Haemogregarina nototheniae n. sp., from the blood of Antarctic nototheniids

A new species of haemogregarina, Haemogregarina nototheniae, is described from the Southern ocean teleosts Notothenia neglecta and Notothenia rossii. Stages identified as macro- and microschizogony and gametogony are described in mononuclear leukocytes from fish caught during the austral summer. The mature gametocyte is the most commonly found stage: it is exoerythrocytic, but carries the host erythrocyte nucleus attached to its external surface near one end. The gametocyte has a central nucleus and 2–16 subterminal eosinophilic granules, but no polar cap. During microschizogony the schizont nucleus undergoes repeated division without cytoplasmic division to give 32 nuclear masses, all of which appear to be in metaphase. Cytoplasmic division yields free merozoites identifiable by the coarse chromatin of the nuclear area. During macroschizogony the intraleukocytic parasite swells to a subspherical mass with a median band of fine heterochromatin granules. The cytoplasm later divides, forming three merozoites. There appear to be two routes by which merozoites proceed to become gametocytes: in winter small merozoites are seen in mature erythrocytes; but in summer, in erythroblasts. The invertebrate definitive host and the means of transmission are unknown, but the parasite is provisionally assigned to the genus Haemogregarina.     

Observations on Haemogregarina balli sp. n. from the Common Snapping Turtle,Chelydra serpentina*

SYNOPSIS. Haemogregarina balli sp. n. is described from the blood and organs of the common snapping turtle Chelydra serpentina serpentina and from the gastric and intestinal ceca of the presumed invertebrate hosts, the leeches Placobdella parasitica and Placobdella ornata. In the peripheral blood of the turtle, male and female gametocytes and immature erythrocytic schizonts are found within erythrocytes. The maturation of erythrocytic schizonts containing 6–8 merozoites is recorded from liver imprints. Schizonts with 13–25 merozoites are found in various cells of the liver, lung and spleen. In the gastric ceca of the leeches the host erythrocytes are digested, releasing the gametocytes and immature erythrocytic schizonts. Immature erythrocytic schizonts degenerate. Association of the gametocytes occurs in the intestinal ceca. The microgametocyte apparently gives rise to 4 nonmotile microgametes, one of which fertilizes the macrogamete while the other remain as condensed, residual nuclei on the periphery of the developing oocyst. The oocyst increases in size with maturity. A mature oocyst produces 8 sporozoites from a single germinal center. Sporozoites liberated from the oocyst are found in the tissues of the leech. Transovarial transmission of the parasite does not occur in the turtle. Attempts at experimental transmission failed. Previously unfed (control) leeches were negative for the parasite. Haemogregarina balli is compared with other haemogregarines described from C. serpentina. Features of species of Haemogregarina and Hepatozoon as well as the taxonomy of these genera are discussed.     

Plasmodium octamerium n. sp., an Avian Malaria Parasite from the Pintail Whydah Bird Vidua macroura*

SYNOPSIS. A new species of avian malaria parasite is described from the pintail whydah Vidua macroura, a very small African finch of the weaver bird family (Ploceidae). Its structure has been studied chiefly in the canary, to which it is easily transmissible by blood inoculation. Since the segmenters most often produce 8 merozoites, the name Plasmodium octamerium n. sp. is proposed. Other characteristics include sexual stages which are usually elongate, often slender, and do not displace the host cell nucleus, and gametocytes indistinguishable from those of many species of Haemoproteus. Erythrocytes are the only blood cells parasitized. The new species resembles Plasmodium fallax in many respects, but gives rise to fewer merozoites and the asexual forms are smaller. Blood-induced infections are also of strikingly different type in some host species. Among susceptible host species are several kinds of finches, pigeons, quail, young chicks, chukars, tree and song sparrows. In most of these hosts infections are mild, but some tree sparrows die as the result of blood infection, and chukars usually die because of massive invasion of the capillary endothelium of the brain by exoerythrocytic forms. These are of the gallinaceum type and may be quite large, producing hundreds of merozoites. Exoerythrocytic stages were sought but not found in other host species.     

Haemogregarina vltavensis n. sp. from perch (Perca fluviatilis) in Czechoslovakia

A new species, Haemogregarina vltavensis n. sp., is described from the blood of perch (Perca fluviatilis) in southwestern Czechoslovakia. Both intra-erythrocytic and free stages interpreted as gametocytes were detected. Only one parasite per erythrocyte was found. It displaces the nucleus and fills most of the volume of the infected host cell. No other developmental stages were discovered.     

