Diagnosis of Mycoplasma hyopneumoniae.
TL;DR: The use of serology, the polymerase chain reaction and various assays to detect the presence of M. hyopneumoniae in tissue is common in diagnostic laboratories as mentioned in this paper.
Abstract: Mycoplasma hyopneumoniae, the cause of enzootic pneumonia, remains an important pathogen in the swine industry. This small, complex organism colonizes the ciliated cells of the respiratory tract, resulting in little exposure to the immune system. Confirming the presence of M. hyopneumoniae, as well as identifying its role in respiratory disease and pneumonia, remains challenging to the veterinary profession. While culture of the organism remains the gold standard for identification, the use of serology, the polymerase chain reaction and various assays to detect the presence of M. hyopneumoniae in tissue is common in diagnostic laboratories. Because of the role M. hyopneumoniae plays in increasing the severity of pneumonia associated with concurrent bacterial and viral infections, understanding the pathogenesis and diagnostic assays available is critical for developing effective intervention strategies to control respiratory disease on a herd basis.
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TL;DR: In this article , the authors used a piecewise exponential model to account for within-pen transmission dynamics followed by a mixed-effect logistic regression to detect Mycoplasma hyopneumoniae (MHP) DNA in pen-based oral fluid samples.
2 citations
TL;DR: The findings suggest that the study on the characteristics of M. hyopneumoniae strain ES-2 will guide the rapid and accurate drug use in the clinic, and develop a theoretical foundation for accurately diagnosing and treating the infection caused by pathogenic M.hyop pneumoniae.
Abstract: Mycoplasma hyopneumoniae is the primary pathogen of swine enzootic pneumonia and causes great economic losses to the swine industry worldwide. In China, M. hyopneumoniae seriously hinders the healthy development of the native black pigs. To prevent and treat porcine respiratory disease caused by M. hyopneumoniae, the characteristics of M. hyopneumoniae strain ES-2 isolated from Chinese native black pig lungs with gross lesions at post-mortem were studied for the first time in this study. Strain ES-2 cell was round or oval cells and most sensitive to kanamycin. The diameters of most strain ES-2 cells ranged from 0.4 to 1.0 μm with maximum viability of 1010 CCU/ml. Experimental challenge of animals with strain ES-2 showed respiratory disease could be reproduced, with pneumonic lung lesions evident. Comparative genomics analysis identified that 2 genes are specific to pathogenic M. hyopneumoniae strains, which may be predicted to be a molecular marker. These findings suggest that the study on the characteristics of M. hyopneumoniae strain ES-2 will guide the rapid and accurate drug use in the clinic, and develop a theoretical foundation for accurately diagnosing and treating the infection caused by pathogenic M. hyopneumoniae.
2 citations
Dissertation•
28 Feb 2011
TL;DR: Mycoplasma hyopneumoniae e o agente etiologico da Pneumonia Enzootica Suina (PES), uma das doencas respiratorias de maior incidencia na criacao de suinos no mundo, faz-se necessaria a busca de novas alternativas para a profilaxia da PES.
Abstract: Mycoplasma hyopneumoniae e o agente etiologico da Pneumonia Enzootica
Suina (PES), uma das doencas respiratorias de maior incidencia na criacao de
suinos no mundo. As vacinas disponiveis comercialmente consistem de celulas
inteiras inativadas (bacterina), as quais proporcionam apenas uma protecao
parcial e nao previnem a colonizacao pelo microrganismo. Neste contexto, faz-se
necessaria a busca de novas alternativas para a profilaxia da PES. Alguns
antigenos vem sendo testados em diferentes sistemas de vacinacao, porem
nenhum deles foi mais eficiente que as bacterinas comerciais no controle da PES.
