Genetic characterization of domestic pigs in the core zone of swine production of Argentina.

Argentina is a small player in the global pork market, contributing only 0.7% of the total production. With increasing global demand for meat, there is an opportunity for countries with an agricultural profile to grow their pork production. However, there is a need to understand the current state of the pork production sector in all aspects to inform decision-making. The aim of this study was to genetically characterize pig herds from different production strata in the primary region for pork production in the country. For this purpose, phylogenetic and genetic variability analyses were performed using the mitochondrial control region marker (n=95 pig samples). Moreover, genotyping of ryr1 and PRKAG3 genes (n=108 pig samples) were performed to evaluate the frequency of deleterious alleles for meat quality traits in the region. The results showed high levels of genetic variability in the pig herds (Hd= 0.840 ± 0.031 and π= 0.010 ± 0.001), with a creole sow and Iberian lineage standing out in the phylogeny. The genotyping of the ryr1 marker revealed the presence of the deleterious t allele in all analyzed strata. However, the RN-allele of the PRKAG3 gene was detected only in the two lower strata. This study represents the first analysis of the phylogenetic relationships among domestic pigs from Argentina and provides an initial assessment of genetic variability in the region. Additionally, the results present, for the first time, the frequency of deleterious alleles for pig production in the productive core area, demonstrating their prevalence.

Molecular detection of Rickettsia in ectoparasites (Siphonaptera and Phthiraptera) of domestic and feral pigs from Argentina.

Rickettsioses are distributed among a variety of hematophagous arthropods, and represent an emergent threat. The presence of rickettsial bacteria in ectoparasites collected from pigs from Argentina is still unknown. This study investigated the presence and identity of Rickettsia spp. in fleas, Pulex irritans, and sucking lice, Haematopinus suis, of domestic and feral pigs, Sus scrofa, from Central-Northern Argentina, through the genes gltA and ompB. Rickettsial bacteria were detected in 50% of fleas and 24% of lice. The BLASTn analysis of the ompB gene fragments in P. irritans samples showed identities 99% and 100% with R. felis. Positive samples of H. suis were 99% similar with species from the spotted fever group, future amplifications of a more polymorphic fragment of the ompB gene will allow to corroborate the identity of the Rickettsia species present in these lice samples. The Rickettsia spp. reported in the present study are having eventually been associated with cases of human diseases, and the circulation of these agents in arthropods has already been reported in several countries. Therefore, the identification of circulating pathogenic agents, such as reported in this study, is crucial for development of preventive measures for the control of ectoparasite-borne rickettsiosis diseases. Further studies, using serology techniques, will be allow to explore the ability of pigs as a possible Rickettsia reservoir and its role as part of transmission cycle of Rickettsia spp. in the studied scenarios.