Showing papers in "Journal of Parasitology in 1982"
TL;DR: In this paper, an ad hoc committee was established to establish working definitions of a few terms used and misused by parasitological ecologists as a guide for authors submitting papers to The Journal of Parasitology.
Abstract: In February 1981, ASP President Elmer Noble on recommendation from the Editor, Austin Maclnnis, appointed an ad hoc committee \"to establish working definitions of a few terms used and misused by parasitological ecologists\" as a guide for authors submitting papers to The Journal of Parasitology. Appointed to the committee were Drs. Gerald Esch, John Holmes, Armand Kuris, Gerhard Schad, and Leo Margolis (Chairman). As a starting point the committee examined the recommendations (Margolis et al., 1982) prepared by a similar committee established by the Parasitology Section of the Canadian Society of Zoologists. The Canadian Committee concerned itself only with terms required to express concepts related to the number of hosts in a sample infected with a particular species of parasite, and to the number of individuals of a particular parasite in each host in a sample. As noted below the present committee also dealt with several other ecological terms that are not now being used in a consistent manner in parasitological literature. The following are the committee's recommendations, annotated as required:
1,923 citations
1,682 citations
TL;DR: Dynamic aspects of the cellular responses of juvenile Biomphalaria glabrata to newly penetrated Schistosoma mansoni strains were studied at the ultrastructural level and evidence was found to suggest that hemocytes were lysed, or formed multinuclear syncytia, during the encapsulation response.
Abstract: Dynamic aspects of the cellular responses of juvenile (2-3 mm shell diameter) 10-R2 strain Biomphalaria glabrata to newly penetrated Schistosoma mansoni (NIH-Sm-PR-1 strain) were studied at the ultrastructural level. As early as 3 hr postexposure (PE), host hemocytes had contacted the parasite's surface and by 7.5 hr, had phagocytosed sporocyst microvilli and small pieces of underlying tegument. Most sporocysts observed at 24 hr PE lacked tegumental cytoplasm, and germinal cells and other internal structures showed extensive pathological changes. By 48 hr, capsules were filled with hemocytes containing numerous, large phagosomes, and only scattered remnants of sporocyst material remained. Capsules were difficult to find at 4 days PE, suggesting that hemocytes participating in the encapsulation response had dispersed. Hemocytes responsible for the rapid and consistent destruction of S. mansoni sporocysts in the head-foot region typically formed extensive pseudopodia and contained large numbers of lysosomelike bodies, characteristics associated with granulocytes of B. glabrata. No evidence was found to suggest that hemocytes were lysed, or formed multinuclear syncytia, during the encapsulation response.
114 citations
TL;DR: A new liquid medium, TYSGM-9, devised to facilitate the transition of Entamoeba histolytica from xenic to axenic conditions of growth has proved valuable for initiation and maintenance of cultures of the following protozoa inhabiting the intestine or mouth of man.
Abstract: A new liquid medium, TYSGM-9 (Trypticase, yeast extract, serum, gastric mucin), devised to facilitate the transition of Entamoeba histolytica from xenic to axenic conditions of growth has proved valuable for initiation and maintenance of cultures of the following protozoa inhabiting the intestine or mouth of man: E. histolytica, E. coli, E. gingivalis, and Dientamoeba fragilis. Its utility in cultivation of other protozoa from these sites has not been tested. Moreover, its usefulness as a diagnostic medium has yet to be established. In each case studied, microscopy had demonstrated the parasite(s) in the source material prior to culturing. An Entamoeba resembling E. gingivalis recovered from the genital tract of a user of an intrauterine device (deMoraesRuehsen et al., 1980, Acta Cytol. J. 24: 413420) and which could not be grown in LES medium was isolated in the new medium. The medium which has been in use for 2 years offers certain advantages over others commonly employed for xenic cultivation of these parasites. Its clarity permits examination of the protozoa in situ, obviating the necessity of sampling the cultures between transfers to monitor them as must be done with diphasic media, e.g., LES (Boeck and Drbohlav, 1925, Am. J. Hyg. 5: 371-407, modified by Reardon and Rees, 1939, J. Parasitol. 25(Suppl.): 13-14). Egg-yolk infusion, probably the most widely used liquid medium for isolation and culture maintenance, requires overnight to prepare and involves numerous procedural steps (Balamuth, 1946, Am. J. Clin. Pathol. 