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: The main effects of vaccination include less clinical symptoms, lung lesions and medication use, and improved performance, however, bacterins provide only partial protection and do not prevent colonization of the organism.
370 citations
TL;DR: Lung samples from 148 finishing pigs with cranioventral lobular bronchopneumonia consistent with porcine respiratory disease complex (PRDC) in Denmark revealed a broad range of microscopical lesions and the diversity and number of pathogens were higher in these animals compared with controls.
172 citations
TL;DR: In this review, the characteristics of M. hyopneumoniae related to pathogenesis and control measures will be discussed and special emphasis will be placed on vaccination strategies that have been proposed with the use of reverse vaccinology approaches.
75 citations
TL;DR: It is indicated that vaccination does not significantly reduce the transmission of this respiratory pathogen in nursery pigs under field conditions.
Abstract: This study investigated the effect of vaccination against Mycoplasma hyopneumoniae on its transmission in nursery pigs under field conditions. Seventy-two pigs were randomly allocated at weaning into vaccinated (V) and non-vaccinated (NV) groups. Animals in the V group were vaccinated at 3 weeks of age with a commercial M. hyopneumoniae bacterin vaccine. Broncho-alveolar lavage fluid taken at weaning and at the end of the nursery period was assessed for the presence of M. hyopneumoniae by nested PCR, and the reproduction ratio of infection (Rn) was calculated. The percentage of positive pigs in the V and NV groups was 14% and 36% at weaning, and 31% and 64% at the end of the nursery period, respectively. The Rn-values for the V and NV groups were 0.71 and 0.56, respectively (P > 0.05). The study indicates that vaccination does not significantly reduce the transmission of this respiratory pathogen.
62 citations
TL;DR: A proteomic analysis, based on two-dimensional gel electrophoresis of soluble protein extracts, immunoblot and mass spectrometry, which was carried out aiming the identification of gene products and antigenic proteins from the M. hyopneumoniae pathogenic strain 7448 produced a proteome map that is expected to serve as a reference for comparative analyses for methabolic studies based on cells cultured under modified conditions.
62 citations
References
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Book•
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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