Chlamydia trachomatis and Neisseria gonorrhoeae rectal infections: Interplay between rectal microbiome, HPV infection and Torquetenovirus.

Men having sex with men (MSM) represent a key population, in which sexually transmitted rectal infections (STIs) caused by Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and high-risk HPV (HR-HPV) are very common and linked to significant morbidity. Investigating the anorectal microbiome associated with rectal STIs holds potential for deeper insights into the pathogenesis of these infections and the development of innovative control strategies. In this study, we explored the interplay at the rectal site between C. trachomatis, N. gonorrhoeae, HR-HPV infection, and the anorectal microbiome in a cohort of 92 MSM (47 infected by CT and/or NG vs 45 controls). Moreover, we assessed the presence of Torquetenovirus (TTV), a non-pathogenic endogenous virus, considered as a possible predictor of immune system activation. We found a high prevalence of HR-HPV rectal infections (61%), especially in subjects with a concurrent CT/NG rectal infection (70.2%) and in people living with HIV (84%). In addition, we observed that TTV was more prevalent in subjects with CT/NG rectal infections than in non-infected ones (70.2% vs 46.7%, respectively). The anorectal microbiome of patients infected by CT and/or NG exhibited a reduction in Escherichia, while the presence of TTV was significantly associated with higher levels of Bacteroides. We observed a positive correlation of HR-HPV types with Escherichia and Corynebacterium, and a negative correlation with the Firmicutes phylum, and with Prevotella, Oscillospira, Sutterella. Our findings shed light on some of the dynamics occurring within the rectal environment involving chlamydial/gonococcal infections, HPV, TTV, and the anorectal microbiome. These data could open new perspectives for the control and prevention of STIs in MSM.

Non-pathogenic Neisseria species of the oropharynx as a reservoir of antimicrobial resistance: a cross-sectional study.

Commensal Neisseria species of the oropharynx represent a significant reservoir of antimicrobial resistance determinants that can be transferred to Neisseria gonorrhoeae. This aspect is particularly crucial in 'men having sex with men' (MSM), a key population in which pharyngeal co-colonization by N. gonorrhoeae and non-pathogenic Neisseria species is frequent and associated with the emergence of antimicrobial resistance. Here, we explored the antimicrobial susceptibility of a large panel of non-pathogenic Neisseria species isolated from the oropharynx of two populations: a group of MSM attending a 'sexually transmitted infection' clinic in Bologna (Italy) (n=108) and a group of males representing a 'general population' (n=119). We collected 246 strains, mainly belonging to N. subflava (60%) and N. flavescens (28%) species. Their antimicrobial susceptibility was evaluated assessing the minimum inhibitory concentrations (MICs) for azithromycin, ciprofloxacin, cefotaxime, and ceftriaxone using E-test strips. Overall, commensal Neisseria spp. showed high rates of resistance to azithromycin (90%; median MICs: 4.0 mg/L), and ciprofloxacin (58%; median MICs: 0.12 mg/L), whereas resistance to cephalosporins was far less common (<15%). Neisseria strains from MSM were found to have significantly higher MICs for azithromycin (p=0.0001) and ciprofloxacin (p<0.0001) compared to those from the general population. However, there was no significant difference in cephalosporin MICs between the two groups. The surveillance of the antimicrobial resistance of non-pathogenic Neisseria spp. could be instrumental in predicting the risk of the spread of multi-drug resistant gonorrhea. This information could be an early predictor of an excessive use of antimicrobials, paving the way to innovative screening and prevention policies.

Limosilactobacillus vaginalis Exerts Bifidogenic Effects: A Novel Postbiotic Strategy for Infant Prebiotic Supplementation.

