Search Results (496)

Background: Genital tract infections and dysbiosis-related conditions contribute substantially to women’s sexual and reproductive morbidity. In South America, evidence on clinically relevant genital microorganisms remains fragmented across countries, populations, and diagnostic approaches. This systematic review and meta-analysis synthesized the prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Gardnerella vaginalis, and Candida spp. among women in South America. Methods: We searched PubMed/MEDLINE, Web of Science, Cochrane Library, and SciELO for studies published from 1 January 2014 to 29 February 2024. Eligible studies reported prevalence data for at least one target microorganism in female populations from South American countries. Two reviewers independently screened studies, extracted data, and assessed methodological quality using Joanna Briggs Institute criteria for prevalence studies. Crude prevalence and random-effects pooled prevalence estimates with 95% confidence intervals were calculated. The review protocol was registered in PROSPERO (CRD420261324060). Results: Of 629 records identified, 51 studies from eight South American countries and French Guiana met the eligibility criteria for the systematic review, and 46 contributed to the main pooled prevalence meta-analysis. Substantial between-study heterogeneity was observed across all pathogen-specific analyses. Pooled prevalence was highest for G. vaginalis (28%), followed by Candida spp. (12%), C. trachomatis (7%), T. vaginalis (6%), and N. gonorrhoeae (3.2%). Conclusions: This review highlights the heterogeneous burden of clinically relevant genital microorganisms among women in South America and supports standardized diagnostic approaches, clearer phenotypic definitions, and stronger surveillance across underrepresented regional settings. Full article

Neisseria gonorrhoeae is a major sexually transmitted pathogen and global public health concern. A porA pseudogene-targeting TaqMan quantitative PCR (qPCR) assay was evaluated as a complementary laboratory-based method for the qualitative detection of N. gonorrhoeae and exploratory Z017-calibrated molecular estimation in cultured reference strains. Two candidate probe sets were evaluated, and the probe set generating a 157 bp amplicon was selected for a defined two-step qPCR workflow with a 52 min on-instrument amplification runtime. In silico analysis showed compatible target site arrangements in all 201 N. gonorrhoeae genomes and none in 114 non-target organisms. The assay detected N. gonorrhoeae DNA down to 1 × 10⁻⁵ ng/µL, with no amplification of the tested non-target organisms. All 23 N. gonorrhoeae reference strains and 80 N. gonorrhoeae-positive clinical specimens were detected, whereas no amplification was observed in the 20 negative clinical specimens, using DNA extracted from the primary clinical specimens. A standard curve was generated from the titered Z017 reference material (R² = 0.999; efficiency, 94.6%), which enabled reproducible qPCR-derived CFU/mL-equivalent molecular estimation in cultured World Health Organization reference strains. The qPCR-derived estimates were lower than the paired culture-derived CFU/mL values, and the paired log10-transformed values did not show a statistically significant correlation. These findings provide an assay design and validation-oriented laboratory-based framework combining in silico sequence assessment, the qualitative detection of N. gonorrhoeae in clinical specimens, and exploratory molecular estimation in cultured reference strains, supporting future assay development and bacterial burden research. Full article

