Gómez-Laguna Jaime, Islas Armando, Muñoz Dennis, Ruiz Alvaro, Villamil Aura, Carrasco Librado, Quezada Manuel
CICAP - Food Research Centre, 14400 Pozoblanco, Córdoba, Spain.
Pathology and Preventive Medicine Department, Faculty of Veterinary Medicine, University of Concepción, Chillán, Chile.
Vet Microbiol. 2014 Oct 10;173(3-4):332-9. doi: 10.1016/j.vetmic.2014.08.015. Epub 2014 Aug 26.
Actinobacillus pleuropneumoniae, the causative agent of porcine contagious pleuropneumonia (PCP), causes significant economic losses associated mainly with growth stunting of animals. Although serotypes can be distinguished according to their virulence, most of the studies are focused in A. pleuropneumoniae infections with virulent serotypes. There is little information regarding the role of acute phase proteins (APPs) and proinflammatory cytokines in infections with isolates of mild or moderate virulence. Thus, the present study aims to evaluate the kinetics of infection with an A. pleuropneumoniae serotype 6 (Ap6) field isolate of moderate virulence and the changes in the serum concentration of specific antibodies and different APPs and proinflammatory cytokines. Control animals showed no clinical signs or lesions throughout the study. Infected animals showed increased rectal temperature, respiratory distress and depression from 24hpi, and typical gross and microscopic lesions of PCP from 6hpi onwards. Ap6 was isolated from nasal swabs of four out of five inoculated animals at 24hpi, and from nasal swabs, tonsil and lung samples from all inoculated animals at 72hpi. Specific antibodies against Ap6 or changes in the serum concentration of IL-1β, IL-10 and TNF-α were not detected throughout the study. The serum concentration of IL-6 increased from 6hpi as well as serum A amyloid, C-reactive protein and haptoglobin from 24hpi onwards. Our results highlight the onset of the acute phase response after the infection with a field isolate of A. pleuropneumoniae of moderate virulence from 24hpi onwards which may be of interest in the study of the pathogenesis of this disease.
胸膜肺炎放线杆菌是猪传染性胸膜肺炎（PCP）的病原体，主要导致动物生长发育迟缓，造成重大经济损失。虽然可根据血清型区分其毒力，但大多数研究集中于强毒血清型的胸膜肺炎放线杆菌感染。关于急性期蛋白（APPs）和促炎细胞因子在轻度或中度毒力菌株感染中的作用，相关信息较少。因此，本研究旨在评估中度毒力的胸膜肺炎放线杆菌血清型6（Ap6）田间分离株的感染动力学，以及特异性抗体、不同APPs和促炎细胞因子血清浓度的变化。在整个研究过程中，对照动物未表现出临床症状或病变。感染动物在感染后24小时开始出现直肠温度升高、呼吸窘迫和抑郁，从感染后6小时起出现典型的PCP大体和微观病变。在感染后24小时，从五只接种动物中的四只的鼻拭子中分离出Ap6，在感染后72小时，从所有接种动物的鼻拭子、扁桃体和肺样本中分离出Ap6。在整个研究过程中未检测到针对Ap6的特异性抗体或IL-1β、IL-10和TNF-α血清浓度的变化。IL-6的血清浓度从感染后6小时开始升高，血清A淀粉样蛋白、C反应蛋白和触珠蛋白从感染后24小时开始升高。我们的结果突出了感染中度毒力的胸膜肺炎放线杆菌田间分离株后，从感染后24小时起急性期反应的开始，这可能对该疾病发病机制的研究具有重要意义。
