ObjectiveThe research aims to elucidate the pathogenic mechanisms of Candida parapsilosis infection after keratoplasty and provide evidence-based guidance for the clinical management of Candida infections in ophthalmic practice.MethodBiofilms were cultured from 45 strains of Candida. The total biomass of the biofilms was measured using the crystal violet staining method, and the biofilm activity was assessed via the XTT reduction assay. Cell surface hydrophobicity and adhesion were evaluated for all Candida strains. The minimum inhibitory concentration (MIC) of planktonic Candida was determined using the colorimetric microbroth dilution method, while the MIC of biofilm-embedded Candida was measured via the XTT reduction assay. The release of 1, 3-β-D-glucan was detected using the G-test, and the chemotactic ability of 1, 3-β-D-glucan on neutrophils was evaluated via the Transwell assay. Molecular typing of Candida parapsilosis was performed using microsatellite genotyping. Statistical analysis was conducted using the Kruskal-Wallis (K-W) test.ResultsIn 45 postoperative ocular Candida isolates, Candida parapsilosis accounted for 48.9% (22/45), Candida albicans 35.6% (16/45), Candida tropicalis 11.1% (5/45), and Candida glabrata 4.4% (2/45). The total biofilm biomass and metabolic activity of Candida parapsilosis at 4°C were significantly higher than those of the other Candida species. In the cell surface hydrophobicity assay, Candida parapsilosis was more hydrophobic than Candida albicans and Candida glabrata, but less hydrophobic than Candida tropicalis. Among Candida parapsilosis isolates, 77.3% (17/22) showed strong adhesion ability and 81.8% (18/22) showed strong biofilm-forming ability (OD450>0.16). Candida colony and spore morphology were found to correlate with biofilm-forming ability. Strains with strong biofilm-forming ability had wrinkled, dry colonies; Gram-stained spores appeared as pseudohyphae; and lactophenol cotton blue staining showed spores that were uniformly and deeply stained. In the biofilm-antigenicity analysis, the non-biofilm-forming group’s 1, 3-β-D-glucan release was significantly higher than that of the strong biofilm group, thereby attracting more neutrophils. In antifungal susceptibility tests, except for C. tropicalis, biofilm-grown Candida showed higher minimum inhibitory concentrations (MICs) than planktonic cells for all antifungal drugs. Caspofungin was active against all isolates in both states.ConclusionsThis study demonstrates that C. parapsilosis has greater adhesion ability and a stronger capacity to form biofilms at 4°C (with higher metabolic activity) than other Candida species. When laboratory findings reveal a Candida isolate with a rough colony morphology, its biofilm-forming ability should be tested and antifungal susceptibility should be assessed under biofilm-growing conditions rather than in planktonic culture.Clinically, we recommend shifting antifungal therapy to caspofungin for such infections.

PURPOSE. To identify the basic genomic profile of Acanthamoeba, obtain information on Acanthamoeba endosymbionts, and analyze the correlation between these endosymbionts and the prognosis of Acanthamoeba keratitis (AK) patients. METHODS. Whole-genome sequencing was conducted on 30 cornea-derived Acanthamoeba strains. Pan-genome analysis was performed, and endosymbionts were identified by metagenomic analysis. Gimenez staining, fluorescence in situ hybridization, and transmission electron microscopy were used to prove the existence of endosymbionts. Linear discriminant analysis effect size was used to associate endosymbiont species with AK clinical prognosis. The correlation between the endosymbiont Ralstonia and pathogenicity was experimentally validated by assessing the biological characteristics of Acanthamoeba and by performing clinical and histopathological evaluations in AK mouse models. RESULTS. Whole genome sequencing revealed that the Acanthamoeba genome size was 37.1-105.0 Mb and GC content was 53.9%-60.5%. Pan-genomic analysis indicated an open state of the Acanthamoeba genome. Metagenomic analysis identified the presence of endosymbionts within Acanthamoeba, notably the endosymbiont Ralstonia, which was associated with poor prognosis at the genus level (P = 0.047). Acanthamoeba harboring the endosymbiont Ralstonia exhibited an increased migration area, enhanced adhesion, and had a more pronounced cytopathic effect. The size of clinical scores and corneal ulcers showed a significant increase in mouse models induced by Acanthamoeba with endosymbiont Ralstonia. CONCLUSIONS. Whole-genome sequencing highlighted the symbiotic relationship between Acanthamoeba and associated microorganisms. The presence of the endosymbiont Ralstonia influenced the biological characteristics of Acanthamoeba and was correlated with clinical poor prognosis in AK, suggesting its potential as a target for clinical intervention.