16: 380-384). In contrast, TYSGM-9 can be prepared within a few hours from ingredients commonly stocked in diagnostic microbiological laboratories. It has a storage life of a month or more at 4 C. In established cultures, yields of protozoa are consistently better than those obtained with LES and equal to or greater by twofold than those obtained with egg-yolk infusion. Inocula of 5,000 organisms/ml medium taken from established cultures yield the following fold increases in 48 hr: E. histolytica, 30 to 40; E. coli, 20 to 30; E. gingivalis, 15 to 25; and D. fragilis, 20 to 30. TYSGM-9 was derived from TYI-S-33, a medium developed for axenic cultivation of E. histolytica and related Entamoeba (Diamond et al., 1978, Trans. R. Soc. Trop. Med. Hyg. 72: 431-432). It is prepared as follows. Basal medium: Add and dissolve in 600 ml of glass-distilled water: potassium phosphate, dibasic, 2.8 g; potassium phosphate, monobasic, 0.4 g; sodium chloride, 7.5 g; Trypticase (BBL Microbiology Systems, Cockeysville, Maryland), 2.0 g; and yeast extract (BBL), 1.0 g. Bring total volume to 970 ml with distilled water. Place 200 mg gastric mucin (U.S. Biochemical Corp., Cleveland, Ohio, # 16025) in dry, sterile, screw-capped Erlenmeyer flasks (125-ml capacity). Add 97 ml of broth to each flask. Autoclave 15 min, 121 C, 15 lb to both solubilize the gastric mucin and sterilize the medium. Cool to room temperature. Aseptically add 3 ml of bovine serum (inactivated 30 min, 56 C), and 0.05 ml of Tween 80 prepared as a 10% solution (v/v) in absolute ethanol. Swirl vigorously to keep gastric mucin particulates in suspension and dispense in 8-ml portions to 16 x 125-mm screw-capped tubes. The pH of the medium is 7.2; the osmolality, 320 mosmol/kg. Biosate (BBL), 3 g, can substitute for Trypticase and yeast extract. Gastric mucin should be of the type prepared according to the New and Nonofficial Remedies (N.N.R.) 1953. Rice supplement: Purified rice starch is preferred, but unpolished rice flour can be used. The rice is placed in 500-mg amounts in 16 x 125-mm screw-capped tubes and sterilized with dry heat at 150 C, 2.5 hr. To assure sterilization the tubes are positioned horizontally with the rice dispersed in a thin layer and the screw cap loosened to allow free movement
108 citations
TL;DR: The specific gravities of ten species of helminth eggs were determined using sucrose density gradient centrifugation and the specific gravITIES of P. equorum, T. suis, Taenia sp.
Abstract: The specific gravities of ten species of helminth eggs were determined using sucrose density gradient centrifugation. Fecal or egg concentrate was layered over a 3 to 54% sucrose density gradient. The gradient was then centrifuged at 800 g for 20 min, allowing 5 min for acceleration and 5 for deceleration. Bands formed were identified and measured. Refractive index was measured at the middle of narrow bands, or at the level at which the concentration of eggs was highest, in the case of wide bands or when no band was formed. The specific gravity corresponding to this refractive index was taken as the specific gravity of the eggs. The ten species of helminth eggs studied and specific gravities measured on three or four gradients were: Toxascaris leonina, 1.0559; Ancylostoma caninum, 1.0559; Toxocara canis, 1.0900; Parascaris equorum, 1.0969; Toxocara cati (embryonated), 1.1005; Ascaris suum, 1.1299; Trichuris suis, 1.1299; Trichuris vulpis, 1.1453; Taenia sp., 1.2251; and Physaloptera sp., 1.2376. These determinations agree with or approximate those of previous workers. The specific gravities of P. equorum, T. suis, Taenia sp., and Physaloptera sp., are reported for the first time.
91 citations
TL;DR: To determine the intermediate host range, six avian species, including canaries, zebra finches, budgerigars, pigeons, chickens, and guinea fowl were inoculated orally with Sarcocystis sporocysts derived from experimentally infected opossums.
Abstract: The life cycle of an avian Sarcocystis has been completed in the laboratory, originating with naturally infected icterids and passing alternately between opossums (Didelphis virginiana) and experi- mentally infected birds. To determine the intermediate host range, six avian species, including canaries (Serinus canarius), zebra finches (Poephila guttata), budgerigars (Melopsittacus undulatus), pigeons (Co- lumba livia), chickens (Gallus gallus), and guinea fowl (Numida meleagris), were inoculated orally with Sarcocystis sporocysts derived from experimentally infected opossums. All birds but the Galliformes were susceptible to merogony. Pigeons (Columbiformes) were susceptible to early merogony but apparently not to muscle stages. Passeriformes and Psittaciformes were completely susceptible and the parasite de- veloped into muscle cysts in them.
