Infectivity, persistence and serological response of nineTrichinellagenotypes in rats

Abstract

Summary:Domestic and sylvatic Trichinella genotypes were evaluated for infectivity, muscle larvae persistence, and host antibody responses in rats. Groups of rats were inoculated with T. spiralis, T. nativa, T. britovi, three genotypes of T. pseudospiralis (from USSR, USA, and Australia), T. murrelli, Trichinella T6, and T. nelsoni, respectively. The muscle larvae intensity (larvae per gram), total larval burden (Ipg x rat weight), and the antibody levels were determined at necropsy 5, 10, 20, and 40 weeks post inoculation. All Trichinella genotypes were established in the rats, but infectivity and persistence differed significantly: T. spiralis established and persisted in high numbers, the three T. pseudospiralis genotypes were also highly infective but differed significantly in persistence, T. britovi and T. nativa had limited infectivity and persistence, Trichinella T6 had low infectivity and very low persistence, and T. murrelli and T. nelsoni were almost non-infective. Except for T. spiralis, initial total muscle larval burdens declined significantly for other genotypes during the experiment. A high initial serological response was detected for all genotypes, but the antibody levels decreased rapidly in relation to decreasing larval burdens. After 20 w.p.i. the antibody levels I remained high only in T. spiralis and T. pseudospiralis infected rats. The high infectivity and persistence of T. pseudospiralis in rats, suggests that in addition to T. spiralis, this species might be of significant importance in the domestic cycle of trichinellosis.

Epidemiology, Diagnosis, Treatment, and Control of Trichinellosis

“…The predominant Trichinella epitopes inducing humoral immunity are localized on the so-called TSL-1 antigen, which is found in the stichocyte cells and on the surface of the parasite's cuticle and which is secreted by first-stage larvae in the muscle (5,112). TSL-1 antigen epitopes are highly conserved, and a high cross-reactivity between Trichinella antigens derived from different species and genotypes was revealed, allowing serology to detect infection with all of these Trichinella species (5,51,69,86,104). Tyvelose has been identified as being a major carbohydrate epitope of the TSL-1 antigen, and a synthetic variant of tyvelose has been developed for use in ELISA (143,161).…”

Development of cellular immune response of mice to infection with low doses of Trichinella spiralis, Trichinella britovi and Trichinella pseudospiralis larvae

“…Potential differences in a development of the host immune response to different Trichinella species and host-parasite interactions are rarely studied under in vivo conditions (Malakauskas et al 2001;Bolas-Fernández 2003;Lee and Ko 2006). Andrade et al (2007) described interspecies results from in vitro study, where the differences in NO production of macrophages after stimulation with L1 antigens from encapsulated and non-encapsulated Trichinella species were demonstrated.…”

Opinion of the Scientific Panel on biological hazards (BIOHAZ) on the on the “Risk assessment of a revised inspection of slaughter animals in areas with low prevalence of Trichinella”

“…In case T. spiralis is present in the environment, rodents may transmit the infection to piglets even those that are not weaned. The same applies, to a lesser extent, to T. britovi, which does not readily infect rats (Malakauskas et al, 2001), but infects mice.…”