Background: Hypervirulent Klebsiella pneumoniae (K. pneumoniae) easily causes bacteremia and liver abscess, and invades the eye via blood circulation to trigger blinding endogenous endophthalmitis. Widespread multidrug resistance limits antibiotic treatment, while traditional capsular polysaccharide vaccines cannot provide cross-serotype protection. Methods: We established a mouse model of intraperitoneal infection-induced endogenous endophthalmitis. BALB/c mice received two intramuscular injections of LNP-encapsulated PstS-YidR fusion mRNA vaccine, followed by challenge with hypervirulent K1 or K2 strains. We monitored body weight, quantified multi-tissue bacterial loads, detected IL-1β, IL-6 and TNF-α, and performed slit-lamp observation and liver/ocular histopathology. Results: The vaccine relieved systemic symptoms and weight loss, suppressed bacterial dissemination across peritoneal, blood, liver, lung and eye tissues, and reduced excessive inflammatory factor release. It alleviated intraocular suppurative lesions, preserved ocular structure, and mitigated liver abscess and hepatocellular necrosis, with equal protective efficacy against K1 and K2 and favorable in vivo safety. Conclusions: The PstS-YidR fusion mRNA vaccine blocks systemic spread and intraocular invasion of hypervirulent K. pneumoniae and alleviates multi-organ inflammatory damage. It serves as a safe candidate vaccine for preventing K1/K2-type hypervirulent Klebsiella infections and endogenous endophthalmitis.

BACKGROUND:Adult inclusion conjunctivitis (AIC) caused by non-trachomatous Chlamydia trachomatis is often under-recognised due to variable and non-specific clinical features. This study aimed to describe its clinical and laboratory characteristics, ompA serotype distribution, and their association with clinical presentation and outcome. METHODS:This retrospective cohort study included 22 patients with laboratory-confirmed AIC diagnosed at a tertiary eye centre between February 2023 and January 2026. Clinical signs were graded using a structured conjunctival scoring system. Diagnosis was based on conjunctival cytology, nucleic acid amplification testing and cell culture. C. trachomatis ompA genotyping was performed by PCR and sequencing with phylogenetic analysis. Patients were classified into serovar D and non-D groups, and clinical severity scores and time to resolution were compared using the Mann-Whitney U test. RESULTS:Patients presented with subacute or chronic conjunctivitis with variable conjunctival hyperaemia, follicular reaction, papillary hypertrophy and discharge. ompA genotyping revealed a heterogeneous serovar distribution, with serovar D predominating. Overall clinical scores at presentation were higher in patients with non-D serovars than in those with serovar D (p<0.05), while only papillary reaction differed among individual signs. Time to clinical resolution after standard antibiotic therapy varied but did not differ significantly between groups. CONCLUSION:This study provides a clinical and molecular profile of AIC and highlights variability across ompA serotypes. By generating data from a Chinese cohort, it helps address the limited evidence base in this setting and may support improved clinical recognition and future genotype-phenotype research.

