APP Serotype 15 Capable of Surviving Colder Temperatures than Previously Thought

Research funded by the Swine Health Information Center has shown Actinobacillus pleuropneumoniae serotype 15 is capable of surviving colder temperatures than previously thought.Actinobacillus pleuropneumoniae is a bacterial infection that results in coughing, high fever, respiratory distress and high mortality.

In response to a severe outbreak of APP serotype 15 in finishing barns in Iowa in 2021, Iowa State University conducted a series of studies to compare different strains and define the risks posed by this emerging infection.

Swine Health Information Center Associate Director Dr. Lisa Becton says researchers looked at sows from farms that suppled pigs to outbreak locations and at finisher pigs that had gone through an outbreak.

Quote-Dr. Lisa Becton-Swine Health Information Center:

It was noted that APP 15 could survive at minus 4 degrees Fahrenheit for seven days and 72 hours at just below 40 degrees Fahrenheit.But also of note was the survivability on different surfaces such as concrete, rubber and steel with concrete being the longest at seven-day survivability.The significance of these things, it does give us a bit of insight.

While we had PCR positives but no bacteria cultured at the rendering, this is an area that shows there could be a backflow of bacteria into the finisher locations that were impacted.The increased survivability during cold weather also challenges the thought that this bacteria may not survive in cold weather.
That could be another plausible reason why the bacteria was able to survive and transmit.

If we look at the temperatures during the period of the outbreak, it was determined there was cold ambient temperatures that the bacterial could potentially have survived in.So, it gives us some insight into how this bacteria may have been able to get into a location and survive and then subsequently spread to multiple locations.

Dr. Becton says this work adds to our body of knowledge and can be used by producers, veterinarians and even other researchers.
Full results of this work can be accessed at swinehealth.org.