Frontiers in Cellular and Infection Microbiology最新文献

Introduction: Brucella canis is a zoonotic pathogen that infects both dogs and humans, yet its evolutionary and phylogenetic characteristics are poorly understood.

Methods: Here, we comprehensively characterized an isolated strain of B. canis through integrated bacteriological, comparative genomic, and whole-genome sequencing-based core genome single-nucleotide polymorphism (WGS-cgSNP) analyses.

Results: B. canis YN20042 was isolated from a febrile patient (38 °C) with sweating and fatigue. The culture exhibited rough, grayish white, sticky, and opaque colonies. The isolate was identified as Brucella strain by a BCSP-31 polymerase chain reaction (PCR) assay, which yielded an amplicon of the expected 223-bp size, and was classified as a B. canis strain by conventional biotyping. The patient reported frequent contact with dogs and livestock. The strain showed a 99.99% average nucleotide identity to the B. canis reference strain ATCC 23365 (GCA_000018525.1). An in silico multilocus sequence typing (MLST) analysis showed that the strain belonged to sequence type 21, which was consistent with its classification within B. canis. The genome of strain YN20042 exhibited strong synteny with the reference strain and showed no detectable structural variations. It harbored 12 predicted virulence factors encompassing 71 associated genes, although it notably lacked the wbpL gene but contained a Brucella suis mprF gene. A further analysis identified predicted mutations in key virulence genes (eryA, pagN, bmaC, cfa1, and cfa2) and predicted multiple horizontally acquired genes, collectively suggesting a complex evolutionary trajectory involving both gene variants and potential recombination events. A WGS-SNP analysis revealed that YN20042 clustered closely with strains isolated from Zhejiang and Beijing, indicating a high degree of genetic relatedness.

Conclusion: The first isolation of B. canis in the region expands the local spectrum of pathogenic Brucella and highlights the substantial infection risk for individuals with close dog and livestock contact. Enhanced surveillance, targeted screening of high-risk populations, and public health education are necessary to mitigate the risk of B. canis transmission.

Purpose: The vaginal microecological parameters as a critical immune barrier, yet their age-dependent interaction with Human papillomavirus (HPV) infection remains poorly understood. To characterize age-dependent vaginal microbiota composition and function across the female lifespan, and to evaluate the selective impact of HPV infection on microecological stability and infectious risk.

Methods: A total of 23,672 women were stratified into four age groups (18-34, 35-44, 45-55, and >55 years). Vaginal microecology was evaluated using Gram-staining, pH, hydrogen peroxide (H₂O₂), leukocyte esterase, and sialidase assays. HPV genotyping was performed in 2,116 women. Statistical analysis employed univariate screening, LASSO regression for variable selection, and multivariate logistic regression to identify independent microecological risk factors, with Benjamini-Hochberg false discovery rate (FDR) correction applied across all tests. A targeted subset (n = 88) underwent 16S rRNA sequencing with differential taxa analysis using LEfSe and Random Forest, as well as BugBase phenotype prediction and COG/KEGG pathway analysis, to validate age-specific HPV-microbiome interactions.

Results: Normal flora prevalence declined linearly with age (78.7% vs. 48.8% postmenopause, q<0.001), while microbial diversity peaked during perimenopause. HPV infection was selectively associated with increased bacterial vaginosis (BV) (41.58% vs. 36.46%, q=0.032) and sialidase activity (28.14% vs. 21.69%, q=0.002), but decreased vulvovaginal candidiasis (VVC, 10.57% vs. 15.66%, q=0.003). Functional analyses revealed HPV-driven anaerobic enrichment (Gardnerella, Atopobium) and profound metabolic reprogramming specifically in women aged 35-44 years, marked by upregulation of lipopolysaccharide biosynthesis (fold change [FC] = 37.3, q = 0.028), arachidonic acid metabolism (FC = 33.3, q = 0.038), and NOD-like receptor signaling (FC = 62.1, q < 0.001), with concurrent apoptosis suppression (FC = 0.35, q = 0.046). Age-stratified risk modeling identified loss of H₂O₂-producing Lactobacilli as the strongest HPV risk factor in younger women (18-34 years, adjusted odds ratio [aOR] = 0.59), whereas BV and sialidase dominated in midlife (35-44 years, aOR = 1.64); no significant risk factors emerged postmenopause.

Conclusion: HPV infection selectively remodels vaginal microbiota composition and metabolic function in an age-dependent manner, with midlife women (35-44 years) representing a critical window for microbiota-based HPV prevention strategies.