BACKGROUND:Pseudomonas aeruginosa (P. aeruginosa) keratitis can progress rapidly to vision-threatening disease, even with intensive therapy. Virulence-associated genes are key determinants of ocular-surface pathogenesis. We therefore sought to develop a composite wbp-exo genotyping framework for risk stratification and to guide wbp-dependent, LPS-directed, levofloxacin-polymyxin B (LVX-POL) combination therapy for high-risk corneal infections. METHODS:A well-characterised clinical P. aeruginosa keratitis cohort was integrated with whole-genome sequencing. Based on comprehensive virulence-gene identification and annotation, the relationship between strain-level genetic features and clinical prognosis was analysed. The differences between WBP1 strains and WBP2 strains in adhesion, invasion, and biofilm formation in corneal epithelial cells were further evaluated. To establish biological plausibility, wbp genotypes were correlated with LPS O-antigen electrophoretic profiles and in vivo corneal inflammatory phenotypes in murine infection, including the observation of leucocyte recruitment and cytokine responses. To further confirm the key role of wbp gene status and LPS O-antigen in pathogenicity, wbpL knockout and reconstitution strains were constructed. Their appearances in vitro and in vivo were evaluated. Finally, a mechanistic rationale for an LPS-directed LVX-POL regimen was tested in a high-risk WBP1 P. aeruginosa murine keratitis. FINDINGS:Whole-genome sequencing was performed on 46 clinical P. aeruginosa isolates and identified an average of 332 virulence- and fitness-associated genes per strain. The exo and wbp gene families were significantly associated with patient prognosis. A fusion model (AUC = 0.86) outperformed single-gene-family models (EXO: 0.66; WBP: 0.72) for predicting clinical outcomes. Intact wbp cassettes were enriched in poor-outcome isolates, and electrophoretic LPS profiles indicated that WBP1 strains produce highly polymerised O-antigen associated with sustained neutrophil recruitment and cytokine production. Murine experiments further implicated wbp genes in clinical pathogenesis, showing stronger immune responses and higher expression of TLR4, MyD88, TRAF6, p65, p-p65, IL-6, TNF-α, and IL-1β throughout the inflammatory course. After knocking out wbpL gene, the WBP1 strain got stronger in biofilm formation and adhesion but weaker in inflammation and ocular surface survival. In the high-risk WBP1 P. aeruginosa keratitis model, LVX-POL combinations achieved complete ulcer resolution and markedly improved stromal infiltration and hypopyon, outperforming LVX monotherapy. INTERPRETATION:The wbp gene family was identified as a key genetic factor that contributes to the LPS O-antigen structure, inflammatory intensity, bacterial ocular surface survival and poor prognosis in P. aeruginosa keratitis. A WBP1-targeted, LPS-directed LVX-POL regimen was proposed as a mechanistically informed option for high-risk strains. FUNDING:This research was supported by Beijing Public Health High-level Talent Training Program (Phase III-03-14), Prevention and Control of Emerging and Major Infectious Diseases-National Science and Technology Major Project (2026ZD01909300) and Beijing Natural Science Foundation "QiYan" Undergraduate Research Fund (QY26496).

BACKGROUND:Acanthamoeba keratitis (AK) is a severe infectious disease that causes serious visual impairment and low quality of life. This study aims to investigate the immune landscape in AK, with the goal of improving treatment outcomes through immunotherapy. METHODS:We conducted single-cell transcriptome sequencing on corneal tissues from nine patients (3 AK patients, 3 patients with fungal keratitis and 3 patients with bacterial keratitis). Bioinformatic analysis calculated the cell subsets and their proportions within different infectious keratitis. CellChat analysis elucidated the differential expression of chemokines in keratitis. After that, screening amebic nano-antibodies, synthesizing antibody-chemokine fusion proteins, and validated their affinity and chemotactic abilities in vitro and in vivo. And assessing of the therapeutic efficacy of antibody-chemokine fusion proteins. FINDINGS:The UMAP plot demonstrated the 13 major cell clusters in infectious keratitis. Compared with non-AK group, the neutrophil proportion of AK group is markedly reduced. Cell communication indicated a diminished CXCL pathway in AK. Acanthamoeba-specific antibodies were obtained by screening a natural antibody library derived from alpacas. The amoeba-specific antibodies were conjugated with the CXCL1 chemokine, and this fusion protein exhibited robust binding affinity to Acanthamoeba and chemotactic capacity both in vitro and in vivo. Furthermore, in vivo animal investigations indicated that the fusion protein presented excellent therapeutic effect and could effectively eliminate the Acanthamoeba burden. INTERPRETATION:This study revealed an immune evasion mechanism employed by Acanthamoeba and offered a therapeutic approach. It presents promising potential for enhancing the treatment of infectious diseases by targeting and overcoming challenges posed by immune evasion. FUNDING:This work was funded by National Natural Science Foundation of China (grant number 82171017 and 82471041) and the Beijing Municipal Public Welfare Development and Reform Pilot Project for Medical Research Institutes (PWD&RPP-MRI, JYY2023-6).

