Horses with bacterial respiratory infections caused by Staphylococcus aureus or Bordetella bronchiseptica may be more susceptible to infection by equine herpevirus-1 (EHV-1), researchers suggest.

The respiratory tract of the horse has developed multiple antiviral barriers in response. However, these can become compromised by environmental threats. Pollens and mycotoxins are known to increase mucosal susceptibility to EHV-1 by interrupting cell junctions, allowing the virus to reach its basolateral receptor.

The study, they said, is the first to report that bacterial exotoxins increase the horse’s sensitivity to EHV-1 infection.

“Therefore, we propose that horses suffering from infection by S. aureus or B. bronchiseptica may be more susceptible to EHV-1 infection.” In effect, the bacterial infections could “pave the way” for a primary EHV-1 infection to occur.

“Our findings,” they said, “are directly relevant for the veterinary practitioner. So far, no successful curative therapies are available against EHV-1, and the current commercial vaccines have not been overly effective in the prevention of clinical disease.

“We therefore argue that the prevention of EHV-1 infections should always be combined with the control of environmental factors that may promote the onset of EHV-1 replication.”

Acknowledging the importance of predisposing factors and identifying them is a prerequisite in the prevention of EHV-1, they said.
The Gent university research team comprised Van Crombrugge, Emma Vanbeylen, Jolien Van Cleemput, Wim Van den Broeck, Kathlyn Laval and Hans Nauwynck.

Source: doi.org