Polymicrobial consortia in the pathogenesis of biofilm vaginosis visualized by FISH. Historic review outlining the basic principles of the polymicrobial infection theory.

The manuscript disputes the exclusive mono-infectious way of thinking, which presumes that for every infection only one pathogen is responsible and sufficient, when infectious vectors, close contact and reduced immunity meet. In situations involving heavily colonized anatomical sites such an approach often ends in insoluble contradictions. Upon critical reflection and evaluation of 20 years research on spatial organization of vaginal microbiota it is apparent, that in some situations, pathogens may act and operate in permanent, structurally organized consortia, whereas its individual components may be innocuous and innocent, failing to express any pathogenic effect. In these cases, consortia are the true pathogens responsible for many infectious conditions, which usually remain unrecognized as long as improperly diagnosed. The structure of such consortia can be unraveled using ribosomal fluorescence in situ hybridization (FISH). FISH methodology, that not only offers an ex vivo opportunity to recognize bacterial species, but provides unique physical insight into their specific role in the pathogenesis of polymicrobial infections. Ribosomal FISH technique applied to both, women with bacterial vaginosis (BV) and their male partners, has added significantly to our understanding of the pathogenesis of this condition and contributed to appreciating the mechanisms of polymicrobial, community-based infection, potentially leading to therapeutic advances.

Bacterial Vaginosis: Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry No. 015/028, June 2023).

Aim This official guideline was coordinated and published by the DGGG, OEGGG and SGGG with the involvement of additional professional societies. The aim of the guideline is to evaluate the relevant literature and use it to provide a consensus-based overview of the diagnosis and management of bacterial vaginosis. Methods This S2k-guideline was developed by representative members from different medical professional societies on behalf of the guidelines commission of the above-listed societies using a structured consensus process. Recommendations This guideline provides recommendations on the diagnosis, management, counselling, prophylaxis, and other aspects related to bacterial vaginosis.

Bacterial Vaginosis-Vaginal Polymicrobial Biofilms and Dysbiosis.

BACKGROUND: Bacterial vaginosis (BV) is the most common genital disease worldwide in women of sexually active age, with a prevalence of 23-29%. Its traditional definition as dysbiosis, i.e., a disruption of the normal balance of the vaginal microbiota, with a massive increase of facultative and obligate anaerobic bacteria (mainly Gardnerella spp.) and a loss of lactobacilli, accurately describes the change in the vaginal microbiota, but does not explain the underlying pathophysiology. METHODS: This review is based on information in pertinent articles retrieved by a selective literature search and on the authors' own research findings. RESULTS: Fluorescent in situ hybridization (FISH) has revealed Gardnerella spp.-dominated polymicrobial vaginal biofilm as a cause of ascending gynecologic and pregnancy-related infections, preterm birth, and infertility in patients with BV. The biofilm-induced disturbance of epithelial homeostasis favors co-infection with pathogens of sexually transmitted infection (STI). Standard antibiotic therapy is ineffective against biofilms, and there is thus a recurrence rate above 50%. The characteristic biofilm can be followed as a diagnostic marker and is considered evidence of sexual transmission when heterosexual couples and ejaculate samples are examined. FISH studies have shown that, in addition to biofilm-related vaginosis, there are other dysbiotic changes in the vaginal microbiota that have not yet been characterized in detail. It is therefore justified to speak of a "bacterial vaginosis syndrome." CONCLUSION: The simplistic view of BV as dysbiosis, characterizable by microscopic reference methods, has so far led to inadequate therapeutic success. An evaluation of molecular genetic testing methods that would be suitable for routine use and the development of therapeutic agents that are effective against biofilms are urgently needed if the "bacterial vaginosis syndrome" is to be effectively treated.

Clue Cells and Pseudo Clue Cells in Different Morphotypes of Bacterial Vaginosis.