Este trabalho teve como objetivo a producao e avaliacao da antigenicidade e
imunogenicidade de antigenos de M. hyopneumoniae administrados como vacinas
de DNA e/ou subunidade recombinante, visando o desenvolvimento de uma
vacina contra a PES. As vacinas de subunidade recombinante foram obtidas
atraves da expressao de onze proteinas recombinantes de M. hyopneumoniae em E.
coli e purificacao por cromatografia de afinidade, enquanto que as vacinas de DNA
foram obtidas pela clonagem de quatro genes de M. hyopneumoniae no vetor
pcDNA3. A antigenicidade das proteinas recombinantes foi verificada
confrontando-as com soro de suinos convalescentes. A imunidade humoral e
celular destas vacinas foi avaliada em camundongos imunizados
intramuscularmente. Todas as proteinas recombinantes avaliadas foram
reconhecidas pelo soro de animais convalescentes, em ensaios de ELISA e/ou
Western blot, em especial a proteina MHP0418, indicando serem expressas
durante o processo infeccioso. Estas proteinas recombinantes, bem como P37,
P42, P46 e P95 apresentaram capacidade imunogenica, induzindo ambas as
respostas imune Th1 e Th2. As proteinas P37, P42, P46 e P95, e a vacina de
DNA pcDNa3/P46 tambem foram capazes de induzir a expressao de INFγ,
citocina associada a resposta imune celular e reduzir a expressao de TNFα e IL1,
relacionadas com as lesoes em suinos, durante infeccao por M. hyopneumoniae,
sugerindo o potencial destas como candidatas vacinais. A estrategia de
imunizacao utilizando proteinas combinadas potencializou a resposta imune,
sendo que as proteinas MHP0443 e MHP0372 foram as principais responsaveis
pela imunogenicidade induzida pelos Mix1 e Mix2, respectivamente. Alem disso,
MHP0107, MHP0418 e MHP0372 induziram anticorpos que reagiram
especifiamente contra proteinas das cepas 7448, 4722 e J de M. hyopneumoniae,
nao apresentando reacao cruzada com M. hyohinis e M. flocculare, podendo,
portanto, serem utilizadas em ensaios de imunodiagnostico.
1 citations
Dissertation•
05 May 2010
TL;DR: Multiple loci variable number of tandem repeats analysis (MLVA) and PCR-restriction fragments length polymorphism (PCR-RFLP) analyses showed a high diversity among field M. hyopneumoniae isolates, however, there seemed to be greater homogeneity within the same herd.
Abstract: Mycoplasma hyopneumoniae, the causative agent of porcine enzootic pneumonia, is present in swine herds worldwide. However, little is known about the prevalence of this microorganism in Quebec and Canadian herds. A total of 160 swine lungs with lesions suggestive of enzootic pneumonia were recovered from two slaughterhouses. They were cultured and tested by PCR for M. hyopneumoniae and Mycoplasma hyorhinis and for the porcine reproductive and respiratory syndrome virus (PRRSV), the influenza virus, and the porcine circovirus type 2 (PCV2). Samples were also cultured for other commonly encountered swine pathogenic bacteria. Ninety percent of the samples were positive for M. hyopneumoniae (Real-time PCR) whereas 5.6% were positive only for M. hyorhinis (PCR). Among 25 selected M. hyopneumoniae positive lungs (culture or real-time PCR), 10 demonstrated a co-infection with Pasteurella multocida, 12 with Streptococcus suis, 9 with PCV2 and 2 with the PRRSV. Multiple loci variable number of tandem repeats analysis (MLVA) and PCR-restriction fragments length polymorphism (PCR-RFLP) analyses showed a high diversity among field M. hyopneumoniae isolates. However, there seemed to be greater homogeneity within the same herd. The MLVA analysis also demonstrated that almost half of the field isolates presented less than 55% homology with the vaccine and reference strains used in this study. The absence of amplification of one locus (locus 1) of M. hyopneumoniae was significantly associated with lower numbers of bacteria and a lower severity of lung lesions. All M. hyopneumoniae isolates showed low to intermediate MICs against the antimicrobials tested. Isolates with intermediate MICs for tetracyclines, macrolides and lincosamides were tested for the presence of previously described resistance genes tetM, ermB and L4, L22 and 23S rRNA point mutations. None of these genes were
1 citations
References
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Book•
[...]
01 Jul 1952
TL;DR: In this article, the characteristics of a variety of diseases of swine and methods for their prevention and treatment are described, as well as methods to detect and treat these diseases in swine.
Abstract: Describes the characteristics of a variety of diseases of swine, and methods for their prevention and treatment.
1,722 citations
TL;DR: Results indicate that M. hyopneumoniae infection potentiates PRRSV-induced disease and lesions, which is important with respect to the control of respiratory disease in pigs and has implications in elucidating the potential contribution of mycoplasmas in the pathogenesis of viral infections of other species, including humans.