90 citations
TL;DR: Hypoxanthine and glutathione are identified as two of the factors critical for the ability of human serum to support the growth of the parasites and give a two- to four-fold increase in the final parasitemia over the original Trager-Jensen culture method.
Abstract: We attempted to optimize some of the variables involved in the in vitro culturing of Plasmodium falciparum. Irrespective of the isolates used, suspension cultures in glucose-enriched RPMI-1640 medium buffered with TES yielded about twice the amount of parasites than could be obtained from static, thin-layer cultures with HEPES-buffered RPMI-1640 without additional glucose. In suspension cultures, methylcellulose (1 mg/ml) was added to protect the erythrocytes. In addition the erythrocytes were found to be more suitable for culturing P. falciparum when stored as a concentrate in saline-adenine-glucose than as whole blood in citrate-phosphate-dextrose. With a cloned isolate of P. falciparum (Tak9/clone 96) a further stimulation of the final parasitemia could be achieved by supplementing the medium with hypoxanthine (50 micrograms/ml) and reduced glutathione (600 micrograms/ml). Moreover, we identified hypoxanthine and glutathione as two of the factors critical for the ability of human serum to support the growth of the parasites. These modifications give a two- to four-fold increase in the final parasitemia over the original Trager-Jensen culture method, thus allowing more parasites to be isolated for biochemical studies.
90 citations
TL;DR: A study of the early life history of Eimeria tenella with the electron microscope confirmed that sporozoites do not directly enter the enterocytes of the crypts, but are carried there by host cells, which are not macrophages, as previously thought.
Abstract: A study of the early life history of Eimeria tenella with the electron microscope confirmed that sporozoites do not directly enter the enterocytes of the crypts, in which they develop, but are carried there by host cells. However, these cells are not macrophages, as previously thought, but intraepithelial lymphocytes. The evidence presented demonstrates that sporozoites first penetrate surface enterocytes and then enter intraepithelial lymphocytes that leave the epithelium, pass through the lamina propria and enter the crypts.
75 citations
TL;DR: Results, associated with the absence of lipid synthesis in host cells, mean that the enzymes controlling these two pathways could serve as enzymatic markers of parasites.
Abstract: Metabolic pathways leading to phospholipid biosynthesis in Plasmodium-infected simian erythrocytes were tested and quantified by incubating leucocyte-free erythrocytes in the presence of labelled precursors. Plasma fatty acids and lysophospholipids both served as sources of the fatty acids required for cellular phospholipid biosynthesis. However, the entry of free fatty acids and lysophospholipids appeared to be controlled by a competitive mechanism. A powerful deacylase-acylase system was detected, the nature and specificity of which remain to be defined. Glycerol-3-phosphate incorporation into cellular lipids accounted for most of the new phospholipid molecules formed in parasitized cells, and into cellular lipids accounted for most of the new phospholipid molecules formed in parasitized cells, and this compound, rather than the lysophospholipids, appeared to be the natural acceptor of the acyl groups. By incorporation of nitrogenous bases into cellular phospholipids, we identified significant pathways not previously detected in Plasmodium-infected erythrocytes: the formation of phosphatidylethanolamine by phosphatidylserine decarboxylation, and the formation of phosphatidylcholine by the methylation of phosphatidylethanolamine. These results, associated with the absence of lipid synthesis in host cells, mean that the enzymes controlling these two pathways could serve as enzymatic markers of parasites.
75 citations
TL;DR: The apicomplexan protozoan genus Atxoplasma Garnham, 1950 is resurrected and the family Atoxoplasmatidae n.
Abstract: The apicomplexan protozoan genus Atoxoplasma Garnham, 1950 is resurrected and the family Atoxoplasmatidae n. fam. established for homoxenous blood parasites of birds that develop asexually in both the blood and intestinal cells, and form oocysts that are passed unsporulated in the feces, sporulate on the ground, and then infect new hosts. A list of 19 species of Atoxoplasma is given. Atoxoplasma desseri n. sp. of the evening grosbeak Coccothraustes vespertinus and rose-breasted grosbeak Pheucticus ludovicianus is named.
68 citations
TL;DR: During an outbreak of human toxoplasmosis attempts were made to isolate Toxoplasma from soil near Além Paraíba, Brazil, only one soil sample gave rise to infection in mice, and two young cats, seronegative by the Sabin-Feldman dye test, subsequently ingested the cyst-positive mouse brain.
