[The life-history of Sarcocystis singaporensis Zaman and Colley, 1976 in the definitive and intermediate host (author's transl)]

Sporulated oocysts and sporocysts (9.3 x 7.3 micrometer) of Sarcocystis singaporensis - isolated from freshly imported snakes (Python reticulatus) - were fed to various animals to test their function as suitable intermediate hosts (NMRI-mice, albino rats, Meriones unguiculatus, golden hamsters, guinea pigs, Mastomys natalensis, field-voles [Microtus arvalis], pigeons, and chickens). Only in rats were muscle-cysts formed. The optimal dose was 150 sporocysts per rat. Two generations of merogony could be observed, the first about the 6th day, the second about the 16th day post infection. In the skeletal muscles metrocytes were seen in the young cysts initially, and from the 40th day post infection cystozoites were present. The full grown muscle-cysts measured 1226 x 184 micrometer. They were chambered and possessed a 9.6 micrometer broad stable bristle layer. Older cysts (100 days post infection and more) had shorter processes. To demonstrate the complete life-cycle we fed cyst-containing rat muscles to four reticulated pythons. On the 8th and 13th post infection the feces for 73 to 117 days. Histologic examination of surgically removed parts of the midgut showed that gamogony and sporogony take place in the duodenum and the anterior third of the midgut. Oocysts with sporoblasts were first seen on the 4th day post infection.

Efficacy of Stenorol (halofuginone). I. Against recent field isolates of six species of chicken coccidia

The efficacy of Stenorol (halofunginone) was tested against six species of chicken Eimeria in a series of four battery experiments utilizing 3- to 4 1/2-week-old Cobb color-sexed broiler chickens. There were five replicates of eight chickens per replicate for each treatment of an experiment or a total of 1080 birds used in the study. The isolates were predominantly E. tenella, E. maxima, E. acevulina, E. necatrix, E. brunetti, or E. mivati and had previously been proven partially to totally resistant to several commercially available anticoccidial drugs. Halofunginone, at 3 ppm in the ration, was highly effective (P less than .01) against all six isolates as measured by weight gain at D+6 or +7and D+12 or +14 postinoculation; feed efficiency at D-2 to D+12 or +14; morbidity; mortality; dropping score; lesion score (D+6 or +7); and oocyst production during 4 or 5 days postinoculation (D = day of inoculation). The drug was not as effective against E. acervulina as against the other species, and increasing halofuginone to 4 ppm failed to improve activity of the drug signif;cantly against this isolate. However, 3 ppm of drug was effective against two other isolates of E. acervulina (from Alabama and Mississippi); 4 ppm was quite effective (P less than .01) in reducing dropping and lesion scores, but not significantly better than 3 ppm as measureed by other parameters. No relapse occurred after drug withdrawal and halofuginone was found to be cidal rather than static.

Efficacy of Stenorol (halofuginone). II. Plus roxarsone or bacitracin MD against selected strains of chicken Eimeria

A total of 879 broiler strain chickens ranging from 2 1/2- to 7 1/2 weeks of age was utilized in four battery experiments to determine whether Roxarsone and/or bacitracin MD added to halofuginone were compatible and beneficial in reducing the effects of coccidial infections. The additives were generally beneficial as measured by weight gain and feed efficiency but not as measured by other parameters such as dropping score, lesion score, or oocyst production. The addition of 200 g of bacitracin/ton of feed did not give an additional response above that from 50 g/ton. Roxarsone in the ration was more effective in younger chickens (2 1/2 week old) than older ones (6 weeks, 2 days and 7 weeks, 3 days).

