Lesions Caused by Natural Infection with<i>Streptococcus Suis</i>Type 9 in Weaned Pigs

Vasconcelos, Daphne; Middleton, Dorothy M.; Chirino-Trejo, J M

doi:10.1177/104063879400600309

Cited by 19 publications

(11 citation statements)

References 23 publications

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“…e Bordetella bronchiseptica podem estar envolvidos sozinhos ou em combinação em estudos da doença natural em suínos (Dungworth 1993, Ross 1999, Know et al 2002. Streptococcus suis causa broncopneumonia supurativa como infecção única ou em combinação com P. multocida (Reams et al 1994, Vasconcelos et al 1994.…”

Section: Discussionunclassified

Pneumonia enzoótica em javalis (Sus scrofa)

Ecco

Lazzari²,

Guedes

2009

Pesq. Vet. Bras.

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RESUMO.-O objetivo desse estudo foi descrever o quadro clínico e epidemiológico, os achados patológicos, bacteriológicos e imuno-histoquímicos de um surto de pneumonia em uma granja de Javalis do Distrito Federal, Brasil. Em um período de cinco meses, morreram 90 javalis. Desses, 63 tinham lesões pulmonares. Clinicamente apresentavam atraso no desenvolvimento corporal, diminuição do apetite, letargia, tosse e dificuldade respiratória, principalmente quando movimentados. Constatou-se elevação da temperatura, 40 o C em média. Na auscultação, havia crepitações e estertores pulmonares de intensidade moderada. As alterações macroscópicas nos pulmões analisados eram típicas de broncopneumonia lobular. As lesões caracterizavam-se por consolidação crânio-ventral na maioria dos pulmões. A coloração variava de difusamente vermelho-escuro a um padrão mosaico (ló-bulos vermelho-escuros intercalados por lóbulos cinzas) ou difusamente acinzentados. Na maioria dos pulmões observou-se exsudato mucopurulento na luz dos brônquios e fluindo do parênquima. Histologicamente, as alterações eram de broncopneumonia purulenta e histiocitária com focos de necrose. Em alguns animais havia também hiperplasia do BALT e, na maioria dos animais, infiltração The aim of this paper is to describe the clinical, epidemiological, pathological, bacteriological and immunohistochemical aspects of a pneumonia outbreak in a wild pig farm in the Distrito Federal, Brazil. Ninety wild pigs died in a period of five months, and 63 of these had pulmonary lesions. Clinically, the pigs presented reduced growth rate, anorexia, lethargy, cough and dyspnea, especially after they were moved. High body temperature (40 o C in average) was verified in some animals. Auscultation revealed moderate pulmonary crepitation and stertors. Pulmonary gross lesions were typical of lobular bronchopneumonia. Lung lesions were characterized by ventral-cranial consolidation in the majority of the cases. The color of affected pulmonary areas varied from diffuse dark red to mosaic pattern (dark red lobule intercalate by grayish lobule) or diffusely grayish. The majority of the lungs had mucopurulent exsudate in the bronchial lumen that also drained from the parenchyma cut surface. Upon microscopy, the changes were characterized by purulent and histiocytic bronchopneumonia with necrotic foci. In some animals, there was BALT hyperplasia associated with perivascular and peribronchial plasma cells and lymphocytes infiltration in most of these cases. Bordetella bronchiseptica and Streptococcus spp. were the most frequently isolated bacteria. Immunohistochemistry evaluation demonstrated Mycoplasma hyopneumoniae on the luminal surface of bronchial and bronchiolar epithelial cells, and the DNA of bacteria was detected by PCR. This is the first report of bronchopneumonia in wild boars associated with M. hyopneumoniae infection.

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Section: Discussionunclassified

Pneumonia enzoótica em javalis (Sus scrofa)

Ecco

Lazzari²,

Guedes

2009

Pesq. Vet. Bras.