Development of Haemogregarina boueti in the toad Bufo regularis*

SYNOPSIS. Haemogregarina boueti França, 1910, was found to be the commonest blood parasite in the common toad, Bufo regularis Reuss, in Egypt. The rate of infection was about 30% (of 689 toads examined). In properly fixed blood films, the parasites were almost exclusively intraerythrocytic. Most characteristic was the encapsulated “elongate” form averaging 22.3 by 6 μ with a more-or-less central nucleus and a pointed, slightly bent, posterior end. Infected red cells were conspicuously hypertrophied and their nuclei were markedly displaced and frequently broken into 2-4 parts. Young and growing blood forms as well as two types of hepatic schizonts are described for the first time. Schizonts of the first type develop in hepatic cells, are 28–30 μ in diameter and produce numerous elongate oval merozoites about 8 × 2.2 μ radially arranged around a residual body about 10 μ in diameter. Schizonts of the second type start their growth in erythrocytes but later complete their development as free bodies in the liver sinusoids. When mature, they are 32–35 μ in diameter and produce a larger number of thin merozoites about 8 × 1.5 μ, surrounding a larger residual body about 19 μ in diameter.     

Plasmodium (Sauramoeba) pelaezi n. sp., a malaria parasite of the mexican iguanid lizardUrosaurus bicarinatus bicarinatus (Dumeril, 1856) (Sauria: Iguanidae)

A new Mexican species of saurian malaria parasite,Plasmodium (Sauramoeba) pelaezi, is described from the iguanid lizardUrosaurus bicarinatus bicarinatus. Two out of 12 specimens collected at Chila de la Sal (Puebla, México) were found infected. The species is characterized by round and oval gametocytes. Schizonts are mostly round with a single mass of pigment and with 16 merozoites in mature forms. Gametocytes cause shrinkage of infected cells and schizonts render the host cell nuclei spherical.     

Haemogregarina georgianae n. sp., a new haemogregarine parasite from the Antarctic teleost Parachaenichthys georgianus

Haemogregarina georgianae n. sp. occurs frequently in the bathydraconid teleost Parachaenichthys georgianus from the western Antarctic portion of the Southern Ocean. The haemogregarine and its developmental stages in the vertebrate have been found in erythrocytes of the fish: both microschizogony and macroschizogony have been seen in fish caught during the austral summer. Morphological evidence suggests the merozoites from macroschizogony give rise to the microschizont, and that the microschizont merozoites give rise to gametocytes. Comparison of H. georgianae with other haemogregarines known from teleosts shows that it has a previously undescribed morphology.     

The ultrastructure of penetrating stages of Babesia major infecting the ovary of Haemaphysalis punctata

The ultrastructure of penetrating stages of Babesia major merozoites responsible for causing trans-ovarian infection of the tick Haemaphysalis punctata was studied. These merozoites were different from forms of other Babesia species previously described in the tick in that they were highly pleomorphic. Most of the organelles found in these forms were similar to those found in other stages: however, the apical complex was found to be very active. Micronemes were found to be predominant in the cytoplasm of these merozoites and a cytoplasmic projection anterior to the polar ring and bounded by concentric rings was visible. A polar ring with radiating ribs, and microtubules was present. It is thought that the apical complex of these merozoites plays an important role in assisting the parasite to infect the ovary of the tick.     

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.     

Fine Structure of Schizonts and Merozoites of Eimeria nieschulzi*

SYNOPSIS. Schizonts of E. nieschulzi lie in a vacuole within the host cell. After nuclear division the cell membrane invaginates forming merozoites. Differentiation of the pellicle and other organelles occurs while merozoites are still attached to the schizont cytoplasm. Merozoites have a pellicle thickened at the anterior end to form a polar ring. Radiating posteriorly from the ring, directly beneath the pellicle, are about 25 microtubules. Within the polar ring is a dense conoid. Extending posteriorly from within the conoid is a paired organelle. The paired organelle varies in size and shape in each generation of merozoites. Numerous toxonemes occupy the anterior half of the merozoites. Two paranuclear bodies are present in 1st generation merozoites. One or 2 granular bodies were seen in the anterior end of 2nd generation merozoites. In 3rd generation merozoites 6 or more granular bodies were seen anterior to the nucleus. Each merozoite has a single nucleus containing diffuse chromatin material. Elongate mitochondria and glycogen granules are present. The vacuole surrounding mature merozoites contains residual cytoplasm of the schizont and some granular material. Microvilli project into the vacuole from the host cell membrane.     