Introduction: Clue cells (epithelial cells heavily covered with adherent bacteria) are an accepted clue to the diagnosis of bacterial vaginosis. However, the exact morphologic criteria of clue cells and bacterial adherence were never elaborated. Materials and Methods: We investigated adhesive and cohesive patterns of main microbiota groups in vaginal discharge using fluorescence in situ hybridization (FISH). Samples from 500 women diagnosed with bacterial vaginosis and positive for clue cells with classic microscopy were collected from 42 gynecologic practices in Berlin and reexamined in our FISH laboratory for the spatial distribution of Bifidobacteriaceae, Gardnerella, Fannyhessea vaginae (Atopobium); low G+C (guanine+cytosine) bacteria, lactobacilli, Lactobacillus iners; Lactobacillus crispatus, Gamma-Proteobacteria; and Enterobacteriaceae, Prevotella-Bacteroides, Veillonella, and Coriobacterium groups. Results: Bacterial taxa present in vaginal smears were not accidentally assembled according to their relative abundance but were built in group-specific distribution patterns, which can be well described by two features: cohesiveness to each other and adherence to epithelial cells. Accordingly, four patterns can be distinguished: dispersed (non-adherent bacteria), dispersed adherent bacteria, cohesive (non-adherent) bacteria, and cohesive adherent bacteria. Direct cohesive adherence to the epithelial cells representing true clue cells was unique for Gardnerella species and observed only in 56% of the investigated samples. In the remaining vaginal samples, the epithelial cells were mechanically entrapped in bacterial masses, and the composition was unrelated to the epithelial cell surface, building non-adherent pseudo clue cells. The proportion of women with true clue cells in their samples from different gynecologic practices varied from 19% to 80%. Discussion: Taxon indifferent imaging is inadequate for the exact analysis of the microbial layer adjacent to the vaginal epithelial cells. Morphologically seen bacterial vaginosis is a mix of at least two different conditions: biofilm vaginosis and bacterial excess vaginosis.

Antimicrobial Susceptibility of Microbiota in Bacterial Vaginosis Using Fluorescence In Situ Hybridization.

BACKGROUND: Testing of antibiotic resistance of intact vaginal microbiota in pure culture is not feasible. METHODS: Metronidazole, antiseptic octenisept®, antimycotic ciclopirox, bacterial probiotic Lactobacillus crispatus, yeast probiotic Saccharomyces boulardii, Gardnerella-phage-endolysin named phagolysin and phagolysin in combination with probiotics were tested for bacteriolytic activity. Included were vaginal swabs from 38 random women with Amsel-confirmed bacterial vaginosis (BV). Test aliquots were incubated by 37° for 2 and 24 h. Gardnerella, low G+C, Atopobium, lactobacilli, Lactobacillus iners and crispatus, Prevotella-Bacteroides, and Gammaproteobacteria microbial groups were quantified using fluorescence in situ hybridization (FISH). RESULTS: The probiotic strain Lactobacillus crispatus demonstrated the weakest bacteriolytical effects, followed by metronidazole. Both had no impact on Gardnerella species, instead lysing Prevotella-Bacteroides, Enterobacteriaceae (by L.crispatus) or LGC, Atopobium and Prevotella-Bacteroides (by metronidazole) groups of the microbiota. Cytolytic activity on Gardnerella was highly pronounced and increased from octenisept to ciclopirox, phagolysin, phagolysin with L.crispatus, being best in the combination of phagolysin with S.boulardii. Universally active ciclopirox and octenisept® suppressed nearly all microbial groups including those which are regarded as beneficial. Phagolysin had no effect on naturally occurring Lactobacillus crispatus. Conclusions: FISH susceptibility testing allows unique efficacy evaluation of individually adjusted topical therapy without microbial isolation facilitating optimal therapy choice.

Engineered Phage Endolysin Eliminates Gardnerella Biofilm without Damaging Beneficial Bacteria in Bacterial Vaginosis Ex Vivo.

Bacterial vaginosis is characterized by an imbalance of the vaginal microbiome and a characteristic biofilm formed on the vaginal epithelium, which is initiated and dominated by Gardnerella bacteria, and is frequently refractory to antibiotic treatment. We investigated endolysins of the type 1,4-beta-N-acetylmuramidase encoded on Gardnerella prophages as an alternative treatment. When recombinantly expressed, these proteins demonstrated strong bactericidal activity against four different Gardnerella species. By domain shuffling, we generated several engineered endolysins with 10-fold higher bactericidal activity than any wild-type enzyme. When tested against a panel of 20 Gardnerella strains, the most active endolysin, called PM-477, showed minimum inhibitory concentrations of 0.13-8 µg/mL. PM-477 had no effect on beneficial lactobacilli or other species of vaginal bacteria. Furthermore, the efficacy of PM-477 was tested by fluorescence in situ hybridization on vaginal samples of fifteen patients with either first time or recurring bacterial vaginosis. In thirteen cases, PM-477 killed the Gardnerella bacteria and physically dissolved the biofilms without affecting the remaining vaginal microbiome. The high selectivity and effectiveness in eliminating Gardnerella, both in cultures of isolated strains as well as in clinically derived samples of natural polymicrobial biofilms, makes PM-477 a promising alternative to antibiotics for the treatment of bacterial vaginosis, especially in patients with frequent recurrence.

