Urban Forsum

Vaginal Lactobacillus Flora of Healthy Swedish Women

ABSTRACT Species of the Lactobacillus acidophilus complex are generally considered to constitute most of the vaginal Lactobacillus flora, but the flora varies between studies. However, this may be due to difficulties in identifying the closely related species within the L. acidophilus complex by using traditional methods and to variations in the vaginal status of the participants. Two hundred two isolates from the vaginal fluids of 23 Swedish women without bacterial vaginosis, as defined by the criteria of Nugent et al. (R. P. Nugent, M. A. Krohn, and S. L. Hillier, J. Clin. Microbiol. 29:297-301, 1991), were typed by randomly amplified polymorphic DNA (RAPD) analysis and identified to the species level by temporal temperature gradient gel electrophoresis, multiplex PCR, and 16S ribosomal DNA sequencing. The vaginal flora of most participants was dominated by a single RAPD type, but five of them harbored two RAPD types representing two different species or strains. The most frequently occurring species were Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii. L. iners has not previously been reported as one of the predominant Lactobacillus species in the vagina.

Incidence of pelvic inflammatory disease after first-trimester legal abortion in women with bacterial vaginosis after treatment with metronidazole: A double-blind, randomized study

OBJECTIVE The purpose of this study was to evaluate the effect of metronidazole treatment on the incidence of postoperative pelvic inflammatory disease after first-trimester abortion in women with bacterial vaginosis. STUDY DESIGN A double-blind, randomized, multicenter study was conducted on 231 women undergoing first-trimester legal abortion and fulfilling the criteria for bacterial vaginosis. The women were randomized to either metronidazole 500 mg three times daily for 10 days or placebo. Treatment was started at the outpatient visit the week before the operation. RESULTS Among the 174 women who could be evaluated, pelvic inflammatory disease developed in 14 after the abortion. In the treatment group there were three infections (3.8%) compared with 11 (12.2%) in the placebo group (p less than 0.05). CONCLUSION These data suggest that patients with bacterial vaginosis should be treated in conjunction with first-trimester abortion because treatment with metronidazole reduces the postoperative infection rate more than three times.

Bacterial vaginosis - a microbiological and immunological enigma

The development of bacterial vaginosis (BV) among women of childbearing age and the resulting quantitative and qualitative shift from normally occurring lactobacilli in the vagina to a mixture of mainly anaerobic bacteria is a microbiological and immunological enigma that so far has precluded the formulation of a unifying generally accepted theory on the aetiology and clinical course of BV. This critical review highlights some of the more important aspects of BV research that could help in formulating new basic ideas respecting the biology of BV, not least the importance of the interleukin mediators of local inflammatory responses and the bacterial shift from the normally occurring lactobacilli species: L. crispatus, L. gasseri, L. jensenii, and L. iners to a mixed flora dominated by anaerobic bacteria.

Bacterial vaginosis - Transmission, role in genital tract infection and pregnancy outcome: An enigma

Whether bacterial vaginosis (BV) is acquired from an endogenous or an exogenous source is subject to controversy. Despite findings of an association between sexual behaviour and BV, some data indicate that BV is not a sexually transmitted infection in the traditional sense, while other data indicate that BV is an exogenous infection. A third aspect of BV is its tendency to go unnoticed by affected women. All of this will have a strong impact on how physicians view the risks of asymptomatic BV. This review focuses on whether or not BV should be regarded as a sexually transmitted infection (STI), its role in postoperative infections and pelvic inflammatory disease (PID), and on whether or not treatment of BV during pregnancy to reduce preterm delivery should be recommended. The reviewed studies do not lend unequivocal support to an endogenous or exogenous transmission of the bacteria present in BV. For women undergoing gynaecological surgery such as therapeutic abortion, the relative risk of postoperative infection is clearly elevated (approx. 2.3–2.8). A weaker association exists between BV and pelvic inflammatory disease. Data on treatment of BV as a way of reducing preterm delivery are inconclusive and do not support recommendations for general treatment of BV during pregnancy. The discrepant associations between BV and preterm birth found in recent studies may be explained by variations in immunological response to BV. Genetic polymorphism in the cytokine response – both regarding the TNF alleles and in interleukin production – could make women more or less susceptible to BV, causing different risks of preterm birth. Thus, studies on the vaginal inflammatory response to microbial colonization should be given priority.

Bacterial vaginosis--a disturbed bacterial flora and treatment enigma.

The syndrome bacterial vaginosis (BV) is characterized by a disturbed vaginal microflora in which the normally occurring lactobacilli yield quantitatively to an overgrowth of mainly anaerobic bacteria. As BV is a possible cause of obstetrics complications and gynaecological disease – as well as a nuisance to the affected women – there is a strong impetus to find a cure. In BV treatment studies, the diagnosis criteria for diagnosis of BV vary considerably and different methods are used for cure evaluation. The design of study protocols varies and there is no consensus respecting a suitable time for follow‐up visits. For the purpose of this review, available data were recalculated for 4‐week post treatment cure rates. For oral metronidazole the 4‐week cure rate was found not to exceed 60–70%. Treatment regimens with topical clindamycin or topical metronidazole have the same cure rates. It can thus be said that no sound scientific basis exists for recommending any particular treatment. There is no evidence of beneficial effects on BV engendered by partner treatment, or by addition of probiotics or buffered gel. Long‐term follow‐up (longer than 4 weeks) shows a relapse rate of 70%. With a primary cure rate of 60–70%, and a similar relapse rate documented in the reviewed literature, clinicians simply do not have adequate data for determining treatment or designing clinical studies. This is unfortunate since – apart from the obvious patient benefits – clinical studies can often serve as a guide for more basic studies in the quest for underlying disease mechanisms. In the case of BV there is still a need for continued basic studies on the vaginal flora, local immunity to the flora and host‐parasite interactions as an aid when designing informative clinical studies.