Plasmodium falciparum: isolation and purification of spontaneously released merozoites by nylon membrane sieves

A new procedure for isolating spontaneously released merozoites from in vitro cultures of Plasmodium falciparum (FVO and FCB strains) is described. The mature forms of relatively synchronous cultures containing predominantly trophozoites and few schizonts were concentrated with Plasmagel and then incubated at 37 C, without adding fresh red blood cells, until trophozoites matured into schizonts. Merozoites which were subsequently released were harvested and freed from host red blood cell material by low-speed centrifugations and nylon membrane sieves (3- and 1.2-μm pore size). From a culture containing about 5.2 × 10⁹ mature-form parasites, a total of about 10.7 × 10⁹ merozoites were released during three consecutive harvests and about 69% of these merozoites were recovered after the isolation and purification procedures. As demonstrated by both light and electron microscopy, most merozoites were morphologically intact and the merozoite preparations were free of host cell constituents. SDS-acrylamide gel electrophoresis confirmed the absence of host cell material and also showed that merozoites had a complex protein pattern of apparent molecular weights between 225 and 15 kdaltons. Such purified merozoite preparations will be invaluable for malaria immunization studies, for identification of protective antigens of P. falciparum, and for other immunological and biochemical studies.     

A new hemogregarine from marine fishes.

Haemogregarina uncinata sp. n. is described from the blood of 2 marine eelpouts, Lycodes lavalaei and Lycodes vahlii (Perciformes: Zoarcidae). Erythrocytic schizogony occurred in peripheral and cardiac blood, but mature schizonts were restricted to the latter site. Mature and rupturing schizonts contained 10 to 30 merozoites, which were short and thick in small schizonts while slender and long in larger schizonts. Gametocytes developed in mature erythrocytes and displayed morphologic and morphometric characters that distinguished them from other species described. Syzygy and gamete formation occurred in the gut of a leech, Johanssonia sp. Each microgametocyte produced up to 4 apparently nonflagellated gametes. Oocysts developed intracellularly in the epithelial wall of the intestine and at maturity produced under 100 sporozoites from (apparently) several germinal centers. Sporozoites subsequently migrated to the probosces of the leeches. The failure to transmit the parasite to a sculpin (Myoxocephalus octodecemspinosus) and 3 Atlantic cod (Gadus morhua) via regurgitation by the leeches might be indicative of host specificity.     

Studies on African saurian malarias: Plasmodium holaspi n. sp. from the flying lacertid Holaspis guentheri

The African flying lizard Holaspis guentheri (Lacertidae) from the Uluguru Mountains, Tanzania was found infected by an undescribed malarial parasite, Plasmodium holaspi n. sp. Gametocytes were elongate, approximately twice the size of host cell nuclei, and showed prominent, irregular pigment granules. Schizonts were oblong or formed as rosettes, approximated the host cell nucleus in size, and produced 8-18 merozoites. Maturing gametocytes contained large masses or blocks of chromatin which can obscure sexual differentiation by staining reaction, while young gametocytes and asexual stages almost always occupy marginal positions in host cells. These characteristics distinguish P. holaspi from all other saurian Plasmodium species. This is the first malarial parasite described from African lacertid species.     

Development of Haemogregarina pestanae in the toad Bufo regularis*

SYNOPSIS. Haemogregarina pestanae França, 1910, is apparently rare in Egypt, having been found in 1 toad Bufo regularis Reuss out of 689 examined. Capsulated capped, young thin, and young and advanced broad forms were present in the peripheral blood. Schizogony occurred in the liver. Two types of schizonts were present—macroschizonts producing 150 or more elongate oval merozoites surrounding a large residual body, and microschizonts producing 60 or less banana-shaped merozoites often radiating from a small, eccentric residual body. Merozoites of the first type developed into a large broad form representing early schizonts of the second type. The latter developed into thin young intraerythrocytic forms and apparently later into encapsulated capped gametocytes. H. pestanae, H. aegyptia and H. tunisiensis all occur in toads (Bufo regularis for the first two, and B. mauritanicus for the third), and produce characteristic encapsulated looped gametocytes in peripheral blood. The capsules contain dark-staining material condensed into a single well-developed cap in H. aegyptia and 1 or 2 much smaller caps in H. pestanae; this material is scattered regularly around the parasite in H. tunisiensis. The capsule of H. pestanae is more or less cylindrical along most of its length, more slender and slightly shorter than the regularly oval capsule of H. tunisiensis or the spindle- or egg-shaped capsule of H. aegyptia.     

