The Life Cycle of Eimeria dispersa Tyzzer, 1929 in Turkeys

SYNOPSIS. The life cycle of a turkey strain of Eimeria dispersa Tyzzer was studied in Beltsville Small White turkeys. There were 4 asexual generations. Mature schizonts of the first generation were present 30 h postinoculation (PI); those of the 2nd, 3rd, and 4th generations were present 48, 72, and 96 h PI, respectively. Average size of schizonts and number and size of merozoites for each generation were as follows: first , 14.3 × 13.0 μm with 19.2 merozoites, each 4.5 × 1.2 μm; second , 8.0 × 7.2 μm with 13.5 merozoites, each 4.5 × 1.1 μm; third , 8.9 × 8.9 μm with 15.1 merozoites, each 5.6 × 2.1 μm; fourth , 11.6 × 10.5 μm with 6.7 merozoites, each 8.2 × 2.0 μm. Sporozoites and developmental stages of the first generation were in close association with an epithelial cell nucleus and located between the brush border and the "row" of epithelial cell nuclei; developmental stages of the other 3 generations were not associated with a nucleus and were located just under the brush border. Early macrogametes and microgametocytes were present 96 h PI. Development was confined to the epithelial cells of the villus and extended from the tip of the villus to ∼ 1/2 the distance down the sides in all areas of the intestine except the cecum. The prepatent period was between 114 and 120 h. Percentage of sporulation was 15, 57, and 90, at 24, 36, and 48 h, respectively. Sporulated oocysts averaged 24.5 × 20.2 μm.     

The Life Cycle of Eimeria vermiformis Ernst,Chobotar and Hammond, 1971 in the Mouse Mus musculus1

SYNOPSIS. The life cycle of Eimeria vermiformis from the mouse Mus musculus is described from experimental infections. The prepatent period was 7 days, and the patent period 7–22+ days. Endogenous stages were in the lower 2/3 of the small intestine. Two generations of schizonts were found. Mature 1st generation schizonts, seen 4 days after inoculation, were 16–25 × 9–16 μ and had long vermiform merozoites. Mature 2nd generation schizonts were first seen 5 days after inoculation. They were 8–18 × 7–14 μ (mean 11.2 × 13.1 μ). Mature microgametocytes, 17–32 × 12–25 μ, were present 6 days after inoculation. Macrogametes with plastic granules were found at the same time. The life cycle of E. vermiformis is compared with those of other species of Eimeria from Mus.     

Observations on Eimeria raillieti in the "Slow-worm", Anguis fragilis (Reptilia, Anguidae)

SYNOPSIS. The oocysts, sporulation process, and endogenous stages of Eimeria raillieti (Léger, 1899) Galli-Valerio, 1930 from the slow-worm, Anguis fragilis , in England are described. The oocysts average 18 × 15 μ. Schizonts, microgametocytes and macrogametocytes were found in the ileum, and macro-gametocytes alone in the duodenum.     

The Endogenous Development of Eimeria alabamensis Christensen, 1941, an Intranuclear Coccidium of Cattle

SUMMARY. The endogenous development of the life cycle of Eimeria alabamensis Christensen, 1941, occurs in the nucleus of the intestinal cells of cattle. Calves were killed at various intervals after inoculation with infective oöcysts to study the endogenous cycle. Excysted sporozoites were found in the contents or scrapings from the walls of rumen, omasum, small intestine, cecum, and colon. They were found in the cytoplasm of intestinal epithelium at 2 days. Schizonts were found in the nuclei beginning at 2 days, but the number was low by the 8th day. Merozoite numbers usually ranged between 16 and 32. Some host nuclei contained as many as 48 or more, but these appeared to be the result of more than one schizont merging in the same host nucleus. Merozoites were slender, spindle-shaped bodies while still in the schizont walls, but were short with bluntly rounded tips when found in intracellular spaces and crypts. Gametocytes were found as early as the 4th day. Most of the stages of gametogenesis were limited to the lowest third of the small intestine, but in heavy infections some were also found in the cecum and upper colon. Microgametocytes were multinucleate and were more densely stained than the uninucleate macrogametocytes. The ratio of macrogametocytes to microgametocytes in 100 gametes was 78: 22. Oöcysis with "shells" were found in sections of the lower 20 feet of the ileum on the 6th day, which coincided with the shortest prepatent period reported previously. As many as three schizonts or microgametocytes or four or five macrogametocytes or oöcysts could be found in the same host nucleus. The variations in shape of the oöcysts appeared to be dependent on the number of oöcysts crowded into each nucleus.     

