A new molecular approach to assess the occurrence of Sarcocystis spp. in cattle and products thereof: preliminary data

Abstract

The genus Sarcocystis consists of more than 200 species. Those protozoa are characterised by a biological cycle composed by two obligatory hosts, definitive and intermediate. Apart from being possibly pathogenic for the intermediate host, a number of authors consider the intestinal sarcocystosis a minor zoonotic disease. Humans, in fact, can act as definitive host for two sarcosporidian species, S. suihominis e S. hominis, being infected through the consumption of raw or undercooked pig and bovine meat, respectively. Other two species could parasitise cattle: S. cruzi and S. hirsuta, having canids and felids as definitive hosts, respectively. The three species differentiate from each other in dimensions and cystic wall morphology, this latter being the basis for taxonomical studies. In 2010, the European Food Safety Authority (EFSA) highlighted the absence of reliable methods for epidemiological studies on the presence of Sarcocystis spp. in animals and products thereof. On this basis, the present study has been developed a new molecular method for the identification of Sarcocystis in bovine meat. For the development of the polymerase chain reaction (PCR) protocol, a set of samples of bovine meat from cattle (N=15), slaughtered at the didactic abattoir at the Veterinary Faculty of Turin University, has been collected, sequenced and used as reference samples during the study. A second set of samples (N=29), gathered from the same abattoir (N=12) and from abattoirs of Piedmont region (N=17), has been used for applicability tests. The overall positive rate for Sarcocystis spp. in our samples has been 91% (40/44), with S. cruzi representing the species with higher rates (68%), followed by S. hominis (43%) and S. hirsuta (2%). Based on the results of specificity and applicability tests performed in this study, the newly developed protocol proved to be reliable and suitable for epidemiologic purposes.

Keywords

• Sarcocystis
• Multiplex PCR
• Cattle