Abstract: During an outbreak of human toxoplasmosis attempts were made to isolate Toxoplasma from soil near Alem Paraiba, Brazil. Five soil samples were collected from the gardens and also from humid shady areas near the houses. After several washings, these soil samples were centrifuged in a glucose solution, and the supemate removed to be centrifuged in water. The sediments obtained from each of the five soil samples were then inoculated orally in groups of mice. Only one soil sample, obtained from a vegetable garden, gave rise to infection in mice. Toxoplasma-like cysts were found in the brains of two mice and also a few mice from all the four subsequent passages. Cyst-positive mice presented antibodies against T. gondii. Two young cats, seronegative by the Sabin-Feldman dye test, subsequently ingested the cyst-positive mouse brain. One cat eliminated Tox- oplasma-like oocysts between the 5th and 11th days after the infection and the other cat between the 6th and 16th days. Seroconversion was observed in both cats, 15 days after the inoculation. These results further emphasize sanitary precautions essential to the control of Toxoplasma.
TL;DR: It was shown that the drug exerts its anticoccidial effect on the primary invasive stage and on the gametogonous stage of E. tenella and E. necatrix by initiating treatment of chickens with monensin at different times in relation to infection.
Abstract: Sporozoites of Eimeria tenella were treated with different anticoccidial drugs in vitro and their subsequent viability was tested by inoculating them into chicken embryos. Monensin, salinomycin, lasalocid, and arprinocid, at concentrations between 0.01 and 1.0 micrograms/ml, greatly reduced sporozoite viability as judged by mortality, hemorrhage and specific lesions in the embryo chorioallantois. Monensin was also effective in reducing the viability of sporozoites of E. mivati and E. tenella as judged by oocyst production occurring in embryos; activity of monensin was greater against E. tenella than against E. mivati. Monensin (0.1 mg) inoculated into embryos inhibited development of E. tenella. Oocysts which were produced in the presence of the drug sporulated normally and sporozoites obtained from them were fully infective. By initiating treatment of chickens with monensin at different times in relation to infection, it was shown that the drug exerts its anticoccidial effect on the primary invasive stage and on the gametogonous stage of E. tenella and E. necatrix. The effect of gametogony was tested by initiating infections with second generation merozoites of E. tenella. Significant reduction in oocyst production occurred in three of four strains of E. tenella tested. Medication with monensin initiated before merozoite inoculation was effective in inhibiting oocyst production, but medication starting 5 hr after merozoite inoculation was not. This differed from the effects of arprinocid and sulfaquinoxaline which were expressed both before and 5 hr after merozoite inoculation. The results show that the ionophorous anticoccidial drugs exert their anticoccidial action primarily against the invasive stages of Eimeria.
TL;DR: Biological differences between two strains of Boophilus microplus were examined, suggesting that some laboratory-maintained strains of ticks may be unsuitable for ecological or acaricide studies.
Abstract: Biological differences between two strains of Boophilus microplus were examined. The A-strain of ticks had been maintained at the laboratory for many years and the N-strain was recently isolated, being a composite strain derived from ticks from different sources in the field. In three experi- ments, up to three times as many N-strain ticks grew to maturity than did A-strain ticks, although A-strain ticks matured earlier. N-strain ticks were 17 to 60% heavier, and laid 50 to 100% more eggs than A-strain ticks. N-strain eggs were significantly more fertile than A-strain eggs. Unfed, N-strain larvae survived much longer than A-strain larvae. The reduced vitality of the A-strain is attributed to its long history in the laboratory during which time it has become biologically disadvantaged through inbreeding. These results suggest that some laboratory-maintained strains of ticks may be unsuitable for ecological or acar- icide studies. The tick Boophilus microplus is a major pest in many countries including Australia. The main hosts are cattle, but it occurs frequently on sheep, deer, horses, and occasionally on buffalo, pigs, and goats (Hoyte, 1964). Its pathogenic effects are twofold: heavy infes- tations have a serious debilitating effect on the host, and it acts as a vector for babesiosis and anaplasmosis. We studied biological differences between an old and a new laboratory strain of B. mi- croplus, comparing times it took each strain to grow to maturity, total numbers of ticks re- covered from infested cattle, weights of ticks, fecundity and fertility, and larval survival times. When large differences were demon- strated we performed an experiment to test the possibility of a host-parasite reaction manifesting itself to a greater degree against one of the strains. Our results suggest that a loss of vitality has occurred in the old strain.
TL;DR: In adult Schistosoma mansoni and S. japonicum carbohydrate utilization, formation of lactic acid and ATP levels were the same under aerobic and anaerobic conditions, therefore, these parasites exhibited no pasteur effect and do not derive metabolic energy from respiration.