Infant microbiota shaping strictly influences newborns' well-being and long-term health, and babies born by cesarean-section and formula-fed generally show low microbial gut diversity and are more prone to develop various disorders. The supplementation with beneficial microbes of vaginal origin or derivatives (postbiotics, including heat-inactivated cells) represents a valid strategy to drive the correct gut microbiota shaping. Here, we explored for the first time the bifidogenic activity of a heat-killed vaginal strain (Limosilactobacillus vaginalis BC17), in addition to the assessment of its safety. L. vaginalis BC17 whole genome was sequenced by Nanopore technology and highlighted the absence of antibiotic resistance genes and virulence factors, indicating the strain safety profile for human health. MIC values confirmed that L. vaginalis BC17 is susceptible to widely employed antibiotics. Heat-killed BC17 cells significantly enhanced the planktonic growth of Bifidobacterium spp. For the first time, stimulating effects were observed also toward biofilm formation of bifidobacteria and their pre-formed biofilms. Conversely, heat-killed BC17 cells exerted antibacterial and anti-biofilms activities against Gram-positive and Gram-negative pathogens. Lyophilized heat-killed BC17 cells were formulated in a sunflower oil suspension (1010 heat-killed cell/g) intended for infant oral intake. This possessed optimal technological (i.e., re-dispersibility and stability) and functional properties (i.e., bifidogenic activity) that were maintained even after pre-digestion in acidic conditions.

Role of D(-)-Lactic Acid in Prevention of Chlamydia trachomatis Infection in an In Vitro Model of HeLa Cells.

A vaginal microbiota dominated by certain Lactobacillus species may have a protective effect against Chlamydia trachomatis infection. One of the key antimicrobial compounds produced is lactic acid, which is believed to play a central role in host defense. Lactobacillus strains producing the D(-)-lactic acid isomer are known to exert stronger protection. However, the molecular mechanisms underlying this antimicrobial action are not well understood. The aim of this study was to investigate the role of D(-)-lactic acid isomer in the prevention of C. trachomatis infection in an in vitro HeLa cell model. We selected two strains of lactobacilli belonging to different species: a vaginal isolate of Lactobacillus crispatus that releases both D(-) and L(+) isomers and a strain of Lactobacillus reuteri that produces only the L(+) isomer. Initially, we demonstrated that L. crispatus was significantly more effective than L. reuteri in reducing C. trachomatis infectivity. A different pattern of histone acetylation and lactylation was observed when HeLa cells were pretreated for 24 h with supernatants of Lactobacillus crispatus or L. reuteri, resulting in different transcription of genes such as CCND1, CDKN1A, ITAG5 and HER-1. Similarly, distinct transcription patterns were found in HeLa cells treated with 10 mM D(-)- or L(+)-lactic acid isomers. Our findings suggest that D(-) lactic acid significantly affects two non-exclusive mechanisms involved in C. trachomatis infection: regulation of the cell cycle and expression of EGFR and α5ß1-integrin.

Measles virus and cytomegalovirus co-infection, in a child with recent SARS-CoV-2 infection, during COVID-19 pandemic: a case report.

Measles virus (MV) and cytomegalovirus (CMV) may cause pediatric infection. We report the first described case of MV and CMV co-infection in an unvaccinated 13-mo-old girl, with a recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, occurred during coronavirus disease 2019 (COVID-19) pandemic. The COVID-19 pandemic context, combined with patient's complex clinical scenario, presenting symptoms as persistent fever, diarrhea, vomiting, maculopapular rash and edema, in addition to high level of inflammatory markers, led to a suspicion of multisystemic inflammatory syndrome in children (MIS-C). The final diagnosis and the successfully management of the case, discharged after resolution of symptoms, was achieved by a proper virological diagnosis and a close two-way cooperation between pediatricians and clinical microbiologists. The report mainly highlights that awareness about measles should be raised in unvaccinated patients with consistent symptoms, even in the COVID-19 era.

Whole Genome Sequencing of a Chlamydia trachomatis Strain Responsible for a Case of Rectal Lymphogranuloma Venereum in Italy.

Lymphogranuloma venereum (LGV) is a systemic sexually transmitted infection caused by Chlamydia trachomatis serovars L1 to L3. The current LGV cases in Europe are mainly characterized by an anorectal syndrome, spreading within men who have sex with men (MSM). Whole-genome sequencing of LGV strains is crucial to the study of bacterial genomic variants and to improve strategies for contact tracing and prevention. In this study, we described the whole genome of a C. trachomatis strain (LGV/17) responsible for a case of rectal LGV. LGV/17 strain was isolated in 2017 in Bologna (North of Italy) from a HIV-positive MSM, presenting a symptomatic proctitis. After the propagation in LLC-MK2 cells, the strain underwent whole-genome sequencing by means of two platforms. Sequence type was determined using the tool MLST 2.0, whereas the genovariant was characterized by an ompA sequence evaluation. A phylogenetic tree was generated by comparing the LGV/17 sequence with a series of L2 genomes, downloaded from the NCBI website. LGV/17 belonged to sequence type ST44 and to the genovariant L2f. Nine ORFs encoding for polymorphic membrane proteins A-I and eight encoding for glycoproteins Pgp1-8 were detected in the chromosome and in the plasmid, respectively. LGV/17 was closely related to other L2f strains, even in the light of a not-negligible variability. The LGV/17 strain showed a genomic structure similar to reference sequences and was phylogenetically related to isolates from disparate parts of the world, indicative of the long-distance dynamics of transmission.

