''Limosilactobacillus vaginalis'' is a

lactic acid bacterium Lactobacillales are an order of gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod-shaped (bacilli) or spherical (cocci) bacteria that share common metabolic and physiological characteristics. These bact ...

that is a normal, but infrequent part of the

vaginal microbiome Vaginal flora, vaginal microbiota or vaginal microbiome are the microorganisms that colonize the vagina. They were discovered by the German gynecologist Albert Döderlein in 1892 and are part of the overall human flora. The amount and type of ...

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'' 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 countries ...

'', facilitating sustainment of infection. The isolates initially designated ''

Limosilactobacillus fermentum ''Limosilactobacillus fermentum'' is a Gram-positive species in the heterofermentative genus ''Limosilactobacillus.'' It is associated with active dental caries lesions. It is also commonly found in fermenting animal and plant material includin ...

'' were compared to the reference strains of a number of heterofermentative species using the

DNA–DNA hybridization In genomics, DNA–DNA hybridization is a molecular biology technique that measures the degree of genetic similarity between pools of DNA sequences. It is usually used to determine the genetic distance between two organisms and has been used ex ...

method, and have shown a maximal DNA homology of 35% with ''

Limosilactobacillus reuteri ''Limosilactobacillus reuteri'' is a lactic acid bacterium found in a variety of natural environments, including the gastrointestinal tract of humans and other animals. It does not appear to be pathogenic and may have health effects. Discove ...

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

Description

''Limosilactobacillus vaginalis'' is a Gram-positive, 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 natu ...

as the metabolic end-product of carbohydrate fermentation. Similarly to most other vaginal ''Lactobacillus'' species, ''L. vaginalis'' does not directly metabolize

glycogen Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. The polysaccharide structure represents the main storage form of glucose in the body. Glycogen functions as one o ...

, 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 vaccine Lactobacillus vaccines are used in the therapy and prophylaxis of non-specific bacterial vaginitis and trichomoniasis. The vaccines consist of specific inactivated strains of '' Lactobacilli'', called "aberrant" strains in the relevant literatur ...

s, a therapy method of chronic vaginal infections that respond poorly to antibiotic treatment, available in German-speaking 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