BackgroundThe incidence of nosocomial candidemia has increased in recently years, however, the epidemiological data remain insufficient in China.MethodsA total of 234 candidemia patients were included from Xiamen University Zhong Shan hospital between January 2006 and October 2024. Incidence, species proportion, distribution, antifungal drug resistance of candidemia was analyzed. A nomogram model for 30-day morbidity of candidemia was determined using the least absolute shrinkage and logistic regression analysis.ResultsThe incidence of candidemia increased in recent years (2020: 0.025%, 2021: 0.029%, 2023:0.022%). The dominant species of candidemia were Candida albicans (n=99,42.31%), Candida parapsilosis (n=47,20.09%), Candida tropicalis (n=43,18.38%), Candida glabrata (n=31,13.25%). Departments with a higher detection of candidemia included intensive care unit (n=55), emergency department (n=24) and hepatobiliary surgery (n=22). Candida tropicalis performed the highest resistance to azole (fluconazole: 55.81%, voriconazole:55.00% and itraconazole:58.14%). The resistance of Candida albicans to fluconazole, voriconazole and itraconazole were 32.32%, 23.53% and 31.31%. The mortality rate of 30-day discharge for candidemia reached 52.99%. 205 cases of candidemia patients from January 2006 to December 2023 were included as the training set, while 29 cases of candidiasis patients from January to October 2004 were included as the validation set. Five independent factors included Candida albicans, decreased albumin, multiple organ dysfunction syndrome, solid tumor and septic shock were adopted in a nomogram for 30-days mortality of candidemia. In the training set, the area under curve was 0.866 (95%CI: 0.817-0.916), the optimal cutoff value was 0.617, the sensitivity was 80% and the specificity was 80.4%. In the validation set, the area under curve was 0.808 (95%CI:0.737-0.970), the optimal cutoff value was 0.543. The sensitivity was 72.7% and the specificity was 83.3%.ConclusionThe incidence of nosocomial candidemia has risen in recent years. Candida albicans remains the primary species, with the highest incidence is intensive care unit. Candida tropicalis exhibits the highest resistance rate to azole drugs. A nomogram predicting 30-day mortality discharge for candidemia patients has been constructed, and the independent risk factors including Candida albicans, multiple organ dysfunction syndrome, septic shock, solid tumors, and decreased albumin.

Purpose:To develop an in vitro human corneal epithelial cell (HCEC) coculture model for differentiating pathogenic from nonpathogenic ocular Staphylococcus epidermidis isolates. Methods:HCECs were cocultured with S. epidermidis strains (104-108 CFU/mL) for 12 to 72 hours. Cell viability was assessed using calcein AM staining. Seventeen strains were evaluated in this model and validated in mouse keratitis models. Cytotoxicity profiles of pathogenic versus nonpathogenic strains were compared, and receiver operating characteristic analysis was performed to evaluate HCEC viability as a predictor of pathogenicity. Results:A 24-hour HCEC coculture assay reliably quantified bacterial cytotoxicity across concentrations. In vivo, 12 of 17 strains (70.6%) were pathogenic in mouse keratitis models. In vitro, cytotoxicity was detected in 50.0% of pathogenic strains (6/12) at 104 CFU/mL, 58.3% (7/12) at 105 CFU/mL, and 83.3% (10/12) at 106 CFU/mL, whereas no nonpathogenic strains induced cytotoxicity at ≤106 CFU/mL. At 106 CFU/mL, HCEC viability was significantly lower with pathogenic than nonpathogenic strains (P = 0.006). Receiver operating characteristic analysis identified a 91.36% viability cutoff at 106 CFU/mL of S. epidermidis to distinguish pathogenic strains, yielding an area under the receiver operating characteristic curve of 0.9167, with 100% specificity and 91.7% sensitivity. Conclusions:This HCEC coculture assay provides a rapid and reliable method to distinguish pathogenic from nonpathogenic S. epidermidis ocular isolates, with strong concordance with in vivo keratitis outcomes. Translational Relevance:This model offers a practical diagnostic tool to identify clinically relevant S. epidermidis strains, supporting earlier and more accurate diagnosis of bacterial keratitis and guiding targeted therapy.

Ottowia massiliensis sp.nov. is a slow-growing and Gram-stain-negative bacillus, first isolated from the stool sample of a healthy volunteer. Due to its slow growth and challenging cultivation, it is easily overlooked in clinical microbiology laboratories. This case report is the first case of its pathogenicity. This case report describes a case of canaliculitis caused by Ottowia massiliensis sp.nov. The patient, an 80-year-old woman, presented with bilateral epiphora and discharge lasting for 4 years, which worsened with redness and swelling over the past week. Microbial culture of the lacrimal duct secretion after 72 h on Columbia blood agar showed small colonies. MALDI-TOF MS did not yield accurate results, but 16 S rDNA sequencing identified the bacterium as Ottowia massiliensis sp.nov. (LT960589.1). Antimicrobial sensitivity tests showed high activity against most ophthalmic drugs. In the case described here, we discuss the diagnosis and treatment strategies for eye infections caused by Ottowia massiliensis sp.nov., laying the foundation for improving clinical and laboratory awareness of this bacterium.

