Equine Science Update

Equine hospitals may be an important source of antimicrobial-resistant bacteria, according to recent research.

The study, by Dr Mohamed O Ahmed and co-workers from the University of Liverpool, is published in the journal, Microbial Drug Resistance.

There is  growing concern about  micro-organisms developing resistance to antimicrobial drugs that are used to control them. This is a particular problem in individuals whose immune system is compromised by many factors, leaving them defenceless against potentially life threatening infections.

The work was carried out in the north-west of England. The research team examined faeces from 138 horses. They collected samples from horses at the University of Liverpool Equine hospital and from nearby livery yards and riding schools.

Important differences (risk factors) were identified between faeces samples from hospitalised and non-hospitalised horses.

Analysis of the data showed that the equine hospital was a major source of resistant- and multiple-drug-resistant (MDR) E.coli. Antimicrobial-resistant E. coli was more likely to be found in faeces from horses hospitalised for a gastrointestinal problem (Odds Ratio 8.5) or if they had received antibiotic by mouth (OR 3.52)

The risk of shedding antibiotic resistant E coli was also slightly higher in horses that had been treated with more than one antibacterial drug.

Interestingly, the researchers found that the risk of shedding antibiotic-resistant E. coli actually appeared to be lower in horses given antibiotics intravenously.

Multiple drug resistance was associated with hospitalisation, and with antibiotic treatment while in hospital. The risk of carrying MDR E.coli also increased with age.

The researchers conclude that equine hospitals appear to be an important source of both antibiotic-resistant and multiple-drug-resistant E coli. They emphasise that it is important to control the use of antimicrobial treatment in hospitalised horses, to minimise the risk of antimicrobial resistance.





For more details see: Analysis of risk factors associated with antibiotic-resistant Escherichia coli.
M O Ahmed, NJ Williams, PD Clegg, JC van Velkinburgh, KE Baptiste, M Bennett.
Microbial Drug Resistance. E-pub ahead of print: doi:10.1089/mdr.2011.0213

See also:

Antimicrobial resistance in equine faecal Escherichia coli isolates from north-west England. MO Ahmed, PD Clegg, NJ Williams, KE Baptiste, M Bennett.
Annals of Clin Microb Antimicrob (2010) 9, 12

http://www.ann-clinmicrob.com/content/9/1/12