Smokeless tobacco (SLT) consumption is a significant risk factor for oral dysbiosis and oral cancer in South Asian countries, including India. However, its impact on oral microbial ecology, functional restructuring, and sex-specific microbial responses remains unclear. The present study aimed to evaluate tobacco-associated oral microbiome dysbiosis across different subject groups (addicted male/AM, addicted female/AF, non-addicted male/NAM, and non-addicted female/NAF) using a controlled sibling-based pooled temporal representative framework. To reduce short-term temporal variability and generate representative oral microbiome profiles, oral gargle samples were collected daily for seven days and pooled within each study group prior to DNA extraction and 16S rRNA gene sequencing. Proteobacteria, Firmicutes and Bacteroidetes were the dominant phyla in all samples. Addicted users showed a higher Firmicutes/Bacteroidetes ratio, fewer cultivable species, and more pathobionts, along with lower Shannon diversity in tobacco addiction and a partial separation in beta diversity between addicted and non-addicted samples. The enrichment of Streptococcus, Gemella, Neisseria, Veillonella, Acinetobacter, and Pseudomonas in tobacco-associated microbiomes and Comamonas, Chryseobacterium, Delftia, Flavobacterium, and related taxa in non-addicted individuals were consistently identified by all three analyses, that is, differential abundance, STAMP, and SIMPER. A shared core oral microbiome and unique “tobacco-associated” microbial signatures were observed. Orotype mapping showed that the transition in the microbial community to a Streptococcus-dominated (S-type) dysbiotic state was driven by tobacco addiction, introducing a novel conceptual framework, the Tobacco-Associated Dysbiosis Index (TDI), which showed higher values in addicted participants. Furthermore, functional prediction analysis revealed increased enrichment of ammonia oxidation, dehalogenation, sulfate reduction, nitrite reduction, chitin degradation, and xenobiotic metabolism pathways, highlighting microbial adaptation towards detoxification. In summary, chronic exposure to smokeless tobacco is linked to ecological imbalance, pathobiont enrichment, loss of microbial diversity, functional dysbiosis, and metabolic reprogramming, suggesting descriptive ecological patterns that may be relevant to chronic inflammation and oral carcinogenesis. Full article

Infectious diseases remain a major global public health concern, disproportionately causing morbidity and mortality in low- and middle-income countries. Sexually Transmitted Infections (STIs) heavily affect sexually active populations. Sex workers, encompassing female sex workers (FSWs), male sex workers (MSWs), and transgender/gender-diverse individuals, face heightened vulnerabilities due to occupational exposures, structural barriers, stigma, and criminalization. While substantial focus has historically centered on HIV, non-HIV STIs such as Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum, and viral hepatitis present significant co-morbidity. Crucially, drug resistance across these pathogens presents distinct biological and epidemiological challenges: bacterial antimicrobial resistance (AMR) in N. gonorrhoeae and C. trachomatis, antiretroviral (ARV) resistance in HIV, and direct-acting antiviral (DAA) resistance in hepatitis B and C. This perspective article synthesizes the current epidemiological landscape, critiques the reliance on syndromic management over molecular diagnostics (e.g., NAATs, point-of-care, and genomic surveillance), highlights diagnostic stewardship, and outlines priority public health strategies aligned with the WHO 2022–2030 Global Health Sector Strategies. Full article

Canine periodontitis is one of the most prevalent chronic diseases for dogs over two years of age. Periodontal pockets may serve as a reservoir for opportunistic bacteria including Pasteurella stomatis, Neisseria animaloris, and Streptococcus canis; however, data on their antimicrobial susceptibility and potential One Health relevance remain limited. This pilot study investigated culturable bacterial isolates recovered from periodontal pockets of dogs with different stages of periodontal disease. Subgingival samples were collected under general anesthesia after periodontal probing and dental radiographic assessment during routine comprehensive oral health assessment and treatment (COHAT) procedures. Bacterial isolates were cultured, identified using MALDI-TOF MS, and tested for minimum inhibitory concentrations (MIC) against amoxicillin (AML), doxycycline (DX), trimethoprim–sulfamethoxazole (SXT), gentamicin (CN), chloramphenicol (C), and ciprofloxacin (CIP). In total, 122 isolates from 101 dogs were analyzed, including Pasteurella stomatis (n = 54), Neisseria animaloris (n = 33), and Streptococcus canis (n = 35). MIC distributions varied between bacterial species and antimicrobial agents, while interpretation was limited by the lack of species-specific veterinary medicine breakpoints for some isolates. These preliminary findings highlight the need for larger standardized studies to support antimicrobial resistance surveillance in canine oral microbiota. Full article