Purpose: Fungal keratitis caused by Aspergillus flavus (A. flavus) can result in severe inflammation and corneal stromal melting, leading to visual impairment. This study aimed to identify virulent genes correlated with the severity of A. flavus keratitis using whole-genome sequencing. Methods: Whole-genome sequencing of 21 clinical A. flavus strains from cornea was performed to elucidate the pathogenesis of A. flavus in infectious keratitis, followed by pan-genome analysis and virulence analysis. To further understand the results from the previous analyses, growth phenotypes and virulence effect of mutant strains were validated experimentally, including the spore counting, growth pattern under different conditions, and clinical and pathological evaluation of A. flavus keratitis in mice models. Results: The A. flavus pan-genome was composed of 17,326 gene clusters with a core genome of 5378 (31.0% of the pan-genome) orthogroups in all 21 isolates. Virulence gene analysis revealed 183 genes contributing to A. flavus pathogenesis and mutation of the kexB gene was associated with the severity of keratitis. The kexB mutant (ΔkexB) strains showed significantly reduced conidia formation and lower growth rates in the presence of the cell-wall perturbing agents. Further, the mice models validated that clinical score, and corneal perforation rates significantly decreased in the group infected by ΔkexB strains. Infiltration of immune cells, gene expression of cytokines, and matrix metalloproteinase (MMP) were also decreased in the mutant group. Conclusions: The role of kexB gene in A. flavus keratitis was identified through whole-genome sequencing. Its mutation impairs conidia formation, cell wall integrity, and invasion, leading to milder clinical symptoms.

Purpose. Acanthamoeba keratitis (AK) is a severe infection linked to orthokeratology lens use, whereas the involvement of conjunctival microbiota in AK remains poorly understood. This study investigates microbiota dysbiosis in AK pathogenesis to inform microbiota-based interventions. Methods. Conjunctival swabs from 14 patients with AK and 10 healthy controls underwent 16S rRNA sequencing. Microbiome analysis compared diversity, taxa, and metabolic pathways. Functional assays quantified Achromobacter-enhanced Acanthamoeba adhesion and migration. Metagenomics and fluorescence in situ hybridization (FISH) with species-specific probes confirmed endosymbiosis. Results. Patients with AK showed reduced bacterial diversity compared with the healthy controls (P < 0.001) but similar richness. Relative abundance of Achromobacter in the AK group was higher compared to the healthy control group (P < 0.001). Achromobacter dominated microbiota among the AK group, being identified as a key biomarker via the linear discriminant analysis effect size (LEfSe). In vitro, Achromobacter increased Acanthamoeba adhesion (P = 0.007) and the migration area (P < 0.05). Metagenomic analysis and FISH further showed Achromobacter spp. as potential endosymbionts of Acanthamoeba. Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed upregulated phenylalanine, fatty acid, and propanoate metabolism in the AK group (all P < 0.001). MetaCyc highlighted enriched pyruvate fermentation to isobutanol, aerobic respiration I, and L-isoleucine biosynthesis II in the AK group (P < 0.001). Conclusions. AK-associated conjunctival dysbiosis features Achromobacter dominance, reduced diversity, and altered metabolism. Achromobacter is associated with enhanced adhesion and migration of Acanthamoeba, indicating a possible symbiotic interaction and its potential as a biomarker and therapeutic target.

ObjectiveThis study investigated the susceptibility of various Fusarium fungi to five topical antifungal agents: natamycin, voriconazole, chlorhexidine, natamycin combined with chlorhexidine, and voriconazole combined with chlorhexidine. And to explore the clinical feasibility of combination therapy in the treatment of corneal infections caused by F. solani, with the goal of optimizing the treatment regimen for fungal keratitis.MethodsA total of 194 strains of Fusarium were isolated from the corneas between 2013 and 2024 and identified to the species level using mass spectrometry. The MICs was determined using a commercial microdilution plate to assess the in vitro activity of the drugs used alone and in combination (natamycin/chlorhexidine, voriconazole/chlorhexidine). Additionally, the clinical efficacy was prospectively observed in 5 patients with corneal infections caused by F. solani. The treatment regimens included 5% natamycin combined with 0.04% chlorhexidine, chlorhexidine used alone, or natamycin used alone, with follow-up lasting up to 90 days.ResultsF. solani species complex (FSSC, 46.91%) and the F. fujikuroi species complex (FFSC, 45.88%) were the predominant isolates, with a geographical distribution concentrated in Northern China. The MICs for natamycin in FSSC and FFSC were both 2–8 μg /mL, respectively. The MICs for FSSC and FFSC respectively ranged from 0.25–16 and 1–8 μg/mL for voriconazole and 2 to > 16 μg/mL and 1 to > 16 μg/mL for chlorhexidine. The MICs of natamycin were not significantly different between FSSC and FFSC. However, voriconazole, chlorhexidine, natamycin combined with chlorhexidine, and voriconazole combined with chlorhexidine had significantly higher MICs for FSSC compared with FFSC. Compared with voriconazole, voriconazole combined with chlorhexidine exhibited enhancement of antifungal activity against 100% of tested Fusarium strains. Compared with natamycin, enhancement of antifungal activity of natamycin combined with chlorhexidine was 81.4% for all Fusarium spp., and the activity were significantly lower for F. solani (65.9%) than for non-F. solani species (93.6%). Among the 5 patients, 3 patients received treatment with natamycin combined with chlorhexidine, resulting in clinical cure in 2 patients (in 1-1.5 months), while 1 patient required a corneal transplant due to delayed treatment. One patient treated with natamycin alone and one treated with chlorhexidine alone both achieved clinical cure (in 2-3 months).ConclusionNatamycin combined with chlorhexidine and voriconazole combined with chlorhexidine exhibited enhancement of antifungal activity against Fusarium spp. during in vitro sensitivity tests. The findings of this study provide valuable guidance for establishing the epidemiological cutoff and clinical MIC values for Fusarium spp. This study paves the way for future multicenter studies on the treatment of FK with natamycin and chlorhexidine.

