Plasmodium Lophurae Research Articles

Effect of drugs on the folic and folinic acid contents of erythrocytes infected with malaria parasites

Treatment with sulfadiazine prevented most of the increase in folic and folinic acid which otherwise occurred in the red blood cells of ducks infected with Plasmodium lophurae. The same effect was observed when a sulfadiazine-resistant strain of P. lophurae was treated with sulfadiazine at doses having no effect on the infection: the increase in folic and folinic acids was markedly less than that in untreated infections with the same strain. When the sulfadiazine-resistant strain was treated with pyrimethamine, to which it was also resistant, the increase in folinic acid was inhibited, but not that in folic acid. Each drug exerted its characteristic inhibitory effect on the folinic acid-synthesizing mechanism, yet the parasites of the resistant strain continued to multiply. This synthetic mechanism may reside in the infected red cells rather than in the parasites. The resistance to sulfadiazine and pyrimethamine appears to depend on a decreased requirement for the products of the reactions inhibited by these drugs.

The Role of the Cytoplasm during Reproduction in a Malarial Parasite (Plasmodium lophurae) as Revealed by Electron Microscopy*

An electron microscope study of Plasmodium lophurae maintained in vivo and in vitro provided information concerning the sequence of events during reproduction, and the role of the cytoplasm in this process.Contrary to the generally held opinion that nuclear fissions precede cytoplasmic division, it was found that the last nuclear fission takes place during advanced stages of cytoplasmic segmentation. This study also supplied evidence that in addition to repeated nuclear divisions, a number of changes occur in all major components of the cytoplasm. These changes are considered as preparatory for reproduction. The cytoplasm continues to be active during the formation of merozoites. At this stage a segregation of cytoplasmic components takes place resulting in the incorporation into the offspring of a condensed cytoplasm containing all the organelles. The watery part of the cytoplasm with the lipids and food vacuoles is withheld and at the end of reproduction forms the residual body, a separate structure bound by a membrane.

Ammonium Sulfate and Water Dialysis Fractionation of Chicken Serum as Studied by Paper Electrophoresis

PREVIOUS investigations employing the chemical fractionation of serum have presumably isolated immune factors for the avian malaria parasite, Plasmodium lophurae (Becker et al., 1951; Trager and McGhee, 1950; and Truong, 1957). Electorophoretic analysis has also identified serum alterations which appear to be linked to an immune response (Sherman and Hull, 1960). One of the logical adjuncts to the study of the serological changes described by paper electrophoresis is the isolation, purification and characterization of these entities, and correlation of the chemical fractions with the electrophoretic species. Studies of the chemical fractions by means of paper electrophoresis were initiated in the hope of better understanding the relationships between these fractionation procedures.MATERIALS AND METHODSFor the chemical fractionation, whole blood was withdrawn from the jugular vein of mature, uninfected Hyline chickens. These samples were incubated at 39°C. in lusteroid centrifuge tubes for one hour to assure maximum clot formation. They were …

An Auto-Immune Reaction Produced in Ducklings in Response to Injections of Duck Embryo Blood Infected with Plasmodium Lophurae

against noninfected as well as infected erythrocytes has occurred to several investigators (1,2, 3). In general, speculation was directed toward the associated disease of blackwater fever, which is characterized by massive hemagglutination and hemolysis of circulating red blood cells. Hypotheses, generally unsupported, have appeared in the literature and will be referred to more specifically where they pertain to the discussion of the foregoing experiments. Evidences of auto-immune responses in avian malaria infections are even

The Pigment (hemozoin) and Proteins of the Avian Malaria Parasite Plasmodium lophurae.*