Characterization of Gardnerella vaginalis isolates: correlations among clades, biofilm formation and cytokine stimulation.

We characterized 61 Gardnerella vaginalis (GV) strains isolated from women with bacterial vaginosis. GV clade 1 was the most commonly found (52.5%), followed by clade 4 (36.1%). All the strains were susceptible to ampicillin and clindamycin, whereas 96.7% and 6.6% of strains showed metronidazole and tetracycline resistance, respectively. Isolates within clade 4 tended to possess the highest ability to form biofilm. Strains resistant to metronidazole and tetracycline were all intermediate or high biofilm producers. All GV clades significantly upregulated the production of pro-inflammatory cytokines by HeLa cells, especially IL-8 and IL-6. Clade 4 induced a significantly higher production of IL-1ß compared to other clades.

Prebiotic Activity of Vaginal Lactobacilli on Bifidobacteria: from Concept to Formulation.

The gut of babies born vaginally is rapidly colonized by Bifidobacterium spp. after birth, while in infants born by cesarean section (C-section), the presence of bifidobacteria drops dramatically, increasing the risk of developing gastrointestinal disorders. Considering that newborns naturally come into contact with maternal lactobacilli as they pass through the birth canal, the aim of this work is to exploit for the first time the bifidogenic activity exerted by the cell-free supernatants (CFSs) from lactobacilli of vaginal origin, belonging to the species Lactobacillus crispatus, Lactobacillus gasseri, Limosilactobacillus vaginalis, and Lactiplantibacillus plantarum. CFSs were recovered after 7 h, 13 h, and 24 h of fermentation and assessed for the ability to stimulate the planktonic growth and biofilms of Bifidobacterium strains belonging to species widely represented in the gut tract. A bifidogenic effect was observed for all CFSs; such activity was maximal for CFSs recovered in exponential phase and was strongly dependent on the species of lactobacilli. Importantly, no stimulating effects on an intestinal Escherichia coli strain were observed. CFSs from L. vaginalis BC17 showed the best bifidogenic profile since they increased bifidobacterial planktonic growth by up to 432% and biofilm formation by up to 289%. The CFS at 7 h from BC17 was successfully formulated with a hyaluronic acid-based hydrogel aimed at preventing and treating breast sores in lactating women and exerting bifidogenic activity in infants born mainly by C-section. IMPORTANCE Bifidobacteria in the gut tract of infants play crucial roles in the prevention of gastrointestinal diseases and the maturation of the immune system. Consequently, strategies to trigger a bifidogenic shift in the infant gut are highly desirable. Evidences suggest that the presence of a maternal vaginal microbiota dominated by health-promoting lactobacilli and the development of a bifidobacterium-enriched gut microbiota in newborns are interconnected. In this context, we found out that the cell-free supernatants from lactobacilli of vaginal origin were able to effectively stimulate the proliferation of Bifidobacterium spp. grown in free-floating and biofilm forms. The cell-free supernatant from Limosilactobacillus vaginalis BC17 showed excellent bifidogenic behavior, which was preserved even after its incorporation into a nipple formulation for lactating women. Lactobacilli derivatives, such as cell-free supernatants, have gained increasing interest by virtue of their safer profile than that of living cells and can be proposed as an ecosustainable approach to favor gut colonization of infants by bifidobacteria.

Longitudinal Changes of Ocular Surface Microbiome in Patients Undergoing Hemopoietic Stem Cell Transplant (HSCT).