Brucellosis in a refugee who migrated from Syria to Germany and lessons learnt, 2016.

A teenage woman migrating from Syria arrived in May 2015 in Germany. She gave birth to a healthy child in early 2016, but became febrile shortly after delivery. Blood cultures revealed Brucella melitensis. In retrospect, she reported contact with sheep in Syria and recurrent pain in the hip joints over about five months before diagnosis of brucellosis. We discuss consequences for adequate treatment of mother and child as well as for clinical and laboratory management.

Functional anatomy of the colonic bioreactor: Impact of antibiotics and Saccharomyces boulardii on bacterial composition in human fecal cylinders.

Sections of fecal cylinders were analyzed using fluorescence in situ hybridization targeting 180 bacterial groups. Samples were collected from three groups of women (N=20 each) treated for bacterial vaginosis with ciprofloxacin+metronidazole. Group A only received the combined antibiotic regimen, whereas the A/Sb group received concomitant Saccharomyces boulardii CNCM I-745 treatment, and the A_Sb group received S. boulardii prophylaxis following the 14-day antibiotic course. The number of stool cylinders analyzed was 188 out of 228 in group A, 170 out of 228 in group A/Sb, and 172 out of 216 in group A_Sb. The colonic biomass was organized into a separate mucus layer with no bacteria, a 10-30µm broad unstirred transitional layer enriched with bacteria, and a patchy fermentative area that mixed digestive leftovers with bacteria. The antibiotics suppressed bacteria mainly in the fermentative area, whereas abundant bacterial clades retreated to the transitional mucus and survived. As a result, the total concentration of bacteria decreased only by one order. These effects were lasting, since the overall recovery of the microbial mass, bacterial diversity and concentrations were still below pre-antibiotic values 4 months after the end of antibiotic treatment. Sb-prophylaxis markedly reduced antibiotic effects and improved the recovery rates. Since the colon is a sophisticated bioreactor, the study indicated that the spatial anatomy of its biomass was crucial for its function.

Polymicrobial Gardnerella biofilm resists repeated intravaginal antiseptic treatment in a subset of women with bacterial vaginosis: a preliminary report.

PURPOSE: Bacterial vaginosis is a recalcitrant polymicrobial biofilm infection that often resists standard antibiotic treatment. We therefore considered repeated treatment with octenidine, a local antiseptic that has previously been shown to be highly effective in several biofilm-associated infections. METHODS: Twenty-four patients with recurrent BV were treated with a 7-day course of octenidine (octenidine dihydrochloride spray application with the commercial product Octenisept). In case of treatment failure or relapse within 6 months, patients were re-treated with a 28-day course of octenidine. In case of recurrence within 6 months after the second treatment course, patients were treated again with a 28-day course followed by weekly applications for 2 months. Treatment effect was evaluated by assessment of the presence of the biofilm on voided vaginal epithelial cells through fluorescence in situ hybridisation. RESULTS: The initial cure rate following a 7-day course of octenidine was as high as 87.5%. The 6-month relapse rate was, however, as high as 66.6%. Repeated treatment for 28 days led to an overall cure rate of 75.0%; however, it was also associated with emergence of complete resistance to octenidine in a subset of women. The overall cure rate after three treatment courses with 1-year follow-up was 62.5 %, with 37.5 % of the patients showing complete resistance to octenidine. CONCLUSION: Our preliminary results showed that octenidine dihydrochloride was initially highly effective, but the efficacy of repeated and prolonged treatment dropped quickly as challenge with the antiseptic rapidly led to bacterial resistance in a considerable subset of women.

Infection through structured polymicrobial Gardnerella biofilms (StPM-GB).

