Lactobacillus crispatus

It is a species in the phylum Firmicutes, in the class Bacilli, in the order Lactobacillales, in the family Lactobacillaceae and the genus Lactobaccillus.[6] It is one of 122 other species identified within the genus.

Even within L. crispatus there is substantial genetic variation: strains of L. crispatus have genome sizes ranging from 1.83 to 2.7 Mb, and encode 1,839 (EM-LC1) to 2,688 (FB077-07) proteins.[7]

The genome of Lactobacillus crispatus strain ST1, which colonizes chicken, consists of about 2,043,161 nucleotides[6] and encodes 2,024 proteins,[6] 76 RNA genes[6] and has a circular chromosomal shape.[6]

The strain of Lactobacillus crispastus was originally isolated from a pouch in a chicken gullet[6] and is considered to be one of the strongest H₂O₂-producing lactobacilli. Like many other Lactobacillus species, it can be severely altered by changes to the immune system, hormone levels and from the use of antimicrobials. Lactobacillus crispatus is a normal inhabitant of the lower reproductive tract in healthy women.[8][9]

CTV-05 gelatin suppository capsules[4] are inserted into the vagina as a probiotic that can help maintain healthy flora. Studies have shown that L. crispastus CTV-05 effectively colonized the vagina and helped prevent and treat recurrent bacterial vaginosis and other genital infections. Scientists have stated that evidence from clinical trials proves that these probiotics will safely and effectively treat bacterial vaginosis if used alone or alongside an antibiotic treatment if an infection had already arisen.[3]

Condom use has showed increased colonization of Lactobacillus crispatus in the vagina because it protects against both bacterial vaginosis (BV) and human immunodeficiency virus (HIV).[10]

The lactic acid bacterium Lactobacillus crispatus is a natural resident of the vagina. It produces lactic acid, contributing to an acid vaginal environment.

Bacterial vaginosis The lactic acid bacterium Lactobacillus crispatus is a natural resident of the vagina. It produces lactic acid, contributing to an acid vaginal environment. This acidity is important, as pathogenic bacteria generally do not like a low pH. However, the vagina does not always have a low pH. An elevated pH is sometimes accompanied by bacterial vaginosis, indicating that the vaginal microbiome is out of balance. A large diversity of harmful bacteria suppresses the Lactobacillus, adversely affecting the protective mucous layer of the vagina. This situation can cause irritation and an unpleasant smell. Bacterial vaginosis also heightens the risk of acquiring sexually transmitted diseases (STDs) and increases the chances of premature births.

A different layer An important question is how exactly bacterial vaginosis develops. Is Lactobacillus crispatus suppressed by other types of bacteria, or do changing conditions in the vagina disrupt the dominance of this bacteria and prevent it from keeping the pH low? Perhaps the Lactobacillus species itself changes, inhibiting its capacity to dominate. Micropia professor Remco Kort investigated this process in his research group at Vrije Universiteit Amsterdam by comparing dozens of Lactobacillus crispatus strains that came from both healthy and disbalanced vaginas. His study, which has been published in the Microbiome journal, shows that L. crispatus strains from a healthy vagina have more trouble creating a ‘different layer’ – the outer membrane.

A new probiotic? The external layer of a bacterial cell, the outer membrane, is a hard cell wall with polysaccharide components. By modifying these sugars, the cell may no longer be detectable by the human immune system. Another effect of this ‘different layer’ may be that the bacterial cell can no longer be attacked by viruses that kill the bacteria (known as bacteriophages). This theory may explain why only L. crispatus strains with this property can still be present in the case of bacterial vaginosis (with an enhanced activity of the immune system or the presence of certain bacteriophages). These interesting hypotheses all have yet to be investigated. Down the line, this discovery could contribute to the selection of probiotic bacteria with this special property that can combat the common condition of bacterial vaginosis. In any event, many commonly used methods turn out to be ineffective, including antibiotics or vaginal douches with lactic acid.

• Type strain of Lactobacillus crispatus at BacDive - the Bacterial Diversity Metadatabase
• https://www.micropia.nl/en/discover/news/2019/5/27/A-healthy-vagina-with-Lactobacillus-crispatus-bacteria/