The Correlation of Bacteriocin Production with Lactobacillus spp. Habitat and the presence of plnl , plnD , orf38 , and orf12 Genes

Abstract

The relation of bacteriocin production with the habitat of Lactobacillus spp. and the presence of target genes was investigated by isolating Lactobacillus spp. from stool samples of 163 diarrheal and 90 healthy children. Ninety-seven of 111 Lactobacillus spp. isolates exhibited antibacterial activity (against Salmonella typhi, Shigella spp., and Aeromonas hydrophilia pathogens) in primary screening, whereas only 18 of them demonstrated bacteriocin production effectiveness in secondary screening (showed an inhibition zone against the three indicators), with a higher frequency in healthy (21.6%) than patient isolates (16.3%). Molecular identification using the 16S rRNA gene revealed that only 15 of the 18 active isolates belonged to Lactobacillus spp. Their sequencing showed that two isolates showed 100% similarity with reference Lactiplantibacillus plantarum, four with reference Limosilactobacillus fermentum, and two with reference Lacticaseibacillus rhamnosus, all submitted to GenBank. The incidence of the plnD, plnI, orf12, and orf38 genes in eight isolates revealed a higher significant variation (P=0.0084**). Lactiplantibacillus plantarum (SMHA16) obtained from the patient habitat revealed the incidence of plnD, plnI, and orf38 genes and showed a higher average of bacteriocin production activity.