Showing papers in "Journal of Parasitology in 1975"
380 citations
TL;DR: Part 1 Arthropods: insects ticks mites, Protozoans: flagellates and amoebas cocidians hemosporidians, and Diagnostic parasitology: antemortem diagnosis postmortem diagnosis histopathological diagnosis.
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TL;DR: Studies were done on the development of infectivity during ontogeny of the sporozoite of the rodent malaria parasite, Plasmodium berghei, and indicated that populations of salivary gland sporozoites were more than 10,000 times as infective as populations of oocyst sporzoites from the same mosquitoes.
Abstract: Studies were done on the development of infectivity during ontogeny of the sporozoite of the rodent malaria parasite, Plasmodium berghei. Populations of sporozoites were separated from the oocysts, the hemocoel, and the salivary glands, with special precautions being taken to avoid cross-contamination between the different populations. The results indicated that populations of salivary gland sporozoites were more than 10,000 times as infective as populations of oocyst sporozoites from the same mosquitoes. The development of this infectivity appears to be asynchronous, in some cases taking place in the hemocoel, while in other cases not occurring until after the sporozoites have invaded the salivary glands. Thus, the development of infectivity seems to be time-dependent rather than site-dependent. There is also a continued increase in sporozoite infectivity during their residence in the salivary gland. The development of infectivity may be associated with other aspects of sporozoite maturation, including changes in their antigenicity and motility.
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TL;DR: The effect of in vivo treatment with mebendazole on the ultrastructural morphology of Ascaris suum intestine was investigated and it was revealed that the accumulated secretory granules in the Golgi area contained glycoproteins or polysaccharides.
Abstract: The effect of in vivo treatment with mebendazole on the ultrastructural morphology of Ascaris suum intestine was investigated. Pigs, infected with A. suum, were fed ad libitum a medicated food containing mebendazole at a concentration of 30 ppm. Control and treated animals were killed 6, 9, 15, and 24 hr after the onset of feeding. The parasites were quickly collected from the pig intestinal tract and prepared for ultrastructural and cytochemical examination. Absence of secretory granules in the terminal web, accumulation of secretory granules in the Golgi region, formation of autophagic vacuoles in the apical cell part, and loss of glycogen were the characteristic changes observed after 6 and 9 hr of treatment. Degenerative changes were very pronounced after 15 and 24 hr and involved almost the entire cytoplasm. Microvilli were decreased in number and appeared swollen in the majority of absorptive cells. Some more severely altered cells were completely devoid of microvilli. Cytochemistry revealed that the accumulated secretory granules in the Golgi area contained glycoproteins or polysaccharides. Microvilli, lysosomes, and Golgi apparatus were reactive for acid phosphatase in the control intestinal cells. After treatment, the enzyme activity was localized in numerous autophagic vacuoles, whereas the secretory granules remained unstained. The acid phosphatase activity in the microvilli decreased or was completely absent. The possible significance of these modifications in view of mebendazole's anthelmintic activity is discussed.
112 citations
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TL;DR: Throughout the entire life of the fluke the spines anterior to the ventral sucker are arranged in approximately 60 rings each of 60 to 70 spines, but just prior to entry into the bile ducts, all spines have metamorphosed from single pointed to multipointed forms by division at the spine tips.
Abstract: Throughout the entire life of the fluke the spines anterior to the ventral sucker are arranged in approximately 60 rings each of 60 to 70 spines. The spines on the posterior body are scattered without any pattern of rings and by 1 week post infection (p.i.) their numbers have doubled (from 3,000 on the newly excysted juvenile) to 6,000 and by 3 weeks p.i. their numbers have multiplied by 8 to 24,000. Just prior to entry into the bile ducts, between 2 and 3 weeks p.i., all spines, anterior and posterior, have metamorphosed from single pointed to multipointed forms by division at the spine tips. Spines on the anterior body of mature flukes recovered from the bile ducts of mice 26 weeks p.i. have between 10 and 15 points whereas those on the posterior body have up to 30 points. The tegument forms a rectangular pattern of plateaux and valleys around each spine on the posterior body of mature flukes but this pattern is not present on the anterior body.
