Pallarés F J, Añón J A, Rodríguez-Gómez I M, Gómez-Laguna J, Fabré R, Sánchez-Carvajal J M, Ruedas-Torres I, Carrasco L
Department of Anatomy, Comparative Pathology and Toxicology, Faculty of Veterinary Medicine, University of Córdoba, 14014, Córdoba, Spain.
Ecuphar Veterinaria SLU, 08016, Barcelona, Spain.
Porcine Health Manag. 2021 Mar 8;7(1):26. doi: 10.1186/s40813-021-00204-3.
Mycoplasma hyopneumoniae causes a chronic respiratory disease that produces important economic losses due to poor productive performance, increased mortality and costs for several control strategies. The prevalence of mycoplasma-like lesions (MLL) at abattoir has been widely studied in different countries, making use of different scoring systems. However, most of them are difficult to apply in abattoirs with high number of pigs sacrificed per hour. For that reason, it is necessary to adapt the scoring system to the reality of the modern abattoir, even if there is a loss of accuracy. Our purpose was to investigate the prevalence and severity of MLL at abattoirs in Spain and Portugal using a 0 to 5 scoring system adapted to abattoirs with high number of sacrificed pigs per hour and to highlight the histopathological diagnosis as confirmatory method to identify patterns of pneumonia correlated to gross lesions.
Cranioventral pulmonary consolidation, a typical MLL, was the most frequent lung lesion (30.97 %) detected at the abattoir, followed by dorsocaudal infarcts with pleurisy (12.51 %) and pleurisy alone (6.26 %). The average score for all examined lungs at abattoir was 1.99 out of 5 points. The histopathological study revealed that the 78.17 % of the randomly selected lungs with MLL presented microscopic lesions compatible with M. hyopneumoniae infection. Most bronchointerstitial and interstitial pneumonia lesions had a chronic course while most suppurative and fibrinous bronchopneumonia lesions had an acute course and a higher degree of severity. The combination of microscopic lesions more frequently observed was bronchointerstitial pneumonia + interstitial pneumonia + suppurative bronchopneumonia.
The prevalence of MLL at abattoir was 30.97 %, however, after microscopic examination the real prevalence of lungs with lesions compatible with M. hyopneumoniae infection was reduced up to 24.21 %. The six more prevalent combinations of lesions in the microscopic study involved the 66.13 % of examined lungs, and in all of them, microscopic lesions characteristic of M. hyopneumoniae infection were found, what supports the importance of M. hyopneumoniae as a primary pathogen in cases of PRDC.
猪肺炎支原体可引发一种慢性呼吸道疾病，因生产性能不佳、死亡率上升以及多种防控策略的成本问题而造成重大经济损失。在不同国家，利用不同的评分系统，对屠宰场中支原体样病变（MLL）的患病率进行了广泛研究。然而，其中大多数评分系统难以应用于每小时屠宰猪数量众多的屠宰场。因此，即使会损失一定准确性，也有必要使评分系统适应现代屠宰场的实际情况。我们的目的是使用一种适用于每小时屠宰猪数量众多的屠宰场的0至5分评分系统，调查西班牙和葡萄牙屠宰场中MLL的患病率和严重程度，并强调组织病理学诊断作为确认与大体病变相关的肺炎模式的确诊方法。
颅腹侧肺实变是屠宰场中最常见的肺部病变（30.97%），这是一种典型的MLL，其次是伴有胸膜炎的背尾侧梗死（12.51%）和单纯胸膜炎（6.26%）。屠宰场中所有检查肺部的平均得分为1.99分（满分5分）。组织病理学研究表明，随机选择的有MLL的肺部中，78.17%呈现出与猪肺炎支原体感染相符的微观病变。大多数支气管间质性和间质性肺炎病变病程为慢性，而大多数化脓性和纤维素性支气管肺炎病变病程为急性且严重程度更高。最常观察到的微观病变组合是支气管间质性肺炎 + 间质性肺炎 + 化脓性支气管肺炎。
屠宰场中MLL的患病率为30.97%，然而，经过微观检查后，与猪肺炎支原体感染相符的肺部病变的实际患病率降至24.21%。微观研究中六种最常见的病变组合涉及66.13%的检查肺部，并且在所有这些组合中，均发现了猪肺炎支原体感染的特征性微观病变，这支持了猪肺炎支原体作为猪呼吸道疾病综合征（PRDC）病例中的主要病原体的重要性。