PURPOSE: To evaluate changes in the ocular surface microbiome (OSM) between pre- and post-haemopoietic stem cell transplant (HSCT) in the same patient, and to assess the potential impact of these changes in ocular graft-versus-host disease (o)GVHD development. METHODS: Lower fornix conjunctival swabs of 24 patients were obtained before and after HSCT and subjected to DNA extraction for amplification and sequencing of the V3-V4 regions of the bacterial 16S rRNA gene. The obtained reads were reconstructed, filtered, and clustered into zero-radius operational taxonomic units (zOTUs) at 97% identity level before taxonomic assignment, and biodiversity indexes were calculated. Transplant characteristics were recorded, and dry eye was diagnosed and staged 1-4 according to the Dry Eye WorkShop (DEWS) score. RESULTS: No significant difference in OSM alpha diversity between pre- and post-transplant was found. A significant difference in beta diversity was observed between patients with a DEWS score of 1 versus 3 (p = 0.035). Increased corneal damage between pre- and post-HSCT was significantly associated with a decrease in alpha diversity. The changes in OSM were not associated with oGVHD, nor with any transplant parameter. CONCLUSIONS: This preliminary study is the first study to analyse changes in the OSM before and after HSCT longitudinally. No trend in OSM biodiversity, microbial profile, or overall composition changes before and after HSCT was significant or associated with oGVHD onset. The great variability in the observed OSM profiles seems to suggest the absence of a patient-specific OSM "signature".

Torquetenovirus in pregnancy: Correlation with vaginal microbiome, metabolome and pro-inflammatory cytokines.

Torquetenovirus (TTV) is a negative sense, single-stranded DNA virus present in many body fluids of apparently healthy individuals. At present, it is considered a non-pathogenic endogenous virus. TTV can be detected in the vagina of pregnant women, its abundance being modulated with the extent of immune system activation. Until now, there is only scarce information regarding the association between TTV and the composition of the vaginal environment. Therefore, this study aimed to assess the presence of TTV in the vaginal ecosystem of a cohort of white women with a normal pregnancy (n = 60) at different gestational stages (first, second and third trimester) and in 9 subjects suffering a first trimester miscarriage. For each woman, we determined (i) the presence and titer of TTV, (ii) the vaginal bacterial composition by means of Nugent score and 16S rRNA gene sequencing, (iii) the vaginal metabolic profiles through 1H-NMR spectroscopy, and (iv) the vaginal concentration of two pro-inflammatory cytokines (IL-6 and IL-8). More than one third of women were found negative for TTV at all gestational stages. Although not statistically significant, the positivity for TTV dropped from 53.3% in the first to 36.6% in the third trimester. TTV loads varied greatly among vaginal samples, ranging between 2 × 101 and 2 × 105 copies/reaction. No difference in TTV prevalence and loads was observed between women with normal pregnancies and miscarriages. The presence of TTV was more common in women with a higher vaginal leucocyte count (p = 0.02). The levels of IL-6 (p = 0.02), IL-8 (p = 0.03), propionate (p = 0.001) and cadaverine (p = 0.006) were significantly higher in TTV-positive samples. TTV titer was positively correlated with the concentrations of 4-hydroxyphenyllactate (p < 0.0001), isoleucine (p = 0.01) and phenylalanine (p = 0.04). TTV-positive samples were characterized by a higher relative abundance of Sneathia (p = 0.04) and Shuttleworthia (p = 0.0009). In addition, a trend toward a decrease of Lactobacillus crispatus and Lactobacillus jensenii, and an increase of Lactobacillus iners was observed for TTV-positive samples. In conclusion, we found that TTV is quite common in women with normal pregnancy outcomes, representing a possible predictor of local immune status.

A Deep Look at the Vaginal Environment During Pregnancy and Puerperium.