The natural occurrence of Trypanozoon in domestic chicken in the Ivory Coast

From a natural infected chicken (Gallus gallus var. domesticus) in the Ivory Coast trypanosomes were isolated using Mastomys natalensis as recipient animal. Trypanosomes were diagnosed as belonging to the subgenus Trypanozoon from its morphology and its infectivity for rodents. The stabilated stock was able to infect a laboratory chicken. The stock proved to be human plasma subresistant and showed electrophoretic patterns of three enzymes (ALAT III, ME I, PEP III) so far only seen in pig and dog originated Trypanozoon stocks from the same region surveyed. The discovery for the first time of chicken harbouring Trypanozoon has to be considered in epizootiology and epidemiology of trypanosomiases.

Studies on Eimeria dispersa Tyzzer 1929 in turkeys

Eimeria dispersa was isolated from young, intensively housed turkeys in Britain. The parasite has morphological features in common with those of the original description. At least two generations of schizonts occur before gametogony and one or two more schizont generations are concurrent with gametogony. Four generations of schizonts are needed to account for the observed reproduction index of 2.08 x 10(6)/oocyst inoculated. The first oocysts were discharged by 105 h and these sporulated within 30 h at 30 degree C. A single dose of between 1 x 10(2) and 1 x 10(6) oocysts depressed body weight gain of 3-week-old poults and 2 poults died 6 and 12 days after receiving 1 x 10(4) or 1 x 10(6) oocysts. A single dose of oocysts protected against a challenge inoculation given 14 days later. Poults immunized against E. dispersa were resistant to challenge with a strain of E. dispera obtained from the United States. Electrophoretic examination of 2 enzymes from both strains of E. dispersa showed that they had similar mobilities. Attempts to infect chickens, guinea-fowl and Japanese quail with E. dispersa were unsuccessful. The strain of E. dispersa isolated here is best referred to as E. dispersa (Briston).

Isolation of a virus strain from Argas persicus ticks

A previously undescribed virus was isolated from Argas persicus ticks collected on sentinel chicken in western Slovakia. The strain was lethal for suckling mice only after intracerebral inoculation. No symptoms were induced in adult mice. The virus strain was insensitive to sodium deoxycholate and resistant to ether treatment. An antigen prepared from the virus did not agglutinate goose or human O erythrocytes. The single strain obtained in 1976 appeared to be untrelated to a large number of known arboviruses when tested by the complement-fixation reaction.

[The assimilation by Eimeria tenella coccidia of DNA and RNA precursors from the host cell]

The assimilation of purine and pyrimidine bases, their nucleosides and orotic acid from the host cell by coccidian E. tenella was studied by means of radioactive precursors of DNA and RNA. It has been established that within their development and reproduction the parasites use selectively different precursors of DNA and RNA from the host cell. Coccidians use intensively the purine base 14C-adenine, assimilate negligibly the pyrimidine base 14C-uracil and nucleoside 14C-uridine and do not use at all 14C-thymidine and 14C-thymine. The coccidians were found to assimilate most intensively 14C-orotic acid, the lower precursor of pyrimidine bases.

The appearance of bisporocytic oocysts of Eimeria maxima in drug-treated chicks

A line of Eimeria maxima acquired resistance to Lerbek (a mixture of clopidol and methyl benzoquate) after serial passage against rising drug levels. Abnormal bisporocystic oocysts which appeared throughout this series were picked out individually and these produced infections in further groups of chicks. Serial passages of selected bisporocystic forms raised their proportion in oocyst yields to about 80% after 10-14 passages, but a few normal oocysts were still present.

[Tapeworm fauna of gallinaceans (Galliformes) of Vietnam]

131 specimens of 3 species of Galliformes from Vietnam were investigated (Gallus gallus dom., G. g. jaboruillei, Francolinus pintadeanus and Lophora nycthemerus). In them 9 species of cestodes were found as follows: Davainea proglottina (Davainea, 1860), Cotugnia digonopora (Pasquale, 1890), Raillietina tetragona (Molin, 1858), R. echinobothrida (Megnin, 1880), Skrjabinia cesticillus (Molin, 1858), Paroniella tinguiana Tubangui et Masilungan, 1937, Amoebotaenia cuneata (Linstow, 1872), Echinolepis carioca (Magalhaes, 1898), Dilepidoides bauchei (Joyeux, 1924). In domestic hens there were found all 9 species of cestodes while in wild Galliformes--only 7, which are mentioned for them for the first time.