Comparative Cultivation of Poultry Coccidia in Mammalian Kidney Cell Cultures

SYNOPSIS. Excysted sporozoites of Eimeria meleagrimitis, E. necatrix, E. acervulina , and E. gallopavonis were inoculated into monolayer cell cultures of bovine, ovine, porcine, and human kidney. E. meleagrimitis developed only in bovine embryonic kidney. Mature schizonts were found in the 11th, 16th, and 20th serial passages, but only immature schizonts were in the 4th and 6th passages. E. necatrix developed to mature schizonts in the 3rd, 4th, 6th, 11th, 16th, and 20th passages of bovine kidney and also to immature schizonts in the 175th and 189th passages of PK-15 (cell line porcine kidney). Schizonts, however, did not develop in the 140th and 145th passages of CCI-33 (cloned PK-15). Neither E. meleagrimitis nor E. necatrix developed in the primary, 1st or 2nd passages of bovine embryonic kidney, primary porcine kidney, 45th and 52nd passages of a human embryonic kidney cell line, or in the primary, 5th and 18th passages of ovine kidney. Eimeria acervulina and E. gallopavonis did not develop in any of the cultures.
E. meleagrimitis and E. necatrix probably completed only one asexual generation in culture. The structure of mature schizonts of both species differed greatly from those in the natural host. Schizonts of E. meleagrimitis present at 48 hours were small (13–18 by 12–14 μ) and contained only 12–28 merozoites that were 3.2–3.8 μ long. At 48 hours, E. necatrix schizonts were 15–18 μ in diameter or less and contained only 15–20 merozoites (2.0–3.5 μ long); at 96 hours they were 50–70 by 10–35μ and contained either hundreds of small merozoites (2.0–3.5 μ long) or a lesser number of larger merozoites (9–11 μ).     

Scanning Electron Microscopy of Schizogony in Eimeria tenella

SYNOPSIS. Developing 2nd- and 3rd-generation schizonts of Eimeria tenella were found in the ceca of chicks infected orally with sporulated oocysts. Several free 2nd-generation schizonts, which varied in diameter from 11 to 21.6 μm, were found on the epithelial surface of the cecum. Some schizonts appeared to have lost merozoites. Other schizonts were intact, one of which was surrounded by an unbroken membrane that followed the contours of the merozoites. Third-generation schizonts, much smaller than 2nd-generation schizonts and with fewer merozoites, were found only on cut or fractured surfaces of the cecal tissue. Third-generation merozoites appeared shorter and thicker than those of the 2nd-generation and were attached to the schizont residuum. A form with conical protuberances and another with 4 triangular segments were found; they were believed to be developing stages 3rd-generation schizonts.     

Endogenous Cycle of the Swine Coccidium Eimeria debliecki Douwes, 1921*

SYNOPSIS. A pure strain of Eimeria debliecki (University of Illinois strain A) established from a single oocyst was used to determine the endogenous cycle. Young parasite-free pigs 2 weeks to 3 months old were used throughout the study. The endogenous cycle was found to take place in the small intestine where the parasites were located in the distal portion of the striated simple columnar epithelial cells of the villi. The first generation schizonts were found in only the jejunum (15% of small intestine). The second generation schizonts and gametes occurred in the jejunum and ileum (70% of small intestine), a slight posterior progression occurring with each stage. The entire cycle required 6.5 days. The schizogonous cycle comprised 2 generations. The first generation schizonts required 2.5 days to reach maturity, measured 8-12 μ, contained 16 merozoites measuring 12-15 μ and had a polar residual mass. The second generation schizonts required 2 days to reach maturity, measured 13-16 μ, contained 32 rotund merozoites measuring 6–8 μ, and had only a few granules of residual material. Gametogony took place in 1.5 days. The macrogametes measured 12-16 μ, and the microgametocytes measured 9-14 μ with microgametes measuring 5–6 μ.     

