A novel and improved selective media for the isolation and enumeration of Klebsiella species

Association Between Biofilm Formation and Extended-Spectrum Beta-Lactamase Production in Klebsiella pneumoniae Isolated from Fresh Fruits and Vegetables

The presence of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae in fresh fruits and vegetables is a growing public health concern. The primary objective of this study was to investigate the relationship between biofilm formation and extended-spectrum β-lactamase (ESBL) production in K. pneumoniae strains obtained from fresh fruits and vegetables. Out of 120 samples analysed, 94 samples (78%) were found to be positive for K. pneumoniae. Among the K. pneumoniae strains isolated, 74.5% were from vegetables, whereas the remaining (25.5%) were from fresh fruits. K. pneumoniae isolates were resistant to at least three different classes of antibiotics, with ceftazidime (90%) and cefotaxime (70%) showing the highest resistance rates. While the high occurrence of ESBL-producing and biofilm-forming K. pneumoniae strains were detected in vegetables (73.5% and 73.7%, respectively), considerable amounts of the same were also found in fresh fruits (26.5% and 26.3%, respectively). The results further showed a statistically significant (P < 0.001) association between biofilm formation and ESBL production in K. pneumoniae strains isolated from fresh fruits and vegetables. Furthermore, the majority (81%) of the ESBL-producing strains harbored the blaCTX-M gene, while a smaller proportion of strains carried the blaTEM gene (30%), blaSHV gene (11%) or blaOXA (8%). This study highlights the potential public health threat posed by K. pneumoniae in fresh fruits and vegetables and emphasizes the need for strict surveillance and control measures.

Omics for deciphering oral microecology

The human oral microbiome harbors one of the most diverse microbial communities in the human body, playing critical roles in oral and systemic health. Recent technological innovations are propelling the characterization and manipulation of oral microbiota. High-throughput sequencing enables comprehensive taxonomic and functional profiling of oral microbiomes. New long-read platforms improve genome assembly from complex samples. Single-cell genomics provides insights into uncultured taxa. Advanced imaging modalities including fluorescence, mass spectrometry, and Raman spectroscopy have enabled the visualization of the spatial organization and interactions of oral microbes with increasing resolution. Fluorescence techniques link phylogenetic identity with localization. Mass spectrometry imaging reveals metabolic niches and activities while Raman spectroscopy generates rapid biomolecular fingerprints for classification. Culturomics facilitates the isolation and cultivation of novel fastidious oral taxa using high-throughput approaches. Ongoing integration of these technologies holds the promise of transforming our understanding of oral microbiome assembly, gene expression, metabolites, microenvironments, virulence mechanisms, and microbe-host interfaces in the context of health and disease. However, significant knowledge gaps persist regarding community origins, developmental trajectories, homeostasis versus dysbiosis triggers, functional biomarkers, and strategies to deliberately reshape the oral microbiome for therapeutic benefit. The convergence of sequencing, imaging, cultureomics, synthetic systems, and biomimetic models will provide unprecedented insights into the oral microbiome and offer opportunities to predict, prevent, diagnose, and treat associated oral diseases.

High Prevalence of Multidrug-Resistant Bacteria in the Trachea of Intensive Care Units Admitted Patients: Evidence from a Bangladeshi Hospital

Recent research has shown that antibiotic-resistant microorganisms are becoming more prevalent in intensive care units (ICUs) at an exponential rate. Patients in the ICU can get infected by pathogens due to invasive operation procedures and critical health conditions. This study primarily emphasized tracheal samples from ICU patients due to their reliance on ventilators, increasing their susceptibility to Ventilator-Associated Pneumonia (VAP). Moreover, the rise of multidrug-resistant (MDR) pathogens makes treatment strategies more challenging for these patients. In this study, we tested 200 tracheal specimens to determine the prevalence of microorganisms and analyzed the antibiotic susceptibility of these isolates against regular antibiotics, including 4th generation drugs. Among the 273 isolates, 81% were gram-negative bacteria, 10% were gram-positive bacteria, and 9% were fungi. The most prevalent gram-negative bacteria were Acinetobacter spp. (34%), Klebsiella spp. (22%), Pseudomonas spp. (14%), and Escherichia coli (9.2%). The most prevalent gram-positive bacteria were Staphylococcus aureus (5.9%), and the fungi were Candida spp. (7.3%). Among the most prevalent bacteria, except Staphylococcus aureus isolates, around 90% were resistant to multiple drugs, whereas 60% of Acinetobacter spp. and Pseudomonas spp. were extensively drug resistant. Sensitivity analysis against the gram-negative and gram-positive drug panel using a one-way ANOVA test followed by Tukey's post hoc test showed that in the in vitro assay, colistin was the most effective antibiotic against all gram-negative bacteria. In contrast, linezolid, vancomycin, and fusidic acid were most effective against all gram-positive bacteria. Regular monitoring of nosocomial infections and safe management of highly resistant bacteria can help prevent future pandemics.