Summary auto-generated
This study describes the identification and characterization of a novel lactic acid bacterium isolated from the human vagina. Researchers analyzed 21 strains from vaginal fluid samples using protein profiling, DNA fingerprinting (RAPD-PCR), and 16S rRNA gene sequencing. Most strains were identified as known Lactobacillus species including L. johnsonii, L. acidophilus, L. gallinarum, and L. crispatus. However, four strains (TV 1010, TG 1013, TV 1018T, and TV 1045) formed a distinct cluster that differed phenotypically and genetically from all known species. Phylogenetic analysis based on 16S rRNA sequences revealed these strains belonged to rRNA group I Lactobacillus, with approximately 5% sequence divergence from related species. The researchers propose these strains represent a new species, Lactobacillus fornicalis, characterized as obligately homofermentative rods that produce lactic acid from glucose and display specific carbohydrate fermentation patterns distinguishing them from related vaginal lactobacilli. The type strain TV 1018T (also designated DSM 13171T and ATCC 700934T) has a G+C content of 37 mol% and was the source for phylogenetic characterization.
Key findings
- Four strains isolated from human vaginal fluid represent a novel Lactobacillus species, designated L. fornicalis sp. nov., based on polyphasic taxonomic analysis including protein profiling, RAPD-PCR, and 16S rRNA gene sequencing
- L. fornicalis is phylogenetically classified within rRNA group I Lactobacillus with approximately 5% sequence divergence from other members including L. delbrueckii, L. acidophilus, L. crispatus, and L. jensenii
- L. fornicalis is distinguishable from related vaginal lactobacilli by specific carbohydrate fermentation patterns, including fermentation of mannitol, sorbitol, and ribose, but not lactose or melibiose
- RAPD-PCR analysis proved more reliable than protein profiling for differentiating closely related species within the L. gasseri and L. jensenii complex
This summary was generated automatically from the article PDF and is not part of the original publication. Refer to the PDF for the authoritative text.
Abstract
Twelve strains isolated from the posterior fornix fluid of the human vagina were identified as Lactobacillus johnsonii, Lactobacillus acidophilus, Lactobacillus gallinarum and Lactobacillus crispatus based on numerical analyses of total soluble cell protein profiles and randomly amplified polymorphic DNA (RAPD)-PCR banding patterns. Five strains grouped with the type strains of Lactobacillus gasseri (DSM 20077(T)) and Lactobacillus jensenii (DSM 20557(T)) at r >= 0.83 in one protein profile cluster, well separated from the other species included in this study. However, numerical analysis of the RAPD-PCR banding patterns of representative strains selected from the L. gasseri--L. jensenii protein cluster clearly indicated that they belong to two different species. Four strains (TV 1010, TG 1013, TV 1018(T) and TV 1045) grouped into another well separated protein profile cluster at r >= 0.87. Strains selected from this cluster displayed very similar RAPD-PCR banding patterns and clustered at R(2) >= 0.78, separate from the other strains examined. Sequencing of the 16S rRNA of two representative strains, TV 1018(T) and TG 1013, of this group indicated that it represents a new member of rRNA group I Lactobacillus, which includes Lactobacillus delbrueckii, the type of the genus, and close relatives Lactobacillus acetotolerans, Lactobacillus kefiranofaciens, Lactobacillus iners, L. jensenii, L. crispatus, L. acidophilus, Lactobacillus helveticus, Lactobacillus amylovorus, Lactobacillus hamsteri, L. johnsonii, L. gasseri and Lactobacillus amylolyticus. The name Lactobacillus fornicalis sp. nov. is proposed for strains TV 1010 (DSM 13172), TG 1013, TV 1018(T) and TV 1045, with strain TV 1018(T) (=DSM 13171(T)=ATCC 700934(T)) as the type.