Future microbiology最新文献

Aims: Excluding bacteremia is clinically important in patients with Staphylococcus aureus bacteriuria (SABU), yet reliable predictors of concomitant S. aureus bacteremia (SAB) remain insufficiently defined. This study aimed to evaluate whether routine urinalysis parameters can predict concomitant SAB in patients with SABU.

Methods: This retrospective cohort study included 82 patients with SABU. Demographic characteristics, urinalysis findings, inflammatory markers, and blood culture results were analyzed. Receiver operating characteristic (ROC) curve analysis and multivariate logistic regression were performed to identify predictors of SAB.

Results: Concomitant SAB was detected in 29 patients (35.4%). Urinary bacterial count (31 vs 1/high-power field (HPF)) and erythrocyte count (39 vs 8/HPF) were significantly higher in bacteremic patients, together with elevated C-reactive protein (CRP) levels (all p < 0.05). ROC analysis identified an optimal cutoff value of 11/HPF for urinary bacterial count, with 82.8% sensitivity, 81.1% specificity, and a negative predictive value of 89.6% (AUC: 0.867). In multivariate analysis, urinary bacterial count, age, and CRP level remained independently associated with concomitant SAB.

Conclusions: In conclusion, increased urinary bacterial count was associated with concomitant SAB and demonstrated a high negative predictive value for excluding bacteremia. Routine urinalysis parameters may contribute to early risk stratification in patients with SABU.

Aims: This study aimed to evaluate in vitro activity of β-lactam/β-lactamase inhibitor (BL/BLI) combinations, colistin, tigecycline, and eravacycline against carbapenemase producing Enterobacterales (CPE) uropathogens.

Methods: This cross-sectional study included 162 urine samples from UTI patients. Enterobacterales isolates were identified using the Remel RapID ONE system. Minimum inhibitory concentrations (MICs) were determined using Sensititre panels, and carbapenemase genes (bla_NDM, bla_KPC, and bla_OXA-48) were detected by PCR and confirmed by sequencing.

Results: Of 162 urine samples, 120 (74.1%) were culture-positive, yielding 145 isolates, of which 117 (81%) were Enterobacterales. Carbapenem resistance was detected in 104/117 (89%) isolates, encoding bla_NDM (45%), bla_KPC (24%), and bla_OXA-48 (30.7%). bla_NDM harboring isolates were resistant to all tested BL/BLI combinations, whereas bla_KPC and bla_OXA-48 carrying isolates remained susceptible to CZA and IMR. bla_KPC carrying pathogens were susceptible to MEV. Colistin, tigecycline, and eravacycline showed good activity against all isolates except Proteus mirabilis.

Conclusions: The efficacy of BL/BLI combinations is limited by the high prevalence of bla_NDM producing pathogens. In contrast, bla_KPC and bla_OXA-48 encoding isolates remained susceptible against CZA and IMR while colistin, tigecycline, and eravacycline retained their activities. It highlighted the importance of molecular surveillance to guide appropriate therapy for CPE-associated UTIs.

Screening with tuberculin remains widely used in humans and livestock for detecting mycobacterial immune sensitization, but tuberculin skin test (TST) interpretation is influenced by Bacillus Calmette-Guérin vaccination, environmental non-tuberculous mycobacteria (NTM), cutoff selection, and epidemiological context. The TST uses purified protein derivative (PPD), a complex mycobacterial antigen preparation, to elicit delayed-type hypersensitivity measured as local skin induration. Aquaculture vaccination is established for farmed fish, whereas vaccines targeting fish mycobacteriosis remain largely experimental, including BCG, attenuated or heat-inactivated mycobacteria, DNA vaccines, mycolic acids, and defined antigen combinations. This Perspective asks whether experimental mycobacterial vaccination of fish could plausibly influence human TST interpretation in occupationally exposed aquaculture workers. Such an interaction would require antigenic overlap with PPD, environmental release or persistence of mycobacterial material linked to vaccination, repeated worker exposure through water, biofilms, fish tissues, surfaces, or skin microtrauma, immune sensitization or amplification, and an induration shift sufficient to alter classification at operational cutoffs. The article defines this as a testable One Health interface and proposes construct-level antigen mapping, environmental monitoring around vaccination events, and prospective worker studies using continuous TST measurement with parallel IGRA testing.

Cryptococcus neoformans and Cryptococcus gattii are a globally distributed fungal pathogen that causes a significant number of cryptococcosis worldwide, especially among immunocompromised individuals, although immunocompetent may also be affected. This infection begins when Cryptococcus is inhaled from the environment into the lungs resulting in pneumonia. Critically, the fungus can disseminate systemically and cross the blood-brain barrier causing cryptococcal meningitis (CM), the severe clinical form of the disease. CM, when untreated, is fatal in a short period of time causing high mortality rates. This mortality is associated with immunosuppression, failures in treatment, diagnostic problems, and the virulence of Cryptococcus. We often attribute epidemiological and pathogenesis studies to knowledge acquired from C. neoformans; however, studies have shown that pathogenic differences exist between various Cryptococcus species complexes. In this review, we will present the literature about epidemiology and virulence factors of C. neoformans and C. gattii, emphasizing their differences and pointing out unexplored research. Moreover, we will demonstrate strategies aimed at inhibiting virulence factors that can become a valuable source for the development of new drugs.Literature search: PubMed, Scopus, and Web of Science (from database inception to June 2026).

Objective: To evaluate the synergistic antifungal activity of tedizolid (TDZ) in combination with fluconazole (FLC) against Candida albicans, including drug-resistant strains, and to elucidate the underlying mechanisms of synergistic action.