A deep comprehension of the vaginal ecosystem may hold promise for unraveling the pathophysiology of pregnancy and may provide novel biomarkers to identify subjects at risk of maternal-fetal complications. In this prospective study, we assessed the characteristics of the vaginal environment in a cohort of pregnant women throughout their different gestational ages and puerperium. Both the vaginal bacterial composition and the vaginal metabolic profiles were analyzed. A total of 63 Caucasian women with a successful pregnancy and 9 subjects who had a first trimester miscarriage were enrolled. For the study, obstetric examinations were scheduled along the three trimester phases (9-13, 20-24, 32-34 gestation weeks) and puerperium (40-55 days after delivery). Two vaginal swabs were collected at each time point, to assess the vaginal microbiome profiling (by Nugent score and 16S rRNA gene sequencing) and the vaginal metabolic composition (1H-NMR spectroscopy). During pregnancy, the vaginal microbiome underwent marked changes, with a significant decrease in overall diversity, and increased stability. Over time, we found a significant increase of Lactobacillus and a decrease of several genera related to bacterial vaginosis (BV), such as Prevotella, Atopobium and Sneathia. It is worth noting that the levels of Bifidobacterium spp. tended to decrease at the end of pregnancy. At the puerperium, a significantly lower content of Lactobacillus and higher levels of Gardnerella, Prevotella, Atopobium, and Streptococcus were observed. Women receiving an intrapartum antibiotic prophylaxis for Group B Streptococcus (GBS) were characterized by a vaginal abundance of Prevotella compared to untreated women. Analysis of bacterial relative abundances highlighted an increased abundance of Fusobacterium in women suffering a first trimester abortion, at all taxonomic levels. Lactobacillus abundance was strongly correlated with higher levels of lactate, sarcosine, and many amino acids (i.e., isoleucine, leucine, phenylalanine, valine, threonine, tryptophan). Conversely, BV-associated genera, such as Gardnerella, Atopobium, and Sneathia, were related to amines (e.g., putrescine, methylamine), formate, acetate, alcohols, and short-chain fatty-acids (i.e., butyrate, propionate).

Gardnerella vaginalis clades in pregnancy: New insights into the interactions with the vaginal microbiome.

Gardnerella vaginalis (GV) is an anaerobic bacterial species involved in the pathogenesis of bacterial vaginosis (BV), a condition of vaginal dysbiosis associated with adverse pregnancy outcomes. GV strains are categorized into four clades, characterized by a different ability to produce virulence factors, such as sialidase. We investigated the distribution of GV clades and sialidase genes in the vaginal ecosystem of a cohort of pregnant women, assessing the correlations between GV clades and the whole vaginal microbiome. A total of 61 Caucasian pregnant women were enrolled. Their vaginal swabs, collected both at the first and third trimester of pregnancy, were used for (i) evaluation of the vaginal status by Nugent score, (ii) vaginal microbiome profiling by 16S rRNA sequencing, (iii) detection and quantification of GV clades and sialidase A gene by qPCR assays. DNA of at least one GV clade was detected in most vaginal swabs, with clade 4 being the most common one. GV clade 2, together with the presence of multiple clades (>2 simultaneously), were significantly associated with a BV condition. Significantly higher GV loads and sialidase gene levels were found in BV cases, compared to the healthy status. Clade 2 was related to the major shifts in the vaginal microbial composition, with a decrease in Lactobacillus and an increase in several BV-related taxa. As the number of GV clades detected simultaneously increased, a group of BV-associated bacteria tended to increase as well, while Bifidobacterium tended to decrease. A negative correlation between sialidase gene levels and Lactobacillus, and a positive correlation with Gardnerella, Atopobium, Prevotella, Megasphaera, and Sneathia were observed. Our results added knowledge about the interactions of GV clades with the inhabitants of the vaginal microbiome, possibly helping to predict the severity of BV and opening new perspectives for the prevention of pregnancy-related complications.

First-Void Urine Microbiome in Women with Chlamydia trachomatis Infection.

BACKGROUND: Chlamydia trachomatis (CT) is the agent of the most common bacterial sexually transmitted infection worldwide. Until now, little information is available about the microbial composition of urine samples during CT urethritis. Therefore, in this study, we characterized the microbiome and metabolome profiles of first-void urines in a cohort of women with CT urethral infection attending an STI clinic. METHODS: Based on CT positivity by nucleic acid amplification techniques on urine samples, the enrolled women were divided into two groups, i.e., "CT-negative" (n = 21) and "CT-positive" (n = 11). Urine samples were employed for (i) the microbiome profile analysis by means of 16s rRNA gene sequencing and (ii) the metabolome analysis by 1H-NMR. RESULTS: Irrespective of CT infection, the microbiome of first-void urines was mainly dominated by Lactobacillus, L. iners and L. crispatus being the most represented species. CT-positive samples were characterized by reduced microbial biodiversity compared to the controls. Moreover, a significant reduction of the Mycoplasmataceae family-in particular, of the Ureaplasma parvum species-was observed during CT infection. The Chlamydia genus was positively correlated with urine hippurate and lactulose. CONCLUSIONS: These data can help elucidate the pathogenesis of chlamydial urogenital infections, as well as to set up innovative diagnostic and therapeutic approaches.

Distribution of ermB, ermF, tet(W), and tet(M) Resistance Genes in the Vaginal Ecosystem of Women during Pregnancy and Puerperium.

