Novos conhecimentos sobre a flora bacteriana vaginal

Abstract

The aim of this review is to update knowledge about the vaginal ecosystem, emphasizing non-cultivation methods for bacterial identification (gene amplification), the several Lactobacillus species that comprise normal vaginal flora and influence of host genetics on bacterial interactions with local innate and acquired immune defenses. A Medline (Pubmed) search from 1997-2009 for relevant articles was performed and the most informative articles were selected. The use of non-cultivable techniques (genes amplification techniques) have enabled a better knowledge about the composition of the vaginal ecosystem. In most women in the reproductive age there is a predominance of one or more species of Lactobacillus: L. crispatus, L. inners and L gasseri. However, in other apparently healthy women there is a deficiency or complete absence of Lactobacilli, which are substituted by other lactic acid-producing bacteria: Atobium, Megasphaera and/or Leptotrichia species. The infectivity and/or proliferation of pathogenic bacteria in the vagina is suppressed by lactic acid production, by products of endogenous bacteria and by activation of local innate and acquired immunity. Vaginal epithelial cells produce several compounds with antimicrobial activity. These cells have Toll-like receptors on their membrane that recognize molecular patterns associated with pathogens. Recognition leads to production of pro-inflammatory cytokines and stimulation of antigen-specific immunity. The production of IgG and IgA antibodies is also triggered in the endocervix and vagina in response to infection. Vaginal flora composition and the immune mechanisms constitute important defense mechanisms. Criteria of normal and abnormal flora have to be reviewed and genetic polymorphism can explain variations in flora composition. This new knowledge should be included in the clinical practice of gynecologists and obstetricians to improve patients care.

Qualitative and semiquantitative analysis of Lactobacillus species in the vaginas of healthy fertile and postmenopausal Chinese women

“…A study of multinational populations showed that L. crispatus was the most commonly predominant species in most populations (Pavlova et al, 2002). The association between geographical area and Lactobacillus species may be partly explained by genetic factors, because the genetic capacity to produce antimicrobial factors could affect vaginal bacteria including Lactobacillus species (Linhares et al, 2010). In addition, diet may influence the Lactobacillus species in the intestinal tract and the vagina (Lamont et al, 2011).…”

Identification of culturable vaginal Lactobacillus species among reproductive age women in Mysore, India

“…Research using culture-based methods among women living mostly in industrialized countries first suggested that a healthy vaginal flora was dominated by four species: L. fermentum; L. brevis; L. jensenii; and L. casei (Antonio et al, 1999). More recently, studies using molecular methods in similar populations have narrowed the predominant species seen in the vaginal mucosa of most reproductive age women to L. crispatus, L. iners and L. gasseri (Linhares et al, 2010).…”

Análise Dos Laudos De Papanicolaou Realizados Em Uma Unidade Básica De Saúde

“…Por outro lado, Lactobacillus sp é a espécie dominante na microbiota vaginal; estudos recentes apontam que, em algumas mulheres, microbiota vaginal não dominada por esse microrganismo pode ser normal e não necessariamente patogênica (15) .…”