Purpose:To investigate the clinical features, antifungal susceptibility patterns, and treatment outcomes of pediatric fungal keratitis (FK) at a tertiary eye center in North China. Methods:A retrospective study of pediatric FK cases diagnosed between July 2000 and October 2023 at Beijing Tongren Hospital, confirmed by fungal culture or microscopy. Data on demographics, predisposing factors, clinical signs, microbiological findings, treatment, and prognosis were analyzed. Results:Eighty-eight pediatric FK cases (66 males, 22 females; mean age 10.8 ± 2.3 years) were collected. Trauma history (35.2%) was primarily from toys and writing tools. Dense infiltrates (100%), feathery margins (69.2%), and multifocal lesions (38.5%) were the common features. Hypopyon was less frequent (15.5%); no endothelial plaques, collar-button lesions, and pigment deposits were observed. Fusarium (43.9%) and Aspergillus (25.8%) were the predominant isolates. Amphotericin B demonstrated both in vitro and clinical efficacy. Treatment duration (median 48.1 days) varied by risk factors (P < 0.001), age (P = 0.013), and fungal type (P = 0.016). Multivariate analysis identified ocular surgery (hazard ratio [HR] = 0.04, P < 0.001) and toddler age (HR = 3.67, P = 0.013) as the strongest predictors of prolonged and faster treatment duration, respectively. Conclusions:Trauma is the leading risk factor of pediatric FK in North China, with Fusarium and Aspergillus being the predominant pathogens. Amphotericin B is the most effective antifungal, and early diagnosis and treatment are critical for improving outcomes. Translational Relevance:This study provides evidence-based data on fungal trends, antifungal susceptibility, and treatment outcomes, guiding optimal drug selection and therapeutic strategies to reduce visual impairment in pediatric FK.

Bacterial keratitis (BK) is a severe ocular infection that can lead to vision loss, with antimicrobial resistance (AMR) posing a growing challenge. This study retrospectively analyzed 1071 bacterial isolates from corneal infections over a 10-year period (2014–2024) at a tertiary ophthalmic center in Beijing, categorizing them into three distinct phases: pre-COVID-19, during COVID-19, and post-COVID-19. The results indicated significant changes in pathogen distribution, including a marked decrease in Gram-positive cocci (from 69.8% pre-COVID-19 to 49.3% in post-COVID-19, p < 0.001), particularly in Staphylococcus epidermidis. In contrast, Gram-positive bacilli, particularly Corynebacterium spp., increased from 4.2% to 16.1% (p < 0.001). The susceptibility to gatifloxacin, moxifloxacin, and ciprofloxacin significantly declined in both Gram-positive cocci and bacilli during the COVID-19 period (all p < 0.01). Gatifloxacin resistance in Staphylococcus rose from pre-COVID-19 (15.2%) to COVID-19 (32.7%), remaining high post-COVID-19 (29.7%). A similar trend was observed in Streptococcus and Corynebacterium, where resistance rose sharply from 12.0% and 22.2% pre-COVID-19 to 42.9% during COVID-19, and remained elevated at 40.0% and 46.4% post-COVID-19, respectively (p < 0.01). These findings emphasize the rapid rise of fluoroquinolone resistance in several bacterial groups, underscoring the urgent need for continuous surveillance and improved antimicrobial stewardship to enhance treatment outcomes.