The life cycle of Eimeria dispersa Tyzzer 1929 from the turkey in gallinaceous birds

The life cycle of a turkey strain of Eimeria dispersa was studied in chickens, Chukar partridge, Ring-necked pheasant, and Bobwhite quail. Endogenous development in partridge and quail differed from development in chickens and pheasant. In partridge and quail, mature 1st-, 2nd-, and 3rd-generation schizonts, macrogamets, and oocysts were found in tissue sections at an earlier time interval, mature 1st-generation schizonts were larger, and mature 1st-, 2nd-, and 3rd-generation schizonts contained a greater number of merozoites that were longer. The only apparent similarity among the 4 hosts was the size of mature 2nd- and 3rd-generation schizonts. The life cycle was completed in all 4 species of birds. The prepatent period was approximately 6 hr shorter in partridge and quail than in chickens and pheasant. Two partridge and 2 quail given 50,000 sporulated oocysts each shed a total of 23 million and 135 million oocysts, respectively, during 4-day interval. Two chickens and 2 pheasant given the same dosage shed a total of only 70,000 and 1 million oocysts, respectively, during the same interval. Oocysts from partridge and quail sporulated more quickly and were slightly larger than those from chickens and pheasant.

Studies on the reproductive system of Philophthalmus gralli using techniques of transplantation and autoradiography

Adult Philophthalmus gralli exposed in vitro to 3H-thymidine for 6 hr showed label on autoradiograms over actively dividing cells in the testes, ovary, and vitellaria. In worms transplanted to chicks, oogonia became primary oocytes within 4 days and these were first found enclosed in newly formed eggs by 12 days. Tertiary spermatogonia at the periphery of the testes developed into sperm by 144 hr and were found in the serminal vesicle by 168 hr. Vitelline cells required 96 hr to travel from gland areas to become incorporated into eggs. In adults labeled in vitro for 1 hr with 3H-tyrosine and transplanted singly to chicks, only 2 of 28 self-inseminated. Labeled worms transplanted with unlabeled worms never self-inseminated but cross-inseminated with approximately 40% of the available worms. Transplanted worms localized in the chick's orbit in 3 microhabitats. In only 1 of 21 experiments did a labeled worm inseminate unlabeled worms outside of the microhabitat where it was found.

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.

Effect of dimetridazole on transmission of Histomonas meleagridis by Heterakis gallinarum

The administration of an antihistomonal drug, dimetridazole, at a dose of 0.08% in feed, controlled experimental infections with Histomonas meleagridis in chickens. The treated birds developed no lesions and the duration of infection with H. meleagridis was reduced. This drug regimen, however, did not always prevent incorporation of H. meleagridis into eggs of Heterakis gallinarium; heterakid eggs pooled from medicated chickens in which H. meleagridis had never been detected transmitted the protozoan to 1 of 10 turkeys fed the eggs. Thus, therapeutic treatment of chickens with dimetridazole may reduce, but not eliminate, transmission of H. meleagridis by eggs of H. gallinarum from medicated birds.

Morphological and histochemical observations on the intestinal epithelium of Ascardia galli (Nematoda: Ascaridida)

The intestinal epithelium of Ascardia galli has been studied with various cytological and cytochemical techniques. It consists of large epithelial cells resting on a thick collagenous basal lamina. Their luminal surface is provided with microvilli. The intestinal cells store considerable amounts of glycogen and neutral lipids. Some intracellular granular inclusions, which stain for proteins, phospholipids and lipoproteins, are distributed throughout the cytoplasm. The brush border is composed of microvilli whereas the outer surface coat consists of saliva resistant PAS-positive material. The detailed histochemical analysis of surface material has revealed that it is composed of nonacetylated acid mucopolysaccharides rich in hyaluronic acid with carboxylate polyanions. The brush border shows intense activities of acid phosphatase and glucose-6-phosphatase, moderate of ATPase, and lipase, weak of 5'-nucleotidase. Acid phosphatase-positive intracellular structures are seen in the intestinal epithelium which form distinct aggregations.