83 citations
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TL;DR: Three types of presumed sensory endings were distinguished by scanning electron microscopy: a ciliated type, a domed type, and a pit, which had a ciliary basal body and rootlet but it lacked a cilium.
Abstract: Three types of presumed sensory endings were distinguished by scanning electron microscopy: a ciliated type, a domed type, and a pit. The ciliated and domed type were also serially sectioned for transmission electron microscopy. Six of the pit type were observed, a group of 3 on each side of the oral sucker. The ciliated type were found only among the tegumental spines, and on the anterior ventrolateral surfaces except for an anterodorsal pair. The domed type resembled the ciliated type in that it had a ciliary basal body and rootlet but it lacked a cilium. It was found only in the tegument above the suckers where it probably serves as a pressure or contact receptor. Movement in vitro occurred by alternate attachment and release of the suckers with a vermiform peristalsis and the rings of spines between the suckers were considered to aid this movement in vivo.
TL;DR: The results suggest that terminal ligands similar or identical withalpha-D mannose, alpha-D glucose, and alpha- D galactose are present in the surface membrane of L. braziliensis.
Abstract: The infective stages of Leishmania braziliensis, amastigotes and promastigotes subcultured a limited number of times, were agglutinated by Ricinus communis agglutinin and Concanavalin A. These results suggest that terminal ligands similar or identical with alpha-D mannose, alpha-D glucose (specific receptors for Con A), and alpha-D galactose (specific receptor for RCA) are present in the surface membrane of L. braziliensis. Noninfective promastigotes from the same stock, but subcultured approximately 500 times, were not agglutinated by RCA suggesting either the absence of the alpha-D galactose groups in the surface membrane or their presence in a very reduced number. Agglutination with soybean agglutinin, wheat germ agglutinin, or phytohemagglutinin P was not observed in any of the L. braziliensis forms tested. The difference in polysaccharide residues on the surface membrane of L. braziliensis may be related to the different pathogenic properties of the cell.
TL;DR: The absorption kinetics of some 14-C-labeled simple sugards in adults of Schistosoma mansoni are described, and the nature of sugar transport in schistosomes and other flatworms is similar to that in vertebrates.
Abstract: The absorption kinetics of some 14-C-labeled simple sugards in adults of Schistosoma mansoni are described. The influx of fructose and 3-0-methylglucose was by diffusion alone, while glucose, 2-deoxyglucose (2DOG), galactose, glucosamine, and mannose were absorbed by mediated transport as well as by diffusion. Although absorbed glucose was rapidly metabolized, uptake rates of radio-glucose in 2-min incubations corresponded with the amount of glucose (determined chemically) removed from the incubation medium. In 30-min incubations 2DOG was slowly metabolized and accumulated against an apparent concentration difference. The mediated transport of glucose and 2DOG was inhibited in Na+-free media, and by the presence of ouabain, phlorizin, phloretin, and other sugars. Accordingly, influxes of glucose of 2DOG and 22-Na+ were coupled. On a per mg protein basis, female worms transported more 2DOG and glucose, but less glycine, than did males. However, the rate of glucose metabolism by male and female worms incubated together was greater than that of either males or females incubated separately. The nature of sugar transport in schistosomes and other flatworms is similar to that in vertebrates.
TL;DR: Evidence is presented showing that the subcuticular region of the lateral chords of the adult subperiodic Brugia malayi comprises a functional complex of basal infoldings, multivesicular bodies, and associated mitochondria, which is probably engaged in the exchange of solutes across a permeable cuticle.