In contrast to honeybees, the Australian stingless bee Tetragonula carbonaria appears to be robust against microbial pathogens. Streptomyces sp. 127Q, isolated from T. carbonaria, inhibited the growth of Lysinibacillus sphaericus, which is the only microorganism reported to affect T. carbonaria. The antimicrobials were purified from Streptomyces sp. 127Q by bioassay-guided isolation using ethyl acetate extraction and Diaion HP20 chromatography, followed by reverse phase HPLC fractionation. The antimicrobial compounds were identified by high-resolution mass spectrometry, UV-Vis-spectroscopy, nuclear magnetic resonance spectroscopy, and genome mining as new members of the trioxacarcin/gutingimycin family having a 1,2-dihydroxyanthraquinone aromatic core structure. A closely related gutingimycin with a 1,2-dihydroxyanthraquinone moiety was previously observed in a crystallisation experiment of trioxacarcin A with an oligonucleotide. Streptomyces sp. 127Q produces a wide range of trioxacarcins/gutingimycins. At the onset of trioxacarcins production, Streptomyces sp. 127Q appeared to rapidly convert trioxacarcin epoxides with water, guanine, and nicotinic acid. The 1,2-dihydroxyanthraquinone trioxacarcins, trioxacarcin 692 and trioxacarcin 780, inhibited L. sphaericus with minimal inhibitory concentrations (MICs) of 37.5 μM and 75 μM, respectively. The MIC against Escherichia coli and Staphylococcus aureus was 75 μM and 150 μM, respectively. In the photoantimicrobial screening, the MIC for trioxacarcin 692 against E. coli and S. aureus decreased by 8-fold, and for trioxacarcin 780 by 4-fold. Following light pretreatment, trioxacarcin 692 (9.4 μM) inhibited E. coli and S. aureus at concentrations comparable to those of the established antibiotics ciprofloxacin and vancomycin. Neisseria gonorrhoeae was only inhibited at an MIC of ca. 18.8 μM after light preincubation. The 1,2-dihydroxyanthraquinone trioxacarcins constitute powerful antimicrobial compounds belonging to the trioxacarcin/gutingimycin family. Full article

Toxoplasmosis is a zoonotic disease caused by the intracellular protozoan parasite Toxoplasma gondii, with marsupials recognized as particularly vulnerable hosts. This is a case report of the integrated investigation of fatal illness in a captive red kangaroo (Osphranter rufus). Multisystemic lesions with hemorrhages and congestion of the lungs, liver, spleen, kidneys, heart, and intestines were detected during gross necropsy. Hematological analysis demonstrated leukopenia (2.90 × 10⁹/L), neutropenia (1.19 × 10⁹/L), lymphopenia (1.53 × 10⁹/L), and increased hematocrit (61.2%). The serum alanine aminotransferase level was very high (216 U/L), and urea nitrogen and creatinine were elevated, indicating involvement of the liver and kidneys. A bacteriological investigation based on the sequences of 16S rDNA revealed the presence of Neisseria weaveri from the heart and Staphylococcus arlettae from the kidney; no Salmonella spp. or Clostridium perfringens were isolated. The DNA of T. gondii was detected by PCR in various tissues, including spleen (low-level) and lung (high-level). Pathohistological examination of the spleen demonstrated lymphoid depletion and inflammatory infiltration without tissue cysts, tachyzoites, granulomatous inflammation, or multifocal necrosis. Characteristic lesions are absent, and there is no way to definitively attribute mortality to fatal toxoplasmosis, as the lung had the strongest PCR signal. Collectively, these results support PCR-based molecular detection of disseminated T. gondii DNA and emphasize the necessity of comprehensive histopathological correlation with all PCR-positive organs in future investigations. Full article

