''Limosilactobacillus vaginalis'' is a lactic acid bacterium that is a normal, but infrequent part of the vaginal microbiome.

Discovery and taxonomy

The species was identified by Embley and his coworkers in the course of a vaccine development against

trichomoniasis Trichomoniasis (trich) is an infectious disease caused by the parasite ''Trichomonas vaginalis''. About 70% of affected people do not have symptoms when infected. When symptoms occur, they typically begin 5 to 28 days after exposure. Symptoms ca ...

. The vaginal secretions of women suffering from trichomoniasis were examined for the presence of certain proposed ''

Lactobacillus ''Lactobacillus'' is a genus of Gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-spore-forming bacteria. Until 2020, the genus ''Lactobacillus'' comprised over 260 phylogenetically, ecologically, and metabolically div ...

'' strains exhibiting mutualistic behavior with ''

Trichomonas vaginalis ''Trichomonas vaginalis'' is an anaerobic, flagellated protozoan parasite and the causative agent of a sexually transmitted disease called trichomoniasis. It is the most common pathogenic protozoan that infects humans in industrialized countri ...

'', facilitating sustainment of infection. The isolates initially designated '' Limosilactobacillus fermentum'' were compared to the reference strains of a number of heterofermentative species using the DNA–DNA hybridization method, and have shown a maximal DNA homology of 35% with '' Limosilactobacillus reuteri'', far below the standard threshold of 70% recommended for species delineation. The new species ''L. vaginalis'' with type strain NCTC 12197 was proposed, and the description of its carbohydrate fermentation patterns as well as cellular fatty acid composition were provided. Further taxonomic investigations relying on

16S rRNA 16S rRNA may refer to: * 16S ribosomal RNA 16 S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome ( SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The g ...

gene

sequence analysis In bioinformatics, sequence analysis is the process of subjecting a DNA, RNA or peptide sequence to any of a wide range of analytical methods to understand its features, function, structure, or evolution. Methodologies used include sequence alig ...

placed ''L. vaginalis'' in the ''L. reuteri'' phylogenetic group along with 14 other species, including ''L. fermentum''.

Description

''Limosilactobacillus vaginalis'' is a

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bact ...

, facultatively anaerobic, catalase negative bacterium. These obligate heterofermentative lactobacilli produce both and isomers of

lactic acid Lactic acid is an organic acid. It has a molecular formula . It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as nat ...

as the metabolic end-product of carbohydrate fermentation. Similarly to most other vaginal ''Lactobacillus'' species, ''L. vaginalis'' does not directly metabolize glycogen, but rather its depolymerization products. The bacterium occurs in less than 1% of healthy women.

Use

Specific strains of ''L. vaginalis'' characterized by an insufficient protective efficacy against vaginal pathogens are used in lactobacillus vaccines, a therapy method of chronic vaginal infections that respond poorly to antibiotic treatment, available in

German-speaking Europe This article details the geographical distribution of speakers of the German language, regardless of the legislative status within the countries where it is spoken. In addition to the German-speaking area (german: Deutscher Sprachraum) in Europe ...

. ''L. vaginalis'' is not used as a probiotic, nor as a starter culture in the food industry. It is occasionally isolated from fermented dairy products, where it represents an unwanted contaminant.

References

{{Taxonbar, from=Q3825350 Lactobacillaceae