Fine structure of the erythrocytic stages of Plasmodium knowlesi

Summary The fine structure of erythrocytic stages of Plasmodium knowlesi was compared with that of the same parasite isolated from its host cell by a saponin technique. Rhesus monkeys experimentally infected with Plasmodium knowlesi were the source of parasitized red cells. The erythrocytic stages of this Plasmodium showed all the organelles described in other mammalian forms; the nucleus lacked a typical nucleolus but contained a cluster of granules. P. knowlesi did not have protozoan-type mitochondria as do the avian and reptilian forms, but had double-membrane-bounded bodies as observed in other mammalian malarial parasites.The isolation procedure caused a slight swelling of the parasite, but in general, the structure and structural relationships of the parasite were preserved. However, the isolation technique gave a new insight into the connection of the host cell cytoplasm with the large, so-called food vacuoles of the parasite. The parasite freed from its host cell showed clear spaces where the large vacuoles had been. The content of these vacuoles had been removed together with the red cell cytoplasm. As the nature of the isolation procedure precluded any disruption of the parasite itself, these findings support our view that the vacuoles are not true food vacuoles. If these were true food vacuoles, they would be completely enclosed by a parasite membrane within the parasite cytoplasm. However, we have demonstrated that they represent extensions of host cell cytoplasm in direct communication with the rest of the red cell. The outer membrane surrounding the intra-erythrocytic parasites disappeared after isolation of the parasite from the host cell. This strongly suggested that the outer membrane is of host cell origin. The budding process of the merozoites from a schizont was also described and discussed.This paper is contribution No. 558 from the Army Research Program on Malaria and was supported in part by Research Grant AI 08970-01 from the United States Public Health Service.     

Phylogeny of Adeleid Blood Parasites with a Partial Systematic Revision of the Haemogregarine Complex

ABSTRACT. The phylogenetic relationships of taxa representative of blood parasitic adeleids were investigated in a cladistic analysis. Two phylogenetic analyses were performed. Monophyly of species of Haemogregarina (sensu lato) of some marine fishes with species of Haemogregarina (sensu stricto) was not supported in either analysis. A new genus, Desseria n. g., was created to accommodate these species. The historical burden placed on the genus Haemogregarina Danilewsky, 1885 as a repository for poorly known and inadequately described species is partially relieved through taxonomic revisions involving the genera Haemogregarina , and Desseria n. g.     

The saurian malarias of Venezuela: Haemosporidian parasites of gekkonid lizards

Telford S. P., Jr. 1978. The saurian malarias of Venezuela: haemosporidian parasites of gekkonid lizards. International Journal for Parasitology8: 341–353. Five haemosporidian species were found among 185 gekkonid lizards from Estados Portuguesa, Cojedes and Aragua, Venezuela, four of which were new to science. A pigmented Plasmodium species is described from Gonatodes taniae of Estado Aragua. It produces 8–20 merozoites in variably shaped schizonts, and elongate, irregularly margined prematuration gametocytes which contract to form round to broadly elongate mature gametocytes. Phyllodactylus ventralis of Estado Portuguesa is parasitized by two new unpigmented malarial species. One produces 11–35 merozoites in schizonts which are often rounded or elongated, occasionally fan-shaped. Gametocytes are always elongated and usually lie diagonally across one end of the host cell or laterally to the nucleus. The second species forms rounded mature schizonts nearly filled with 14–32 merozoites. The sexual stages are usually round or oval, rarely elongate. Plasmodium aurulentum Telford, 1971 was found in Thecadactylus raplcaudus of Estados Portuguesa and Cojedes. A single Thecadactylus from Cojedes was infected by a haemosporidian species of uncertain generic identity which resembles a parasite found earlier in a Panamanian gecko.     

