Wild pigs (Sus scrofa) population as reservoirs for deleterious mutations in the RYR1 gene associated with Porcine Stress Syndrome.

Porcine Stress Syndrome (PSS) is a disorder codified by the ryanodine receptor 1 gene (RYR1) and affects both animal welfare and the quality of the meat product. As a consequence, individuals with this syndrome generate great worldwide economic losses in the porcine industry. In Argentina, the Buenos Aires Province is the most involved on this activity, and productions are to be in open field with a higher frequency of pigs with diverse pathologies. On the other hand, the biggest and oldest wild pigs population is located on the Atlantic coast of Buenos Aires Province, which presents a continuous bidirectional flow of individuals with the productive areas nearby. The aim of this study is to detect the presence of the RYR1 deleterious allele in the wild population from the Atlantic coast of Buenos Aires, in order to evaluate its possible role as a genetic reservoir for said allele. For this purpose, 106 wild pigs from 28 sites were studied, finding a 6.6% of carrier individuals, indicating that the wild population is not free of this allele. This constitutes the first analysis to detect the presence of the RYR1 deleterious allele, associated to the PSS in wild pigs from Argentina, being one of the few studies to report it worldwide and suggesting wild pigs populations to be a possible genetic reservoir for this disease.

First molecular detection of Mycoplasma suis in the pig louse Haematopinus suis (Phthiraptera: Anoplura) from Argentina.

Porcine haemoplasmosis caused by Mycoplasma suis affects the global pig industry with significant economic losses. The main transmission route of M. suis is through the blood and some haematophagous arthropods, like flies and mosquitoes, could be the vectors to this pathogen. However, the presence of M. suis in pig haematophagous ectoparasites in natural conditions has not yet been studied. The most frequent ectoparasite in pigs is the blood-sucking louse Haematopinus suis, an obligate and permanent parasite. Therefore, this work aims to study the occurrence of M. suis in H. suis samples from both domestic and wild pig populations from Argentina; using the 16S rRNA gene. A total of 98 sucking lice, collected from domestic and wild pigs from Buenos Aires Province in central Argentina, were examined. We found M. suis DNA in 15 H. suis samples (15.30%). Positive lice were detected from all studied populations. This is the first report of M. suis presence in H. suis, being also the first detection in a pig ectoparasite species. We conclude that H. suis could serve as a mechanical vector for M. suis. This information not only extends the knowledge about the pathogen spectrum potentially transmitted by H. suis, but may be also useful in epidemiological studies about Mycoplasma.