The Sporulated Oocysts of Eimeria illinoisensis n. sp. and of Other Species of Eimeria of the Ox

SYNOPSIS. The sporulated oocysts of 12 species of Eimeria occurring in the ox Bos taurus in the United States are described and differentiated. They are E. alabamensis, E. auburnensis, E. bovis, E. brasiliensis, E. bukidnonensis, E. canadensis, E. cylindrica, E. ellipsoidalis, E. illinoisensis n. sp., E. subspherica, E. wyomingensis and E. zuernii. Two other species, not yet found in North America, which are recognized as valid are E. pellita and E. thianethi. The sporulated oocysts of E. illinoisensis n. sp. are ellipsoidal or slightly ovoid, 24–29 by 19–22 μ with a mean of 26.3 by 20.7 μ; their sporocysts are 13–16 by 6–7 μ with a mean of 15.3 by 6.5 μ. This species was found in 3 cattle from one farm in Illinois.     

Life Cycle of Eimeria ferrisi Levine & Ivens, 1965 in the Mouse, Mus musculus

SYNOPSIS. The life cycle of Eimeria ferrisi is described from experimentally infected Mus musculus. The prepatent period was 3 days and the patent period was 3–4 days. The endogenous stages were found only in the cecum and colon. Three generations of schizonts were found. Mature 1st-generation schizonts first seen 24 hr postinoculation (PI) measured 10.9 (7–14) × 10.2 (6–13) μm and had 9.6 (7–14) merozoites. Some 2nd-generation schizonts had uninucleate merozoites and others had multinucleate merozoites. The former were first seen in small numbers 36 hr PI and were most abundant 48 hr PI. They measured 9.6 (5–13) × 7.9 (6–12) μm and had 18 (6–25) merozoites. Schizonts with multinucleate merozoites were seen 72 hr PI. Mature 3rd-generation schizonts were seen 72 hr PI. They measured 14.0 (12–18) × 11-0 (9–13) μm and had 12.5 (5–16) merozoites. Macrogamonts were first seen in 72 hr sections. Each young macrogamont had a large nucleus with a prominent nucleolus. Only one type of cytoplasmic granule appeared to be involved in the formation of the oocyst wall. Mature macrogamonts were 11.0 (5–14) × 10.0 (6–13) μm. Crescent-shaped bodies were observed in the parasitophorous vacuole of trophozoites and young macrogamonts. Early microgamonts were first recognized at 96 hr by the presence of darkly stained and irregularly shaped nuclei. Usually, mature microgametes were arranged in long, narrow whorls at the periphery of the microgamont or in whorls at the surface of 2–5 compartments.     

Coccidiosis in wild grey kangaroos

Deaths occurred among wild grey kangaroos (Macropus giganteus) whose habitat was subject to flooding. A sample of the involved juvenile animals was hypoproteinaemic, and extensive haemorrhagic enteritis, associated with the presence of coccidial life cycle stages was found in the small intestine at necropsy. Masses of small schizonts infected cells of the lamina propria; large schizonts occupied clusters of hypertrophied cells; macrogametes and microgametocytes were observed in cells of the lamina propria. The species of coccidia involved could not be determined, although oocysts of Eimeria cunnamullensis and E. kogoni were found in faeces. Overcrowding, food shortage, damp conditions and possibly feed supplementation with hay on the ground were considered probable epizootiological factors contributing to an outbreak of coccidiosis among juvenile animals.     

