Development and Application of Random DIG-Labelled Probes Based on Total Genomic Lactobacillus DNA

Summary Nine Lactobacillus-specific and non-isotopically (digoxygenin) labelled probes were developed on the basis of Lactobacillus total chromosomal DNA. Their specificity and applicability for Lactobacillus discrimination was proven by DNA–DNA hybridization to reference strains from the American Type Culture Collection (ATCC). The DNA probes were divided into three groups depending on the ability to hybridize to DNA from the same and/or from a group of related Lactobacillus strains. They were assayed in the species-specific detection of vaginal strains from the genus Lactobacillus. Six DNA probes were successfully applied for characterization of 21 newly isolated vaginal Lactobacilli. The species affliation of some isolates was determined. The developed DNA probes were evaluated for usage as a qualitative hybridization test for detection of Lactobacillus species in mixed cultures, obtained directly from vaginal samples without strain isolation.