Clinical, haematological and pathomorphological findings in Mycoplasma suis infected pigs
Julia Stadler1, Julia Ade2, Walter Hermanns3
1Clinic for Swine, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich, Sonnenstr. 16, 85764, Oberschleissheim, Germany. j.stadler@med.vetmed.uni-muenchen.de.
Background:
Mycoplasma suis (M. suis) belongs to the group of haemotrophic mycoplasmas and is known as the causative agent of infectious anaemia in pigs. In the last few years valuable insights into the mechanism of adhesion and invasion, shedding patterns and cell tropism of M. suis were gained by the use of new molecular techniques. However, details on M. suis induced lesions as well as the distribution of M. suis in different organs are still lacking. Therefore, seven splenectomised pigs were experimentally infected and clinical and laboratory investigations as well as a detailed histopathological examination were performed. Detection and quantification of M. suis DNA in blood and various tissue samples was done using a quantitative real-time PCR.
Results:
During the course of experimental infection, periodically occurring signs of infectious anaemia of pigs including severe icteroanaemia, fever, apathy and anorexia were observed. In addition, dermatological manifestations such as haemorrhagic diathesis presenting as petechiae occurred. The most important haematological alterations were normochromic, normocytic anaemia, hypoglycaemia as well as increased bilirubin and urea concentrations. Necropsy revealed predominant evidence of haemolysis with consecutive anaemia, as well as disseminated intravascular coagulation. M. suis was found in all investigated tissues with the highest copy numbers found in the kidneys. In Giemsa stained sections M. suis was only detected red blood cell (RBC)-associated.
Conclusion:
In the present study, no RBC independent sequestration of M. suis was detected in organs of experimentally infected pigs. Pathological findings are most likely resulting from haemolysis, consecutive anaemia as well as from disseminated intravascular coagulation and subsequent organ impairments.
Insights
Mycoplasma suis causes infectious anemia in pigs, leading to hemolysis and organ damage. The bacteria were found in all tissues, primarily kidneys, but only associated with red blood cells.
Area of Science:
- Veterinary Pathology
- Microbiology
- Animal Health
Background:
- Mycoplasma suis is the causative agent of infectious anemia in pigs.
- Recent molecular techniques have improved understanding of M. suis adhesion, invasion, shedding, and tropism.
- However, M. suis-induced lesions and organ distribution remain poorly understood.
Purpose of the Study:
- To investigate the lesions and organ distribution of Mycoplasma suis in experimentally infected pigs.
- To correlate clinical signs and laboratory findings with histopathological changes.
Main Methods:
- Seven splenectomized pigs were experimentally infected with M. suis.
- Clinical, laboratory, and detailed histopathological examinations were performed.
- Quantitative real-time PCR was used to detect and quantify M. suis DNA in blood and tissues.
Main Results:
- Infected pigs exhibited signs of infectious anemia, including icteroanemia, fever, apathy, anorexia, and hemorrhagic diathesis.
- Key hematological alterations included anemia, hypoglycemia, and elevated bilirubin and urea.
- Necropsy revealed evidence of hemolysis, anemia, and disseminated intravascular coagulation; M. suis DNA was detected in all tissues, with highest concentrations in kidneys, and was exclusively associated with red blood cells.
Conclusions:
- Mycoplasma suis infection in pigs leads to significant hemolytic anemia and disseminated intravascular coagulation.
- Pathological findings are attributed to hemolysis, anemia, and subsequent organ impairments.
- No red blood cell-independent sequestration of M. suis was observed in the investigated organs.