The Life Cycle of Isospora felis Wenyon, 1923, a Coccidium of the Cat*

SYNOPSIS. A pure strain of Isospora felis derived from a single oocyst was used to study the endogenous cycle. One and a half to two-month-old laboratory-reared, coccidia-free kittens were used thruout the study. The endogenous stages occurred in the epithelial cells of the distal parts of the villi in the ileum and occasionally duodenum and jejunum. All stages lay above the host cell nucleus. There were 3 asexual generations. The 1st generation schizonts were 11–30 by 10–23 μ when mature and contained 16–17 banana-shaped merozoites 11–15 by 3–5 μ. They became mature in 96 or sometimes in 120 hours. The 1st generation merozoites entered new host cells, rounded up and formed 2nd generation schizonts. These formed within themselves 2–10 or more spindle-shaped bodies resembling 1st generation merozoites in shape and size. These were 2nd generation merozoites. They were uninucleate 120 hours after inoculation, but by 144 hours they became larger, multinucleate and some lost their elongate shape and became ovoid. They were then 3rd generation schizonts. They were 12–16 by 4–5 μ. Each formed up to 6 or more banana-shaped merozoites 6–8 by 1–2 μ. The 3rd generation schizonts and merozoites developed within the same host cell and parasitophorous vacuole as the 2nd generation schizonts and merozoites. Mature schizonts containing only 3rd generation merozoites appeared 144 hours after inoculation, were most abundant 168 hours after inoculation, and might be present as late as 216 hours after inoculation. They were 14–36 by 13–22 μ and contained 36 to more than 70 merozoites. The 3rd generation merozoites entered the sexual cycle. The mature microgametocytes were 24–72 by 18–32 μ and contained a central residuum and a large number of microgametes 5–7 by 0.8 μ with 2 posteriorly-directed flagella. The mature macrogametes were 16–22 by 8–13 μ. Gametogony occurred 144–216 hours after inoculation. The prepatent period was 168–192 hours and the patent period 10–11 days. Peak oocyst production occurred on the 6th day of the patent period.     

A survey of blood and other tissue parasites of leopard frogs Rana pipiens in the United States.

In a survey of blood and other tissue parasites from 137 leopard frogs, Rana pipiens complex, purchased from 13 commercial vendors in 8 states in the United States, Trypanosoma pipientis was found in 2 R. p. berlandieri, Toxoplasma ranae in 1 R. pipiens, Isospora lieberkuehni in 1 leopard frog, Haemogregarina magna in 44, Lankesterella minima in 3, Leptotheca ohlmacheri in 3 and microfilariae of Foleyella sp. in 6. The report of I. lieberkuehni is presumably a new host record. Haemogregarina temporariae (N?ller,, 1920) nov. comb. is established as a new combination for Nematopsis temporariae.     

The Life Cycle of Cryptosporidium baileyi n. sp. (Apicomplexa, Cryptosporidiidae) Infecting Chickens

ABSTRACT. The life cycle and morphology of a previously undescribed species of Cryptosporidium isolated from commercial broiler chickens is described. The prepatent period for Cryptosporidium baileyi n. sp. was three days post oral inoculation (PI) of oocysts, and the patent period was days 4–24 PI for chickens inoculated at two days of age and days 4–14 for chickens inoculated at one and six months of age. During the first three days PI, most developmental stages of C. baileyi were found in the microvillous region of enterocytes of the ileum and large intestine. By day 4 PI, most parasites occurred in enterocytes of the cloaca and bursa of Fabricius (BF). Mature Type I meronts with eight merozoites first appeared 12 h PI and measured 5.0 × 4.9 μm. Mature Type II meronts with four merozoites and a large granular residuum first appeared 48 h PI and measured 5.1 × 5.1 μm. Type I meronts with eight short merozoites and a large homogeneous residuum first appeared 72 h PI and measured 5.2 × 5.1 μm. Microgamonts (4.0 × 4.0 μm) produced 16 micro-gametes that penetrated into macrogametes (4.7 × 4.7 μm). Macrogametes gave rise to two types of oocysts that sporulated within the host cells. Most were thick-walled oocysts (6.3 × 5.2 μm), the resistant forms that passed unaltered in the feces. Some were thin-walled oocysts whose wall (membrane) readily ruptured upon release from the host cell. Sporozoites from thin-walled oocysts were observed penetrating enterocytes in mucosal smears. The presence of thin-walled, autoinfective oocysts and the recycling of Type I meronts may explain why chickens develop heavy intestinal infections lasting up to 21 days. Oocysts of C. baileyi were inoculated orally into several animals to determine its host specificity. Cryptosporidium baileyi did not produce infections in suckling mice and goats or in two-dayold or two-week-old quail. One of six 10-day-old turkeys had small numbers of asexual stages only in the BF. Four of six one-day-old turkeys developed mild infections only in the BF, and sexual stages of the parasite were observed in only one of the four. All seven one-day-old ducks and seven two-day-old geese developed heavy infections only in the BF with all known developmental stages present.