Is Mycoplasma suis Coming Back?

November 16, 2011 — 

A disease known as swine eperythrozoonosis (epe), first recognized in the 1930s and widely controlled with the use of arsanilic acid in feed up to 1986, has been largely forgotten. But there is growing concern that the disease may be a cause of sow fertility, lactation and preweaning mortality problems. Eperythrozoon suis was reclassified in 2002 as Mycoplasma suis (M. suis), but the disease it causes is still known as swine eperythrozoonosis. This blood-borne bacterial organism has been shown to affect pigs of all ages, says Iowa State University (ISU) immunologist Erin Strait, DVM.

“It generally shows up in younger pigs in the form of ill-thrift or anemia. You can have an acute hemolytic anemia, where the pigs are very sick, or a chronic phase, where there probably won’t be any visible signs,” she says.

Less common, there can be acute deaths in sows from hypoglycemic coma caused by low blood sugar levels. During stressful times, such as gestation, a sow might be fine one day but dead the next, Strait says. Close examination prior to death may have shown that affected sows had pale skin and were exercise-intolerant, but this can be subtle and is easy to overlook, she adds. Recent Research Efforts

Mycoplasma suis (M. suis) has not been widely studied, but a group of European scientists in 2007 developed a polymerase chain reaction (PCR) test, which provided a much-improved diagnostic assay over previous blood-staining procedures.

This group used their more sensitive PCR test to conduct a prevalence study of normal-appearing pigs at a German slaughter facility, and found the organism in 79 out of 196 farms.

This research group also identified a field isolate of M. suis that is intra-cellular, so it is not identifiable by blood staining, only by PCR. Tetracyclines can be used to treat the condition, but those antibiotics won’t clear the organism from the pig, she states.

In follow-up work, Strait performed a small survey of pig populations, using a modified PCR test she developed in her lab at ISU, and identified M. suis in normal-appearing pigs.

Read the rest of the story at National Hog Farmer (http://nationalhogfarmer.com/health-diseases/mycoplasma-suis-coming-back-1110/)