Abstract: An experimental model that demonstrates a mycoplasma species acting to potentiate a viral pneumonia was developed. Mycoplasma hyopneumoniae, which produces a chronic, lymphohistiocytic bronchopneumonia in pigs, was found to potentiate the severity and the duration of a virus-induced pneumonia in pigs. Pigs were inoculated with M. hyopneumoniae 21 days prior to, simultaneously with, or 10 days after inoculation with porcine reproductive and respiratory syndrome virus (PRRSV), which induces an acute interstitial pneumonia in pigs. PRRSV-induced clinical respiratory disease and macroscopic and microscopic pneumonic lesions were more severe and persistent in M. hyopneumoniae-infected pigs. At 28 or 38 days after PRRSV inoculation, M. hyopneumoniae-infected pigs still exhibited lesions typical of PRRSV-induced pneumonia, whereas the lungs of pigs which had received only PRRSV were essentially normal. On the basis of macroscopic lung lesions, it appears that PRRSV infection did not influence the severity of M. hyopneumoniae infection, although microscopic lesions typical of M. hyopneumoniae were more severe in PRRSV-infected pigs. These results indicate that M. hyopneumoniae infection potentiates PRRSV-induced disease and lesions. Most importantly, M. hyopneumoniae-infected pigs with minimal to nondetectable mycoplasmal pneumonia lesions manifested significantly increased PRRSV-induced pneumonia lesions compared to pigs infected with PRRSV only. This discovery is important with respect to the control of respiratory disease in pigs and has implications in elucidating the potential contribution of mycoplasmas in the pathogenesis of viral infections of other species, including humans.
344 citations
Journal Article•
TL;DR: A description is given of a new medium with which primary isolation of mycoplasma species of the porcine respiratory tract is usually successful, and various additives often recommended for myCoplasma cultivation have been examined for growth promoting effect.
Abstract: Two mycoplasma species of the porcine respiratory tract: Mycoplasma suipneumoniae and Mycoplasma flocculare, have been notoriously difficult to cultivate. In the present paper a description is given of a new medium with which primary isolation of these organisms is usually successful. The basal medium is made from commercial dehydrated products. Pig serum is added and phenol red used as pH indicator. Contrary to what is customary in the preparation of mycoplasma media, various inorganic salts (Hank's balanced salt solution) are included and penicillin-G replaced as a bacteriostatic by bacitracin and meticillin. The volume of water is adjusted so as to give isotonia. Various additives often recommended for mycoplasma cultivation have been examined for growth promoting effect; apparently, however, they were all without effect. Working procedures for primary isolation trials are briefly described.
294 citations
TL;DR: In vivo- and in vitro-grown Mycoplasma hyopneumoniae organisms were inoculated onto newborn piglet tracheal organ cultures to provide a model for interaction of this organism with ciliated respiratory epithelium.
Abstract: In vivo- and in vitro-grown Mycoplasma hyopneumoniae organisms were inoculated onto newborn piglet tracheal organ cultures to provide a model for interaction of this organism with ciliated respiratory epithelium. Ciliostasis and loss of cilia in tracheal rings were induced by M. hyopneumoniae grown in vivo and with low-passage cultures when grown in vitro. Levels of calmodulin or dehydrogenase enzymes in tracheal ring epithelium were not altered even though ciliostasis and loss of cilia induced by M. hyopneumoniae were extensive. The capacity for inducing epithelial damage diminished with in vitro passage of the organism. Attempts to induce higher-passage cultures to attach to cilia, cause ciliostasis, or cause ciliary damage by supplementation of mycoplasmal medium with porcine lung extract failed. Epithelial damage induced by M. hyopneumoniae in tracheal rings was averted by using porcine immune serum or by separating the organisms from ciliated epithelium with a 0.1-microns-pore-size membrane. Attachment, or at least close association, of M. hyopneumoniae to ciliated epithelium appeared to be necessary to induce ciliostasis and loss of cilia in this model.
173 citations
TL;DR: An evaluation of cultivation, immunofluorescence, ELISA and polymerase chain reaction for demonstration of M. hyopneumoniae in lungs showed that all four methods have a high sensitivity in the acute stages of pneumonia.
154 citations