Abstract: The ultrastruct of the adult subperiodic Brugia malayi (Brug, 1927) within pulmonary arteries of male jirds (Meriones unguiculatus) was studied by transmission electron microscopy. The cuticle consists of 10 sublayers (2 of which are prominently banded) and a typical outer unit membrane. Evidence is presented showing that the subcuticular region of the lateral chords comprises a functional complex of basal infoldings, multivesicular bodies, and associated mitochondria, which is probably engaged in the exchange of solutes across a permeable cuticle. Microbodies with paired, prominent cores, intracisternal A-particle viruslike bodies, nonstaining glycogen patches, and other structures are also present in the lateral chords. The platymyarian somatic musculature shares some coelomyarian characteristics, e.g., apparent neuromuscular connections and prominent glycogen deposits surrounded by mitochondria and other organelles. The alimentary tract has features typical of many nematodes. The luminal segments of the male and female reproductive tracts and their germinal products, excluding microfilariae, are described. Affinities with related species are discussed.
TL;DR: A key is presented for the identification of invasive fish ciliates: Chilodonella, Hemiophrys, Ichthyophthirius, Ophryoglena, and Tetrahymena.
Abstract: Tetrahymena corlissi, a free-living protozoan, apparently caused the death of large number of guppies (Poecilia reticulatus) and occasionally other fishes, in aquaria and hatcheries at several locations. Apparently the disease occurs when the fish and protozoan populations are both at a high level of density. The signs include white spots and epidermal damage. Histologically, T. corlissi could be seen in skin, muscle, and viscera; in some there was marked inflammation, in others there was little tissue reaction. A key is presented for the identification of invasive fish ciliates: Chilodonella, Hemiophrys, Ichthyophthirius, Ophryoglena, and Tetrahymena.
TL;DR: Experiments established that differentiation did not depend upon changes in the external environment after amebase were transferred to encystation medium and, therefore, was initiated by the shift from growth to enCystation medium.
Abstract: Nutritional and culturing requirements for efficient axenic encystation of Entamoeba invadens have been studied. A simple and reliable axenic encystation medium has been developed. It contains 0.5% tryptic digest of casein, 0.5% yeast extract, and 5% dialyzed serum in 5 mM potassium phosphate, pH 7.0. Mass encystation (avg 70%) occurred within 30 hr when axenically growing trophozoites of E. invadens IP-l were transferred to this medium before they entered stationary growth phase. Mass encystation of E. invadens PZ occurred similarly, but less reproducibly. Two E. histolytica strains did not encyst. Experiments established that differentiation did not depend upon changes in the external environment after amebase were transferred to encystation medium and, therefore, was initiated by the shift from growth to encystation medium.
TL;DR: The morphology of tegumental, muscular, flame, duct, and glycogen-containing cells and cells containing lysosomal-like bodies is described and the significance of these findings is discussed in terms of the possible function of these structures and present knowledge on the penetration of macromolecules into hydatid cysts.
Abstract: The ultrastructure of the hydatid cyst germinal membrane was studied. It was divided into 3 regions, the tegument, the tegumental cell region, and the innermost area bordering the cyst cavity. The morphology of tegumental, muscular, flame, duct, and glycogen-containing cells and cells containing lysosomal-like bodies is described. The significance of these findings is discussed in terms of the possible function of these structures and present knowledge on the penetration of macromolecules into hydatid cysts.
TL;DR: The progressive micromorphological changes in Taenia taeniaeformis cysticerci, induced by a single parenteral treatment of the infected mice with mebendazole, are described, including disappearance of microtubules, accumulation of secretory substances in the Golgi areas, decrease in number to complete loss of microtriches, and necrosis of the pseudoproglottids.
Abstract: The progressive micromorphological changes in Taenia taeniaeformis cysticerci, induced by a single parenteral treatment of the infected mice with mebendazole, are described. The time-related alterations concerned the tegument and tegumental cells and were successively: disappearance of microtubules, accumulation of secretory substances in the Golgi areas, decrease in number to complete loss of microtriches, "ballooning" of all tegumental cells with subsequent burst, vacuolization and degeneration of the tegument, and finally necrosis of the pseudoproglottids. Similar but less pronounced injuries were seen in the scolices, although microtubules disappeared as early as in the pseudoproglottids. Microtubules from the host tissues remained intact. The meaning of the apparent primary interference of mebendazole with the microtubular system in relation to the subsequently observed death of the cysticercoids is discussed.