Background: Streptococcus agalactiae increases the risk of adverse pregnancy outcomes and neonatal infections. Clindamycin is a key alternative for intrapartum prophylaxis in penicillin-allergic women, but the prevalence of clindamycin-resistant S. agalactiae is increasing, posing a significant clinical challenge.

Methods: A total of 178 strains isolated from tertiary hospitals in Jinan and Qingdao, Shandong Province, China, were characterized using antimicrobial susceptibility testing, whole-genome sequencing, multilocus sequence typing, serotyping, and analysis of resistance and virulence genes.

Results: All strains were susceptible to penicillin, ampicillin, linezolid, vancomycin, and tigecycline. In contrast, resistance rates to erythromycin, levofloxacin, and tetracycline were 95.5%, 60.1%, and 56.7%, respectively. Six serotypes and 15 sequence types belonging to eight clonal complexes were identified. Notable regional differences were observed. The Ib-ST10-CC12 lineage dominated in Jinan, whereas V-ST529-CC327 was predominant in Qingdao. The resistance gene mreA was ubiquitous (100%), followed by ermB (80.3%). The key virulence genes cylE, hylB, and pavA, were detected in all strains. fbsA (99.4%), the alpha protein family (98.9%), cfb (98.3%), the Pilus Island gene cluster (94.9%), and lmb (92.7%) were also highly prevalent. The two major clindamycin resistance genes, erm and lnuB, exhibited distinctly different enrichment patterns among S. agalactiae clonal complexes, despite a certain overlap in CC19 and CC327. Specifically, erm was significantly enriched in CC12 (serotype Ib), CC19 (III/V), and CC327 (III/V). In contrast, lnuB was predominantly restricted to CC19 and CC327, where it defined a unique phylogenetic subcluster. Significant differences in resistance and virulence gene profiles were observed across different clonal complexes.

Conclusion: Clindamycin-resistant S. agalactiae in late-pregnancy women in Shandong Province, China exhibits a broad resistance spectrum, diverse molecular types, and significant regional heterogeneity. These findings underscore the need for continued surveillance and region-specific strategies for preventing neonatal S. agalactiae infections.

Pulcherriminic acid (PA) relay is a recently discovered phenomenon in which the Bacillus subtilis employs branching biofilms to relay the antimicrobial pigment, pulcherriminic acid towards the pathogen. PA interacts with the free iron in the environment to form the reddish-pink pigment, pulcherimin, which subsequently accumulates on the pathogen depriving them of the essential iron. In Staphylococcus aureus, the ferric uptake regulator (Fur) system plays a vital role in maintaining iron homeostasis, virulence, and biofilm formation. The perspective article discusses the plausible mechanistic insights on the impact of PA relay in hampering the Fur system. Taken together, these findings highlight PA and PA-producing Bacillus species as a promising alternative for mitigating drug resistant S. aureus infections.

Carbapenemase-producing Enterobacterales (CPE) pose a critical public health threat. Recent reports highlight that CPE emergence in companion animals mirrors that found in humans, underscoring the need for a One Health approach to investigating transmission routes. This Perspective article outlines an interdisciplinary model developed as part of the Centers for Disease Control and Prevention-funded Pathogen Genomics Center of Excellence at the Minnesota Department of Health (MDH) to investigate CPE transmission across human and animal populations. This represents one of the first operational One Health models linking companion animal and human CPE via whole genome sequencing (WGS) at a state-level public health laboratory. Using WGS, 94 companion animal isolates were characterized and revealed diverse genetic lineages from December 2022 through December 2024 in the USA. Genetically linked clusters were identified, including CPE isolates from companion animals and humans. One notable cluster linked human infections with CPE detected in a veterinary hospital. Despite the success of this approach to detect clusters, there were significant challenges, including investigation delays related to sequencing and epidemiology priorities and capacity, resource constraints, and human participant hesitancy. Our findings demonstrate the importance of integrating genomic data with clinical and epidemiological insights, fostering communication between veterinary and public health sectors, and expanding veterinary WGS infrastructure. Ultimately, we advocate for broader public health engagement in veterinary settings to mitigate antimicrobial resistance and improve surveillance of zoonotic transmission pathways.

Introduction: Microbiota alterations at multiple sites are associated with cervical cancer (CC). However, it is unclear whether CC lymph node metastasis (LNM) is indeed associated with microbiota alterations, whether the microbiota is generally suitable for screening CC LNM-related taxa.