Abstract: In adult Schistosoma mansoni and S. japonicum carbohydrate utilization, formation of lactic acid and ATP levels were the same under aerobic and anaerobic conditions. Therefore, these parasites exhibited no Pasteur effect. When the metabolic requirements of the parasites were raised by 5-hydroxy- tryptamine-(5-HT)-induced stimulation of the worm's motor activity, aerobic conditions did not reduce the rate of carbohydrate utilization nor the ATP levels of the worms. Therefore, these parasites do not derive metabolic energy from respiration.
TL;DR: It is concluded that cats can be immunized against oocyst shedding by infections where oocysts are produced, or where developmental stages are suppressed by chemoprophylaxis, but not if enteroepithelial stages are absent, as in the oocySt-less strain examined.
Abstract: ABSTRACr: Development of immunity to the shedding of oocysts was examined in 75 kittens that survived infection with the three stages of Toxoplasma gondii. Of 16 kittens fed bradyzoites in cysts, 94% were immune and did not shed oocysts. Of seven injected with tachyzoites 86% were immune. Of 18 fed sporozoites only 11% were immune, but following injection, 54% of 12 were immune. After the administration of either bradyzoites or tachyzoites from nonoocyst-producing strains, only 9% of 22 were immune. Considering all inocula, immunity was present in 93% of kittens that had previously shed oocysts, 25% of those that only develop antibody, and none that had neither shed nor developed an antibody titer. After a second challenge with a different isolate, a similar percentage of immunity was observed. Infection with killed tachyzoites, alone, or together with Freund's complete or incomplete adjuvants was followed by immunity in only one of 24 kittens. Eighty-five percent of 13 kittens were immune, after they had been treated prophylactically with 200 mg/kg monensin, or 60 mg/kg cat sulfadiazine combined with 1 mg/kg cat of pyrimethamine; oocyst shedding had been suppressed in all. It is concluded that cats can be immunized against oocyst shedding by infections where oocysts are produced, or where developmental stages are suppressed by chemoprophylaxis, but not if enteroepithelial stages are absent, as in the oocyst-less strain examined.
TL;DR: Chitin was located in the cyst wall of Entamoeba invadens with colloidal gold-linked wheat germ agglutinin, and observation of cells with the electron microscope revealed that tracer particles were bound specifically to the walls of the surface of the Cyst when cells were exposed in suspension.
Abstract: Chitin was located in the cyst wall of Entamoeba invadens with colloidal gold-linked wheat germ agglutinin. Cysts stained differentially from trophozoites when encysting cultures were treated with the gold tracer; cysts acquired a wine-red coloration while, in general trophozoites remained unstained. Observation of cells with the electron microscope revealed that the tracer particles were bound specifically to the walls of the surface of the cyst when cells were exposed in suspension, and to the cyst wall cross-section, when cells were exposed to the tracer in thin section, indicating that chitin fibers were distributed on the surface as well as throughout the matrix of the cyst wall.
TL;DR: It is hypothesized that the cap cell may play a significant role in helping propel secretions from alveoli to associated ducts in unfed Amblyomma americanum (L.) females.
Abstract: Alveoli in the salivary glands of unfed Amblyomma americanum (L.) females (postnymphal ticks that had not yet taken a bloodmeal as an adult) were studied. As in other species of female ixodid ticks, the salivary glands consisted of three alveoli, one agranular and two granular. The agranular alveoli were directly attached to the anterior portion of the main salivary duct, consisted of approximately 13 to 14 cells, and were without valves. Six peripheral cells had tortuous, plasma membrane infoldings with closely associated mitochondria, an abundance of lipidlike droplets and relatively flat apical surfaces. A relatively large, clear, "central" cell occupied most of the alveolar midsection. The "central" cell made contact with the alveolar tubular lumen through an opening of a previously undescribed, concentric, myoepithelial-like cell that we call a "constrictor" cell. Granular alveoli consisted of approximately 14 to 16 cells. Type II granular alveoli have two complex granular cells in close proximity to the cuticular alveolar valve, whereas Type III alveoli have only one. Thin epithelial cells separate adjacent granular cells in both alveolar types and only one "cap" cell with myoepithelial-like features lining the alveolar lumen in weblike fashion was present. We hypothesize that the cap cell may play a significant role in helping propel secretions from alveoli to associated ducts.
