Comparison between Trichinella patagoniensis and Trichinella spiralis infection in BALB/c mice

Abstract

In Argentina, trichinellosis is an endemic disease acquired mainly through consumption of raw pork infected with nematodes larvae from the Trichinella genus. For years, the only species involved in outbreaks in humans and pig foci in Argentina was Trichinella spiralis. In 2008 the presence of a new Trichinella taxon from a cougar (Puma concolor) was detected and recorded in the province of Rio Negro, Argentina, and the finding was established as a new species in 2012: Trichinella patagoniensis. To the best of our knowledge, there is no information available on the intestinal phase and antibody response in a susceptible host during T. patagoniensis infection. Therefore, our research has been designed to study experimental infection with T. patagoniensis compared to infection with T. spiralis in BALB/c mice. One hundred and twenty eight BALB/c mice were divided into two groups and individuals in each group were infected per os with 500 larvae of T. patagoniensis or 500 larvae of T. spiralis, respectively. After that, they were euthanized on different days. Adult worm recovery from small intestines and artificial digestion of each carcass was performed. Histopathology of small intestines was performed using hematoxylin-eosin staining. Systemic cytokines and antibody kinetics were evaluated. Intestinal adult worm recovery of T. patagoniensis and T. spiralis took place until day 17 and 25, respectively. Systemic IFN-γ, IL-10, and TNF showed significant variations in T. patagoniensis infected mice. Seroconversion was detected in animals as from 15 days post-infection (pi) for both T. patagoniensis and T. spiralis, reaching the highest OD value at 42 days pi. Similar microscopic lesions were observed in the small intestine from mice infected with the same dose of T. spiralis and T. patagoniensis. Our findings contribute new information regarding the intestinal phase and the antibody kinetics of T. patagoniensis in BALB/c mice.

Keywords: Cytokines; Experimental infection; Mice; Trichinella patagoniensis; Trichinella spiralis.