BACKGROUND: We analysed data on bacterial vaginosis (BV) contradicting the paradigm of mono-infection. METHODOLOGY: Tissues and epithelial cells of vagina, uterus, fallopian tubes and perianal region were investigated using fluorescence in situ hybridization (FISH) in women with BV and controls. RESULTS: Healthy vagina was free of biofilms. Prolific structured polymicrobial (StPM) Gardnerella-dominated biofilm characterised BV. The intact StPM-Gardnerella-biofilm enveloped desquamated vaginal/prepuce epithelial cells and was secreted with urine and sperma. The disease involved both genders and occurred in pairs. Children born to women with BV were negative. Monotherapy with metronidazole, moxifloxacin or local antiseptics suppressed but often did not eradicate StPM-Gardnerella-biofilms. There was no BV without Gardnerella, but Gardnerella was not BV. Outside of StPM-biofilm, Gardnerella was also found in a subset of children and healthy adults, but was dispersed, temporal and did not transform into StPM-Gardnerella-biofilm. CONCLUSIONS: StPM-Gardnerella-biofilm is an infectious subject. The assembly of single players to StPM-Gardnerella-biofilm is a not trivial every day process, but probably an evolutionary event with a long history of growth, propagation and selection for viability and ability to reshape the environment. The evolutionary memory is cemented in the structural differentiation of StPM-Gardnerella-biofilms and imparts them to resist previous and emerging challenges.

Presence of a polymicrobial endometrial biofilm in patients with bacterial vaginosis.

OBJECTIVE: To assess whether the bacterial vaginosis biofilm extends into the upper female genital tract. STUDY DESIGN: Endometrial samples obtained during curettage and fallopian tube samples obtained during salpingectomy were collected. Endometrial and fallopian tube samples were analyzed for the presence of bacteria with fluorescence-in-situ-hybridisation (FISH) analysis with probes targeting bacterial vaginosis-associated and other bacteria. RESULTS: A structured polymicrobial Gardnerella vaginalis biofilm could be detected in part of the endometrial and fallopian tube specimens. Women with bacterial vaginosis had a 50.0% (95% CI 24.0-76.0) risk of presenting with an endometrial Gardnerella vaginalis biofilm. Pregnancy (AOR  = 41.5, 95% CI 5.0-341.9, p<0.001) and the presence of bacterial vaginosis (AOR  = 23.2, 95% CI 2.6-205.9, p<0.001) were highly predictive of the presence of uterine or fallopian bacterial colonisation when compared to non-pregnant women without bacterial vaginosis. CONCLUSION: Bacterial vaginosis is frequently associated with the presence of a structured polymicrobial Gardnerella vaginalis biofilm attached to the endometrium. This may have major implications for our understanding of the pathogenesis of adverse pregnancy outcome in association with bacterial vaginosis.

Positive effects of local therapy with a vaginal lactic acid gel on dysuria and E.coli bacteriuria question our current views on recurrent cystitis.

OBJECTIVE: We tested the effect of vaginally applied lactic acid gel on symptoms and bacteriuria in acutely exacerbated recurrent Eschericia coli cystitis. METHODS: Carnoy fixed samples of the morning urine from 20 women with a history of recurrent E.coli cystitis were prospectively investigated for bacteriuria using fluorescence in situ hybridization (FISH). RESULTS: In 11/20 women with acute cystitis, the symptoms and bacteriuria were regressive with lactic acid gel treatment, without the need for antibiotic treatment. The complete regression of symptoms took between 1 week (7 women) and 4 weeks (4 women). In parallel with this regression, the microscopic shape of E.coli bacteria in these women changed from short rods to long curly filaments starting within the first days of therapy. The filamentous transformation affected 100% of the E.coli population in six women and at least 50% of E.coli population in five women and was not observed in urine samples from untreated women or in women without clinical response to lactic acid gel. This could not happen if the bladder was the origin of the infection. CONCLUSIONS: A number of recurrent and probably acute cystitis is a local vagino-urethritis caused by an adhesive invasive E.coli biofilm of the vaginal surface.

Gardnerella biofilm involves females and males and is transmitted sexually.