Materials and methods: We performed 16S rDNA sequencing of samples from oral swabs, feces, urine, and vaginal secretions from CC patients to clarify microbiota characteristics of LNM group. And we constructed a LNM prediction model for CC based on specific flora at each site.

Results: The α-diversity of the urinary microbiota (P _Sob = 0.0272, P _Pielou = 0.0278, P _Shannon = 0.0209 and P _Simpson = 0.0465) was reduced in the LNM group compared to the non-LNM group, and significant differences were observed in the structure of the gut (R² = 0.0266, P = 0.033) and urine (R² = 0.0379, P = 0.002) microbiota between the two groups. The establishment of a predictive model based on oral specific flora, including Erysipelotrichaceae UCG-003 sp., Eubacterium halli group, and Staphylococcus has enabled the differentiation of CC lymph node status. The area under the ROC curve was 0.798. The Yoden index, sensitivity and specificity of this prediction model were 0.520, 57.9% and 94.1%, respectively.

Conclusion: CC patients with LNM have significant microbiological changes at multiple sites. The predictive model based on oral bacteria can provide a noninvasive and simple method for assessing LNM in CC.

Introduction: Chronic pulmonary aspergillosis (CPA) is a major sequela of pulmonary tuberculosis (PTB), posing a significant health burden in high-prevalence regions like China. However, data on the clinical spectrum, diagnostic challenges, and outcomes of PTB-associated CPA in the Chinese population remain limited.

Methods: This retrospective single-center study analyzed 220 patients with PTB-associated CPA in Wuhan Pulmonary Hospital (January-December 2022). CPA was diagnosed and subtyped according to European guidelines: simple aspergilloma (SA, n=31), chronic cavitary pulmonary aspergillosis (CCPA, n=120), chronic fibrosing pulmonary aspergillosis (CFPA, n=39), Aspergillus nodule (AN, n=25), and semi-invasive pulmonary aspergillosis (SAIA, n=5). Data pertaining to demographic and clinical characteristics, comorbidities, imaging findings, diagnostic test performance, antifungal treatment regimens, and clinical outcomes were retrospectively analyzed.

Results: The cohort had a median age of 56.7 years, with a 64.1% male predominance. Cough (94.1%) and sputum (83.2%) were the most common symptoms, while hemoptysis was highest in CFPA (79.5%). Chest CT revealed cavities in 87.7% and a high prevalence of fibrosis in CFPA (89.7%). Serologically, serum Aspergillus IgG was positive in 68.2% of patients, with the highest positivity in CFPA (74.4%). BALF galactomannan positivity was highest in AN (76.0%). Voriconazole was the primary antifungal agent (69.1%), but 70.5% of patients received therapy for ≤6 months. Outcomes varied by subtype. CFPA had the worst prognosis (38.5% disease progression, 10.3% mortality), whereas AN patients demonstrated the highest clinical stability (92.0% stable disease).

Conclusion: PTB-associated CPA in China exhibits distinct subtype characteristics. Accurate diagnosis requires a combination of modalities. Treatment responses vary by subtype, underscoring the need for region-specific clinical guidelines, multidisciplinary management, and further research on treatment duration, multi-center cohort studies, and improved diagnostic approaches.

Objective: This study aimed to assess the association between routine cerebrospinal fluid (CSF) biochemical parameters and metagenomic next-generation sequencing (mNGS) results, and to develop a predictive model to optimize mNGS testing strategies in patients with suspected central nervous system (CNS) infections.

Methods: We retrospectively enrolled 110 patients with suspected CNS infections between December 2019 and January 2024. All underwent both CSF analysis and mNGS testing. Patients were divided into mNGS-positive (n = 62) and negative (n = 48) groups. Logistic regression identified independent predictors, and a nomogram was constructed based on CSF cell count and protein concentration. Model performance was assessed via receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA). Internal validation included 10-fold cross-validation and 1000-sample bootstrap. An external validation was performed using a cohort of 40 patients enrolled from another hospital campus (May-October 2024). The derivation cohort was retrospectively collected, whereas the external validation cohort was prospectively enrolled.