Neisseria meningitidis is a bacterium that can cause high-mortality invasive infections. Asymptomatic carriage can serve as a source of infection. This study aimed to determine the meningococcal colonisation rate and risk factors for colonisation among children aged 1–6 years attending eight childcare institutions in three regions in the Northern part of Hungary. Oropharyngeal swab specimens were obtained from 180 children, and risk factors for carriage were assessed by questionnaires filled out by parents. qPCR was applied to detect meningococci and determine the serogroup. The meningococcal colonisation rate was 15.6% (28/180). One meningococcus detected belonged to serogroup X; all others were non-groupable meningococci. Meningococcal colonisation was significantly more prevalent among girls (21.5% vs. 9.2% in boys) and children living in the Central Transdanubia region. No significant association was found with other risk factors examined. According to the parental answers, 70.0% of the children were vaccinated against meningococcus; this might be an explanation for the absence of vaccine serogroups. This is the first study to examine meningococcal carriage among young children in Hungary. Full article

Smoking is a major modifier of respiratory health, but its effects on the respiratory microbiota remain incompletely defined across airway niches and exposure types. We conducted a PRISMA-guided systematic review of PubMed, Web of Science, and Scopus, to identify human studies using culture-independent sequencing to examine associations between smoking and microbiota composition and diversity in anatomically defined upper and lower airway sites. Thirteen studies met the inclusion criteria. The exploratory meta-analysis of bronchoalveolar lavage inverse Simpson diversity from two studies did not provide a precise pooled estimate between smoking and diversity and was highly heterogeneous (SMD −1.63, 95% CI −5.07 to 1.81; I² = 96%). Across studies, smoking was more often associated with reduced alpha diversity. In the oropharynx, smokers more consistently showed higher abundance of Streptococcus, Veillonella, Actinomyces, and Atopobium, with lower abundance of Neisseria and other oral commensals. In the lower airways, smoking was more often associated with reduced Prevotella and Veillonella. Nasal and nasopharyngeal findings were smaller and more variable. Overall, current evidence suggests site-specific smoking-associated respiratory microbiota remodeling. However, precise pooled estimates remain limited by substantial inter-study heterogeneity. Therefore, the meta-analysis should be interpreted as exploratory and hypothesis-generating. Full article

Salivary microbiome profiling may represent a promising non-invasive approach for characterizing OSCC-associated microbial patterns and longitudinal microbiome dynamics during patient management. This exploratory pilot study aimed to longitudinally assess salivary microbiota profiles in patients with oral squamous cell carcinoma (OSCC) before and after tumor resection using Oxford Nanopore Technology. Unstimulated saliva samples were collected from 16 patients with OSCC at two time points (before and after tumor resection) and from 10 OSCC-free reference subjects. Microbial DNA was extracted using the QIAamp DNA Blood Kit (QIAGEN GmbH, Hilden, Germany) and subjected to long read metagenomic sequencing using the Oxford Nanopore MinION platform (v. 20.06.4, Oxford Nanopore Technologies, Oxford, UK). Taxonomic profiling was performed to longitudinally characterize salivary microbiota composition within patients and to provide descriptive comparisons with the OSCC-free reference cohort. Longitudinal analysis identified differences in salivary microbiota profiles between pre- and post-resection samples. Before surgery, an increased relative abundance of Neisseria subflava and Leptotrichia buccalis was observed. Post-surgical samples showed higher levels of Glaesserella parasuis, Streptomyces anulatus, and Lactobacillus species. Distinct microbial patterns were also descriptively observed between OSCC patients and OSCC-free controls, suggesting disease-associated dysbiosis. This exploratory longitudinal pilot study suggests differences in salivary microbiota profiles between samples collected before and after tumor resection in patients with OSCC, including changes in taxonomic composition and reduced alpha diversity. Given the limited sample size and the potential influence of unmeasured perioperative factors, these findings should be considered hypothesis-generating. Larger, well-controlled longitudinal studies incorporating standardized oral health assessment and detailed perioperative metadata are required to clarify the biological and clinical relevance of these observations. Full article