OBJECTIVE: To study the incidence and distribution of adherent Gardnerella vaginalis. METHODS: Bacteria adherent to desquamated epithelial cells in the urine were detected using fluorescence in situ hybridization (FISH). Urine from patients with bacterial vaginosis (BV, n = 20), their partners (n = 10) and different control populations (n = 344) including pregnant women and their partners, randomly selected populations of hospitalized man, women and children as also healthy controls was investigated. RESULTS: Gardnerella was found in two different forms: cohesive and dispersed. In the cohesive form, Gardnerella were attached to the epithelial cells in groups of highly concentrated bacteria. In the dispersed form, solitary Gardnerella were intermixed with other bacterial groups. Cohesive Gardnerella was present in all patients with proven BV and their partners, in 7% of men and 13% of women hospitalized for reasons other than BV, in 16% of pregnant women and 12% of their male partners, and in none of the healthy laboratory staff or children. In sexual partners, occurrence of cohesive Gardnerella was clearly linked. Dispersed Gardnerella were found in 10-18% of randomly selected females, 3-4% of males and 10% of children and not sexually linked. In daily longitudinal investigations over 4 weeks no transition between cohesive and dispersed Gardnerella and vice versa was observed. Transmission of a cohesive Gardnerella strain could be followed retrospectively over 15 years using molecular genetic methods. CONCLUSIONS: Cohesive Gardnerella biofilm is a distinct, clearly definable entity which involves both genders and is sexually transmitted. The correct name distinguishing it from symptom-defined conditions like BV should be gardnerellosis and for the bacterium Gardnerella genitalis.

An adherent Gardnerella vaginalis biofilm persists on the vaginal epithelium after standard therapy with oral metronidazole.

OBJECTIVE: The purpose of this study was to determine the efficacy of standard treatment with oral metronidazole in the eradication of the bacterial vaginosis biofilm. STUDY DESIGN: We conducted an interventional follow-up study in which 18 patients with bacterial vaginosis were treated with oral metronidazole during 1 week and subsequently had a single random follow-up assessment at 1-week intervals, up to 5 weeks, with 3 patients representing each point in time. Follow-up assessment included conventional scoring of the vaginal microflora and determination of bacterial biofilm characteristics on a vaginal biopsy through bacterial 16/23S recombinant DNA-based fluorescence in-situ hybridization. RESULTS: Although all patients recovered, we consistently observed the resurgence with treatment cessation of a dense and active bacterial biofilm on the vaginal mucosa, primarily consisting of Gardnerella vaginalis and Atopobium vaginae. CONCLUSION: A large reservoir of the core bacteria to bacterial vaginosis persists as a biofilm after metronidazole treatment.

Adherent biofilms in bacterial vaginosis.

OBJECTIVE: Bacterial vaginosis is a common infectious disorder. Although known since ancient times, little progress has occurred in identifying causal factors. Our aims were to study the bacterial community structure and the spatial organization of microbiota on the epithelial surfaces of vaginal biopsy specimens. METHODS: We investigated the composition and spatial organization of bacteria associated with the vaginal epithelium in biopsy specimens from 20 patients with bacterial vaginosis and 40 normal premenopausal and postmenopausal controls using a broad range of fluorescent bacterial group-specific rRNA-targeted oligonucleotide probes. RESULTS: Bacterial vaginosis was associated with greater occurrence and higher concentrations of a variety of bacterial groups. However, only Gardnerella vaginalis developed a characteristic adherent biofilm that was specific for bacterial vaginosis. CONCLUSION: A biofilm comprised of confluent G vaginalis with other bacterial groups incorporated in the adherent layer is a prominent feature of bacterial vaginosis. LEVEL OF EVIDENCE: II-2.

Mucosal flora in inflammatory bowel disease.

BACKGROUND & AIMS: Microorganisms that directly interact with the intestinal mucosa are obscured by fecal flora and poorly characterized. METHODS: We investigated the mucosal flora of washed colonoscopic biopsies of 305 patients with bowel inflammation and 40 controls. The microbial cultures were validated by quantitative polymerase chain reaction with subsequent cloning and sequencing, fluorescence in-situ hybridization, and electron microscopy. RESULTS: We found high concentrations of mucosal bacteria in patients with bowel inflammation, but not in controls. The concentrations of mucosal bacteria increased progressively with the severity of disease, both in inflamed and non-inflamed colon. In patients with >10,000 cfu/microL, a thick bacterial band was attached to the intact mucosa without signs of translocation. Patients with inflammatory bowel disease (IBD) and concentrations of mucosal bacteria >50,000 cfu/microL had characteristic inclusions of multiple polymorphic bacteria within solitary enterocytes located next to the lamina propria, without or having no contact with the fecal stream. The identified bacteria were of fecal origin. CONCLUSIONS: Our findings suggest that the changes in the mucosal flora in IBD are not secondary to inflammation, but a result of a specific host response. We hypothesize that the healthy mucosa is capable of holding back fecal bacteria and that this function is profoundly disturbed in patients with IBD.