The prevalence of Chlamydia trachomatis infection in the genitourinary tract is increasing, with an annual rise of 9 million cases. Individuals afflicted with these infections are at a heightened risk of developing adult inclusive conjunctivitis (AIC), which is commonly recognized as the ocular manifestation of this sexually transmitted infection. Despite its significant clinical implications, the lack of distinctive symptoms and the overlap with other ocular conditions often lead to underdiagnosis or misdiagnosis of AIC associated with C. trachomatis infection. Here, we established six distinct C. trachomatis culture cell lines, specifically highlighting the MA104 N*V cell line that exhibited diminished expression of interferon regulatory factor 3 (IRF3) and signal transducer and activator of transcription 1 (STAT1), resulting in reduced interferons. Infected MA104 N*V cells displayed the highest count of intracytoplasmic inclusions detected through immunofluorescence staining, peaking at 48 h postinfection. Subsequently, MA104 N*V cells were employed for clinical screening in adult patients diagnosed with AIC. Among the evaluated cohort of 20 patients, quantitative PCR (qPCR) testing revealed positive results in seven individuals, indicating the presence of C. trachomatis infection. Furthermore, the MA104 N*V cell cultures derived from these infected patients demonstrated successful cultivation and replication of the pathogen, confirming its viability and infectivity. Molecular genotyping identified four distinct urogenital serovars, with serovar D being the most prevalent (4/7), followed by E (1/7), F (1/7), and Ia (1/7). This novel cellular model contributes to studies on C. trachomatis pathogenesis, molecular mechanisms, and host-pathogen interactions both in vitro and in vivo. It also aids in acquiring clinically relevant strains critical for advancing diagnostics, treatments, and vaccines against C. trachomatis.

Purpose: Our aim was to investigate risk factors, clinical characteristics, and antibiotic susceptibility patterns of cornea-isolated Streptococcus species collected at a tertiary hospital in China over 18 years. Methods: This retrospective study reviewed data from 350 patients diagnosed with Streptococcal keratitis at Beijing Tongren Hospital between January 2006 and December 2023, including demographics, risk factors, clinical signs, in vivo confocal microscopy (IVCM) imaging, and antibiotic susceptibility testing. Results: The predominant type was Streptococcus pneumoniae (n = 108, 29.8%), followed by Streptococcus mitis (n = 90, 24.9%) and Streptococcus oralis (n = 85, 23.5%). Main risk factors included previous ocular surface disease (24.6%), ocular surgery (21.4%), and trauma (16.3%). Significant differences in clinical characteristics were observed among S. pneumoniae, S. oralis, and S. mitis regarding infiltration location (p = 0.038) and size (p = 0.037), as well as hypopyon presence (p = 0.006). IVCM revealed deeper inflammatory cell distribution and structural disruption as the disease progressed. Resistance rates of aminoglycosides, β-lactams, and fluoroquinolones have increased, with significant differences among species for amikacin (p = 0.010), gentamicin (p = 0.007), and others. Poor outcomes correlated with disease duration over one month, central corneal ulcers, dense infiltrations, hypopyon, and scar tissue presence on IVCM. Conclusions:Streptococcal keratitis is a complex ocular infection with multiple risk factors. S. pneumoniae, S. mitis, and S. oralis are the primary causative agents, exhibiting varying clinical features and antibiotic resistance patterns. Key factors associated with poor outcomes include long disease duration, central corneal ulcers, and severe infiltration.

Microbial keratitis (MK) is the fourth leading cause of blindness globally, imposing a substantial burden on the healthcare system. This study aims to determine the cost composition of MK patients and explore factors influencing these expenses. We analyzed the demographics, clinical features, and costs of 602 MK patients treated at Beijing Tongren Hospital from June 2021 to October 2023. The analysis revealed the average total cost of treating MK was USD 1646.8, with a median of USD 550.3 (IQR: 333.3–1239.1). Patients with Acanthamoeba keratitis (AK) incurred the highest median total costs at USD 706.2 (IQR: 399.2–3370.2). Additionally, AK patients faced the highest costs for ophthalmic exams and laboratory tests (both p < 0.001), while patients with fungal keratitis (FK) and viral keratitis (VK) experienced higher medication costs. Costs varied significantly with the severity of MK, especially for outpatients at severity level 4, which was markedly higher than levels 1–3 (USD 1520.1 vs. USD 401.0, p < 0.001). Delayed presentation also resulted in increased costs (USD 385.2 vs. USD 600.3, p < 0.001). Our study highlights the financial burden associated with MK treatment and underscores the importance of timely and accurate diagnosis and intervention.

