Ultrastructural alterations of adult schistosoma haematobium harbored in mice following artemether administration.
OBJECTIVE
To perform a temporal examination of ultrastructural alterations in adult Schistosoma haematobium due to artemether.


METHODS
Eight mice infected with 100-120 S. haematobium cercariae for 81 days were treated intragastrically with 400 mg/kg artemether. At 24 hours, 3, 7 and 14 days post-treatment, groups of 2 mice were sacrificed and schistosomes collected by the perfusion technique. Worm samples were fixed and examined by transmission electron microscopy. Schistosomes were also obtained from 2 untreated mice that served as control.


RESULTS
Typical ultrastructural alterations included swelling, lysis and vacuolization of the tegumental matrix, and disappearance of basal membrane. In sensory organelles and tubercles, there was extensive or local lysis of internal structure. In the musculature, parenchymal tissues, syncytium and gut epithelial cells, focal or extensive lysis, decrease in granular endoplasmic reticulum, vacuolization and degeneration of mitochondria were observed. These alterations became apparent both in male and female worms 24 hours post-treatment. In female worms, severe damage to the vitelline cells was also observed, resulting in the emergence of vacuoles, a decrease in granular endoplasmic reticulum, fusion of vitelline balls or even collapse of damaged vitelline cells. The most extensive tegumental alterations were observed 3-7 days post-treatment. Whilst 14 days post-treatment ultrastructural damage was still apparent, the tegument of some worms showed similar features to those recovered from untreated control mice.


CONCLUSIONS
Administration of artemether to mice infected with adult S. haematobium results in extensive damage to the ultrastructure in the tegument and subtegument tissues of the worms, confirming previous results with other schistosome species.
Xiao
Shu-ua
SU
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, China. shxiao1@yahoo.com
Utzinger
Jürg
J
Shen
Bing-gui
BG
Tanner
Marcel
M
Chollet
Jacques
J
D000818:Animals; D000077549:Artemether; D037621:Artemisinins / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D046529:Microscopy, Electron, Transmission; D012548:Schistosoma haematobium / Q000187:drug effects* / Q000648:ultrastructure*; D012553:Schistosomiasis haematobia / Q000188:drug therapy* / Q000469:parasitology; D012556:Schistosomicides / Q000008:administration & dosage / Q000494:pharmacology; D013997:Time Factors
D037621:Artemisinins; D012556:Schistosomicides; D000077549:Artemether