Identification of randomly selected colonies of lactobacilli from normal vaginal fluid by pyrosequencing of the 16S rDNA variable V1 and V3 regions

The present study aimed to characterize lactobacilli in vaginal fluid from 23 adult healthy women by using high‐throughput DNA sequencing for identification of a large number of randomly selected colonies appearing on Rogosa and blood agar. The typing method was based on broad‐range PCR of 16S rRNA gene variable regions V1 and V3, pyrosequencing, and classification of the fragments by alignment with NCBI‐catalogued sequences and type strain sequences. Four major groups of sequences were found among the 402 isolates clearly corresponding to Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners and Lactobacillus jensenii when compared to the sequences obtained for type strains. Our results indicate that pyrosequencing of 16S rRNA gene fragments as used here is a fast and reliable method well suited for identification to the species level, even within the Lactobacillus acidophilus complex.

Late miscarriage and preterm birth after treatment with clindamycin: a randomised consent design study according to Zelen

Objective  To screen for bacterial vaginosis (BV) and to investigate the effect of treatment with vaginal clindamycin in order to observe the effect on late miscarriage and delivery prior to 37 completed weeks (primary outcome).

Analysis of bacterial vaginosis-related amines in vaginal fluid by gas chromatography and mass spectrometry

ABSTRACT The presence of various amines in vaginal fluid from women with malodorous vaginal discharge has been reported before. The investigations have used several techniques to identify the amines. However, an optimized quantification, together with a sensitive analysis method in connection with a diagnostic procedure for vaginal discharge, including the syndrome of bacterial vaginosis, as defined by the accepted “gold standard,” has not been done before. We now report a sensitive gas chromatographic and mass spectrometric method for identifying the amines isobutylamine, phenethylamine, putrescine, cadaverine, and tyramine in vaginal fluid. We used weighted samples of vaginal fluid to obtain a correct quantification. In addition, a proper diagnosis was obtained using Gram-stained smears of the vaginal fluid that were Nugent scored according to the method of Nugent et al. (R. P. Nugent et al., J. Clin. Microbiol., 29:297–301, 1991). We found that putrescine, cadaverine, and tyramine occurred in high concentrations in vaginal fluid from 24 women with Nugent scores between 7 and 10. These amines either were not found or were found only in very low concentrations in vaginal fluid from women with Nugent scores of 0 to 3. There is a strong correlation between bacterial vaginosis and the presence of putrescine, cadaverine, and tyramine in high concentrations in vaginal fluid.

An international study of the interobserver variation between interpretations of vaginal smear criteria of bacterial vaginosis

An international workshop on vaginal smear‐based diagnosis of bacterial vaginosis was organized where 13 investigators scoring 258 slides with smears from vaginal fluid. Interobserver reproducibility of interpretations of Nugent scores, Hay/Ison scores and wet smear scores for the diagnosis of bacterial vaginosis was shown to be high. Detailed analysis of individual scoring results however indicated that basic standards of quality control to ensure robust individual readings of slides must be adhered to.

Bacterial vaginosis in women attending STD clinic: diagnostic criteria and prevalence of Mobiluncus spp.

The diagnostic criteria of bacterial vaginosis (BV) and the prevalence of Mobiluncus spp as detected by monoclonal antibodies were investigated in all new women patients attending the sexually transmitted disease (STD) clinic in Uppsala during a four month period. Of 455 patients, 164 fulfilled the generally accepted criteria for BV, but in 57 of them simultaneous infection with a recognised pathogen was diagnosed. BV was thus the only clinical diagnosis in 107 (24%) of the women. The sniff test and clue cells in the wet smear were the two criteria most relevant for the diagnosis of BV. The sniff test was positive in 95% (156) of the 164 patients with BV and negative in all other cases. The corresponding figure for the clue cells was 98% (160 of 164), but clue cells were also detected in 19 patients without BV. Though 99% (162) of women with BV had a vaginal pH of more than 4.5, so did 83 women without BV. Only 59% (96) of women fulfilling the criteria of BV had a characteristic discharge. Mobiluncus spp were present in 20% (90) of the 455 women and in 50% (53) of the 107 women with BV only. Of the 90 Mobiluncus spp isolates, M curtisii comprised 44% (40), M mulieris 34% (31), and both strains together 21% (19). Mobiluncus spp were detected with monoclonal antibodies in 35 women who had no motile curved rods on wet smear microscopy. Furthermore, Mobiluncus spp were often detected in women infected with recognised pathogens, as well as in a few women without signs of genital infection.