Coccidian Parasites of Intertidal Fishes from Wales: Systematics, Development, and Cytochemistry

SYNOPSIS. Examination of littoral fish Blennius pholis and Cottus bubalis caught at Aberystwyth and Porth Cwyfan, Wales. U.K., revealed 2 species of coccidia.
Eimeria dingleyi sp. n. Oocysts spherical (16.1–19.2) to subspherical (13.9–14.2 × 18.8–20.0) μm, with thin walls; sporulation outside the host to produce ellipsoid sporocysts; endogenous phases in epithelial cells throughout intestine; 26 of 58 B. pholis infected.
Eimeria variabilis (Thélohan) Reichenow. Oocysts spherical (11.9–14.6) to subspherical (9.2–10.9 × 13.9–14.3) μm; sporulation in lining of pyloric ceca and rectum; previously unrecorded schizonts and gametocytes present; 21 of 25 C. bubalis infected.
Electron microscopy revealed that the oocyst wall of E. variabilis consists of a thin membrane whereas the sporocyst wall is thick and 3-layered. Typical oocyst wall-forming bodies were absent from the macrogamete. Cytochemical tests on the endogenous stages of E. dingleyi and E. variabilis indicated that in general they resembled other coccidia in their chemical constitution.     

Endogenous Stages of the Life Cycle of Isospora rivolta in the Dog

SYNOPSIS. Coccidia-free beagle puppies were experimentally infected with a cloned culture of Isospora rivolta oocysts. The endogenous stages were found in the posterior 1/2 of the small intestine, and rarely in the cecum and colon. Maximum numbers of all stages occurred just anterior to the ileocecal valve. Endogenous stages were found in the distal third of the villi, predominantly parasitizing subepithelial cells of the lamina propria; however, stages were occasionally present in epithelial cells. The number of asexual generations could not be determined from their structure, but evidence based on oocyst production suggested that there were at least 2 asexual generations. The schizonts were 17–24 by 12–25 μ and contained 4–24 merozoites, the most common number being 4 or 8. Schizonts with mature merozoites were found as early as 72 hr, but were present in maximum numbers at 96 hr. Merozoites had slender curved bodies and were 10.5–13.4 by 2.3–3.0 μ. Mature gamonts were found by 144 hr. Mature microgametocytes were 13.4 by 8.7 μ and contained 50–70 microgametes. Microgametes had slightly curved tapering bodies (5.8–6.4 by 0.6 μ) with 2 posteriorly directed flagella 11–14 μ long. Mature macrogametes had reticular cytoplasm and a uniformly large nucleus and nucleolus.
The prepatent period was 142–146 hr. The patent period was 13–23 days with an average of 19 days.     

Endogenous stages of Eimeria tuskegeensis (Protozoa: Eimeriidae) in the cotton rat, Sigmodon hispidus

Endogenous stages of Eimeria tuskegeensis were studied in experimentally infected cotton rats, Sigmodon hispidus. Almost all parasites were located on the basilar side of the nucleus in epithelial cells on the sides and tips of villi of the small intestine. The endogenous cycle consisted of three generations of schizogony followed by gametogony. First-, second-, third-generation schizonts could be distinguished by time of appearance, size and shape of the schizont, and number, size, shape, and arrangement of merozoites. Immature gametogonous stages appeared to 84 hr postinoculation (PI) and developed into mature microgametocytes and macrogametes by 96 hr PI. Microgametocytes had a mono-centric type of development. Intermediate macrogametes had small, basophilic wall-forming bodies and mature macrogametes had large, eosinophilic wall-forming bodies. It was not possible to determine whether these were two distinct types of wall-forming bodies or whether they were different stages of a single type. Two nuclei were seen in the host's epithelial cells parasitized by schizonts, microgematocytes, macrogametes, and oocysts. This binucleate condition was apparently parasite-induced.     