TL;DR: Electron microscopic observations of mixed cultures of N. fowleri and neuroblastoma cells established that the amebae, after 12 hr, had ingested portions of the neuroblastomas target cells without causing cell lysis, and N. gruberi amebAE, after attaching to target cells, disrupted the plasma membrane and cytoplasm of the target cells although the target cell nucleus remained intact.
Abstract: Amebae of Naegleriafowleri and Naegleria gruberi were cytopathic for nine established mammalian cell cultures, including mouse and human fibroblasts, rabbit and monkey kidney cells, rat and mouse neuro- blastoma cells, baby hamster kidney cells, and human epithelioma and carcinoma cells. Nine strains of N. fowleri were equally cytopathic for rodent neuroblastoma cells. As few as one ameba per million neuroblastoma cells destroyed the mammalian target cells after 9 days. The N. fowleri grew and destroyed rat neuroblastoma cells at 30 to 37 C whereas N. gruberi grew and destroyed the target cells at 25 to 30 C. Both N. fowleri and N. gruberi attached efficiently to the target cells at 30 to 37 C; N. gruberi but not N. fowleri attached efficiently at 25 C. Electron microscopic observations of mixed cultures of N. fowleri and neuroblastoma cells established that the amebae, after 12 hr, had ingested portions of the neuroblastoma target cells without causing cell lysis. Conversely, N. gruberi amebae, after attaching to target cells, disrupted the plasma membrane and cytoplasm of the target cells although the target cell nucleus remained intact. The amebae then ingested the target cell debris.
TL;DR: The use of specific activities of selected marker enzymes should be very useful for determining the purity of preparation of parasites when used in conjunction with other methods.
Abstract: Plasmodium falciparum trophozoites, isolated by mechanical rupture of infected human erythro- cytes, were analyzed for purity by determination of the specific activities of a number of marker enzymes selected for high activity, stability, and convenience of assay procedures. The specific activities of the soluble enzymes lactate dehydrogenase and malate dehydrogenase were much higher in the parasite than in the erythrocyte. The soluble enzyme glutamate dehydrogenase (NADP+) was specific for the parasite. Samples of 100,000 g supernate obtained from parasites that appeared to be free from contaminating erythrocytes consistently showed specific activities of about 4, 3 and 0.1 ,Amole/min/mg for lactate dehydrogenase, malate dehydrogenase and glutamate dehydrogenase, respectively. Moreover, preparations of parasites that exhibit these specific activities showed low acetylcholine esterase activity in the membrane fractions. The specific activities of these soluble marker enzymes did not appear to be strain dependent. A preparation of highly purified trophozoites obtained by free flow electrophoresis and analyzed for purity by electron microscopy exhibited the same specific activities for these marker enzymes. The use of specific activities of selected marker enzymes should be very useful for determining the purity of preparation of parasites when used in conjunction with other methods.
TL;DR: Hybridoma cell lines, which secreted antibodies directed against two different strains of Eimeria tenella and one strain of E. mitis, were produced by fusion of spleen cells from sporozoite-immunized Balb/cByJ mice with P3-X63-Ag8 myeloma cells.
Abstract: Hybridoma cell lines, which secreted antibodies directed against two different strains of Eimeria tenella and one strain of E. mitis, were produced by fusion of spleen cells from sporozoite- immunized Balb/cByJ mice with P3-X63-Ag8 myeloma cells. The antibodies demonstrated at least eight different binding patterns on or in air-dried sporozoites as determined by the indirect immunofluorescent antibody (IFA) test. These patterns varied from a general internal fluorescence similar to that seen with sporozoites exposed to hyperimmune chicken serum, to fluorescence observed on the tip, pellicle, and refractile body of the parasite. Five cloned, antibody-secreting cell lines were successfully established. Four of these clones produced antibody that reacted only with various strains of E. tenella and cross- reacted with no other species of coccidia. The fifth clone produced antibody directed against only E. mitis and did not react with any other coccidial species. Rose (1978) has documented that repeated
TL;DR: Percoll, a commercially available product marketed by Pharmacia, to be an excellent medium for the isolation of Plasmodium falciparum in vitro, has been found.
Abstract: The asynchronous growth of Plasmodium falciparum in vitro necessitates the development of procedures for the isolation of specific developmental stages of this important parasite for immunological, biochemical, and vaccination studies. Satisfactory procedures used in our laboratory have been discontinuous sucrose (Siddiqui et al., 1974, J. Parasitol. 64: 168-169) and BSA (Siddiqui et al., 1979, Bull. W.H.O. 57: 75-82) gradient centrifugation. Recently we have found Percoll, a commercially available product marketed by Pharmacia (Piscataway, New Jersey), to be an excellent medium for the isolation of
TL;DR: Four species of Zapus from four states for Coccidia were examined and two eimerians were found, Eimeria zapi Gerard, Chobotar, and Ernst, 1977, and a form which is described here as new, which is only the second eimerian reported from Zapus spp.