Background and Objectives: Antimicrobial resistance in Neisseria gonorrheae threatens the effectiveness of empirical gonorrhoea treatment. Although global surveillance evidence is increasingly available, resistance data are not consistently reported separately for men with urethral or urogenital infection. This review evaluated antibiotic-specific resistance in N. gonorrhoeae isolates from this clinically defined population and examined the geographic and reporting limitations of the available evidence. Materials and Methods: PubMed, Scopus, ScienceDirect, Google Scholar, and relevant WHO GASP/EGASP resources were searched from inception to [updated search date]. Eligible observational or surveillance studies reported categorical resistance classifications or extractable antibiotic-specific resistant counts and denominators for male urethral or urogenital isolates. Antibiotic-specific proportions were synthesized using random-effects meta-analysis where pooling was considered appropriate. Sparse-event outcomes were additionally evaluated using study-specific estimates and aggregate resistant/tested counts. Certainty of evidence was assessed using the GRADE framework adapted for prevalence outcomes. Results: Six studies met the eligibility criteria, including the 2025 multinational EGASP study. Cefixime resistance was reported in 748 of 13,154 isolates, corresponding to an aggregate proportion of 5.69%; however, the random-effects estimate was unstable because three studies reported no resistant isolates and events were concentrated in two large datasets. Ceftriaxone resistance varied from 0% to 5.17%, with a pooled estimate of 0.32% (95% CI 0.05–2.15; I² = 97.8%). Resistance was high but heterogeneous for ciprofloxacin (71.84%, 95% CI 7.53–98.77; I² = 97.3%) and penicillin (62.47%, 95% CI 36.87–82.58; I² = 98.1%). Spectinomycin resistance was 2.57% (95% CI 1.58–4.16; I² = 0%), while azithromycin resistance was 6.38% (95% CI 4.38–9.21; I² = 94.9%). Certainty of evidence was very low for all outcomes. Conclusions: Evidence specifically reporting resistance in male urethral or urogenital N. gonorrhoeae isolates remains limited and geographically uneven. Contemporary EGASP data demonstrate that ceftriaxone resistance is not uniformly low across surveillance settings. The pooled estimates should be interpreted as exploratory summaries rather than current global prevalence values or an independent basis for treatment selection. Standardized reporting of sex, anatomical site, breakpoints, MIC distributions, and resistant/tested counts is needed to improve future surveillance synthesis. Full article

Sexually transmitted infections remain a major public health concern among men who have sex with men (MSM), particularly due to the high frequency of coinfections and the limitations of syndromic management. This study aimed to describe the frequency of bacterial sexually transmitted and urogenital pathogens among symptomatic MSM attending two specialized sexual health clinics in Mexico City. A prospective cross-sectional study was conducted with 150 adult MSM presenting symptoms suggestive of urethritis. Urethral swab samples were analyzed using a multiplex real-time polymerase chain reaction (PCR) assay for the detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum, Ureaplasma parvum, and Trichomonas vaginalis. At least one pathogen was detected in 91/150 participants (60.7%). N. gonorrhoeae was the most frequent pathogen (33.3%), followed by U. urealyticum (15.3%), M. genitalium (9.3%), and C. trachomatis (9.3%). Coinfections were identified in 15 participants, representing 10.0% of the total population and 16.5% of those with a positive PCR result. Most coinfections involved N. gonorrhoeae, particularly with C. trachomatis. These findings provide descriptive microbiological evidence on the frequency and coinfection patterns of bacterial sexually transmitted infections (STIs) associated pathogens among symptomatic MSM attending specialized sexual health clinics in Mexico City. The high detection rate and occurrence of concurrent infections highlight the limitations of syndromic management and support the value of timely multiplex molecular diagnostics to improve etiological characterization, antimicrobial stewardship, and clinical decision-making in this population. Full article

