Assessment of upper respiratory and gut bacterial microbiomes during COVID-19 infection in adults: potential aerodigestive transmission

\ua9 2025. The Author(s). SARS-CoV-2 is the viral pathogen responsible for COVID-19. Although morbidity and mortality frequently occur as a result of lung disease, the gastrointestinal (GI) tract is recognized as a primary location for SARS-CoV-2. Connections and interactions between the microbiome of the gut and respiratory system have been linked with viral infections via what has been referred to as the \u27gut-lung axis\u27 with potential aerodigestive communication in health and disease. This research explored the relationship between the microbiomes of the upper respiratory and GI tracts in patients with COVID-19 and examined Extraesophageal reflux (EOR), a mechanism which could contribute to dysregulated communication between the GI and respiratory tract (as identified in COVID-19). 97 patients with a laboratory diagnosis of COVID-19 infection, and 50 age-matched controls were recruited and stool, saliva and sputum were obtained from each participant. ELISA Pepsin tests and Reflux Symptom Index scores (RSI) were conducted for EOR assessment. DNA sequencing of the V4 region of the 16 S rRNA gene was performed for microbiome analysis. No differences were observed between the fecal microbiome\u27s alpha and Shannon diversity indices; however, a distinct microbial composition was observed in COVID-19 patients (when compared to the controls). The respiratory microbiota from individuals with COVID-19 demonstrated a statistically significant reduction in Shannon diversity and bacterial richness alongside an overall reduction in the prevalence of organisms from a typical healthy respiratory microbiome. Furthermore, the bacterial richness of the stool and sputum samples was significantly lower among COVID-19 patients admitted to ICU. A significantly higher RSI score and salivary pepsin level were detected among those with COVID-19. The data indicates that COVID-19 is associated with a dysregulation of both the gut and lung microbiome with a more marked perturbation in the lung, particularly among COVID-19 patients who had been admitted to the ICU. The presence of increased RSI scores, combined with elevated levels of Pepsin, suggests that increased micro-aspiration may occur, which is consistent with of under-recognized interactions between the GI and lung microbiomes in COVID-19 patients and requires additional study. Such studies would benefit from the insights provided by biological samples which reflect the continuum of the aerodigestive tract

Enhanced Efficacy of Some Antibiotics in the Presence of Silver Nanoparticles Against Clinical Isolate of <em>Pseudomonas aeruginosa</em> Recovered from Cystic Fibrosis Patients

\ua9 2024 Al-Momani et al. Introduction: Given the increasing frequency of drug-resistant bacteria and the limited progress in developing new antibiotics, it is necessary to explore new methods of combating microbial infections. Nanoparticles, particularly silver nanoparticles (Ag-NPs), have shown exceptional antibacterial characteristics; however, elevated concentrations of Ag-NPs can produce noticeable levels of toxicity in mammalian cells. Aim: This study examined the potential synergistic effect of combining a low dosage of Ag-NPs and anti-pseudomonas drugs against Pseudomonas aeruginosa (ATCC strain) and eleven clinical isolates from cystic fibrosis patients. Methods: The Ag-NPs were chemically produced by utilizing a seed extract from Peganum Harmala and characterized via ultraviolet-visible spectroscopy and scanning electron microscopy. The broth microdilution technique was utilized to investigate the minimum inhibitory concentration (MIC) of Ag-NPs and eight antibiotics (Piperacillin, Ciprofloxacin, Levofloxacin, Meropenem, Amikacin, Ceftazidime, Gentamicin, Aztreonam). The fractional inhibitory concentration index (FICI) was determined via the checkerboard method to evaluate the synergistic effects of Ag-NPs and various antibiotics. Results: The biosynthesized Ag-NPs were uniformly spherical and measured around 15 nm in size. When combined with antibiotics, Ag-NP produced statistically significant reductions in the amount of antibiotics required to completely prevent P. aeruginosa growth for all strains. The findings revealed that the MIC of Ag-NPs was 15 ug/mL for all strains which decreased substantially when administered with antibiotics at a dose of 1.875–7.5 ug/mL. The majority of Ag-NP and antibiotic combinations exhibited a synergistic or partially synergistic impact. This was particularly noticeable in combinations containing Meropenem, Ciprofloxacin, and Aztreonam (in which the FIC index was less than or equal to 0.5). Conclusion: The findings revealed that combining Ag-NPs with antibiotics was more effective than using Ag-NPs or antibiotics in isolation and that combinations of Ag-NPs and antimicrobial agents displayed synergistic activity against the majority of strains assessed