Abstract: Of 103 jumping mice (Zapus spp.) examined, 29 (28.2%) had coccidian oocysts in their feces: one of seven (14%) Z. trinotatus eureka from Humboldt Co., California; 25 of 60 (42%) Z. princepsprinceps, including seven of 18 (39%) from Boulder Co., Colorado, and 18 of 42 (43%) from Santa Fe and Taos cos., New Mexico; and three of 36 (8%) Z. h. luteus, including one of one from Sandoval Co., New Mexico, two of 13 (15%) from Apache Co., Arizona, and none of 22 from Otero and Soccoro cos., New Mexico. Twenty-eight of 29 infected mice had only Eimeria zapi oocysts in their feces; the only Z. h. luteus from Fenton Lake, Sandoval Co., New Mexico, had oocysts of a species which we describe here as new. Sporulated oocysts of Eimeria hudsonii sp. n. from Z. h. luteus are elliptical, 20.9 X 14.4 (18-23 X 13-16) ,um with ovoid sporocysts 10.5 X 5.6 (8-11 X 57) gm. A micropyle cap, polar and substieda bodies were absent, but a micropyle, oocyst and sporocyst residua, and Stieda body were present. Sporozoites have one large posterior refractile body. The oocyst wall has two layers. This is only the second eimerian reported from Zapus spp. The geographic distribution of E. zapi closely paralleled genetic and geographic features recently reported within the host taxon Z. h. luteus. Since May 1979, we have collected and examined over 3,000 wild mammals from the United States, northern Mexico, Baja California, and Japan. These collections are part of a continuing study designed to understand the evolutionary relationships of certain groups of congeners and conspecifics using pelage, skeletal, morphologic, electrophoretic, karyotypic, and parasite data. Ultimately we hope to be able to relate host genetics and distribution to susceptibility, parasite burdens, and coccidian specificity. This report is the first on the coccidians of one group of these mammals. We examined four species of Zapus from four states for Coccidia and found two eimerians, Eimeria zapi Gerard, Chobotar, and Ernst, 1977, and a form which we describe here as new. MATERIALS AND METHODS Hosts were killed within a few hours after being live trapped. The abdominal cavity was opened by a longitudinal ventral incision and the intestinal tract, from the duodenum to the anus, was removed. The small intestine was slit lengthwise and placed into a vial of AFA (Humason, 1979) to preserve helminths. The cecum and colon were slit lengthwise and preserved, with their contents, in vials containing 2.5% aqueous (w/v) K2Cr207. Upon return to the laboratory all vials were refrigerated (4 C) until they could be processed and examined. Processing for oocysts consisted of separating fecal contents from cecal-colon tissue by scraping with a scalpel. The fecal-K2Cr207 mixture from each mouse was placed at 23 C for 7 days in a 15-cm Petri dish. Received 28 September 1981; revised 6 January 82, 24 May 1982; accepted 6 June 1982. It was then filtered through 40and 60-mesh brass screens and aliquots of the filtrate were examined by coverslip flotation with a concentrated sucrose solution (sp. gr. 1.15). Oocysts were measured with an ocular micrometer and photographed with either Panatomic-X or Ilford Pan F 35-mm film within a Zeiss Universal Photomicroscope equipped with both brightfield (Neofluar) and Nomarski-interference XI 00 objectives. All measurements are in ,um with the ranges in parentheses following the means.
TL;DR: Most of the fractions containing free parasites did not show contamination with erythrocyte constituents as determined by light and electron microscopy, polyacrylamide gel electrophoresis, and enzymatic analysis, but the various stages of free parasites of Plasmodium falciparum exhibited different electrical surface charges.
Abstract: Parasitized human erythrocytes were concentrated from continuous cultures of Plasmodium falciparum from 5-7% up to 80-95% using Plasmagel. After aggregation of the cells with phythemagglutinin, the aggregated erythrocytes were fragmented by passing them, with minimal force, through successive nylon filters of decreasing pore size (100 microns-3 microns). The mixture of liberated, free parasites, intact erythrocytes and erythrocyte membrane vesicles was separated using free-flow electrophoresis. Most of the fractions containing free parasites did not show contamination with erythrocyte constituents as determined by light and electron microscopy, polyacrylamide gel electrophoresis, and enzymatic analysis. In addition, the various stages of free parasites of Plasmodium falciparum exhibited different electrical surface charges. Rings and trophozoites were highly negatively charged whereas schizonts and, in particular, merozoites showed low negative charges. Thus, the various stages could be isolated separate from each other.
