Increased fucosyl glycoconjugate by Mycoplasma hyopneumoniae enhances adherences of Pasteurella multocida type A in the ciliated epithelial cells of the respiratory tract

Abstract

BackgroundThe objective of this study was to elucidate the pathogenic mechanisms of how Mycoplasma hyopneumoniae enhances secondary Pasteurella multocida type A infection which leads to porcine enzootic pneumonia in infected pigs. Sixteen pigs were experimentally infected with M. hyopneumoniae and then euthanized at 7, 14, 21 and 28 days post inoculation. In situ hybridization for M. hyopneumoniae DNA and Ulex europaeus agglutinin-I (UEA-I) lectin histochemistry for fucosyl glycoconjugate, was performed in serial lung sections to determine alteration of fucosyl glycoconjugate in M. hyopneumoniae-infected bronchial and bronchiolar epithelium. Bacterial overlay assay was performed to determine the affinity of P. multocida type A with L-fucose.ResultsThe luminal surface of bronchial and bronchiolar epithelial cells that were stained with UEA-I always showed hybridization signals for M. hyopneumoniae but it was negative in the unaffected parts of the lung from M. hyopneumoniae-infected pigs and in lung from negative control pigs. Colocalization of M. hyopneumoniae and UEA-I was especially prominent in the luminal surface of bronchial and bronchiolar epithelial cells in serial section of lung. The mean number of M. hyopneumoniae-positive cells correlated with the mean number of UEA-I-positive cells in lungs from infected pigs throughout the experiment. All eight P. multocida type A isolates from naturally occurring enzootic pneumonia, bound strongly at levels of 2 μg and 5 μg of L-fucose.ConclusionsThe results of the present study demonstrate that M. hyopneumoniae increases the L-fucose composition to enhance adherence of P. multocida type A to the bronchial and bronchiolar epithelial cells.

Agents of pneumonia in slaughtered pigs in southern Brazil

“…Although this serotype has been described as a primary role in the induction of lesions in the respiratory tract (Paladino et al 2017, Oliveira Filho et al 2018, in this study we did not observe lesions suggestive of P. multocida highly pathogenic strain. The frequent isolation of P. multocida type A (43.3%; 65/150) in our study is probably related to the correlation between Mycoplasma hyopneumoniae and P. multocida type A infections (Takeuti et al 2013), as we found an average prevalence, in all lungs, of 79.3% of M. hyopneumoniae positive samples by qPCR, reaching 100% of the lungs from company D. The pathogenic mechanisms of this correlation are suggested to be due to the L-fucose composition increased by M. hyopneumoniae and thereby enhancing the adherence of P. multocida type A to the bronchial and bronchiolar epithelial cells (Park et al 2016). In our study, 42.7% of the samples which presented P. multocida type A isolation also showed histopathological lesions suggestive of M. hyopneumoniae and/or IAV infection, which demonstrates the importance of P. multocida type A as a secondary causative agent of pig pneumonia (Takeuti et al 2013, Morés et al 2015.…”

“…Mycoplasma hyopneumoniae is one of the most relevant bacteria in swine production (Pieters & Maes 2019). It is the causative agent of Enzootic Pneumonia and has an important role in the PRDC, facilitating other bacteria or virus infections (Thacker et al 1999, Park et al 2016, Pieters & Maes 2019. A total of 79.3% of the lungs were positive for M. hyopneumoniae by qPCR and four out of five companies presented a high Agents of pneumonia in slaughtered pigs in southern Brazil proportion of lungs positive for M. hyopneumoniae by PCR.…”

Pathomorphological Changes and Bacterial Pathogens Associated With Swine Pneumonias in Southwest Nigeria

“…The partial or complete compression and obliteration of bronchiolar lumen associated with these lesions resulting in collapse of the surrounding alveoli, which was recorded in the present study had been previously described in M. hyopneumoniae-infected pigs (Redondo et al, 2009;Hansen et al, 2010, Olaniyi, 2017, Raymond et al, 2018. The obliteration of the bronchiolar lumen had been attributed to accumulation of mucous and inflammatory exudates in the bronchial lumen as a result of decreased ciliary activities, increased activities of mucous secreting cells and altered glycoprotein (Park et al, 2016), release of pro-inflammatory chemical mediators by alveolar macrophages (van Reeth and Nauwynck, 2000) and the presence of hyperplastic lymphoid aggregates (Maes et al, 1996;Sarradell et al, 2003, Redondo et al, 2009, Hansen et al, 2010. This hyperplasia has been associated with constant antigenic stimulation which associated with chronic recurrent infections.…”

Genomic Variability and Post-translational Protein Processing Enhance the Immune Evasion of Mycoplasma hyopneumoniae and Its Interaction With the Porcine Immune System

“…Earlier research pointed out that Mhp infection could increase the lung susceptibility to Pasteurella multocida ( 113 ). Particularly, Mhp plays a leading role during the adhesion of Pasteurella multocida type A, which can provide binding sites on the epithelial cell surface ( 114 ). In addition, Actinobacillus pleuropneumoniae infection can cause Mhp-infected pigs to show more severe respiratory symptoms ( 115 ).…”