Materials and methods: The antifungal activity of TDZ and FLC combination was assessed against planktonic cells and preformed biofilms of C. albicans in vitro. To assess in vivo antimicrobial effect, a Galleria mellonella larval infection model was employed. Mechanistic investigations included reactive oxygen species (ROS) detection, yeast-to-hypha transition assays, metacaspase activity analysis, intracellular Ca²⁺ measurement, and drug uptake and efflux assays.

Results: Synergistic antifungal effects were observed when TDZ was used in conjunction with FLC against both planktonic cells and preformed biofilms of C. albicans, particularly drug-resistant strains. In vivo, combination therapy significantly improved survival rates and reduced tissue damage in infected G. mellonella. Mechanistic studies revealed that synergistic inhibition was associated with ROS accumulation, impaired filamentous development, metacaspase activation, and disruption of Ca²⁺ homeostasis, but was independent of drug uptake and efflux pathways.

Conclusions: The TDZ and FLC combination demonstrates the significant cooperative antimycotic potential against resistant C. albicans, providing a foundation for developing novel therapeutic strategies against resistant candidiasis and offering valuable insights into new antifungal agent development.

Aim: This cross-sectional study characterized virulence factors, disinfectant resistance genes, and antimicrobial resistance determinants in multidrug-resistant Escherichia coli and Klebsiella pneumoniae from four urban wastewater treatment plants (WWTPs) in Windhoek, Namibia.

Materials and methods: Twenty-three isolates were identified using biochemical tests and MALDI-TOF, followed by antimicrobial susceptibility testing (AST) and whole-genome sequencing (WGS). Bioinformatic analyses assessed antimicrobial resistance genes (ARGs), virulence factors (VFs), disinfectant resistance genes (DRGs), sequence types, phylogenetic relationships, and co-occurrence with plasmid-associated sequences.

Results: High phenotypic resistance was observed to ampicillin (70%) and amoxicillin and cefuroxime (≥50%). WGS identified clinically important lineages, including E. coli ST410 and K. pneumoniae ST70, ST20, and ST219. Isolates harbored extended-spectrum β-lactamase genes, notably bla_CTX-M-15, plasmid-mediated quinolone resistance determinants, and virulence genes associated with iron acquisition (yersiniabactin), adhesion, and capsule biosynthesis. Disinfectant resistance genes, including qacE, were also detected, with several resistance and virulence determinants co-occurring with plasmid-associated sequences. Phylogenetic analysis revealed close genetic relatedness among isolates from treated effluent, indicating persistence of clinically relevant lineages within wastewater systems.

Conclusion: Wastewater-based genomic surveillance provides an effective approach for characterizing AMR, virulence, and disinfectant resistance, supporting genome-informed surveillance and wastewater management in water-scarce settings.

Background: Clostridioides difficile toxin A (TcdA) is a key factor in antibiotic-associated intestinal epithelial injury. (+)-Catechin (CC) exhibits anti-inflammatory and antioxidant properties, but its role in protecting intestinal epithelial barrier function during TcdA exposure remains unclear.

Methods: Human colon epithelial Caco-2 cells were treated with TcdA to induce barrier dysfunction, followed by CC at varying concentrations. Barrier integrity was assessed using trans-epithelial electrical resistance (TEER), Lucifer yellow paracellular flux, and lactate dehydrogenase (LDH) release. The involvement of peroxisome proliferator-activated receptor gamma (PPARγ) and nuclear factor kappa B (NF-κB) signaling was evaluated using short hairpin RNA (shRNA)-mediated PPARγ knockdown.

Results: TcdA treatment disrupted Caco-2 barrier function, indicated by decreased TEER, increased Lucifer yellow flux, and elevated LDH release. TcdA treatment also reduced PPARγ expression and was associated with increased activation of the NF-κB signaling pathway. CC treatment significantly alleviated these effects in a concentration-dependent manner, with 100 μg/mL showing optimal protection. PPARγ knockdown partially attenuated the protective effects of CC and diminished its inhibitory effect on NF-κB activation, suggesting that PPARγ contributes to the barrier-protective role of CC.

Conclusion: CC attenuates TcdA-induced intestinal epithelial barrier dysfunction and is associated with modulation of the PPARγ-NF-κB signaling pathway.

Capnocytophaga canimorsus is a slow-growing, Gram-negative bacterium commonly found as a part of the normal oral flora of dogs and cats, and it is associated with severe systemic infections following dog bites, especially in immunocompromised patients. Although spondylodiscitis due to Capnocytophaga species has been reported in the literature, cases involving previously operated spinal segments are extremely rare. A 52-year-old woman working as a dog trainer presented with fever, headache, photophobia, and lumbar back pain. Her medical history included an L5-S1 hemilaminectomy performed 9-year prior to admission. Following an initial concern for meningitis, imaging studies revealed L4-L5 spondylodiscitis. Microbiological diagnosis was obtained through computed tomography-guided biopsy. Biopsy cultures isolated C. canimorsus after 72 h of anaerobic incubation, subsequently confirmed by MALDI-TOF mass spectrometry and 16S rRNA gene sequencing. The patient was successfully treated with amoxicillin/clavulanic acid, achieving complete resolution of symptoms. Hematogenous seeding, rather than direct surgical site contamination, should be emphasized in patients with a history of prior spinal surgery. Furthermore, C. canimorsus should be included in the differential diagnosis of spinal infections in patients with animal exposure, even in the absence of overt bite wounds.