The first discovery of larval Gnathostoma hispidum (Nematoda: Gnathostomidae) from a snake host, Agkistrodon brevicaudus.

The present study was performed to observe the infection status of several kind of animals with indigenous Gnathostoma in Korea, and morphological characteristics of gnathostome larvae detected from pit-viper, Agkistrodon brevicaudus, for the species identification. To know the existence of Gnathostoma in Korea, 3,450 loaches, 24 bullfrogs, several kinds of snakes, i.e., 55 Elaphe rufodorsata, 2 Dinodon rufozonatum rufozonatum, 62 Rhabdophis tigrinus tigrinus and 87 Agkistrodon spp., and 438 cats were examined. A total of 21 larval gnathostomes was detected from 12 pit-vipers, A. brevicaudus. They were 2,233 x 0.343 mm in average size and covered with about 210 transverse rows of minute cuticular spines. Their characteristic head bulbs were provided with 4 rows of hooklets of which average numbers in each row were 36.8, 39.0, 41.7 and 44.3, posteriorly. In the cross sections of midgut level, the intestinal wall consisted of a single layer of 19-25 elongate epithelial cells with a single nucleus. SEM observation of the larvae revealed unique features of head bulb, cuticular spines on transverse striations and a cervical papilla. On the basis of above morphological characteristics, they were identified as the advanced third-stage larvae of Gnathostoma hispidum. It was first confirmed that the pit-viper, Agkistrodon brevicaudus is the snake intermediate host of G. hispidum.

Demonstration of common and stage-specific anti-Hepatozoon mocassini antibodies in experimentally infected unnatural lizard hosts.

This study examines the immunological response to Hepatozoon mocassini in lizards. Three lizard species were infected experimentally with H. mocassini. Baseline and post-infection (PI) sera were assayed for anti-H. mocassini meront and gametocyte antibody by immunohistochemistry and IFA. Seroconversion occurred at 38 d PI with endpoint IFA titers of 1:64. Antisera from non-parasitaemic and parisitaemic lizards exhibited similar affinities for merozite and gametocyte antigens. Antibody specific for the membranes of gametocyte-infected erythrocytes was demonstrated exclusively in parasitaemic lizards. The results demonstrate that lizards infected with snake haemogregarines mount an antibody response with common and stage-specific components.