Differentiating between Bacillus species is relevant in human medicine. Bacillus thuringiensis toxins might be effective against Strongyloides stercoralis, a nematode causing relevant human morbidity. Our first objective was to evaluate genomic and MALDI-TOF identification methods for B. thuringiensis. Our secondary objective was to evaluate a possible negative selection pressure of B. thuringiensis against S. stercoralis. PCR and Sanger were compared to MALDI-TOF on a collection of 44 B. cereus group strains. B. thuringiensis toxin genes were searched on 17 stool samples from S. stercoralis-infected and uninfected dogs. Metagenomic 16S rRNA was used for microbiome composition. The inter-rate agreement between PCR, Sanger, and MALDI-TOF was 0.631 k (p-value = 6.4 × 10−10). B. thuringiensis toxins were not found in dogs’ stool. Bacteroidota and Bacillota were the major phyla in the dogs’ microbiome (both represented >20% of the total bacterial community). Prevotella was underrepresented in all Strongyloides-positive dogs. However, the general composition of bacterial communities was not significantly linked with S. stercoralis infection. The genomic methods allowed accurate differentiation between B. thuringiensis and B. cereus. There was no association between B. thuringiensis and S. stercoralis infection, but further studies are needed to confirm this finding. We provide the first descriptive results about bacterial fecal composition in dogs with S. stercoralis infection.
Background: A survey conducted by the European Observatory on Cataract Surgery showed high heterogeneity in the use of antiseptics both preoperatively and in the operating room, highlighting the absence of a global consensus regarding ocular infection prophylaxis in cataract surgery. Methods: The antibacterial activity of seven antiseptic ophthalmic formulations (AOFs) registered as medical devices and the two most common disinfectants were evaluated in vitro against five bacterial species. The viability of bacterial strains after exposure to the antiseptic was evaluated with different techniques: the in vitro Minimum Inhibitory Concentration and the subsequent Minimum Bactericidal Concentration, performed on liquid and solid culture medium. Furthermore, a real-time assessment of bacterial viability was conducted using double staining for live/dead bacterial cells by fluorimetric assay. This evaluation was performed on both the time-killing curve and the tear dilution effect test. Results: We observed a high variability across the different AOFs in terms of inhibitory/bactericidal concentration and timing on Gram-positive and Gram-negative bacterial classes. The results indicated that among the tested AOFs, Visuprime, Iodim, and Oftasteril were the most rapid and effective for ocular surface disinfection against the tested bacterial species. Conclusions: The obtained results can support the clinician’s choice of the most suitable AOF for the prevention and treatment of ophthalmic infections associated with surgery.
Acute gastroenteritis is a common condition with a wide and often indistinguishable etiology, requiring laboratory support for an accurate diagnosis. Classical diagnostic methods, including stool culture and antigen-based tests, are limited by restricted pathogen coverage and variable sensitivity. In the present study, 548 stool samples from patients with suspected gastroenteritis were tested using the QIAstat-Dx Gastrointestinal Panel 2 and compared with stool culture and rotavirus/adenovirus antigen tests. The molecular panel showed a positivity rate of 50.4%, consistently higher than stool culture (12.6%) and antigen assays (12.3% for rotavirus and 4.4% for adenovirus). The most frequently detected pathogens included enteropathogenic Escherichia coli (15.3%), Campylobacter spp. (12.0%), and enteroaggregative E. coli (10.2%). Agreement between methods was good for bacterial pathogens but low for viral targets. Discordant viral results were often associated with low antigen cut-off index values and multiple pathogen detections by the molecular panel, suggesting potential limitations of antigen-based assays. Overall, the QIAstat-Dx Gastrointestinal Panel 2 improves pathogen detection and provides rapid, comprehensive diagnostic information, while a combined approach with conventional methods may represent the most appropriate strategy for optimizing patient management.