Immunogenicity of a single sporocyst of Eimeria maxima

Eight out of a total 40 chickens infected with single sporocysts of Eimeria maxima produced infective oocysts. These 8 chickens, when challenged with 4 X 10(5) oocysts per bird at 28 days postinfection, showed at least twice the percent average weight gain of the previously unexposed chickens, indicating that partial immunity was probably conferred by these infections. Also, these successful single sporocyst infections suggest that like E. tenella, sporozolles of E. maxima are probably sexually undifferentiated.

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.

Eimeria tenella: experimental studies on the development of resistance to amprolium, clopidol and methyl benzoquate

The development of resistance by the Houghton strain of Eimeria tenella to the anticoccidial drugs amprolium, clopidol and methyl benzoquate has been studied. Resistance to amprolium and clopidol developed more readily in experiments where a large number of coccidia were exposed to the drug, either by increasing the number of oocysts in the inoculum or by increasing the number of birds in the group. When 45 birds were given 2.0 X 10(6) oocysts, resistance to amprolium and clopidol appeared after 6 and 7 passages respectively. In previous experiments, under similar conditions, resistance to robenidine developed after 6 passages, suggesting little difference between these three drugs. Resistance to amprolium and clopidol arose gradually as the concentration of drug was increased, but resistance to methyl benzoquate appeared in a single step from sensitivity to high-level resistance. Both amprolium and clopidol-resistant lines showed an 8-fold reduction in drug sensitivity. Attempts to measure the degree of resistance by calculation of the ED50 were unsuccessful.

Eimeria tenella: sensitivity of recent field isolants to monensin

Coccidia were propagated from litter samples obtained from broiler production flocks being medicated with monensin. Eimeria tenella was isolated from 48.9% of the litter samples from which coccidia were propagated. Tests of the monensin sensitivity of the 73 E. tenella isolants obtained revealed no monensin-resistant isolants.

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.

[Observations on the second moult of the larvae of Ascaridia galli (author's transl)]

In Ascaridia galli larvae artificially hatched after 11 and 12 days of incubation at 25 degrees C, in larger frequency than in larvae hatched either after 10 and after 14 days of incubation, two different cuticles detached from their bodies were observed. These two detached cuticles indicate that such larvae had undergone two moults before hatching and, consequently, that the infective stage of A. galli is the third larval stage.

[Helminths in chickens in Sudan]

The identification of the helminthic parasites of the poultry in Khartoum province, during the months of October and November, 1969, 230 hens, 6--12 months old, were examined in the laboratory; 87% of the hens exhibited mono- and polyinfections. The following species were found: Subulura brumpti, Raillietina tetragona, Tetrameres americana, Gongylonema ingluvicola and Dispharynx spiralis, mostly as polyinfections.

Changes in the generation cycle of duodenal crypt cells in chickens infected with Eimeria acervulina

Changes in the duration of the progenitor cycle and its four phases were determined for duodenal crypt cells in chickens infected with Eimeria acervulina. Metaphase curves were constructed using percent labelled metaphase nuclei in duodenal crypt cells at short intervals after the injection of [3H]thymidine. The duration of the progenitor cycle and its four phases were calculated using the synthetic index and data obtained from the metaphase curves. The cycle time was reduced from 14 h in control birds to 10.2 h at 2 days and 10.6 h at 4 days postinfection. The change was attributable entirely to a reduction in G1 or the presynthetic phase. In addition, the population of dividing cells within each duodenal crypt was almost doubled in infected birds. These increases in cell production precedes all the histological changes observed earlier in the intestines of E. acervulina infected chickens. At least in this instance, changes in crypt morphology seems, therefore, to result from an induced change in the functional activity of the crypt.

