Zinc Sulfide in Intestinal Cell Granules of Ancylostoma caninum Adults

Abstract

A source of confusion has existed since the turn of the century about the reddish brown, weakly birefringent "sphaerocrystals" located in the intestines of strongyle nematodes, Strongylus and Ancylostoma. X-ray diffraction and energy dispersive spectrometric analyses were used for accurate determination of the crystalline order and elemental composition of the granules in the canine hookworm Ancylostoma caninum. The composition of the intestinal pigmented granules was identified unequivocally as zinc sulfide. It seems most probable that the granules serve to detoxify high levels of metallic ions (specifically zinc) present due to the large intake of host blood.

Immunohistochemical localization of excretory/secretory antigens in adult Ancylostoma caninum using monoclonal antibodies and infected human sera

“…It is also possible that some of the reactions in the epicuticle resulted from the adsorption of ES antigens to that layer. The pigmented granules found within the epithelial cells of the anterior intestine ( Figures 3b-d, 4a and b) were unrelated to our methodology, having been first described almost 100 years ago and recently confirmed to incorporate zinc sulfide (Gianotti, Clark & Dash 1991).…”

Assessment of sulfur, calcium and phosphorus in the cuticle covering the cordons of Desportesius invaginatus (Nematoda, Acuariidae) using energy dispersive X-ray microanalysis (EDXMA)

“…Sulphur, Ca and P are major elements in biological molecules of all representatives of the animal kingdom and previous studies [7,8,9,15,28,30] revealed that they are associated with the development and function of helminth hooks and spines (Table 7) [14,15,28,29,[30][31][32][33] . Phosphorous supports the formation of bones and teeth along with Ca; it gives the hardness, strength and rigidity to resist compressive forces.…”

“…Its characterization capabilities are due to the fundamental principle that each element has a unique atomic structure allowing a unique set of peaks on its X-ray spectrum. The technique has been used to evaluate the element composition and crystalline nature of the structures of cestodes [4] , nematodes [5][6][7][8] and acanthocephalans [9][10][11] . In addition, EDXMA of whole hooks of Echinococcus granulosus protoscoleces demonstrated the presence of S and trace quantities of P. Their X-ray near-edge absorption spectra resembled those of cystine in feather and hair, and showed S to be predominantly in the form of disulphide linkages thus differing from vertebrate keratins [4] .…”