Black-pigmented gram-negative anaerobes in genito-urinary tract and pelvic infections

The Role of Prevotella Species in Female Genital Tract Infections

Female genital tract infections (FGTIs) include vaginal infections (e.g., bacterial vaginosis [BV]), endometritis, pelvic inflammatory disease [PID], and chorioamnionitis [amniotic fluid infection]. They commonly occur in women of reproductive age and are strongly associated with multiple adverse health outcomes including increased risk of HIV/sexually transmitted infection acquisition and transmission, infertility, and adverse birth outcomes such as preterm birth. These FGTIs are characterized by a disruption of the cervicovaginal microbiota which largely affects host immunity through the loss of protective, lactic acid-producing Lactobacillus spp. and the overgrowth of facultative and strict anaerobic bacteria. Prevotella species (spp.), anaerobic Gram-negative rods, are implicated in the pathogenesis of multiple bacterial FGTIs. Specifically, P. bivia, P. amnii, and P. timonensis have unique virulence factors in this setting, including resistance to antibiotics commonly used in treatment. Additionally, evidence suggests that the presence of Prevotella spp. in untreated BV cases can lead to infections of the upper female genital tract by ascension into the uterus. This narrative review aims to explore the most common Prevotella spp. in FGTIs, highlight their important role in the pathogenesis of FGTIs, and propose future research in this area.

Can Porphyromonas gingivalis be a novel aetiology for recurrent miscarriage?

OBJECTIVE

To study the association between Porphyromonas gingivalis (P. gingivalis) infection and recurrent miscarriage.

METHODS

This case control study included women with early pregnancy failure admitted for surgical evacuation of retained products of conception. Cases (group 1) included 50 women with unexplained recurrent early miscarriage whereas the control group (group 2) consisted of 50 women with no such history. The evacuated products of conception, subgingival plaques, cervicovaginal secretions and saliva of all participants were examined to detect P. gingivalis deoxyribonucleic acid (DNA) using a polymerase chain reaction.

RESULTS

The prevalence of P. gingivalis DNA in the chorionic villous tissue samples of group 1 was significantly higher than in group 2 (8 [16%] vs. 1 [2%], respectively; p = 0.036, odds ratio [OR]: 9.3, 95% confidence interval [CI]: 1.1-76.9). The prevalence of P. gingivalis DNA was significantly higher in cervicovaginal secretions of group 1 than in group 2 (9 [18%] vs. 1 [2%], respectively; p = 0.02, OR: 10.8, 95% CI: 1.3-88.5). On the contrary, P. gingivalis DNA could not be detected in subgingival plaques and saliva samples of either group.

CONCLUSION

The current study found an association between P. gingivalis infection of the female genital tract and the occurrence of recurrent miscarriage.

Hidden pathogens uncovered: metagenomic analysis of urinary tract infections

Urinary tract infections (UTIs) are the most common kidney and urologic diseases in industrial nations and are usually caused through faecal contamination of the urinary tract. In this study, we have examined 1449 urine specimens both by culture and by PCR. The majority of UTIs examined were caused by Escherichia coli (35.15%), followed by miscellaneous bacteria (23.03%), and by Enterococcus faecalis (19.39%). A large fraction of fastidious and anaerobic bacteria (22.43%) was not detected under culture conditions but only by using PCR. This group of bacteria evade the standard culture conditions used in routine diagnostic laboratories examining urine specimens. The molecular approach used broad-range 16S rDNA PCR, denaturing high-performance liquid chromatography analysis, sequencing, and bioinformatic analysis to uncover these 'hidden' pathogens and is recommended in particular when examining leukocyte esterase-positive and culture-negative urinary tract specimens.

Phospholipid molecular species distribution of Porphyromonas asaccharolytica ATCC 25260T: effects of temperature, culture age and pH

The aim of this study was to determine the extent to which phospholipid molecular species profiles are affected by different environmental factors in Porphyromonas asaccharolytica ATCC 25260T. Phospholipids were analysed by Fast Atom Bombardment Mass Spectrometry (FAB-MS) in negative-ion mode. Under standard growth conditions (37 degrees C, pH 7.0, 48 h), the most intense high mass anions were m/z 653 and 662. The latter is consistent with the expected presence of PE (30:0). The only changes in profiles were quantitative. These were compared using the Pearson Coefficient of Linear Correlation. The r-values for initial pH comparisons ranged from 0.82 (pH 7.0 vs pH 6.0) to 1.00 (pH 5.0 vs pH 8.0), for incubation period, from 0.86 (48 vs 72 h) to 0.97 (96 vs 168 h), and for temperature, from 0.57 (40 vs 37 degrees C) to 0.96 (37 vs 36 degrees C). Differences were also seen when plates were incubated in anaerobe jars as opposed to an anaerobic work station (r = 0.75). It is concluded that it is essential to standardize growth parameters, and to use an anaerobe jar or an anaerobe work station, but not both.

Balanitis and balanoposthitis: a review

OBJECTIVES

To give an overview of the literature on balanitis, with a special emphasis on infective causes.

METHOD

A data search was performed using the OVID CD plus Medline 1967-1995, using balanitis and balanoposthitis as textword search strategy. Specific subjects such as anaerobic infection, Zoon's balanitis were sought separately and subgroups combined. Original articles and abstracts were referenced to illustrate each condition. These were mainly English language articles, but included appropriate non-English language papers.

CONCLUSIONS

Balanitis is a common condition among genitourinary medicine clinic attendees, the cause often remaining undiagnosed. Many cases are caused by infection, with candida being the most frequently diagnosed. However, gardnerella and anaerobic infections are common, and there are a wide variety of other rarer infective causes. In addition irritant balanitis is probably a contributing factor in many cases. Balanitis which persists and in which the cause remains unclear warrants biopsy.