Presence of <i>Actinobacillus pleuropneumoniae, Streptococcus suis, Pasteurella multocida, Bordetella bronchiseptica, Haemophilus parasuis and Mycoplasma hyopneumoniae</i> in upper respiratory tract of swine in farms from Aguascalientes, Mexico

Abstract

Respiratory diseases are one of the most important health problems in pig herds. The porcine respiratory disease complex (PRDC) is the term used to describe pneumonic diseases caused by multiple infectious agents that provoke weight loss in animals or death. In the PRDC multiple pathogens (bacteria and/or viruses) work in combination to induce this respiratory disease. Within this complex, Actinobacillus pleuropneumoniae, Streptococcus suis, Pasteurella multocida, Bordetella bronchiseptica, Haemophilus parasuis and Mycoplasma hyopneumoniae are the main bacterial pathogens involved in great economic losses to the swine industry. The aim of this work was to estimate the presence of A. pleuropneumoniae, S. suis, P. multocida, B. bronchiseptica, H. parasuis and M. hyopneumoniae in the upper respiratory tract of pigs in representative swine farms in Aguascalientes, Mexico, using PCR technique. The study was performed in 14 swine farms. We obtained a total of 212 nasal swabs. Near 20% of samples were positive for A. pleuropneumoniae (located in the 79% of farms); 17% were positive for S. suis (in 86% of farms), of these, 3% were S. suis serovar 2; 30% were positive for H. parasuis (93% of farms); 23% of the samples to P. multocida (in 79% of farms); and 19% to M. hyopneumoniae (in 64% of farms). B. bronchiseptica was not detected in this study. The results obtained show that bacterial pathogens of PRDC were present in the upper respiratory tract of pigs in all farms studied; therefore, these pathogens are widely disseminated in pig farms of Aguascalientes, Mexico.

Porcine Respiratory Pathogens in Swine Farms Environment in Mexico

“…In the case of S. suis, was identified in water, soil and nasal swab samples ( Table 2), but the serotype 2, the more pathogens of all of them [10] [52] [53], was only found in one nasal sample. The low incidence of S. suis serotype 2 in our farms could be related with the low incidence of this pathogen in North America [30] [54], and these results are consistent with previous results obtained by our group [15]. Moreover, in the case of the bacteria H. parasuis, successfully detected in samples of nasal exudate and water but did not confirm if this was a viable state.…”

“…Moreover, in the case of the bacteria H. parasuis, successfully detected in samples of nasal exudate and water but did not confirm if this was a viable state. However, the percentage of samples found positive for this pathogen from nasal swabs was lower than previously reported in Mexico and in others countries from North America [15] [30]. Similar case is found for M. hyopneumoniae, which was detected only in nasal swabs in a low percentage in this study.…”

“…Likewise, there are few studies on the presence of this pathogen in Mexico. However, our group had reported a high distribution of this pathogen in pig farms in Mexico [15]. Moreover, it is very important to mention that these pathogens were found in a viable state in drinking water, food, air and soil, and in a nasal swab and urine samples.…”

“…Urine samples were taken directly from pigs urinating in sterile tubes. Finally, nasal swab samples were taken like described Loera-Muro et al [15].…”

“…After 24 hours of incubation at 37˚C, 5% CO 2 , bacterial colonies were harvested and resuspended in 1 ml of lysis buffer (15% of sucrose, lisozime 0.3 mg•ml −1 , EDTA 0.05 M and Tris 1M, pH 8) for DNA extraction. DNA isolation was performed as described by Sambrook & Russell [24] and Loera-Muro et al [15] modified. Pellets were dried at 37˚C, resuspended in distilled water and kept at −20˚C until use for the PCR reactions.…”