Eimeria (Protozoa: Eimeriidae) of the Cottontail Rabbit Sylvilagus audubonii in Northeastern Colorado, with Descriptions of Three New Species

SYNOPSIS. All of 100 cottontail rabbits Sylvilagus audubonii were found to be infected with 1-6 species of Eimeria. Three new species, E. audubonii, E. neoirresidua and E. poudrei are described from this host. Sub-spherical oocysts of E. audubonii average 21.2 by 17.1 μ; polar body, micropyle, oocyst residuum and sporocyst residuum are all absent; ellipsoidal sporocysts average 12.9 by 5.8 μ. Ovoid to ellipsoidal oocysts of E. neoirresidua average 25.7 by 17.9 μ; polar body and oocyst residuum are absent; micropyle and sporocyst residuum are present; ellipsoidal sporocysts average 14.5 by 6.4 μ. Ovoid to ellipsoidal oocysts of E. poudrei average 26.0 by 18.1 μ; polar body is lacking; micropyle, oocyst residuum and sporocyst residuum are present; ellipsoidal sporocysts average 14.4 by 6.4 μ. Three species of Eimeria previously described in the literature, E. maior Honess, 1939, E. media form honessi Carvalho, 1943 and E. environ Honess, 1939 are redescribed. A detailed structural and statistical analysis of each species is presented with at least 200 sporulated oocysts measured in each instance. A host list and a key to the Eimeria of cottontails is given. The use of detailed studies of oocyst size and structure as a tool for specific diagnosis of the Eimeria of cottontails is discussed.     

Life Cycle of Isospora canis Nemeséri, 1959 in the Dog*

The life cycle of I. canis Nemeséri, 1959 was studied in experimentally infected dogs. Freshly sporulated oocysts were ovoid and 34–40 × 28–32 μm. The endogenous stages were found directly beneath the epithelium of the distal portion of the small intestinal villi. Most of the endogenous stages were in the lower 1/3 of the small intestine, but occasionally they were found in other portions of the small intestine. Three asexual generations were present. First-generation schizonts were 16–38 × 11–23 μm and contained 4–24 merozoites; mature 1st-generation merozoites were 8–11 × 3–5 μm. First-generation schizogony lasted up to 7 days after inoculation. Second-generation schizonts were 12–18 × 8–13 μm and contained up to 12 merozoites which were 11–13 × 3–5 μm. Second-generation schizogony was present on postinoculation days 6 and 7. Third-generation schizonts were formed by nuclear division of 2nd-generation merozoites. Most 2nd-generation merozoites underwent nuclear division without leaving the parasitophorous vacuole of the 2nd-generation schizont. Mature 3rd-generation schizonts were 13–38 × 8–24 μm and contained 6–72 merozoites. Third-generation merozoites were 8–13 × 1–3 μm. Third-generation schizogony was present on days 6–8 after inoculation. Mature macrogametes were 22–29 × 14–23 μm. Mature microgametocytes were 20–38 × 14–26 μm. Gametes were present on postinoculation days 7–10. Oocysts were present in tissue sections on postinoculation days 8–10 and 12. The prepatent period was 9–11 days.     

Eimeria apsheronica in the goat: endogenous development and host cellular response

Most first generation schizonts of Eimeria apsheronica developed in the jejunum; others were distributed throughout the small intestine and occasionally in the caecum. Some were also found in the mesenteric lymph nodes, which were oedematous and haemorrhagic. In the intestine, haemorrhage and congestion were seen before parasites were detected, and continued throughout all later stages. Schizonts occurred in the lamina propria and occasionally in the submucosa, where they sometimes caused a cellular inflammatory response. Schizonts were first seen at 8 days post-infection (DPI); they had poorly defined nuclei and were enclosed in a capsule-like wall. At 16 DPI, many had matured, had a mean size of 125 x 82 microns, and were filled with numerous spindle-shaped merozoites, which were in ranks and loops. At 18 and 20 DPI, when small white lesions (1-3 mm in diameter) were observed in the jejunum and elsewhere in the small intestine, a second generation of schizonts, macrogametes, microgametocytes and maturing oocysts were seen, in the epithelial cells of the small intestine and caecum. Their mean sizes, respectively, were: 26.2 x 18.9, 24.7 x 18.5, 30.2 x 21.7 and 26.6 x 19.3 microns. Macrogametes contained basophilic central and eosinophilic peripheral granules. The sexual stages were associated with a generalized cellular inflammatory response.     

