Detection of Mycoplasma hyopneumoniae in lungs and nasal swabs of pigs by nested PCR

Abstract

Fifty-four samples were collected from growing and finishing pigs for the molecular diagnosis of enzootic porcine pneumonia. Nineteen lung fragments were obtained from pigs that showed signs of respiratory disease and 35 nasal swabs were obtained from clinically healthy pigs. For the detection of the bacterial genome in the samples, the nested PCR technique was used to amplify a fragment of 706bp. This fragment was subsequently cloned and sequenced. The sequence of obtained nucleotides was compared with six other sequences of Mycoplasma hyopneumoniae and 11 sequences of other bacteria available in the Genbank. To measure the sensitivity of the nested PCR, serial dilutions (10 -1 to 10 -15 ) of cloned fragments were conducted based on the concentration of 300ng. Ten lung fragments and eight nasal swabs showed positive for M. hyopneumoniae and the limit of detection was estimated to be 0.3fg DNA cloned. The sequence of nucleotides obtained showed 99.1% homology with the other sequences of M. hyopneumoniae, demonstrating that the nested PCR used in this study may provide an important diagnostic tool for the detection of this agent.

Occurrence of Mycoplasma hyopneumoniae in slaughter pigs from Southern Brazil

“…According to Vicente et al (2013), 52% of samples collected from different farms in a central region of São Paulo state were seropositive for M. hyopneumoniae. Silva et al (2009) also detected this agent in 52.6% of lung samples collected from southeast Brazil. Moreover, specific data on prevalence per country are not available in the literature, as the disease is not considered obligatory to report and does not limit commercial trade (Maes et al, 2018).…”

Genetic diversity of Mycoplasma hyopneumoniae in finishing pigs in Minas Gerais

“…Mycoplasma hyopneumoniae is one of the most economically impacting respiratory pathogens in the world, detected in almost all swine farms with intensive production countries (Thacker 2006, Silva et al 2009, Maes et al 2018). The bacterium is considered a primary agent of swine enzootic pneumonia and respiratory complex, characterized by coughs, reduced growth rate and high feed conversion rate (Maes et al 1996).…”

INFECÇÃO POR Mycoplasma pulmonis EM RATOS WISTAR PROVENIENTES DE BIOTÉRIO

“…No Brasil, apenas quatro estudos avaliaram a taxa de infecção por M. pulmonis em ratos provenientes de biotérios. Um estudo no Rio de Janeiro curiosamente encontrou uma taxa de infecção de 81,25% num biotério controlado, e de 25% em um biotério convencional (18). Outro estudo em São Paulo detectou taxas de infecção de 83,78% em um biotério sem barreiras microbiológicas, não sendo encontrada infecção em biotério com barreiras (23).…”