Detecção molecular de Mycoplasma suis em suínos de criações extensivas nos municípios de Itapecuru Mirim e Santa Rita no Estado do Maranhão

Abstract

Mycoplasma suis is a pathogenic bacterium that sticks and invades on the surface of swine erythrocytes, generating structural deformations in the parasitized cells. In Brazil, there are few reports on books about the parasite, disease orit’s economic impacts in the productive and sanitary spheres. The parasite in question fits into the group of hemotrophic mycoplasms (hemoplasms) in the order Mollicutes, and is responsible for the etiological agent of swine hemoplasmosis. The aim of the present research was to quantify, having as background the Real Time Quantitative PCR, the molecular detection of Mycoplasma suis in blood samples from 65 pigs from extensive farms in the cities of Itapecuru Mirim and Santa Rita, Maranhão, Brazil. After DNA extraction from the blood samples using the commercial kit, Polymerase Chain Reaction (PCR) was performed for the endogenous GAPDH gene in order to rule out false-negative results due to the presence of inhibitors. The positive samples in the aforementioned reaction were submitted to qPCR assays for Mycoplasma suis based on the 16S rRNA gene. All reactions were performed in compliance with the standards established by the MIQE (Minimum Information for publication of Quantitative real-time PCR Experiments). Of the 65 samples, in Itapecuru Mirim we had 17 (56.6%) that were positive for the endogenous GAPDH gene. As of the 17 samples, 14 (82.35%) were positive for qPCR for Mycoplasma suis, where as in Santa Rita we had 23 (65.7%) that were positive for the endogenous GAPDH gene. Being 15 (65.21%) positive for qPCR for Mycoplasma suis. Absolute quantification ranged from 6.07 X 102 copies to 1.77 X 106 of a fragment of the 16S rRNA / μL gene, with a mean of 2.29 X 105 copies / μL between the positive animals in Itapecuru Mirim and Santa Rita a Absolute quantification ranged from 7.05 X 104 copies at 1.44 X 102 of a fragment of the 16S rRNA / λ1 gene, with a mean of 1.16 X 104 copies / μL among positive animals. This study, although still with unpublished results, shows that Mycoplasma suis circulates among swine from extensive farms in the cities of Itapecuru Mirim and Santa Rita, in the State of Maranhão. The pathogenic potential of the isolates needs further investigation in order to estimate the hemoplasmosis damage in the swine industry in the State of Maranhão. The possible role of these animals as a source of Mycoplasma suis infection for other animals, as well as their pathogenic potential of the isolates, need further investigation.