Survival and Development of Eimeria meleagrimitis Tyzzer, 1929 in Bovine Kidney and Turkey Intestine Cell Cultures

SYNOPSIS. Monolayer cell cultures of embryonic turkey intestine (primary) and bovine kidney (cell line, 20th passage), maintained at 40.6 and 43 C for alternating intervals of approximately 12 hours in Basal Medium Eagle and fetal calf serum at pH 7.0–7.4, were observed for 144 hours after inoculation of Eimeria meleagrimitis sporozoites.
In turkey intestine cultures, which consisted of fibroblast-like cells and patches of epitheliul-like cells, there were decreases of 80 and 81% in the numbers of parasites between 5 and 48 hrs; in bovine cultures, 21–41% decreases. Decreases in the turkey cultures, however, were due to the nonsurvival of sporozoites in fibroblast-like cells; in epitheliul-like cells there was a 42% dcrease between 5 and 48 hrs and only 27% between 48 and 144 hours.
Trophozoites were present in bovine cells at 5 hrs. Small, mature schizonts containing only 12-28 merozoites were present in the bovine cultures and in the epitheliul-like cells within turkey intestine cultures from 48-144 hrs. Larger schizonts (50-115 by 20-70 μ) were present in bovine but not in turkey cultures from 72–144 hrs. Many of these schizonts contained far more merozoites than schizonts of any of the 3 generations described from the host.
In bovine cultures, there was an abundance of liberated merozoites at 50, 52, 74, and 76 hrs; many had reinvaded cells, sometimes as many as 50–60 per cell. In turkey cultures, liberated merozoites were found once at 144 hrs and none were intracellular. At 120 and 144 hrs in bovine cultures, abnormally developed and degenerate forms appeared; in turkey cultures, all were normal.     

Cytochemical localization of acid mucosubstances within intestinal tissue stages of Eimeria acervulina and E. necatrix

Synopsis The distribution of acid mucopolysaccharides in the intestinal tissue stages ofEimeria acervulina andE. necatrix has been investigated. The results show that acid mucopolysaccharides are present in the asexual stages of both species and in the sexual stages ofE. acervulina. It is suggested that an esterified hyaluronic acid-like molecule is present in the cytoplasm of schizonts, merozoites, microgametocytes, macrogametocytes and oocysts as well as in the plastic granules of macrogametocytes and the oocyst wall. Sulphated mucopolysaccharides of the chondroitin type occur as additional components in the cytoplasm of the above stages, as well as in large amounts in the perinuclear area of macrogametocytes and oocysts. The functional significance of acid mucopolysaccharides in the coccidial stages is discussed.     

Eimeria zapi sp. n. from the Meadow Jumping Mouse, Zapus hudsonius Zimmerman in Southwestern Michigan

SYNOPSIS Four of 5 meadow jumping mice ( Zapus hudsonius ) captured had in their feces a previously undescribed species of Eimeria which is named Eimeria zapi sp. n. The sporulated oocysts measured 21.7 (19.5–24.0) × 20.3 (17.5–23.0) μm. The single-layered oocyst wall was 1.5 μm thick, rough, pitted and appeared clear-to-amber. Usually 2 polar granules could be seen. An oocyst residuum was not observed. Each sporocyst averaged 16.0 (12.5–18.0) × 9.7 (7.5–11.5) μm. A substiedal body was present. The sporocyst residuum consisted of a membrane-enclosed packet of 15 to 20 granules. This is the first species of Eimeria to be described from the genus Zapus.