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“…However, when S. suis becomes invasive, it can induce severe diseases associated with meningitis, endocarditis, arthritis or septicemia [9]. An acute disease outbreak can lead to a loss of 4-12% of weaning piglets [7,10]. To date, S. suis has been classified into various serotypes [11][12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Analysis of Porcine Pro- and Anti-Inflammatory Cytokine Induction by S. suis In Vivo and In Vitro

et al. 2020

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Weaning piglets are susceptible to the invasive Streptococcus (S.) suis infection, which can result in septicemia. The aim of this study was to investigate the cytokine profile induced upon S. suis infection of blood, to determine the cellular sources of those cytokines, and to study the potential effects of the induced cytokines on bacterial killing. We measured TNF-α, IL-6, IFN-γ, IL-17A and IL-10 after an experimental intravenous infection with S. suis serotype 2 in vivo, and analyzed whole blood, peripheral blood mononuclear cells (PBMC) and separated leukocytes to identify the cytokine-producing cell type(s). In addition, we used a reconstituted whole blood assay to investigate the effect of TNF-α on bacterial killing in the presence of different S. suis-specific IgG levels. An increase in IL-6 and IL-10, but not in IFN-γ or IL-17A, was observed in two of three piglets with pronounced bacteremia 16 to 20 h after infection, but not in piglets with controlled bacteremia. Our results confirmed previous findings that S. suis induces TNF-α and IL-6 and could demonstrate that TNF-α is produced by monocytes in vitro. We further found that IL-10 induction resulted in reduced secretion of TNF-α and IL-6. Rapid induction of TNF-α was, however, not crucial for in vitro bacterial killing, not even in the absence of specific IgG.

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“…Meningitis lesions in pigs (or humans) infected with Strep. suis are typically characterized by infiltrations with large numbers of neutrophils (Beineke et al , 2008; Lun et al , 2007; Vasconcelos et al , 1994; Williams & Blakemore, 1990). Neutrophils mediate the first line of innate immune defence against invading bacterial pathogens.…”

Section: Introductionmentioning

confidence: 99%

Streptococcus suis DNase SsnA contributes to degradation of neutrophil extracellular traps (NETs) and evasion of NET-mediated antimicrobial activity

et al. 2014

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Streptococcus suis is an important cause of different pathologies in pigs and humans, most importantly fibrinosuppurative meningitis. Tissue infected with this pathogen is substantially infiltrated with neutrophils, but the function of neutrophil extracellular traps (NETs) -a more recently discovered antimicrobial strategy of neutrophils -in host defence against Strep. suis has not been investigated. The objective of this work was to investigate the interaction of Strep. suis with NETs in vitro. Strep. suis induced NET formation in porcine neutrophils and was entrapped but not killed by those NETs. As the amount of NETs decreased over time, we hypothesized that a known extracellular DNase of Strep. suis degrades NETs. Though this nuclease was originally designated Strep. suis-secreted nuclease A (SsnA), this work demonstrated surface association in accordance with an LPXTG cell wall anchor motif and partial release into the supernatant. Confirming our hypothesis, an isogenic ssnA mutant was significantly attenuated in NET degradation and in protection against the antimicrobial activity of NETs as determined in assays with phorbol myristate acetate (PMA)-stimulated human neutrophils. Though assays with PMAstimulated porcine neutrophils suggested that SsnA also degrades porcine NETs, phenotypic differences between wt and the isogenic ssnA mutant were less distinct. As SsnA expression was crucial for neither growth in vitro nor for survival in porcine or human blood, the results indicated that SsnA is the first specific NET evasion factor to be identified in Strep. suis.

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Lesions Caused by Natural Infection withStreptococcus SuisType 9 in Weaned Pigs

Cited by 19 publications

References 23 publications

Pneumonia enzoótica em javalis (Sus scrofa)

Pneumonia enzoótica em javalis (Sus scrofa)

Analysis of Porcine Pro- and Anti-Inflammatory Cytokine Induction by S. suis In Vivo and In Vitro

Streptococcus suis DNase SsnA contributes to degradation of neutrophil extracellular traps (NETs) and evasion of NET-mediated antimicrobial activity

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