The distribution of a primary infestation of Nippostrongylus brasiliensis in the small intestine of laboratory rats

Abstract

The small intestine of rats was divided into twenty sections in a reproducible manner in order to study the distribution of Nippostrongylus brasiliensis by stretching it under a tension of 5g in adrenaline saline.A small but significant difference between the distribution of parasites in male and female rats was observed.As larvae had virtually ceased to reach the intestine by the fifth day all changes in distribution after that day were due to movements of the established adult population.Up to the twelfth day of a primary infestation the majority of the worms were found between the third and tenth sections, the population mode being in the fifth or sixth section. After the thirteenth day the number of worms in this region fell sharply.The female worms had not ceased from egg-laying by the time most of the worms were being rejected.The posterior half of the small intestine, i.e. the eleventh to twentieth sections, was not heavily parasitized, many of the worms seen being in passage to the anus.The first section was not parasitized until the seventh day, but thereafter remained parasitized until long after worms had disappeared from the more posterior sections.The relative number of male worms present increased as the infestation aged.Throughout the experiment the relative number of male worms present at the anterior end of the smaller intestine was higher than that at the posterior.Fourth-stage larvae were found chiefly in the sections that were later most heavily parasitized by adult worms.

Changes in the distribution of Hymenolepis diminuta (Cestoda: Cyclophyllidea) within the rat intestine during prepatent development

“…The entire small intestine was rapidly removed, and arranged in a long dissecting tray which was filled with ice-cold saline. The bottom of the tray was marked out on a bias grid, adapted after Bramble (1965), so that equivalent regions of the intestines of different rats could be compared, irrespective of the actual intestinal lengths.…”

The Sites Occupied by Some Parasitic Helminths in the Alimentary Tract of Vertebrates

“…The following are examples of helminths which appear to reach sexual maturity in the sites initially occupied by their immature stages, and without any major change: Acanthocephala, P o~~o r p h u s minutus (Crompton & Whitfield, 1968 b ;Lingard & Crompton, 1972); Cestoda, Echinococcus granulosus (Smyth, Gemmell & Smyth, 1970), Hydatigera taeniaeformis (Hutchison, 1959) and Hymenolepis exigua (Alicata & Chang, 1939) ; Nematoda, Ancylostoma caninum (Krupp, 1961)) Trichinella spiralis (Larsh & Hendricks, 1949)) Strongyloides ratti and S. venexuelensis (Wertheim, 1970), Nippostrongylus brasiliensis (Brambell, 1965 ; Alphey, 1970)) Syphacia obvelata (Philpot, 1924)) Physaloptera hispida (Schell, 1952)) Obeliscoides cuniculi (Alicata, 1932), Haemonchus contortus (Veglia, 1915 ;Stoll, 1929) and Trichuris muris (Fahmy, 1954) ; Trematoda, Loxogmes arcanum (Crawford, 1938)) Haplometrana utahmis (Olsen, 1937), Psilostomum ondatrae (Beaver, 1939), Echinoparyphium recurvaturn (Soulsby, 1955) and Alaria canis (Pearson, 1956).…”

Drug-abbreviated infections of Trichostrongylus colubriformis and development of immunity in jirds (Meriones unguiculatus)

“…In the present study, adult T. colubriformis were harvested from the small as well as the large intestine of both single-infection and challengeinfection groups. Such posterior delocalisation of nematodes has been reported in other host models such as T. colubriformis in sheep (Wagland et al 1996), guinea pigs (Connan 1966) and rabbits (Bezubik et al 1988); T. vitrinus in sheep (Bendixsen et al 1995); Nippostrongylus brasiliensis in rats (Brambell 1965); and Trichinella spiralis in mice (Larsh et al 1952). Dierent parasitic stages of the nematodes invading the intestinal mucosa act as a trigger for generation of the host immunological response (Anderson and Michel 1977).…”