TL;DR: The hypothesis that North American species of Acanthocephalus interfere with the metabolic pathway for ommochrome pigmentation of isopod hosts is supported.
Abstract: Only small (4.0-5.0 mm) Asellus intermedius could be infected routinely with Acanthoceph- alus jacksoni in the laboratory. Acanthocephlus jacksoni required 90 days at 20 to 25 C to complete development. Thirty days after exposure to parasite eggs, infected isopods could be distinguished visually from uninfected, control isopods on the basis of altered pigmentation. Study of the development of normal integumental pigmentation of Lirceus garmani, L. lineatus, and As. intermedius showed that pigmentation becomes rapidly established during growth of isopods from approximately 2 to 5 mm in length. Suscep- tibility of isopods to infection at this critical time during ommochrome pigment production, and the (statistical) relationship of parasite growth to isopod growth during the 90 days of acanthocephalan de- velopment, support the hypothesis that North American species of Acanthocephalus interfere with the metabolic pathway for ommochrome pigmentation of isopod hosts.
TL;DR: In a highly responsive mouse strain (LAF1/J), larval stages were requisite in stimulation of host resistance to reinfection and a larval challenge was fully susceptible to the effects of that response.
Abstract: In the LAFi/J mouse strain, a single prior exposure to infective larvae of N. dubius given per os resulted in > 90% reduction of an homologous larval challenge; in contrast, a single larval sensitizing infection had no effect on adult worms introduced directly into the duodenum via laparotomy. The LAF,/J mice given a single sensitizing infection of adult worms via laparotomy did not exhibit resistance to homologous challenge of either infective larvae or adult worms. Because all sensitizing infections were removed chemotherapeutically before administration of challenge inocula, potential effects of "overcrowding" on establishment or development of challenge infections were precluded. Worm-specific antibody determinations indicated that adult worms introduced into the gut lumen did not prime the host for a secondary response to a challenge by larval or adult worms. However, a challenge with larvae of mice previously sensitized with an homologous larval infection, did stimulate an anamnestic antibody response. Collectively, the data indicated that in a highly responsive mouse strain (LAFI/J), larval stages were requisite in stimulation of host resistance to reinfection and a larval challenge was fully susceptible to the effects of that response. Mature adult worms apparently did not stimulate nor were they susceptible to the host's immune response.
TL;DR: Cattle subjected to two challenges with unrelated isolates of Trypanosoma congolense developed readily detectable neutralizing antibody to the metacyclic trypanosomes and when infected animals were treated with Berenil prior to rechallenge, they were fully susceptible to the infection.
Abstract: To examine the influence of an established infection on subsequent challenge with another unrelated trypanosome serodeme, cattle were subjected to two challe to 6 wk apart, with unrelated isolates of Trypanosoma congolense. The primary infection inhibited the establishment of the second infection despite the initial absence of detectable antibody to the trypanosomes used for the second challenge. This was true whether the second challenge consisted of bloodstream forms of the parasite or metacyclics from infected Glossina m. morsitans. Rechallenge with bloodstream forms resulted in a slight antibody response, which was only detectable by immunofluorescence and was much less than in the challenge controls. Although animals subjected to the second challenge by tsetse flies showed no appreciable increase in parasitemia and, in most instances, no chancre reaction at the site where the tsetse bit, they developed readily detectable neutralizing antibody to the metacyclic trypanosomes. That this interference effect was not the result of specific immunity and required an active infection was confirmed by the finding that when infected animals were treated with Berenil prior to rechallenge, they were fully susceptible to the infection.
TL;DR: Ponies receiving per os inoculations of L3 irradiated with 70 or 100 Kr were protected from the clinical disease and lesions associated with challenge infections of 4,300 L3, when compared to nonvaccinated controls.
Abstract: Nonimmune pony foals 9 to 12 mo of age were vaccinated with third-stage Strongylus vulgaris larvae (L3) irradiated with 70, 100, or 130 Kr of gamma radiation. Ponies receiving per os inoculations of L3 irradiated with 70 or 100 Kr were protected from the clinical disease and lesions associated with challenge infections of 4,300 L3, when compared to nonvaccinated controls. Similarly, the numbers of worms from the challenging population recovered from successfully vaccinated animals were significantly lower than from nonvaccinated controls. The degree of resistance that develops in individuals can be semiquantitated based on clinical and pathological responses.