Insights into structure, toxicity and antibacterial potential of tungsten oxide–carbon nanocomposites coupled with antibiotics

The Houbara bustard is a vulnerable bird species that often experiences higher morbidity and mortality due to infections caused by the multiple drug-resistant pathogens like Salmonella. Studies exploring alternative therapeutics are essential to strengthen antimicrobial stewardship. This study evaluated the antibacterial potential and toxicity of a tungsten oxide nanocomposite (WO₃/C₃N₄, WNC) combined with antibiotics against multidrug-resistant (MDR) Salmonella enterica strains isolated from Houbara bustards. Preparations used in this study included WNC alone and in combination with ciprofloxacin, penicillin, ampicillin, and oxytetracycline. Characterization of WNC through FTIR showed absorption at 799 cm^-1, indicating W-O-W stretching and confirming WO₃ integration while the particle sizes, as identified through SEM, ranged from 20 to 300 nm. The XRD patterns showed fewer sharp peaks for the WNC, confirming its crystalline nature. The antibacterial potential of these products revealed lowest MICs in case of WNC + ciprofloxacin (16.74 ± 4.76 µg/mL) and WNC + oxytetracycline (30.69 ± 10.44 µg/mL), while WNC alone and with penicillin or ampicillin exceeded 100 µg/mL. The toxicity assay showed the WNC + ampicillin significantly reducing mitotic and phase indices in a dose-dependent manner (p < 0.05) at 24 and 48 h. All treatments showed significant (p ≤ 0.05) dose-dependent genotoxic effects. The study concluded that WNC-antibiotic combinations are effective against MDR Salmonella and relatively safe for host systems, supporting their potential as alternative antibacterial agents.