SYNOPSIS.The use of saponin hemolysis, buffer washings and deoxyribonuclease yields quantities of erythrocyte‐free plasmodia sufficiently pure for physico‐chemical studies. The pigment produced by Plasmodium lophurae, unlike the pigments of the simian and human malarias, is of such low solubility in buffer solutions that urea is necessary as an additive to the buffer for adequate solubilization. On the basis of spectral and electrophoretic qualities, the pigment is a protein‐porphyrin complex closely resembling methemoglobin but clearly distinct from hematin. Extraction of the pigment in solvents which degrade hemoglobin, e.g. phenol, 0.1 N NaOH, cannot be used to ascertain the properties of hemozoin, for the pigment in such solvents shows a spectrum identical to hemoglobin.The soluble parasite proteins which constitute approximately 55% of the totaI volume of the parasite as revealed by electrophoretic and ultracentrifugal analysis appear to be homogeneous. They show a marked similarity to the host hemoglobin, but differ sufficiently to verify their integrity and individuality.

Blood loss and replacement in plasmodial infections. IV. Plasmodium gallinaceum and Plasmodium lophurae in untreated and prebled mature chickens and in untreated chicks.

Blood loss and replacement in plasmodial infections. IV. Plasmodium gallinaceum and Plasmodium lophurae in untreated and prebled mature chickens and in untreated chicks.

Serum Alterations in Avian Malaria*

SYNOPSIS.A study by means of paper electrophoresis of the scrum.proteins and lipoproteins during the course of infection of chicks with Plasmodium lophurae, reveals a qualitative change in the gamma‐globulin and demonstrates: a significant crisis period depression of the albumin; no alteration of the alpha‐globulin or alpha‐lipoprotein; a significant crisis period rise in the beta‐ and gamma‐g'obuiins with the former persisting in higher amounts well after the crisis of the infection. The significance of such changes with reference to previous work and the induced pathology is discussed.

Auto-antibody in rats with Plasmodium berghei.

IN human malaria it has long been recognized that total loss of blood is significantly more extensive than loss which can be attributed to the direct rupture of parasites emerging from infected erythrocytes1. In a comparative survey of loss of blood and replacement in plasmodial infections of other mammals and birds, excessive erythrocyte destruction of the same type has been observed in all except one of the host–parasite combinations studied to date, namely in rats with Plasmodium berghei 2, and Plasmodium vinckei 3, in rhesus monkeys with Plasmodium cynomolgi, Plasmodium gonderi, and Plasmodium knowlesi 4, and in chickens with Plasmodium lophurae (Zuckerman, A., unpublished results).

The enhanced folic and folinic acid contents of erythrocytes infected with malaria parasites

Folic and folinic acids were determined, by microbiological assay, in the washed erythrocytes of normal 2-month-old ducks and of similar ducks infected with Plasmodium lophurae, as well as in suspensions of the parasites free from their host cells. Whereas normal red cells contained about 1 mμg per ml of each of the growth factors, the infected red cells contained 20 to 60 mμg per ml of folic acid and 10 to 20 mμg per ml of folinic acid (expressed as leucovorin). It was calculated that an infected erythrocyte contained about 12 × 10 −9 mμg folic acid and 2 to 4 × 10 −9 mμg leucovorin, of which only 2 to 4 × 10 −9 mμg of folic acid and 0.5 to 1.5 × 10 −9 mμg of leucovorin were contained in the malarial parasite itself. Presumably the remainder of the increased folic and folinic acids was in the infected erythrocyte, so that it seems likely that the metabolism of the host cell with respect to these two growth factors was altered by the presence of the parasite.

Folinic acid and non-dialyzable materials in the nutrition of malaria parasites.

The extracellular survival of the malaria parasite Plasmodium lophurae was favored on the 4th day of incubation in vitro by the presence in the medium of added folinic acid at a concentration of about 5 microg. per ml. The development of the human malaria parasite P. falciparum intracellularly in suspensions of human erythrocytes was better in a medium with a high than in one with a low concentration of folic acid. In the early extracellular development of P. lophurae in vitro erythrocyte extract could be partially replaced by certain yeast protein preparations and by a non-dialyzable fraction, free from hemoglobin, prepared from duck erythrocyte extract by means of starch electrophoresis.