The inhabitants of the vaginal ecosystem can harbor genetic determinants conferring antimicrobial resistance. However, detailed data about the distribution of resistance genes in the vaginal microbiome of pregnant women are still lacking. Therefore, we assessed the presence of macrolide (i.e., erm genes) and tetracycline (i.e., tet genes) resistance markers in the vaginal environment of Caucasian women at different gestational ages. Furthermore, the detection of resistance genes was related to the composition of the vaginal microbiota. A total of 228 vaginal samples, collected at different trimesters of pregnancy or during the puerperium, were tested for the presence of ermB, ermF, tet(W), and tet(M) by in-house end-point PCR assays. The composition of the vaginal microbiota was assessed through a microscopic evaluation (i.e., Nugent score) and by means of sequencing V3-V4 hypervariable regions of the bacterial 16 rRNA gene. Overall, the most detected resistance gene was tet(M) (76.7%), followed by ermB (55.2%). In 17% of women, mainly with a 'normal' vaginal microbiota, no resistance genes were found. Except for tet(W), a significant correlation between the positivity of resistance genes and a dysbiotic vaginal status (i.e., bacterial vaginosis (BV)) was noticed. Indeed, samples positive for at least one resistance determinant were characterized by a decrease in Lactobacillus spp. and an increase of BV-related genera (Prevotella, Gardnerella, Atopobium, Sneathia). A high predominance of vaginal Lactobacillus spp. (>85%) was associated with a lower risk of tet(W) gene detection, whereas the presence of Megasphaera (>1%) increased the risk of positivity for all analyzed genes. Different types of vaginal microbiota are associated with peculiar resistance profiles, being a lactobacilli-dominated ecosystem poor in or free of resistance genes. These data could open new perspectives for promoting maternal and neonatal health.

Vaginal and Anal Microbiome during Chlamydia trachomatis Infections.

Background.Chlamydia trachomatis (CT) is the agent of the most common bacterial sexually transmitted infection worldwide, with a significant impact on women's health. Despite the increasing number of studies about the vaginal microbiome in women with CT infections, information about the composition of the anal microbiome is still lacking. Here, we assessed the bacterial community profiles of vaginal and anal ecosystems associated or not with CT infection in a cohort of Caucasian young women. Methods. A total of 26 women, including 10 with a contemporary vaginal and ano-rectal CT infection, were enrolled. Composition of vaginal and anal microbiome was studied by 16S rRNA gene profiling. Co-occurrence networks of bacterial communities and metagenome metabolic functions were determined. Results. In case of CT infection, both vaginal and anal environments were characterized by a degree of dysbiosis. Indeed, the vaginal microbiome of CT-positive women were depleted in lactobacilli, with a significant increase in dysbiosis-associated bacteria (e.g., Sneathia, Parvimonas, Megasphaera), whereas the anal microbiota of CT-infected women was characterized by higher levels of Parvimonas and Pseudomonas and lower levels of Escherichia. Interestingly, the microbiome of anus and vagina had numerous bacterial taxa in common, reflecting a significant microbial 'sharing' between the two sites. In the vaginal environment, CT positively correlated with Ezakiella spp. while Gardnerella vaginalis co-occurred with several dysbiosis-related microbes, regardless of CT vaginal infection. The vaginal microbiome of CT-positive females exhibited a higher involvement of chorismate and aromatic amino acid biosynthesis, as well as an increase in mixed acid fermentation. Conclusions. These data could be useful to set up new diagnostic/prognostic tools, offering new perspectives for the control of chlamydial infections.

Effect of different fatty acids on Neisseria gonorrhoeae viability.

Neisseria gonorrhoeae (GC) is the agent of one of the most common bacterial sexually transmitted infections worldwide. The possible development of 'untreatable' infections points out the need for antibiotic-sparing methods to reduce the number of gonococcal infections. In this context, fatty acids are interesting candidates as next-generation antibacterial agents. The aim of this study was to investigate the bactericidal effects of selected fatty acids on GC viability, as well as to observe their biological effects by means of transmission electron microscopy. The cytotoxicity of these compounds on human cervical cells (HeLa), chosen as a model of genital mucosa, was assessed as well. Lauric, myristic, and palmitic acid displayed high killing activity against GC in concentrations ranging between 100 µM and 25 µM, whereas the antimicrobial effect of oleic and butyric acids was present in concentrations between 1 mM and 0.25 mM. Modifications induced by fatty acids on the GC cell included the disorganization of the cytoplasmic structure, the distortion of pili/fimbriae, and the separation of the inner and outer membrane layers. For concentrations active against GC, fatty acids were not toxic for cervical cells. Our data can help in promoting innovative antibiotic-free compounds for the treatment of GC infections.