TL;DR: It remains to be determined whether oxidative metabolism actually is required for energy to produce eggs, or whether some reaction yielding no ATP is essential for completion of their developmental process, such as tanning of the eggshall brought about by the oxidation of some phenolic compounds.
Abstract: When S. mansoni adults were cultured in vitro for 12 days in a diphasic medium, their gross morphology, motor activity, frequency of sexual pairings, rates of glucose utilization and of lactic acid production were the same in the presence (90% N2/5% O2/5% CO2) or absence (95% N2/5% CO2) of oxygen. Therefore, no Pasteur effect, nor any reduction in lactic acid formation, was demonstrable under aerobic conditions. While aerobic conditions did not affect the rate of glycolysis, they had a marked effect on egg production. In the presence of oxygen, the rate of egg-laying reached a maximum between days 4 and 6. The average number of viable eggs produced per worm pair during this period was 118 (Sx equals 2.2), which is within the overall range (68 to 248) recorded by others for this same strain in vivo. Conversely, under anaerobic conditions in vitro, virtually no eggs were laid. It remains to be determined whether oxidative metabolism actually is required for energy to produce eggs, or whether some reaction yielding no ATP is essential for completion of their developmental process, such as tanning of the eggshall brought about by the oxidation of some phenolic compounds.
TL;DR: The results indicated that the 2 major genera of nematodes present (Ostertagia and Cooperia) were significantly reduced in number by dung beetle activity.
Abstract: Parasitized steers were used to contaminate 3 pastures containing dung beetle populations of different densities. Six parasite-free calves were then allowed to graze the pastures for 43 to 45 days. Two calves that grazed a pasture with dung beetle population rendered lower than normal by screening and trapping acquired 9 times more parasites than 2 calves that grazed a pasture which captured beetles were released. Two calves that grazed a pasture with a natural dung beetle population acquired 4 times more worms than the calves on pasture with the increased beetle population. The results indicated that the 2 major genera of nematodes present (Ostertagia and Cooperia) were significantly reduced in number by dung beetle activity.
TL;DR: The uptake of purines and pyrimidines by adults of Schistosoma mansoni was studied and results of inhibitor studies suggest the presence of 5 distinct transport sites for these latter compounds.
Abstract: The uptake of purines and pyrimidines by adults of Schistosoma mansoni was studied. Cytosine, thymine, and uracil entered the worms entirely by diffusion. Adenine, guanine, hypoxanthine, and the nucleosides adenosine and uridine were absorbed in part by mediated systems. The results of inhibitor studies suggest the presence of 5 distinct transport sites for these latter compounds. The interaction of adenosine monophosphate with these sites was also studied.
TL;DR: In the Eastern Cape Province of South Africa, larvae and nymphs of Ablyomma marmoreum Koch occur in habitats in which there is tree cover and herbaceous ground cover, and the rate of feeding is temperature-dependent.
Abstract: In the Eastern Cape Province of South Africa, larvae and nymphs of Ablyomma marmoreum Koch occur in habitats in which there is tree cover and herbaceous ground cover. Immatures of A. marmoreum are parasitic on reptiles, birds, and mammals. Adults occur only on reptiles. The major host for all stages is the moutain tortoise (Geochelone pardalis), and in the home areas of tortoises the density of ticks is high. Larvae are active in late summer and autumn. The rate of feeding is temperature-dependent, and some larvae which attach on tortoises in late autumn do not complete feeding until the following spring. Nymphs which occur in the home area of a tortoise become active in response to CO2 in early spring. Adults, and nymphs which occur outside the home area of a tortoise, become active in summer in response to rising temperatures. In nymphs which feed in spring, and hence develop into adults in midsummer, the life cycle is completed in 1 year. In nymphs which fed in midsummer, the life cycle is completed in 2 years.
