetic locus responsible for the production of ABP-118, a novel bacteriocin produced by the probiotic bacterium Lactobacillus salivarius subsp. salivarius UCC118 The GenBank accession number for the sequence reported in this paper is AF408405.

Abstract

ABP-118, a small heat-stable bacteriocin produced by Lactobacillus salivarius subsp. salivarius UCC118, a strain isolated from the ileal-caecal region of the human gastrointestinal tract, was purified to homogeneity. Using reverse genetics, a DNA fragment specifying part of ABP-118 was identified on a 10 769 bp chromosomal region. Analysis of this region revealed that ABP-118 was a Class IIb two-peptide bacteriocin composed of Abp118α, which exhibited the antimicrobial activity, and Abp118β, which enhanced the antimicrobial activity. The gene conferring strain UCC118 immunity to the action of ABP-118, abpIM, was identified downstream of the abp118β gene. Located further downstream of abp118β, several ORFs were identified whose deduced proteins resembled those of proteins involved in bacteriocin regulation and secretion. Heterologous expression of ABP-118 was achieved in Lactobacillus plantarum, Lactococcus lactis and Bacillus cereus. In addition, the abp118 locus encoded an inducing peptide, AbpIP, which was shown to play a role in the regulation of ABP-118 production. This novel bacteriocin is, to the authors' knowledge, the first to be isolated from a known human probiotic bacterium and to be characterized at the genetic level.

Multireplicon genome architecture of Lactobacillus salivarius

“…the cloned fragment in L. lactis and L. plantarum (12). However, the gene LSL 1924 that was truncated in the original cloned fragment encodes a potential bacteriocin transport protein.…”

“…salivarius UCC118 elaborates a two-component Class IIb bacteriocin, Abp118, that has been characterized in ref. 12. The cloned ''chromosomal'' EcoRI fragment containing the Abp118 locus that we previously sequenced was actually derived from pMP118, and the gene now designated LSL 1924 contains the EcoRI site at one end of the cloned fragment.…”

“…This strain has been extensively studied for its probiotic properties in human trials and animal models (8)(9)(10)(11). In addition, L. salivarius UCC118 produces a two-component bacteriocin Abp118 (12), which has broad spectrum activity against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (8).…”

Bacteriocin production as a mechanism for the antiinfective activity of Lactobacillus salivarius UCC118

“…Although the most obvious explanation for the observed protection is the direct killing of Listeria by UCC118, the bacteriocin could also be involved in mediating transient colonization or could be acting as an antigen or signaling molecule to the murine immune system. To eliminate these other possibilities, we created a strain of L. monocytogenes EGDe immune to Abp118 by heterologous expression of the associated immunity determinant, abpIM, a strategy previously shown to confer immunity on heterologous strains (16). The Abp118-immune phenotype was confirmed by using an agar-diffusion assay (Fig.…”

Identification of lactic acid bacteria with bio-preservative potential isolated from contaminated avian blood obtained at the slaughterhouse

“…Some clones of L. salivarius are screened for the presence of potential probiotic properties (Martín et al 2006, Hermans et al 2011. Bacteriocin production by mucosal-associated L. salivarius strains has been described previously (Ocaña et al 1999, Flynn et al 2002. L. salivarius is considered as a potential probiotic bacterium and can be found in many commercial probiotic products.…”