Results: mNGS positivity rate was 56.36%, significantly higher than CSF culture (6.36%), with an overall diagnostic concordance of 79.09%. Compared to the mNGS-negative group, positive patients had significantly higher CSF cell counts, protein levels, turbidity, ICU admission (ICUA), antimicrobial regimen adjustment (AAR), and mortality, while glucose was significantly lower (P < 0.05). Logistic regression confirmed CSF cell count binary variables (BV) and protein-BV as independent predictors (P < 0.05). The areas under curve (AUCs) for the cell-count, protein-only, and combined models were 0.827, 0.813, and 0.782, respectively. Internal validation showed stable results: 10-fold CV AUC = 0.773 ± 0.184 (95% CI: 0.641-0.904), bootstrap AUC = 0.770 ± 0.064 (95% CI: 0.766-0.774). External validation yielded an AUC of 0.763 (95% CI: 0.554-0.918), with sensitivity and specificity of 77.8% and 67.7%. Calibration and DCA demonstrated good agreement and clinical utility.

Conclusion: CSF cell count and protein are reliable predictors of mNGS positivity. The model for practice showed consistent diagnostic performance and may aid in guiding precision mNGS testing, particularly in resource-constrained settings.

Background: Chronic obstructive pulmonary disease (COPD) significantly impacts global health, primarily due to frequent acute exacerbations caused by respiratory infections. Precise microbial characterization may inform prognostic insights and optimize clinical management.

Methods: We conducted a prospective observational study from December 2023 to February 2025 involving 1146 patients (259 COPD; 887 non-COPD) with suspected respiratory infections. Bronchoalveolar lavage fluid samples underwent next-generation sequencing (NGS) and conventional microbiological testing. Multivariate logistic regression identified COPD predictors, and machine learning modeled prognostic outcomes based on microbial profiles.

Results: Distinct pathogen distributions emerged between COPD and non-COPD groups, with COPD patients exhibiting higher prevalence of gram-negative bacteria, particularly Pseudomonas aeruginosa and Haemophilus influenzae, and fungal pathogens. Non-COPD patients demonstrated increased occurrence of atypical pathogens, notably Mycoplasma pneumoniae. COPD patients also presented higher loads of traditionally commensal microorganisms, such as Veillonella parvula and Schaalia odontolytica. Age, dyspnea, smoking duration, elevated leukocyte and neutrophil counts, and decreased lymphocyte levels were significantly associated with COPD presence. Machine learning identified specific microorganisms as strong predictors of adverse outcomes, such as SARS-CoV-2, Veillonella parvula, and Achromobacter xylosoxidans.

Conclusions: Comprehensive microbial profiling using NGS effectively distinguishes pathogen differences between COPD and non-COPD patients, revealing key associations with clinical prognosis. These insights can inform tailored clinical interventions aimed at mitigating COPD exacerbations and improving patient outcomes.

Objective: To investigate the influencing factors associated with the risk of latent tuberculosis infection (LTBI) among people living with HIV/AIDS (PLWHA).

Methods: A cross-sectional study was conducted from July 2023 to July 2024, recruiting PLWHA from Wuxi City and Yangzhou City, Jiangsu Province, China. Data were collected through on-site questionnaire surveys and review of patient disease management records. QuantiFERON-TB Gold In-Tube (QFT) was used to detect LTBI. Multivariate logistic regression analysis was performed to identify factors associated with LTBI among PLWHA. Restricted cubic splines (RCS) models were employed to analyze the dose-response relationships between CD4⁺ cell count, CD8⁺ cell count, and CD4/CD8 ratio with LTBI risk.

Results: A total of 1184 PLWHA were enrolled, with 8.4% having concomitant LTBI. Multivariate logistic regression revealed that age group 45-<60 years (OR = 2.158, 95% CI: 1.339-3.478, P = 0.002) and CD4/CD8 ratio ≥1 (OR = 3.562, 95% CI: 1.627-7.800, P = 0.001) were independent factors associated with LTBI. RCS model fitting results demonstrated a gradually increasing nonlinear dose-response relationship between continuous changes in CD4/CD8 ratio and LTBI. The dose-response relationship between CD4⁺ cell count and LTBI risk exhibited an "initial increase followed by a decrease trend. The dose-response relationship between CD8⁺ cell count and LTBI risk showed a gradual declining trend.

Conclusion: This study identified that middle-aged PLWHA (45-<60 years) might represent a subgroup with relatively higher LTBI prevalence, indicating that screening in this age group may hold greater potential value. Additionally, the CD4/CD8 ratio, in conjunction with QFT findings, could serve as a supplementary reference for LTBI risk assessment. These observations support a more tailored approach to LTBI screening in PLWHA, though their implementation should be validated in prospective studies.