Studies on the attraction of Simulium damnosum s.l. (Diptera: Simuliidae) to its hosts. III. Experiments with animal-baited traps

In the forest zone of the United Republic of Cameroon, a live chicken proved far more attractive to hunting S. damnosum s.l. than did a live sheep; but in the Sudan-savanna zone, a sheep was more attractive than a chicken. It is suggested that the populations of flies in the two areas represented different species of the S. damnosum s.l. complex with different host-finding mechanisms, that in the forest (? S. squamosum) hunting mainly by smell, and that in the Sudan savanna (? S. damnosum s.s.) hunting mainly by sight.

Control of gamete formation (exflagellation) in malaria parasites

The only stages of malaria parasites capable of establishing an infection in a mosquito are the gametocytes that circulate in the blood of the veterbrate host. Within minutes of ingestion by a mosquito the gametocytes transform into mature gametes in the process of "exflagellation." This process is controlled in vitro solely by the change in pH in the blood as it moves from the environment of the circulation to that of the atmosphere, the pH rise being mediated by the fall in carbon dioxide tension as the blood equilibrates with the atmosphere.

[Deviation of the life cycle of Dipetalonema viteae (Filarioidea)]

Dipetalonema viteae is a filarial that can evoluate among hosts zoologically broadly apart (Ixodides and Argasides), but always gathered from meriones burrows. Its evolution is, on the contrary, blocked among most of the other ticks, particularly among Ornithodoros erraticus morphologically very similar to the normal vector. Our work concerns the experimental deviation of the cycle of Dipetalonema viteae, with its possible adaptability in the bosom of an intermediate of fowl tropism and a permanent host, different from a gnawing.

Genetic recombination of precociousness and anticoccidial drug resistance in Eimeria tenella

Two strains of Eimeria tenella differing in decoquinate-resistance and developmental rate were crossed. Strain Wis-F was decoquinate-sensitive (DS) and precocious (P+), while strain 368 was decoquinate-resistant (DR) and had a normal developmental rate (P-). Cultures of the parent strains and a culture derived from a mixture of parent strain oocysts were propagated through drug and developmental barriers to select parasites with the respective parental phenotypes (DS/P + and DR/P-) and the recombinant phenotype (DR/P+). The ability of a portion of the population in the strain-cross culture to reproduce in the presence of simultaneously imposed drug and developmental barrier showed that they were the recombinant phenotype (DR/P+), which had been produced through fertilization by gametes of opposite parent strains of E. tenella.

Ultrastructure of macrogametogenesis of Eimeria mivati

The development of the macrogamete of Eimeria mivati Edgar and Seibold 1964 was studied with the electron microscope. Development of the young gamont was characterized by a loss of organelles such as the apical complex, subpellicular microtubules, rhoptries and micronemes, followed by an increase in micropores, mitochondria, rough endoplasmic reticulum (rER), and Golgi complexes. Nuclear detachment bodies and canaliculi were present in maturing macrogamonts. Amylopectin was first observed as small electron-dense rod-like bodies that eventually became large electron-transparent bodies. Type II wall-forming bodies developed in the cisternae of the rER. Type I wall-forming bodies appeared shortly thereafter in close association with numerous Golgi complexes. Many small vesicles located between the cisternae of the rER and the Golgi complexes formed what appeared to be a secretory pathway whereby protein formed in the cisternae and, modified by the Golgi complex, may produce the type I wall body material. The outer wall of the oocyst developed between two distal membranes on the surface of the macrogamete. Although the actual mechanism of deposition of the wall material was not seen, it was probably by some secretory process. Wall-forming bodies did not fuse.