Biomaterial Database

In vivo and ectopic encystment of Echinostoma revolutum and chemical excystation of the metacercariae. 1997

B Fried, and K A Schmidt, and R E Sorensen

Department of Biology. Lafayette College, Easton, Pennsylvania 18042, USA.

In vivo and ectopic encystment of the cercariae of Echinostoma revolutum from Lymnaea elodes snails in Indiana and chemical excystation of the metacercariae were studied. In vivo encystment occurred in adults of Biomphalaria glabrata and Helisoma trivolvis (Colorado strain) snails and in neonatal and juvenile L. elodes snails. These results were expected because 37-collar-spined Echinostoma species show broad specificity in their second intermediate gastropod hosts. Encysted metacercariae of E. revolutum and Echinostoma trivolvis removed from experimentally infected snails and treated in a trypsin-bile salts excystation medium at 39 C showed 30.3% excystation for the former and 55.7% for the latter at 4 hr. The ducts and openings of the paraesophageal glands of excysted metacercariae of E. revolutum from cysts formed in snails did not stain with neutral red. Abnormal ectopic cysts with distorted outer walls and granular inner walls were obtained within 48 hr of placing E. revolutum cercariae in Locke's 1:1 plus 1% dextrose. These metacercariae excysted rapidly in the excystation medium and their paraesophageal gland ducts and openings stained with neutral red. Differences in ectopic encystment and chemical excystation in vitro can be used to distinguish these closely related species in the E. revolutum complex.

UI	MeSH Term	Description	Entries
D008195	Lymnaea	A genus of dextrally coiled freshwater snails that includes some species of importance as intermediate hosts of parasitic flukes.	Lymnea,Lymnaeas,Lymneas
D003470	Culture Media	Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.	Media, Culture
D004199	Disease Vectors	Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.	Infectious Disease Vectors,Disease Vector,Disease Vector, Infectious,Disease Vectors, Infectious,Infectious Disease Vector,Vector, Disease,Vector, Infectious Disease,Vectors, Disease,Vectors, Infectious Disease
D004449	Echinostoma	A genus of intestinal flukes of the family Echinostomatidae which consists of many species. They occur in man and other vertebrates. The intermediate hosts are frequently mollusks.	Echinostoma ilocanum,Euparyphium ilocanum,Fascioletta ilocanum,Echinostoma ilocanums,Echinostomas,Euparyphium ilocanums,Fascioletta ilocanums,ilocanum, Echinostoma,ilocanum, Fascioletta,ilocanums, Euparyphium
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001700	Biomphalaria	A genus of planorbid freshwater snails, species of which are intermediate hosts of Schistosoma mansoni.	Australorbis,Australorbis glabratus,Australorbi,Biomphalarias
D012908	Snails	Marine, freshwater, or terrestrial mollusks of the class Gastropoda. Most have an enclosing spiral shell, and several genera harbor parasites pathogenic to man.	Snail
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor