Host Immunity against Newborn Trichinella spiralis Larvae of Different Ages

Abstract

The infectivity of newborn Trichinella spiralis larvae of different ages was studied in normal rats. Newborn larvae collected after incubation of adult worms in vitro for 2, 12, or 24 hr were injected intravenously (i.v.) into normal AO rats in 3 separate recipient groups. All recipient rats developed strikingly similar numbers of muscle larvae 20 days later. The susceptibility to immunity by newborn larvae of different ages was also studied. No difference was found when degree of protection was compared by assessing muscle larvae burden or peritoneal anti-newborn larvae effects after injection of newborn larvae of different ages either i.v. or intraperitoneally into immunized recipient rats. We conclude that newborn larvae of any age up to 24 hr have similar infectivity in normal rats and are equally susceptible to anti-newborn larvae immunity in vivo.

Trichinella spiralis : the infectivity of synchronous newborn larvae of different ages inoculated intraocularly

“…A number of studies have reported that the infectivity of T. spiralis NBL is limited. After intravenous injection of NBL of any age up to 24 h, similar numbers of ML were recovered (Wang and Bell 1988b). It is dicult to compare these results with ours because the NBL used in the abovecited report were not synchronous.…”

“…The results demonstrated that NBL possessed similar degrees of infectivity for up to 24 h of age (Wang and Bell 1988b); however, another study showed the low infectivity of 2-h-old NBL and the high infectivity of 20-hold NBL in outbred Swiss mice and the adherence of eosinophils mainly to 2-h-old NBL, whereas macrophages adhered to 20-h-old NBL only (Binaghi et al 1984;GansmuÈ ller et al 1987). Our earlier experimental data demonstrated an``NBL age limit'' for NBL infectivity; however, until now this has not been precisely determined (Wranicz et al 1988).…”