An alarming level of multi-drug resistant pathogens were detected among horses entering a veterinary teaching hospital in Berlin.
Researchers uncovered evidence of a high rate of introduction of transferable multi-drug resistant pathogens into the large clinical setting for horses, which clearly showed the current challenges for veterinary infection control and staff safety.
“It seems clear that more emphasis on prevention is needed for the safety of veterinary patients and staff and the broader community,” the study team reported, “in particular with regard to the general zoonotic transferability of multi-drug resistant pathogens causing infections in horses.”
The study team in Germany had set out to determine the carriage rate of certain pathogens that carry the risk of infecting other horses in the hospital, or jumping to humans.
They said multi-drug resistant pathogens have frequently caused severe infections in horses, which has become an issue of increasing importance in veterinary infection control and biosafety in equine clinical settings.
Birgit Walther and her colleagues selected extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E), Salmonella, and Acinetobacter baumannii as indicator pathogens to estimate the influx of Gram-negative multi-drug resistant strains to the horse clinic at the Freie Universität Berlin.
The researchers used 341 equine patients for their study, 233 of which were admitted for colic and 108 for open wounds. All admissions occurred during a two-year period.
Nasal swabs and faecal samples were taken for microbiological examination, as well as wound swabs from the open-wound group.
“The results showed alarming carriage rates of Gram-negative multi-drug resistant pathogens in equine patients,” the study team reported in the open-access peer-reviewed journal PLOS ONE.
They found that 10.7% of validated faecal specimens (34 of 318 samples) were positive for ESBL-E, with 94% of this bacterial family group identified as ESBL-producing Escherichia coli. The rates differed little between the colic and open-wound groups, with 10.5% in the former and 11% in the latter.
Further analysis found that 92.7% of the ESBL-producing E. coli were resistant to three or more classes of antimicrobials.
A. baumannii was rarely detected (0.9%), and all faecal samples investigated were negative for Salmonella.
Screening results for the equine nostril swabs showed detection rates for ESBL-E of 3.4% among colic patients and 0.9% in the open wound group, with an average rate of 2.6% for both groups.
“The results of this study reveal a disturbingly large fraction of multi-drug resistant and ESBL-producing E. coli among equine patients,” the researchers wrote.
This, they said, posed a clear threat to established hygiene management systems and work-place safety of veterinary staff in horse clinics.
Discussing their findings, the study described the level of multi-drug resistant pathogens detected as alarming.
“This could pose severe therapeutic challenges in case of infectious diseases associated with these isolates, especially when considering the antimicrobials legally available for treatment of infectious diseases in horses in Europe.”
Walther B, Klein K-S, Barton A-K, Semmler T, Huber C, Wolf SA, et al. (2018) Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Acinetobacter baumannii among horses entering a veterinary teaching hospital: The contemporary “Trojan Horse”. PLoS ONE 13(1): e0191873. https://doi.org/10.1371/journal.pone.0191873