Intracellular phagotrophy by malaria parasites: an electron microscope study of Plasmodium lophurae*

SUMMARY. An electron microscope study of thin sections of duck erythrocytes infected with Plasmodium lophurae revealed that the so‐called “residual body” is a food vacuole formed by invagination from the cytoplasm of the host cell. Several such food vacuoles may exist in a single parasite. Digestion of hemoglobin evidently proceeds only within these food vacuoles, since they are the only place in the parasite where the characteristic malarial pigment granules may be found. This finding changes the role ascribed to the residual body and gives a new concept of the feeding mechanisms in P. lophurae and other malaria parasites. The cytoplasm of the host is taken in by the parasite by phagotrophy and not only as previously assumed, by diffusion.The fine structure of P. lophurae shows all major components found in other protozoan and metazoan cells. Some of the organelles appear to have a much simpler structure connected probably with the highly specialized intracellular parasitic life.

Host Resistance and Regulation of the Development of Plasmodium lophurae in Pheasants, Coots and Domestic Pigeons

To know the nature of a parasite one must study it under all conditions compatible with its development. Plasmodia are related to their hosts in a highly specialized manner, and their mode of reproduction enables one to study quantitatively certain fundamental aspects of their behavior in all possible host-parasite combinations. This problem of biological inter-relations was undertaken to determine the effects of various hosts upon the course of development of P. lophurae as reflected by: (1) the rate of reproduction; (2) the course and intensity of parasitemia; (3) the destruction and survival of parasites; and (4) the percentage frequency of merozoite groups. Plasmodium lophurae (Coggeshall, 1938) is capable of reproducing in diverse avian hosts. Indeed, its hosts have lately been extended to include mice (McGhee, 1951). This indicates an unusual adaptability of the schizogonous cycle; therefore it is not surprising that it displays little avian host specificity. Considerable work has been done on various aspects of the biology and morphology of P. lophutrae but detailed studies of the asexual cycle have been carried out using ducks and chickens as hosts.

The Effect of Azaserine against Plasmodium lophurae in Chicks and Attempts to Antagonize This Effect with Metabolites

N2CH-C-O-CH2-CH-COOH I I I 0 NH2 O-diazoacetyl-1-serine It is an amino acid analog, has antitumor activity (Sugiura and Stock, 1955), acts as an antimetabolite with certain microorganisms in vitro (Kaplan and Stock, 1954), and has suppressive activity in avian malaria (Coffey et al, 1954). These facts encouraged further study of the antimalarial activity of azaserine and suggested that the testing of various metabolites for ability to antagonize its activity in vivo might yield useful information on the physiology of the plasmodia and biological activity of the drug. The results of such work are reported here.

An Antimalarial Effect in vitro of Parapyruvic Acid

When the erythrocytic forms of Plasmodium lophurae were maintained extracellularly in vitro the addition of parapyruvate at concentrations down to 25 μg per ml increased the proportion of degenerate parasites present after one day's incubation. In cultures with intracellular parasites in suspensions of intact duck erythrocytes, the addition of the parapyruvate at concentrations down to 8 μg per ml decreased sharply the numbers of parasites present after two days' incubation. Somewhat higher concentrations also interfered with the reinvasion of erythrocytes by merozoites formed in such cultures. No antimalarial effect was observed when the compound was administered intravenously to ducklings infected with P. lophurae

Some Physiological Aspects and Consequences of Parasitism

This little book contains six papers presented at the eleventh annual conference on protein metabolism of the Bureau of Biological Research at Rutgers University. There is a foreword by Cole and introductory remarks by Leslie A. Stauber calling attention to the growing interest in problems of the interactions of hosts and parasites, and of their mutual physiological modifications.In the first paper William Trager discusses “Studies on the Cultivation of Malaria Parasites.” It has been possible to support development of Plasmodium lophurae extracellularly for several days and to study some of its nutritional requirements independent of the host. In the second paper James W. Moulder discusses “The Protein Metabolism of Intracellular Parasites,” and compares the metabolism of bacteriophages, rickettsias and malaria parasites, with special reference to the relative metabolic contributions of host and parasite.