This study aimed to investigate the molecular epidemiological characteristics and drug sensitivity of Cryptococcus from HIV-infected patients and their relationship with patients' prognosis. Seventy-six strains were collected and identified to the species level by matrix-assisted laser desorption ionization-time of flight mass spectrometry, confirmed by internal transcribed spacer sequencing. Multi-locus sequence typing was used for the typing of Cryptococcus, and its antifungal susceptibility was tested using FUNGUS 3. The clinical outcomes of the patients were reviewed at 3-, 6-, 9-, and 12-month follow-ups. All strains were Cryptococcus neoformans var. grubii classified into seven sequence types (STs) dominated by ST5, ST31, and a new ST702 strain. The 6- and 9-month survival rates were highest for patients infected with ST31, ST32, and ST174. The antifungal resistant rates were 13.2%, 2.6%, and 1.4% for fluconazole, amphotericin B, and 5-fluorocytosine. Except itraconazole, the minimum inhibitory concentration (MIC) values and wild type (WT)/non-wild type (NWT) of Cryptococcus for antifungal drugs were not related to the clinical prognosis of HIV-infected patients with cryptococcal infection. ST5 was the main ST type, and the new ST702 type was found in a patient who died in a short period of time. Cryptococcus neoformans var. grubii had a relatively high antifungal drug resistance rate to fluconazole. The WT strain accounted for the highest proportions for 5-fluorocytosine, amphotericin B, fluconazole, voriconazole, and itraconazole. The MIC values of Cryptococcus for first-line antifungal drugs showed no relationship with clinical prognosis, implying that MIC values cannot be used to predict the clinical outcome of these patients.

In this article, we report a male patient infected with HIV presenting with cryptococcal meningitis, pneumonia, and bloodstream infection, along with intestinal obstruction and gastrointestinal bleeding. Cerebrospinal fluid and bloodstream analyses revealed the presence of Cryptococcus neoformans complex. The isolated strain was sequenced and was found to belong to Cryptococcus neoformans var. grubii with a new sequence type (ST). The strain led to fatal multisystemic cryptococcosis in a short time, and the patient died due to hemorrhagic shock because of gastrointestinal bleeding despite emergency rescue efforts. There are few reports about cryptococcosis in HIV-infected patients caused by new ST isolates. We report a new Cryptococcus neoformans ST (ST702) isolate causing infection in an HIV-infected patient, which merits further study and clinical attention.

Background:Nosocomial candidemia is a life-threatening condition, and the incidence has increased in recent years. Thorough epidemiological data is still lacking in China. Methods:A retrospective cohort study was conducted to investigate the patients admitted to Zhongshan Hospital Xiamen University from 1 January 2004 to 31 December 2022. This study included 205 individuals who were diagnosed with candidemia as subjects. Additionally, 303 cases with blood cultures were negative during the same period and were from the same department as a control group. We randomly assigned them to the training and validation groups in a 7:3 ratio. The least absolute shrinkage and selection operator regression, univariate and multivariate logistic regression analyses were used to filtrate independent factors associated with nosocomial candidemia. A nomogram model was established based on the selected variables. Receiver operating characteristic (ROC) curve, calibration plots and decision curve analysis (DCA) were used to evaluate clinical utility. Results:Two hundred and five nosocomial candidemia patients were reported, containing a high proportion of Candida albicans (n = 91,44.39%), followed by Candida parapsilosis (n = 40, 19.51%), Candida tropicalis (n = 37,18.05%), Candida glabrata (n = 23, 11.22%) and Candida guilliermondii (n = 9,4.39%). Multiple organ dysfunction syndrome (OR = 10.372, 95% CI: 4.745-24.14 P < 0.001), increased urea nitrogen of serum (OR=1.088,95% CI: 1.039-1.144 P<0.001), decreased albumin of serum (OR = 0.922 95% CI: 0.850-0.997 P=0.045), mechanical ventilation (OR=4.074,95% CI: 1.397-12.77 P=0.012), central venous indwelling catheter (OR=7.422,95% CI: 3.189-18.41 P<0.001) and solid tumor (OR = 3.036 95% CI: 1.276-7.359 P=0.012) were identified as independent risk factors of candidemia. The area under the curve (AUC) of the nomogram model was 0.925 (95% CI: 0.898-0.952) in the training group and 0.946 (95% CI: 0.881-0.963) in the validation group. The calibration curve revealed good agreement between the probability and the observed values. DCA indicated that this nomogram might be clinically beneficial. Conclusion:The nomogram including multiple organ dysfunction syndrome, elevated blood urea nitrogen, decreased albumin, mechanical ventilation, central venous indwelling catheter and solid tumor could provide reference value to clinicians for identifying nosocomial candidemia.