Susceptibility of rats to Taenia taeniaeformis infection

Intraspecific variation of Taenia taeniaeformis as determined by various criteria

The intraspecific variation of four laboratory-reared isolates of Taenia taeniaformis the SRN and KRN isolates from Norway rats, Rattus norvegicus, captured in Japan and Malaysia, respectively; the BMM isolated from a house mouse, Mus musculus, captured in Belgium; and the ACR isolate from a gray red-backed vole, Clethrionomys rufocanus bedfordiae, captured in Japan was examined by various criteria. Eggs of each of the four isolates were orally inoculated into several species of intermediate host. They were most infective to the rodent species from which the original metacestode of each isolate had been isolated in the field, and only the ACR isolate was infective to the gray red-backed vole. Although little difference was found between the SRN, KRN, and BMM isolates by the other criteria, including the morphology of rostellar hooks, the protein composition of the metacestode, and restriction endonuclease analysis of DNA, the ACR isolate was clearly different from the others. It was considered that the ACR isolate was independent as a strain distinct from the other three isolates.

Bioecology of the parasites of high altitude homeothermic host-parasite systems. II. Infections by strobilocerci of Hydatigera balaniceps (Hall), H. laticollis (Rudolphi) and H. parva (Baer) in relation to sex, size and weight of Indian house rat

The influence of sex, size and weight of the Indian house rat (Rattus rattus) on concurrent liver infections with Hydatigera balaniceps (Hall), H. laticollis (Rudolphi) and H. parva (Baer) has been discussed. A significant inverse relationship was recorded between cestode infection and rat size. Parasitization index and mean worm burden-host weight ratio decreased with increase in rodent weight.

Varying infectivity of Taenia taeniaeformis for rats and mice

Strains of Taenia taeniaeformis were shown to possess markedly differing infectivities for Sprague-Dawley rats and CFI mice. Strains from Scotland, Belgium and Iraq were more infective for mice than rats while this situation was reversed with a Malaysian strain. There were also differences in their ability to infect hosts of different ages within the range 3-12 weeks of age.