Effect of Indian ink on Plasmodium berghei infections in mice.

INJECTIONS of Indian ink, causing so-called ‘blockade’ of the reticulo-endothelial system, have, in the past, been classified with splenectomy and cortisone as agents calculated to lower the resistance of host animals to plasmodial infections. For example, Trager1, working with chickens infected with Plasmodium lophurae, found that indian ink usually caused the development of heavy parasitæmias in the birds receiving it.

Reactions of the connective tissue in chickens to Plasmodium gallinaceum and Plasmodium lophurae. I. Histopathology during initial infections and superinfections.

Journal Article Reactions of the Connective Tissue in Chickens to Plasmodium Gallinaceum and Plasmodium Lophurae I. Histopathology during Initial Infections and Superinfections Get access William H. Taliaferro, William H. Taliaferro From the Department of Microbiology, The University of Chicago, Chicago 37, Illinois Search for other works by this author on: Oxford Academic PubMed Google Scholar Lucy Graves Taliaferro Lucy Graves Taliaferro From the Department of Microbiology, The University of Chicago, Chicago 37, Illinois Search for other works by this author on: Oxford Academic PubMed Google Scholar The Journal of Infectious Diseases, Volume 97, Issue 2, September 1955, Pages 99–139, https://doi.org/10.1093/infdis/97.2.99 Published: 01 September 1955 Article history Received: 21 December 1954 Published: 01 September 1955

Reactions of the connective tissue in chickens to Plasmodium gallinaceum and Plasmodium lophurae. II. Glucose metabolism during initial infections.

Reactions of the connective tissue in chickens to Plasmodium gallinaceum and Plasmodium lophurae. II. Glucose metabolism during initial infections.

Coenzyme A and the Malaria Parasite Plasmodium lophurae

The extracellular development of Plasmodium lophurae in vitro was favored by the addition, to the erythrocyte‐extract medium, of a coenzyme A (CoA) preparation of about 75% purity. The effect of CoA was the same regardless of the concentration of free pantothenate in the medium, indicating that the parasites require the complete coenzyme rather than its pantothenic acid moiety. Erythrocyte extracts were found to contain enzymes which hydrolyzed added CoA at a rate such that 8 units per ml. of coenzyme was only slightly destroyed after 3 hours’incubation but almost completely destroyed after 18 hours’incubation at 40°C. The CoA content of erythrocytes from chickens or ducks heavily infected with P. lophurae was about twice as high as that of erythrocytes from uninfected birds. The increased CoA was associated with the parasites, an observation suggesting that malaria parasites can accumulate this essential growth factor which they cannot synthesize. The CoA concentration in the livers of infected chickens was approximately 40% lower than that in the livers of control chickens. The livers of ducks on the 6th day of infection had a slightly lower CoA concentration than those of uninfected ducks. This depletion in CoA, together with the depletion in biotin previously demonstrated in P. lophurae infection, may play a role in the pathology of this infection.

The Infection of Duck and Goose Erythrocytes by the Mammalian Malaria Parasite, Plasmodium berghei

The infection of mice and baby rats by both Plasmodium lophurae, an avian parasite, and Plasmodium berghei, a mammalian malaria parasite, prompted investigation of the likelihood of P. berghei infecting avian erythrocytes. Though erythrocytes of chick embryos were not infected, those of the goose and duck embryos were. In both these cells the morphology of the parasite was markedly different from that seen in mammalian erythrocytes. Infections were transitory and it was impossible to find parasites after 4 days. Examination of the hosts of both species of parasites showed a rather wide range and examination of the susceptibility of the duck erythrocyte indicated that this cell was peculiarly receptive to infection by a variety of plasmodia.