Agents of pneumonia in slaughtered pigs in southern Brazil

Conti, Elisa Rigo De; Takeuti, Karine Ludwig; Schwertz, Claiton I.; Bianchi, Ronaldo Michel; Driemeier, David; Barcellos, David Emílio Santos Neves de

doi:10.1590/1678-5150-pvb-6669

Cited by 9 publications

(6 citation statements)

References 28 publications

(44 reference statements)

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“…The data of the current study showed that the combination of pathogens, which represented 69.4% of the lungs, was similar to data obtained from slaughtered pigs in southern Brazil, when combinations of 2 or more pathogens was observed in up to 60% of the cases [9,25]. In Denmark, 148 lungs of slaughtered pigs with cranioventral bronchopneumonia were assessed and a wide range of macroscopic lesions, which were correlated with 5 species bacteria, 5 viruses and 2 mycoplasmas in different combinations were observed [14].…”

Section: Discussionsupporting

confidence: 87%

“…These data was already expected, once BALT hyperplasia is highly suggestive of pneumonia caused by M. hyopneumoniae due to high levels of interleukin-β and tumor necrosis factor induced by virulent strains of the bacterium, which have a nonspecific mitogenic effect on lymphocytes, resulting in BALT hyperplasia [2,23,24]. Similar results have been observed [9,17], which also observed association between M. hyopneumoniae detection by PCR and BALT hyperplasia in pigs and wild boars, respectively.…”

Section: Discussionsupporting

confidence: 80%

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Bacterial Pneumonia in Captive Wild Boars in Southern Brazil - Etiological and Pathological Causes

Biondo¹,

Takeuti²,

Montes³

et al. 2021

Acta Scientiae. Vet.

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Background: Respiratory diseases are one of the major health issues described in intensive pig production, causing important economic losses. However, there is little information on the prevalence, etiology and clinical-pathological presentation of these diseases in wild boars. For this reason, this work investigated the presence in captive wild boars of pneumonic lesions and bacterial pathogens commonly detected and associated with respiratory diseases in domestic pigs.Materials, Methods & Results: A total of 226 captive wild boar lungs from two farms were examined in a slaughterhouse in Southern Brazil. The pneumonic lesions were classified as cranioventral, dorsocaudal, and disseminated, and the quantification of lesions was calculated. From the total of 226 lungs, 121 were collected for laboratory examination. Lungs with macroscopic lesions suggestive of pneumonia were collected for histological, bacteriological and molecular analysis. The molecular analysis was performed to detect the presence of Actinobacillus (A.) pleuropneumoniae, Glaesserella (G.) parasuis, Mycoplasma (M.) hyopneumoniae, Mycoplasma (M.) hyorhinis and Streptococcus (S.) suis serotype 2. The percentages of histological lesions and bacterial agents and their association were calculated. Cranioventral consolidation (75.2%) was the most prevalent macroscopic lung lesion, followed by disseminated (21.5%) and dorsocaudal (3.3%) distribution. Microscopically, chronic lesions were the most prevalent, representing 70.2% of the lungs. Moreover, BALT hyperplasia was present in 86.5% of the lungs, suppurative bronchopneumonia in 65.7%, and alveoli infiltrate in 46.8%. Six bacterial pathogens commonly described as agents of pig pneumonia were identified by bacterial or molecular methods: Pasteurella (P.) multocida, S. suis, M. hyopneumoniae, A. pleuropneumoniae, G. parasuis and M. hyorhinis. Twenty-eight different combinations of pathogens were identified in 84 samples (69.4%). The most common combinations were: M. hyopneumoniae and A. pleuropneumoniae (13.1%), M. hyopneumoniae, G. parasuis and M. hyorhinis (10.7%), and M. hyopneumoniae, A. pleuropneumoniae and G. parasuis (8.3%). Additionally, M. hyopneumoniae was the most frequent pathogen detected in this study, representing 58.7% of the samples. The detection of M. hyopneumoniae and M. hyorhinis by PCR was associated with the presence of BALT hyperplasia (P < 0.05) and there was also an association between the detection of M. hyopneumoniae by PCR and suppurative bronchopneumonia (P < 0.05). In addition, a significant association (P < 0.05) between the detection of M. hyopneumoniae and A. pleuropneumoniae by PCR and the histological classification (acute, subacute or chronic lesions) was observed.Discussion: The results of this study were similar to those observed in slaughtered domestic pigs, although, the detection of opportunist pathogens was less frequent than that usually described in pig pneumonia. The high prevalence of pneumonia in captive wild boars at slaughter and the similar characteristics of pneumonia in captive wild boars and domestic pigs suggest that the close phylogenetic relationship between pigs and wild boars could influence the susceptibility of both species to the colonization of the same pathogens, indicating that captive wild boars raised in confined conditions could be predisposed to respiratory diseases, similar to domestic pigs. Keywords: Mycoplasma hyopneumoniae, lung consolidation, slaughter, Sus scrofa, swine.

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Section: Discussionsupporting

confidence: 87%

Section: Discussionsupporting

confidence: 80%

Bacterial Pneumonia in Captive Wild Boars in Southern Brazil - Etiological and Pathological Causes

Biondo¹,

Takeuti²,

Montes³

et al. 2021

Acta Scientiae. Vet.

