The infection of laboratory hosts with cercariae of Schistosoma mansoni and the recovery of the adult worms

Abstract

At present many laboratories throughout the world are studying the chemotherapy and immunology of Schistosoma mansoni in laboratory hosts. Many workers judge the success or failure of their attempts to cure or immunize these hosts from the ratio of the number of living adult worms recovered to the number of infecting cercariae. This ratio is affected, however, not only by the efficacy of any treatment, but also by the methods used to infect the animals and to recover the worms. If these methods result in widely varying worm recoveries amongst the animals in any experimental group, then small but significant effects of treatment might well be missed. Alternatively, such large experimental groups must be used that the work becomes tedious to perform and depends upon the availability of a great deal of technical assistance. This paper describes techniques which are rapid and do not require great skill in their performance. More important, in our hands they have given very consistent results. In this respect, particularly, we believe that these techniques have advantages over others which are currently practised.The techniques described here are those which were used in other investigations reported in this journal (Smithers & Terry, 1965a, b).The strain of S. mansoni used throughout this work was isolated in Puerto Rico and was obtained through the courtesy of Dr W. B. DeWitt of the National Institutes of Health. The parasite is maintained in an albino strain of Australorbis glabratus (Newton, 1955). Snails are exposed individually to ten miracidia overnight at 27 °C.

In vitro effects of artesunate on the survival of worm pairs and egg production of Schistosoma mansoni

“…At 8 weeks post-infection, adult worms were obtained by the perfusion technique, as described previously (Smithers & Terry, 1965), and washed with NCTC 135 medium twice.…”

Pivotal roles of the parasite PGD2 synthase and of the host D prostanoid receptor 1 in schistosome immune evasion

“…At the time of perfusion, the small intestines and the livers were also collected for the measurement of egg numbers within these organs. Tissues were digested in 4% KOH as previously described [43]. Records of the organ weights allowed the calculation of total tissue eggs per organ.…”

Design and testing of PCR primers for the construction of scFv libraries representing the immunoglobulin repertoire of rats

“…Two rats were sacrificed four weeks post-infection and a third rat was sacrificed eight weeks postinfection, and each rat was subjected to liver perfusion (Smithers and Terry, 1965) to recover adult worms. After four weeks, hundreds of worms were recovered while after 7 weeks only a single, immature pair of adult worms was found.…”