Growth, development and pairing of Leucochloridiomorpha constantiae (Trematoda) metacercariae on the chorio-allantois of chick embryos cultivated in vitro

A simple in vitro technique was devised to culture chick embryos in Petri dishes from the 4th to the 21st day of incubation. Leucochloridiomorpha constantiae (Trematoda) metacercariae were placed either singly or multiply (5/embryo) on the chorio-allantois of in vitro grown embryos on day 7 and were removed on day 14. Growth and development studies were also made on worms grown singly or multiply (5/chick) in the bursa of Fabricius of the domestic chick. Worms grown singly or multiply in embryos were sexually mature, although eggs from these worms were abnormal when compared with eggs from worms recovered from chicks. The mean body area of worms from chicks was 2-3 times greater than that of worms from embryos. The mean body area of single worms from embryos was significantly larger than that of worms grown multiply in this site. However, the mean body area of multiple worms from the chick was significantly larger than that of single worms from this site. Worm pairs or clusters were seen in all embryos with the multiple infections.

Concurrent infections of cecal trematodes, Zygocotyle lunata, and Notocotylus sp., in the domestic chick and observations on host-parasite relationships of Notocotylus sp

Single and concurrent infections of cecal trematodes, Zygocotyle lunata and Notocotylus sp., were studied in controlled, laboratory infections in the domestic chick. The recovery of Notocotylus sp. from the chick cecum was reduced significantly in the presence of Zygocotyle lunata. Neither the size nor the distribution of either helminth was affected by the presence of the other. The ventral surface of Notocotylus sp. was associated intimately with the cecal villus, and this fluke fed on host blood.

Thin-layer chromatographic analysis of phospholipids in Echinostoma revolutum (Trematoda) adults

Thin-layer chromatographic analyses were made of phospholipids extracted from adult Echinostoma revolutum (Trematoda) and from the nonnutrient medium in which worms were maintained. Identity of phospholipids was based on comparison with authentic lipid standards and on specific chemical detection tests. The most abundant phospholipids in the extract were phosphatidyl choline, phosphatidyl ethanolamine and phosphatidyl serine; lesser amounts of cerebrosides and lysophosphatidyl choline were detected also. Phospholipids detected in the incubation medium were essentially as described for extracts.

Studies on encystment of Echinostoma revolutum cercariae

Cercariae of Echinostoma revolutum encysted in the kidney of the snail Physa heterostropha within 1 hr and on mucus trails from Helisoma trivolvis, P. heterostropha and Lymnaea sp. within 2 hr. Significantly, more normal cysts were formed in mucus of Helisoma than in mucus of Physa or Lymnaea. Optimal, in vitro encystment occurred within 24 h in either Locke's 1 : 1 or Locke's 1 : 1 + 1% glucose. Significantly more normal cysts occurred in the Locke's 1 : 1 medium. Both normal and abnormal cysts from Lock's media and snail mucus excysted in an alkaline bile trypsin medium. Cercariae did not encyst in Lock'e media supplemented with casein hydrolysate or in agar cultures containing various chemicals.

Host-parasite relationships of Zygocotyle lunata (Trematoda) in the domestic chick

Domestic chicks were infected with Zygocotyle lunata to determine gross and histopathological effects on the caecal tissues, to observe the method of feeding by worms and to examine the effects of crowding on the growth and development of the worm. Caecal weights and dimensions were significantly reduced in infected chicks. Caecal debris, abundant in control chicks, stained positive for proteins, polysaccharides, acid mucopolysaccharides and neutral fats. Caecal debris was rarely seen in infected chicks. The lumen of the intestinal caeca of the worms contained acellular material which showed protease activity and stained positive for proteins, polysaccharides and acid mucopolysaccharides. Histopathological effects of the infection showed a disruption of the architecture of host caecal mucosa, worm to worm attachment, tissue plugs in the worm acetabulum, and an engorgement of host mucosal tissue with erythrocytes. Stunting due to worm crowding was very evident and by 2 weeks post-infection, worms from single-worm infections were sexually mature and more than twice the length of immature flukes obtained from chicks infected with 100-500 cysts.

In vivo and in vitro excystation of Zygocotyle lunata (Trematoda) metacercariae and histochemical observations on the cyst

Encysted metacercariae of Zygocotyle lunata (Trematoda) excyst within 2 hr postexposure in the lower ileum of the domestic chick. Optimal in vitro excystation of this species occurs following pretreatment of the cyst for 15 min in 1% acidified pepsin, treatment in 0.02 M sodium dithionite (a reductant) for 1 to 2 min and then 2 hr treatment in an excystation medium containing 1% sodium glycocholate plus 1% trypsin in Earle's BSS adjusted to pH 8.8 with tris and maintained at 41 C. The cyst of this species is a dome-shaped hemisphere containing an inner and outer wall. The outer wall contains mainly acid mucopolysaccharides, whereas the inner wall is mainly proteinaceous. The cyst contains a ventral lid which only was visualized during excystation.

Histochemical and thin layer chromatographic analyses of neutral lipids in Echinostoma revolutum metacercariae cultured in vitro

Excysted metacercariae of Echinostoma revolutum cultured in vitro in the defined medium, NCTC 135 supplemented with 20% hens' egg yolk, doubled their mean relative body area and showed significant sucker growth within 14 days. Histochemical Oil Red O staining showed neutral fat mainly in the excretory system of excysted metacercariae and in adults grown in the domestic chick. In vitro cultured worms showed neutral fat in the intestine, parenchyma, and excretory system. As detected by TLC the major neutral lipid fractions were free fatty acids for excysted metacercariae; free sterols for adults grown in chicks; and triglycerides, free fatty acids, and free sterols for cultured worms. Excysted metacercariae excreted free fatty acids into a nonnutrient incubation medium, whereas cultured worms excreted diglycerides, triglycerides, and free fatty acids into the medium.

Histochemical and thin layer chromatographic analyses of neutral lipids in metracercarial and adult Cotylurus sp. (Trematoda: Strigeidae)

Histochemical and thin layer chromatographic studies were made on neutral lipids of Cotylurus sp. (Trematoda) metacercariae obtained from Physa heterostropha snails and from adults grown in the upper ileum of the domestic chick. Oil Red O staining demonstrated neutral lipids in the intestinal lumina, eggs and vitellaria of adults, and the excretory system of metarcercariae. As determined by TLC, excysted metacercariae incubated in a non-nutrient salt solution excreted free fatty acids, sterols, and sterol esters into the medium. TLC analysis detected free sterols, free fatty acids and sterol esters in metacercariae and adullts, and triglycerides detected in adults were not found in metacercariae.

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Accumulation and excretion of neutral lipids in the metacercaria of Leucochloridiomorpha constantiae (Trematoda) maintained in vitro

Histochemical and thin-layer chromatographic analyses were made on neutral lipids in Leucochloridiomorpha constantiae (Trematoda) metacercariae incubated in non-nutrient Locke's solution at 37.5 or 42 C for 24 hr. As determined by Oil Red O staining, lipid droplets accumulate mainly in the intestine of incubated worms. Attempts to distinguish specific neutral lipid fraction of metacercariae obtained directly from snails is free sterol. During incubation, metacercariae accumulate triglycerides and to a lesser extent cholesterol esters, and excrete free sterol into the medium.