TL;DR: The results suggest that, in metacestode infections of medical importance, it may be possible to kill the parasite by delivering a drug to its immediate vicinity, and so to reduce the required dosage with respect to the host.
Abstract: In mice infected with metacestodes of Taenia crassiceps, the following compounds were at least partially effective when injected intraperitoneally at the dosage indicated: cambendazole (500 mg/kg), mebendazole (6.25 mg/kg), oxibendazole (500 mg/kg), 5-benzamido-2(4-thiazolyl)benzimidazole (500 mg/kg), 2-carboethoxyamino benzimidazole (125 mg/kg), and 2-carbomethoxyamino benzimidazole (500 mg/kg). The following were inactive at the dosage indicated: parbendazole (500 mg/kg), thiabendazole (1,000 mg/kg), and fenbendazole (1,000 mg/kg). Mebendazole, which showed some activity at 6.25 mg/kg, was highly active as a single intraperitoneal dose at 25 mg/kg. When injected subcutaneously, mebendazole was much less active than when given intraperitoneally. In mice infected with metacestodes of Echinococcus multilocularis, intraperitoneal injection of mebendazole at 75 to 150 mg/kg, daily for 3 days, was highly effective (95 to 100% reduction in cyst mass). In contrast, oral administration at 1,000 mg/kg, daily for 3 days, was only partially effective. The drug was also effective when given intraperitoneally to infected cotton rats. A water-soluble benzimidazole, carboxymethyleneamino cambendazole, was approximately 50% effective in mice when injected daily for 3 days at a dosage of 75 or 150 mg/kg. The results suggest that, in metacestode infections of medical importance, it may be possible to kill the parasite by delivering a drug to its immediate vicinity, and so to reduce the required dosage with respect to the host.
TL;DR: Old World monkeys inoculated intrathecally succumed to acutely fatal meningoencephalitis, while the other 7 survived with no obvious permanent brain damage and appeared to be influenced by the strain virulence, growth phase, and cultural condition of the amebae, as well as age, immune competence, and other as yet unknown host factors.
Abstract: Studies were conducted on 27 Old World monkeys to determine their susceptibility to pathogenic strains (HB-1 and C-66) of Naegleria fowleri by intranasal, intravenous, or intrathecal inoculation of trophozoites. No clinically detectable disease resulted from either intranasal or intravenous inoculation, but 11 of 18 monkeys inoculated intrathecally succumed to acutely fatal meningoencephalitis, while the other 7 survived with no obvious permanent brain damage. Pathogenicity of N. fowleri appeared to be influenced by the strain virulence, growth phase, and cultural condition of the amebae, as well as age, immune competence, and other as yet unknown host factors.
TL;DR: Rhesus monkey kidney cell cultures were inoculated with Toxoplasma gondii organisms obtained from peritoneal fluid of mice infected with the RH strain and pyrimethamine and sulfadiazine were added either singly or in combination to the cultures 4 hr after inoculation indicating a synergistic action of the 2 drugs.
Abstract: Rhesus monkey kidney cell cultures were inoculated with Toxoplasma gondii organisms obtained from peritoneal fluid of mice infected with the RH strain. Pyrimethamine and sulfadiazine were added either singly or in combination to the cultures 4 hr after inoculation. Twenty-four hours later the effect of the drugs on the parasites were studied by light and electron microscopy. Pyrimethamine (1.0 mug/ml) inhibited multiplication of the parasites and caused striking morphological changes. Organisms were rounded and often had a fragmented nucleus. Division was inhibited as indicated by abnormal daughter membrane formation during endodyogeny. No effect was evident in sulfadiazine-treated parasites when concentrations up to 50 mug/ml were used. However, combination of ineffective levels of pyrimethamine (0.1 mug/ml) and sulfadiazine (0.5 mug/ml) produced effects similar to those seen at a higher concentration of pyrimethamine indicating a synergistic action of the 2 drugs.
