Abstract
The development of alternatives to antibiotics is essential for the treatment of animal infections and as a measure to reduce the selective pressure on antibiotics that are critical for human medicine. Metal complexes have been highlighted for their antimicrobial activity against several bacterial pathogens. In particular, manganese carbonyl complexes have shown efficacy against multidrug-resistant Gram-negative pathogens, and relatively low cytotoxicity against avian macrophages and in wax moth larval models. They are thus potential candidates for deployment against Avian Pathogenic Escherichia coli (APEC), the aetiological agent of avian colibacillosis, which results in severe animal welfare issues and financial losses worldwide. This study aimed to determine the efficacy of [Mn(CO)3(tqa-κ3N)]Br in Galleria mellonella and chick models of infection against APEC. The results demonstrated in vitro and in vivo antibacterial activity against all antibiotic-resistant APEC test isolates screened in the study.
•In vitro [Mn(CO)3(tqa-κ3N)]Br exposure results in bacterial killing at 4-hours.•[Mn(CO)3(tqa-κ3N)]Br reduces mortality in G. mellonella post APEC infection.•[Mn(CO)3(tqa-κ3N)]Br significantly reduces bacterial shedding in chicks.•Bacterial colonisation is reduced in chicks after [Mn(CO)3(tqa-κ3N)]Br treatment.