Pathogenicity & virulence of Mycoplasma hyopneumoniae.

Mycoplasma hyopneumoniae: is the etiological agent of porcine enzootic pneumonia (EP), a disease that impacts the swine industry worldwide. Pathogen-induced damage, as well as the elicited host-response, contribute to disease. Here, we provide an overview of EP epidemiology, control and prevention, and a more in-depth review of M. hyopneumoniae pathogenicity determinants, highlighting some molecular mechanisms of pathogen-host interactions relevant for pathogenesis. Based on recent functional, immunological, and comparative "omics" results, we discuss the roles of many known or putative M. hyopneumoniae virulence factors, along with host molecules involved in EP. Moreover, the known molecular bases of pathogenicity mechanisms, including M. hyopneumoniae adhesion to host respiratory epithelium, protein secretion, cell damage, host microbicidal response and its modulation, and maintenance of M. hyopneumoniae homeostasis during infection are described. Recent findings regarding M. hyopneumoniae pathogenicity determinants also contribute to the development of novel diagnostic tests, vaccines, and treatments for EP.

Lung consolidation caused by Mycoplasma hyopneumoniae has a negative effect on productive performance and economic revenue in finishing pigs.

This study aimed to measure the impact of productivity and the consequent economic losses related to lung lesions caused by M. hyopneumoniae. Five-hundred 75 days-old pigs were selected and weighed at the beginning and at the end of the finishing phase to assess the average daily gain (ADG). These animals were evaluated at the slaughter, and samples were collected for laboratory analysis to confirm the presence of M. hyopneumoniae DNA. The lungs of each pig were examined and classified into groups based on the extension of macroscopic lung lesions. Four-hundred eighty-six lungs were examined and 68.5% (n = 333) had macroscopic lung lesions. All pigs with lesions were positive for M. hyopneumoniae in qPCR. Linear mixed regression models (proc Glimmix) were performed on SAS to estimate the effect of macroscopic lung lesion scores on the ADG of finishing pigs. All pairwise comparisons among lesion score groups were performed using p < 0.05. For each increase of one percent in the lesion area, there was a decrease of 1.8 g in the daily weight gain. All the groups had a numerically lower ADG when compared to Group 1 (no lesions). The economic analysis was performed by simulation on Excel to estimate and compare the financial performance of the different lung lesion score groups. The negative correlation found between the group with no lung lesions and the group with more than 15.1% of lesions, showed a statistical difference in ADG, which could mean an opportunity to gain up to $ 6.55 per pig at slaughter. The presence of lesions causes the animals to decrease their productive potential, causing financial loss and generating impacts on the production system.

Lesões pulmonares em suínos abatidos no matadouro Público Municipal de Esperança, Paraíba / Pulmonary lesions of slaughtered pigs at the municipal public slaughterhouse of Esperança, Paraíba

O objetivo do presente estudo foi avaliar as lesões macroscópicas e histológicas em pulmões de suínos abatidos no abatedouro público de Esperança, Paraíba. Foram inspecionados pulmões de 180 suínos entre julho e dezembro de 2013. Destes, 34 (18,8%) apresentaram lesões. Na análise anatomopatológica dos fragmentos coletados, 82,3% (28/34) exibiram lesões sugestivas de Pneumonia Enzoótica Suína (PES). Seis (17,7%) amostras apresentaram alterações causadas pela distribuição irregular de sangue. Casos sugestivos de PES crônica foram observados em 57,1% (16/28) dos fragmentos coletados. Em 42,9% (12/28) das amostras foram definidos como sugestivos de PES subaguda. Nenhum pulmão apresentou lesões sugestivas de PES aguda. A pesquisa demonstrou que lesões pulmonares em suínos são frequentemente detectadas no abatedouro de Esperança, Paraíba, sendo a maioria destas lesões sugestivas de PES.(AU)

The objective of the present study was to evaluate the macroscopic and histological lesions in the lungs of slaughtered pigs at the public slaughterhouse of Esperança, Paraíba. Lungs from 180 pigs were inspected between July and December 2013. Lesions were observed in 34 (18.8%) lungs. In the anatomopathological analysis of the collected fragments, 82.3% (28/34) presented suggestive lesions of Swine Enzootic Pneumonia (SEP). Six (17.7%) samples presented alterations caused by irregular blood distribution. Suggestive cases of chronic SEP were observed in 57.1% (16/28) of the collected fragments. In 42.9% (12/28) of the samples were defined as suggestive of subacute SEP. No lungs presented lesions suggestive of acute PES. The research showed that lung lesions in pigs are frequently detected in the Esperança, Paraíba slaughterhouse, with the majority of these lesions suggestive for SEP.(AU)

Lesões pulmonares em suínos abatidos no matadouro Público Municipal de Esperança, Paraíba / Pulmonary lesions of slaughtered pigs at the municipal public slaughterhouse of Esperança, Paraíba

O objetivo do presente estudo foi avaliar as lesões macroscópicas e histológicas em pulmões de suínos abatidos no abatedouro público de Esperança, Paraíba. Foram inspecionados pulmões de 180 suínos entre julho e dezembro de 2013. Destes, 34 (18,8%) apresentaram lesões. Na análise anatomopatológica dos fragmentos coletados, 82,3% (28/34) exibiram lesões sugestivas de Pneumonia Enzoótica Suína (PES). Seis (17,7%) amostras apresentaram alterações causadas pela distribuição irregular de sangue. Casos sugestivos de PES crônica foram observados em 57,1% (16/28) dos fragmentos coletados. Em 42,9% (12/28) das amostras foram definidos como sugestivos de PES subaguda. Nenhum pulmão apresentou lesões sugestivas de PES aguda. A pesquisa demonstrou que lesões pulmonares em suínos são frequentemente detectadas no abatedouro de Esperança, Paraíba, sendo a maioria destas lesões sugestivas de PES.

The objective of the present study was to evaluate the macroscopic and histological lesions in the lungs of slaughtered pigs at the public slaughterhouse of Esperança, Paraíba. Lungs from 180 pigs were inspected between July and December 2013. Lesions were observed in 34 (18.8%) lungs. In the anatomopathological analysis of the collected fragments, 82.3% (28/34) presented suggestive lesions of Swine Enzootic Pneumonia (SEP). Six (17.7%) samples presented alterations caused by irregular blood distribution. Suggestive cases of chronic SEP were observed in 57.1% (16/28) of the collected fragments. In 42.9% (12/28) of the samples were defined as suggestive of subacute SEP. No lungs presented lesions suggestive of acute PES. The research showed that lung lesions in pigs are frequently detected in the Esperança, Paraíba slaughterhouse, with the majority of these lesions suggestive for SEP.