Stadler J, Jannasch C, Mack S L, Dietz S, Zöls S, Ritzmann M, Hoelzle K, Hoelzle L E
Clinic for Swine, Ludwig-Maximilians-University Munich, Oberschleissheim, Germany.
Institute of Environmental and Animal Hygiene and Veterinary Medicine (with Animal Clinic), University Hohenheim, Stuttgart, Germany.
Vet Microbiol. 2014 Aug 6;172(1-2):294-300. doi: 10.1016/j.vetmic.2014.05.012. Epub 2014 May 13.
Mycoplasma suis causes infectious anaemia in pigs (IAP), which can manifest in various degrees of severity depending on the virulence and the host's susceptibility. As M. suis cannot be cultured in vitro experimental infections of splenectomised animals play an essential role for pathogenesis research. The aim of the present study was to characterise the course of experimental infection using the highly virulent and red blood cell (RBC-) invasive M. suis strain KI3806, to compare the experimental course in splenectomised and non-splenectomised pigs and to correlate clinical and haematological parameters with M. suis blood loads. All infected splenectomised pigs (n=7) were PCR-positive 2 days post infection (DPI) with maximum mean bacterial loads of 1.61 × 10(10)M. suis/mL on 8 DPI. They developed severe anaemia and massive hypoglycaemia by 8 DPI and had to be euthanised preterm (until 8 DPI) without seroconversion. The non-splenectomised pigs (n=7) became PCR-positive within 23 DPI and reached a maximum mean M. suis load of 1.64 × 10(5)M. suis/mL on 8 DPI. They developed mild anaemia, massive skin alterations with petechiae and haemorrhagic diathesis and seroconverted within 35 DPI. The study demonstrated that experimental infection of splenectomised pigs with the highly virulent M. suis strain KI3806 induces a fulminant course of infection. In contrast, M. suis strain KI3806 induces a mild course of disease in non-splenectomised pigs, which resembles the situation in naturally infected pigs. Therefore, these infection models are valuable for future pathogenesis studies on acute and chronic M. suis infections.
猪支原体可引起猪的传染性贫血（IAP），其严重程度因毒力和宿主易感性而异。由于猪支原体无法在体外培养，因此对脾切除动物进行实验性感染在发病机制研究中起着至关重要的作用。本研究的目的是利用高毒力且能侵入红细胞（RBC）的猪支原体菌株KI3806来描述实验性感染的过程，比较脾切除和未脾切除猪的实验过程，并将临床和血液学参数与猪支原体血载量相关联。所有感染的脾切除猪（n = 7）在感染后2天（DPI）PCR呈阳性，在8 DPI时平均细菌载量最高达1.61×10¹⁰猪支原体/mL。它们在8 DPI时出现严重贫血和大量低血糖，不得不提前安乐死（直至8 DPI）且未发生血清转化。未脾切除猪（n = 7）在23 DPI内PCR呈阳性，在8 DPI时平均猪支原体载量最高达1.64×10⁵猪支原体/mL。它们出现轻度贫血、伴有瘀点的大量皮肤改变和出血素质，并在35 DPI内发生血清转化。该研究表明，用高毒力猪支原体菌株KI3806对脾切除猪进行实验性感染可诱导暴发性感染过程。相比之下，猪支原体菌株KI3806在未脾切除猪中诱导出轻度病程，类似于自然感染猪的情况。因此，这些感染模型对于未来猪支原体急性和慢性感染的发病机制研究具有重要价值。
