Jose A. Simoes

Gardnerella vaginalis Isolated from Patients with Bacterial Vaginosis and from Patients with Healthy Vaginal Ecosystems

The differences in the phenotype and genotype of Gardnerella vaginalis isolates from patients with bacterial vaginosis (BV) and from patients without BV are unknown. In our study, 43 isolates of G. vaginalis were examined for biotype (hippurate hydrolysis, lipase, and beta-galactosidase activity), sensitivity to metronidazole, and genotype. Of the 117 women visiting the gynecology clinic at Rush-Presbyterian-St. Lukes Medical Center who were included in the study, 27.4% were found to have BV. G. vaginalis was found in samples from 87.5% of women with BV, from 34.0% of women with intermediate BV, and from 26.4% of women with healthy vaginal ecosystems. Among patients with G. vaginalis, biotypes 7 and 8 were isolated from 32% and 20% of patients, respectively. Biotype 5 was predominantly associated with a healthy vaginal ecosystem (P=.0004). Biotypes 5 and 7 were the most resistant to metronidazole. No specific phenotype or genotype of G. vaginalis causes BV.

Antimicrobial protein produced by vaginal Lactobacillus acidophilus that inhibits Gardnerella vaginalis

Objective: To isolate bacteriocin from a vaginal strain of Lactobacillus acidophilus. Methods: L. acidophilus 160 was grown on two media. The first was MRS broth for 18 hours; the cells were harvested, washed, and placed into a chemically defined medium. The second medium resembled vaginal fluid minus protein. Bacteriocin was precipitated from both media using ammonium sulfate. The growth-inhibiting activity of bacteriocin was determined by a bioassay using nine different isolates of Gardnerella vaginalis. Results: MRS broth is not a suitable medium for extracting bacteriocin, because it binds with Tween 80. Bacteriocin was isolated, without contaminating constituents, from chemically defined medium and identified as a single band by electrophoresis. Bacteriocin has a molecular weight of 3.8 kDa. All nine isolates of Gardnerella were inhibited by the bacteriocin isolated from L. acidophilus 160. Conclusions: Bacteriocin produced by L. acidophilus 160 was isolated from the chemically defined medium (starvation medium) in a partially pure form. L. acidophilus 160 bacteriocin inhibited growth of all nine isolates of Gardnerella vaginalis.

Two Novel Vaginal Microbicides (Polystyrene Sulfonate and Cellulose Sulfate) Inhibit Gardnerella vaginalis and Anaerobes Commonly Associated with Bacterial Vaginosis

ABSTRACT This is the first report demonstrating the in vitro inhibitory activity of two novel microbicides (cellulose sulfate and polystyrene sulfonate) against bacterial vaginosis (BV)-associated bacteria. Vaginal application of these microbicides not only may reduce the risk of acquisition of human immunodeficiency virus and other sexually transmitted infection-causing organisms but may also decrease the incidence of BV.

Antibiotic resistance patterns of group B streptococcal clinical isolates

OBJECTIVES: To determine the in vitro resistance of group B streptococcus (GBS) to 12 antibiotics. To determine if there has been any decrease in sensitivity to the penicillins or other antibiotics currently used for GBS chemoprophylaxis in pregnant women. Find suitable alternative antibiotics to penicillin. Find an antibiotic that will have minimal selective pressure for resistance among the endogenous resident vaginal microflora. METHODS: The antibiotic susceptibility profiles of 52 clinical isolates of GBS were evaluated to 12 antibiotics: ampicillin, azithromycin, cefamandole, cefazolin, ceftriaxone, ciprofloxacin, clindamycin, erythromycin, nitrofurantoin, ofloxacin, penicillin and vancomycin. Antibiotic sensitivities were determined using disk diffusion and microdilution methods according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS). RESULTS: All isolates were sensitive to vancomycin, ofloxacin, ampicillin, ciprofloxacin, nitrofurantoin and penicillin. However, the following number of clinical isolates exhibited intermediate or decreased sensitivity, nine (17%) to ampicillin, eight (15%) to penicillin, 14 (32%) to ciprofloxacin and one (2%) to nitrofurantoin. Thirty-one percent of the isolates were resistant to azithromycin and ceftriaxone, 19% to clindamycin, 15% to cefazolin and 13% to cefamandole. Eighteen (35%) of the clinical isolates tested were resistant to 6 of the 12 antibiotics tested. CONCLUSIONS: The relatively high rates of resistance for 6 of the 12 antibiotics tested suggest that for women allergic to penicillin and colonized with GBS, antibiotic sensitivities to their isolates should be determined. The antibiotic selected for intrapartum chemoprophylaxis should be guided by the organisms antibiotic sensitivity pattern. Patients with GBS bacteriuria should be treated with nitrofurantoin.

