A 16S rRNA-targeted Probe for Detection of Lactobacilli and Enterococci in Faecal Samples by FluorescentIn SituHybridization

Abstract

A group-specific 16S rRNA-targeted oligonucleotide probe S-G-Lab-0158-a-A20 (Lab158) was designed and validated to quantify species of the phylogenetic group lactobacilli-enterococci. The Lab158 probe detects nearly all species of the genera Lactobacillus, Enterococcus, Pediococcus, Weissella, Vagococcus, Leuconostoc and Oenococcus. The specificity of the probe was tested on various species of the target group and on a range of common intestinal bacteria. For these experiments, procedures to permeabilize these groups of Gram-positive bacteria were optimized and fluorescent in situ hybridization (FISH) conditions for maximum specificity were determined. In addition, we showed that it is possible to distinguish the predominant gut-enterococci i.e. E. faecalis among the Lab158 probe-positive cells with the E. faecalis