TL;DR: Both the inbred and outbred strains given multiple oral infections developed a protection response similar to that strain's response following parenteral vaccination, and the specificity of this protection was demonstrated using various complex foreign antigens.
Abstract: Strains of outbred (ICR/CD1 and S--W) and inbred (BALB/C and C57BL/6) mice vaccinated subcutaneously (SQ) with 500, 1,000, or 2,000 exsheathed Heligmosomoides polygyrus larvae developed varying levels of protection upon subsequent oral challenge with larvae. In contrast, the inbred C3H/HEJ strain failed to develop protection at any dosage level tested. ICR/CD1 mice vaccinated intraperitoneally with exsheathed larvae developed a high level of resistance but exhibited extensive adhesions of the viscera. When ensheathed larvae were used for vaccination, ICR/CD1 mice developed a moderate level of protection; but 1% of the vaccine dose was recovered in the intestine as adult stages. Both the inbred and outbred strains given multiple oral infections developed a protection response similar to that strain's response following parenteral vaccination. The specificity of this protection was demonstrated using various complex foreign antigens. In contrast, the self-cure response was observed only in the S--W strain.
TL;DR: Evidence is presented suggesting that fluctuations of environmental parameters may disrupt the timing of transmission and alter the distribution and abundance of the parasite, and the magnitude of such changes in parasite abundance may be related to the complexity of the host-parasite system.
Abstract: The distribution and abundance of the nematode Camallanus oxycephalus infecting white bass, Morone chrysops, in western Lake Erie was studied for over 2 years. Infection was generally more frequent and of higher intensity in large fish. The frequency distributions of nematode abundance in all segments of the fish population followed the negative binomial distribution. The data show seasonal cycles in population structure, site selection, intensity of infection, maturation, and reproduction. Infection occurs during July and August with a resulting peak in population density; during late summer and autumn, mortality, probably density-dependent, reduces the population by 30 to 60%; surviving worms are eliminated at 1 year of age. Growth and development of female worms is arrested from November to April, then proceeds at a rapid rate until the worms release their larvae and die. This growth pattern is probably related to temperature but may also involve host hormone cycles. The dispersal period of the nematode coincides with the annual maximum density of the intermediate host, a cyclopoid copepod,and is interpreted as an adaptation which increases the probability of successful transmission. Because the number of larvae produced by each female worm is a function of body volume, natural selection has favored rapid spring growth and attainment of large body size relative to the male worm. Both seasonal timing in the life cycle and the number of larvae produced are important factors in determining the abundance of this and perhaps other parasites. Evidence is presented suggesting that fluctuations of environmental parameters may disrupt the timing of transmission and alter the distribution and abundance of the parasite. It is hypothesized that the magnitude of such changes in parasite abundance may be related to the complexity of the host-parasite system.
TL;DR: The morphological data that T. cervi is distinct from T. theileri is supported and is differentiated on morphological grounds from the cosmopolitan bovine species, T. ingens and T. mazamarum.
Abstract: Trypanosoma cervi sp. n. is described from 22 trypomastigote syntypes from the blood of elk, Cervus canadensis, in North America (type locality: Wyoming). The blood trypomatigotes of T. cervi are compared with various culture forms: epimastigotes in 22 to 25 C NNN cultures; trypomastigotes in 37 C NNN cultures; and trypomastigotes from CAM chick embryo (10-day) cultures. Trypanosoma cervi is differentiated on morphological grounds from the cosmopolitan bovine species, T. theileri, and from T. ingens and T. mazamarum. Transmission of T. cervi to cattle was attempted using infected elk blood. No trypanosomal stages were recovered when recipients were examined by blood culture. The findings support the morphological data that T. cervi is distinct from T. theileri.