Pre-Pregnancy Diet and Vaginal Environment in Caucasian Pregnant Women: An Exploratory Study.

Vaginal microbes and their metabolic products have crucial functions, affecting local immunity development and maternal-fetal health. The composition of the vaginal microbiome can vary in response to various factors, including body mass index (BMI), and diet. In this study we get new insights into the vaginal ecosystem of Caucasian women (n = 24) at the first trimester of pregnancy, assessing whether pre-pregnancy diet can affect the structure of the vaginal environment in terms of bacterial composition and vaginal metabolite concentration. We characterized 1) the vaginal bacterial composition (Nugent score), 2) the vaginal metabolic profiles (1H-NMR spectroscopy), and 3) the dietary nutrient intake by means of a validated food frequency questionnaire. Pre-pregnancy BMI was negatively related to vaginal health status, indicating that women who begin pregnancy overweight/obese have a greater occurrence of vaginal dysbiosis during pregnancy. A lactobacilli-dominated vaginal microbiota was negatively associated with higher pre-pregnancy intake of animal-sourced protein. Conversely, a higher pre-pregnancy consumption of total carbohydrates and sugars seemed to be a protective factor for vaginal health. The vaginal environment of BV-women was characterized by higher levels of biogenic amines and organic acids, whereas higher levels of phenylpropionate and diverse amino acids were fingerprints of a healthy vaginal status. A significant association between a higher pre-pregnancy BMI and several dysbiosis-related vaginal metabolites was also found. Our study shed light on the role of pre-pregnancy BMI and diet on the vaginal environment during pregnancy, underlining the importance of limiting protein intake from animal foods to maintain a healthy lactobacilli-dominated microbiota.

New Insights into Vaginal Environment During Pregnancy.

During pregnancy, the vaginal ecosystem undergoes marked changes, including a significant enrichment with Lactobacillus spp. and profound alterations in metabolic profiles. A deep comprehension of the vaginal environment may shed light on the physiology of pregnancy and may provide novel biomarkers to identify subjects at risk of complications (e.g., miscarriage, preterm birth). In this study, we characterized the vaginal ecosystem in Caucasian women with a normal pregnancy (n = 64) at three different gestational ages (i.e., first, second and third trimester) and in subjects (n = 10) suffering a spontaneous first trimester miscarriage. We assessed the vaginal bacterial composition (Nugent score), the vaginal metabolic profiles (1H-NMR spectroscopy) and the vaginal levels of two cytokines (IL-6 and IL-8). Throughout pregnancy, the vaginal microbiota became less diverse, being mainly dominated by lactobacilli. This shift was clearly associated with marked changes in the vaginal metabolome: over the weeks, a progressive reduction in the levels of dysbiosis-associated metabolites (e.g., biogenic amines, alcohols, propionate, acetate) was observed. At the same time, several metabolites, typically found in healthy vaginal conditions, reached the highest concentrations at the end of pregnancy (e.g., lactate, glycine, phenylalanine, leucine, isoleucine). Lower levels of glucose were an additional fingerprint of a normal vaginal environment. The vaginal levels of IL-6 and IL-8 were significantly associated with the number of vaginal leukocytes, as well as with the presence of vaginal symptoms, but not with a condition of dysbiosis. Moreover, IL-8 concentration seemed to be a good predictor of the presence of vaginal Candida spp. Cytokine concentrations were negatively correlated to lactate, serine, and glycine concentrations, whereas the levels of 4-hydroxyphenyllactate, glucose, O-acetylcholine, and choline were positively correlated with Candida vaginal loads. Finally, we found that most cases of spontaneous abortion were associated with an abnormal vaginal microbiome, with higher levels of selected metabolites in the vaginal environment (e.g., inosine, fumarate, xanthine, benzoate, ascorbate). No association with higher pro-inflammatory cytokines was found. In conclusion, our analysis provides new insights into the pathophysiology of pregnancy and highlights potential biomarkers to enable the diagnosis of early pregnancy loss.