Although blood-feeding hookworms infect over a billion people worldwide, little is known about the molecular mechanisms through which these parasitic nematodes cause gastrointestinal hemorrhage and iron deficiency anemia. A cDNA corresponding to a secreted Kunitz type serine protease inhibitor has been cloned from adult Ancylostoma ceylanicum hookworm RNA. The translated sequence of the A. ceyl...

Some terrestrial mollusks are natural hosts of Angiostrongylus costaricensis. In the laboratory, this nematode can be maintained in certain planorbids, which are aquatic mollusks and intermediate hosts of Schistosoma mansoni. Mollusks can be infected with Angiostrongylus costaricensis by ingestion of or active penetration by the first-stage larvae. In this work we assessed the ability of Biomph...

A novel filarial serine protease inhibitor (SPI) from the human parasitic nematode Onchocerca volvulus, Ov-SPI-1, was identified through the analysis of a molting third-stage larvae expressed sequence tag dataset. Subsequent analysis of the expressed sequence tag datasets of O. volvulus and other filariae identified four other members of this family. These proteins are related to the low molecu...

TITOY, G.A.P. & SCHWAN, E.V. 1994. Bile enhances the infectivity of third stage larvae of Dictyocaulus filaria. Onderstepoort Journal of Veterinary Research, 61:395-396 Incubating metacyclic larvae of Dictyocaulus filaria in ovine bile solution prior to per os infection significantly enhanced their infectivity to sheep. INTRODUCTION Although there are several reports on the effect of bile on th...

The development of the nematode Procamallanus saccobranchi Karve, 1952, a parasite in the stomach of the fish Heteropneustes fossilis (Bloch), was studied in Mesocyclops crassus (Fischer) and Mesocyclops leuckarti (Claus). After being ingested by the copepods the nematode first-stage larvae penetrated into the haemocoel of the intermediate host; there they moulted twice (on days 3 and 5 p.i. at...

An agar plate (AP) method has been developed for culturing infectious larvae of the hookworm Ancylostoma ceylanicum. The third-stage larvae reared using the AP method displayed similar morphology to those cultured using Baermann or Harada-Mori coproculture techniques. The yield of viable larvae from the AP method (50%) was comparable to that of the Baermann (47%), and both were superior to Hara...

The embryological and postembryological development of Thelastoma bulhoesi was determined. Initial cleavage was into unequal cells and occurred within 1-2 hours at 25 C. Cell division was holoblastic but no true morula is formed. Gastrulation occurred at approximately 48 hours by epibolic synectic mechanisms. First-stage larvae were fully developed at 96 hours. The molt to second-stage larvae w...