New treatment tackles antibiotic-resistant chicken infections
Manganese carbonyl may treat APEC without the use of antibiotics.
A study investigating the treatment of Avian Pathogenic Escherichia coli (APEC) has revealed that manganese carbonyl may help treat the infection without the use of antibiotics.
APEC is a deadly respiratory infection of chickens, which has been becoming increasingly resistant to antibiotics. There is evidence that the infection could potentially spread to humans.
The research, led by the University of Surrey, tested the effectiveness of the metal complex manganese carbonyl on Greater Wax Moth larvae with APEC.
The international research team also included the Animal and Plant Health Agency, the University of Connecticut, the University of Sheffield and Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg.
The larvae were split into two groups, with one group receiving manganese carbonyl and the control group receiving either phosphate-buffered saline (PBS) or dimethyl sulfoxide (DMSO).
After four days, the survival rate of larvae which received manganese carbonyl was 56 - 75 per cent. The control group saw survival rates of 24 – 45 per cent (PBS) and 19 – 45 per cent (DMSO).
The test was repeated with chickens infected with APEC, with subjects either receiving manganese carbonyl or PBS. Bacterial shedding in the faeces of chickens was significantly lower 24 hours post-treatment in those that received manganese carbonyl than in the PBS control group.
This, as well as caecal samples taken three days post-treatment, suggests a bacterial killing effect in manganese carbonyl. Tissue samples from the livers of the birds also indicated no toxic effects from the compound, which was found in the larvae.
Professor Roberto La Ragione, professor of Veterinary Microbiology and Pathology at the University of Surrey, said: "Antimicrobial resistance is one of the biggest threats to human and animal health. Not being able to use antibiotics to treat an infection not only prolongs an illness and associated welfare issues, but also increases the likelihood of it spreading.
"Coronavirus demonstrated how easily a pandemic can happen, and the threat of another is looking more likely as antibiotics to treat simple bacterial infections are no longer working."
Dr Jonathan Betts, a research fellow at the University of Surrey School of Veterinary Medicine, said: "The development of alternatives to antibiotics is vital to safeguard our future health. Metal complexes such as manganese carbonyl could do this, as we have shown not only are they effective, but they are much cheaper to produce than traditional antibiotics.
"Discovering the effectiveness of manganese carbonyl in treating APEC is a monumental step forward in tackling antimicrobial resistance as it shows we don't necessarily need more antibiotics; we just need to think more innovatively in developing treatments."
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