Effect of Metronidazole on the Growth of Vaginal Lactobacilli in vitro

Objective: To determine whether metronidazole has an adverse effect on the growth of Lactobacillus. Methods: Hydrogen peroxide- and bacteriocin-producing strains of Lactobacillus were used as test strains. Concentrations of metronidazole used ranged from 128 to 7000 μg/ml. Susceptibility to metronidazole was conducted by the broth microdilution method recommended by the National Committee for Clinical Laboratory Standards. Results: Growth of Lactobacillus was partially inhibited at concentrations between 1000 and 4000 μg/ml (p = 0.014). Concentrations ≥ 5000 μg/ml completely inhibited growth of Lactobacillus. Concentrations between 128 and 256 μg/ml stimulated growth of Lactobacillus (p = 0.025 and 0.005, respectively). Concentrations of metronidazole between 64 and 128 μg/ml or ≥ 512 μg/ml did not have an inhibitory or a stimulatory effect on the growth of Lactobacillus compared to the control. Conclusions: High concentration of metronidazole, i.e. between 1000 and 4000 μg/ml, partially inhibited the growth of Lactobacillus. Concentrations ≥ 5000 μg/ml completely suppressed the growth of Lactobacillus. Concentrations between ≥ 128 and ≤ 256 μg/ml stimulated the growth of Lactobacillus. Further investigation to determine the ideal concentration of metronidazole is needed in order to use the antimicrobial agent effectively in the treatment of bacterial vaginosis.

Role of the vaginal microbiological ecosystem and cytokine profile in the promotion of cervical dysplasia: a case- control study

OBJECTIVE: To identify alterations in the cytokine profile and microbial ecosystem of the vagina in association with cervical dysplasia. METHODS: Demographics, lifestyle variables and Papanicolau (Pap) smear results of subjects presenting to the same site for gynecologic complaints, obstetric visits or colposcopy were prospectively recorded. Vaginal smear for Gram stain, aerobic and anaerobic culture, pH, and wet mount and KOH examination for Trichomonas vaginalis, Gardnerella vaginalis and yeast organisms were performed. Vaginal lavage specimens were centrifuged, and the pellets and supernatants were assayed for human papillomavirus (HPV) by polymerase chain reaction and for cytokines interleukin (IL)-1beta IL-6, IL-10 and IL-12 by enzyme-linked immunosorbent assay (ELISA) respectively. Subjects with abnormal Pap smears underwent colposcopy and biopsy as indicated. RESULTS: Of 51 patients, 32 were referred for colposcopy, 12 presented with gynecologic needs, and seven presented for obstetric visits. Median age was 24 years. Demographics did not differ significantly between the dysplasia and control groups except for a trend towards more sexual partners in the dysplasia group. Biopsies were performed in 81% (26/32) of patients presenting for colposcopy and 17 revealed cervical intraepithelial neoplasia. IL-1beta, IL-6, IL-10, and IL-12 levels were elevated in 63% (20/32), 38% (15/39), 4% (2/49), and 0% of samples respectively. Elevated vaginal lavage IL-1beta was associated with a 6.1 odds ratio (95% confidence interval 1.06-35) of cervical dysplasia. Alterations in other variables studied were not associated with cervical dysplasia. CONCLUSIONS: Elevated IL-1beta, possibly representing a complex host inflammatory response to multiple pathogens, was demonstrated in patients with cervical dysplasia.

The Inhibitory Effect of Clindamycin on Lactobacillus in vitro

Objective: To evaluate the in vitro effect of varying concentrations of clindamycin on Lactobacillus spp. Methods: Concentrations of clindamycin ranging from 1.95–20 000 mg/ml were studied for their effect on the growth of six strains of Lactobacillus . Results: Clindamycin concentrations between 1.95–31.25 mg/ml had no statistically significant effect on growth of lactobacilli (p > 0.05). Concentrations 125 and 250 mg/ml had a bacteriostatic effect. The mean minimum inhibitory concentration (MIC) for studied Lactobacillus strains was determined as 1000 mg/ml. Conclusion: High concentrations of clindamycin achieved in the vagina by intravaginal application might be inhibitory for Lactobacillus .