Antimicrobial resistance in Neisseria gonorrhoeae is a global concern. Spectinomycin is unusual in that resistance can emerge rapidly during localized outbreaks yet often disappears from clinical populations after drug withdrawal, suggesting an associated growth cost. To investigate evolutionary routes to spectinomycin resistance, we performed in vitro selection on two N. gonorrhoeae strains and two commensal Neisseria species. Derived cell lines were characterized by minimum inhibitory concentration (MIC) determination, whole-genome sequencing, growth-kinetics analysis, and molecular modelling of the RpsE (ribosomal protein S5) interface with the ribosome. All high-level resistant isolates (MIC > 2048 mg/L) acquired substitutions or deletions in loop 2 of RpsE. Modelling showed that these mutations perturb the conserved network of stabilizing contacts between RpsE residues Lys25 (Lys23 in E. coli numbering) and Lys28 (Lys26), as well as helix 34 nucleotides G922, A923, and C1069 of 16S rRNA, potentially altering the architecture of the spectinomycin-binding site. These mutations were associated with high-level resistance but reduced growth rates, with the resulting growth costs depending on the specific pattern of contact rearrangements. Convergent evolution towards loop 2 mutations supports the existence of a constrained mutational pathway to high-level spectinomycin resistance in the strains and species examined here. This constraint may help explain the rapid decline of resistant variants in the absence of drug pressure and underscores the importance of genomic surveillance. Full article

Invasive bacterial infections caused by Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis remain a major public health concern. This study aimed to perform the molecular characterization of bacterial strains responsible for meningitis in patients of all ages who met the World Health Organization case definition for meningitis and had cerebrospinal fluid samples collected between January 2021 and December 2022 at the Clinical Bacteriology Laboratory of the National Public Health Institute of Mali. We conducted a surveillance-based observational study using national surveillance data collected between January 2021 and December 2022. Data were collected continuously and in real time throughout the study. The analysis was cross-sectional and descriptive. Data were obtained from samples received at the laboratory, accompanied by individual clinical notification forms. For each sample, demographic data and additional clinical information, including vaccination status, were collected. Infection was diagnosed by isolating invasive strains through culture, confirmed by real-time triplex PCR, and positive cases were further characterized by real-time triplex PCR for serotyping. Overall, 103 infections were confirmed among the 1000 samples received, corresponding to a positivity rate of 10.3%. S. pneumoniae predominated with 62%, followed by H. influenzae type b with 36% and N. meningitidis serogroup X with 2%. The identified serotypes of pneumococcus were predominantly not covered by existing vaccines, particularly serotype 23A (38.30%), while others, including serotypes 1 (17.02%) and 3 (10.63%), are included in the PCV13 vaccine. The distribution of cases by age and gender shows a predominance of males, accounting for 60.2% of cases (62/103). The 0–5 age group is by far the largest, accounting for 76.7% of cases (79/103), with males representing 58. 22% (46 cases). These findings highlight the importance and the need for continuous monitoring surveillance of circulating strains and strengthening vaccination efforts to improve prevention. Full article

Sample adequacy control (SAC) is a validated specimen-specific marker or metric, threshold, and reporting rule used to decide whether a negative molecular result is supported by the submitted specimen. SAC is not simply a cell-count or biomass check. Depending on specimen type and target, an unsupported negative result may reflect insufficient or nonrepresentative material, adequacy-marker degradation, inefficient transfer or extraction, matrix-associated inhibition, or mismatch between marker and anatomical compartment. SAC is therefore best understood as an integrated specimen-process adequacy control for negative-result interpretation. Its result should be reported as valid, borderline, or invalid for the intended negative interpretation, not as detected/not detected like the disease-specific biomarker. This perspective synthesizes quantitative polymerase chain reaction (qPCR) control guidance, preanalytical-quality literature, respiratory and enteric sampling studies, human papillomavirus (HPV) evidence, cartridge-assay precedents, and decentralized workflows. Direct prospective evidence that SAC improves patient or epidemiologic outcomes remains limited; available evidence is outcome-adjacent or operational, including HPV cellularity-control associations, Chlamydia trachomatis/Neisseria gonorrhoeae (CT/NG) and Ebola cartridge precedents, respiratory workflows showing lower pathogen positivity at higher SAC quantification cycle (Cq) strata, and reporting rules that change validity or recollection decisions. We propose a risk-based framework for selecting, validating, reporting, and monitoring SAC, with particular value in direct-amplification, point-of-care, and self-collection workflows where preanalytical failures affect negative-result interpretation. Full article