Self Cite

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“…However, the percentages they found were different, with P. multocida type D present in 27.3% of samples, P. multocida type A in 24%, and Actinobacillus pleuropneumoniae in 14.6%. De Conti et al (2021) isolated P. multocida type A from 54.2% of 150 samples of lung lesions in slaughter pigs, however, in this study, 68% of the samples had histopathological lesions suggestive of the involvement of more than one agent, with Mycoplasma hyopneumoniae and influenza virus being the most prevalent. Apart from A. pleuropneumoniae which is considered a primary agent of pleuropneumonia in pigs, the isolation of P. multocida and Streptococcus suis from pulmonary lesions in samples of chronic pleuritis is not a guarantee that the bacteria isolated were the cause of this pleural lesion since they are most times opportunistic agents and S. suis is part of the microbiota in the respiratory tract of pigs (Hansen et al 2010).…”

Section: Discussioncontrasting

confidence: 66%

Economic impact of chronic pleural lesions and consequent disqualification of carcasses for export during inspection in swine slaughterhouses

et al. 2022

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Chronic pleuritis is the main reason for sending pig carcasses to the Department of Final Inspection (DIF), condemnation and led to economic losses to industries and producers. Most pleura lesions detected after slaughter are sequelae from bacterial infections by agents that do not pose risks to pork consumers. The objective of the present study was to generate science-based information for decision making in the evaluation and destination of chronic pleuritis by the Federal Inspection Service (SIF). Therefore, 200 carcasses, with and without pleurisy, from a swine slaughterhouse with SIF were assessed following the visual classification of the inspection agent. The study was carried out in two stages. In stage 1, 50 carcasses with pneumonic lesions adjacent to chronic pleuritis and 50 carcasses with only chronic pleuritis lesions were evaluated, through macroscopy, histopathology, and bacterial culture. In stage 2, 50 swine carcasses with chronic pleuritis and 50 without this lesion were sampled in the parietal pleura region to bacterial culture and PCR. The economic impact of not exporting these carcasses with chronic pleuritis was also assessed. Considering the stages of evolution of the lesions, the macroscopic examination showed high correlation with the histological examination. There was no bacterial isolation through pleural swabs, regardless of the presence or not of adjacent pulmonary lesions. Isolation was restricted to the adjacent pulmonary lesions of 70% samples, with Pasteurella multocida type A found in 48% of them, followed by P. multocida type D and Streptococcus suis in 12%, and Actinobacillus pleuropneumoniae in 3%. Only Streptococcus suis DNA was detected in 5/100 samples, with no correspondence to the isolation of viable bacteria. The reliability demonstrated in the macroscopic evaluation carried out during inspection, the absence of viable bacteria in the chronic pleural lesions, and the negative economic impact suggest that carcasses with chronic pleuritis can be submitted to pleura removal, with no need of sending to DIF.

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“…Pneumonia is one of the most commonly used Genetic diversity of Mycoplasma hyopneumoniae in finishing pigs in Minas Gerais indicators in health monitoring to diagnose the impact of infection on herds. Previous national studies show that the prevalence of pneumonia in slaughter pigs is high, with values around 72 to 75% (Silva et al 2001, Gabardo et al 2013, De Conti et al 2021. M. hyopneumoniae is known to be widely distributed in countries where there is commercial pig farming and is considered the main primary bacterial agent in this process.…”

Section: Discussionmentioning

confidence: 99%

Genetic diversity of Mycoplasma hyopneumoniae in finishing pigs in Minas Gerais

et al. 2023

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Mycoplasma hyopneumoniae is one of the most challenging respiratory pathogens involved with swine pneumonia worldwide, responsible for a chronic infection with high morbidity, which predisposes secondary bacterial infections in growing and finishing pigs. Advances in diagnostic techniques allowed identification of genetic characteristics associated with high antigenic and proteomic variability among bacterial strains. This study aimed to evaluate the genetic diversity of M. hyopneumoniae strains in lungs with pneumonic lesions obtained from 52 pig farms located in Minas Gerais, one of the largest swine production states in Brazil. Genotyping was performed using multilocus variable number of tandem repeat (VNTR) analysis (MLVA), targeting two loci encoding P97 and P146 adhesins VNTR. The results showed that this agent is widely disseminated in pig farms and there is a high polymorphism of M. hyopneumoniae variants circulating in the state of Minas Gerais. Different M. hyopneumoniae genotypes are randomly distributed in several regions of the state, with no specific geographic population structure pattern. M. hyopneumoniae association with viral agents was sporadic (3.17% with Influenza A and 1.9% with PCV2).

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Agents of pneumonia in slaughtered pigs in southern Brazil

Cited by 9 publications

References 28 publications

Bacterial Pneumonia in Captive Wild Boars in Southern Brazil - Etiological and Pathological Causes

Bacterial Pneumonia in Captive Wild Boars in Southern Brazil - Etiological and Pathological Causes

Economic impact of chronic pleural lesions and consequent disqualification of carcasses for export during inspection in swine slaughterhouses

Genetic diversity of Mycoplasma hyopneumoniae in finishing pigs in Minas Gerais

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