Bulinus forskalii (Basommatophore: Planorbidae), New Experimental Intermediate Host of Trematoda Paramphistomum microbothrium Fischoeder 1901

Abstract

The objective of this study was to gain a better knowledge of the biological cycle of Paramphistomum microbothrium in order to develop effective control strategies. The adult specimens of P. microbothrium were gathered alive from the stomach mucous membrane of cattle (Bos taurus) at Kolda slaughterhouses. Then they were put in Petri dishes containing distilled water for egg laying. The majority of eggs hatched at day 19 and gave miracidiae which were used to infest artificially 75 infestation-free Bulinus forskalii (hatched and raised in the laboratory). These started to produce cercariae four weeks after infestation. The success rate of Bulinus forskalii infestation was 34.67% and the real percentage of infestation was 35.29%. The produced cercariae were encysted in metacercariae before being given to four young cattle, which were subjected to fecal samplings and, later, sacrificed for postmortem examination. Each animal received a single dose of 500 metacercariae at 2, 3, 4 and 5 weeks of maturation, respectively. No eggs of P. microbothrium were found in the feces of the animals during the six months of postinfection monitoring. Adult forms of P. microbothrium were found in the rumen of the four sacrificed cattle. Success rates were 62.6, 69.0, 83.8 and 56.4% for cattle infested with metacercariae aged 2, 3, 4 and 5 weeks after maturation, respectively. B. forskalii can thus be considered as a good experimental intermediate host of P. microbothrium