The putative haemobartonella that influences Plasmodium falciparum parasitaemia in squirrel monkeys is a haemotrophic mycoplasma

Neimark, Harold; Barnaud, Antoine; Gounon, Pierre; Michel, Jean‐Claude; Contamin, Hugues

doi:10.1016/s1286-4579(02)01588-5

Cited by 40 publications

(26 citation statements)

References 21 publications

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“…Both scanning and transmission EM showed the presence of several short fibrils that formed bridges between cells and the erythrocyte surface (Figs 1 and 2); the origin of these fibrils and whether they have a function in attachment is currently not known. These fibrils are similar to fibrils observed in thin sections of mycoplasma-infected erythrocytes from squirrel monkeys (Saimiri sciureus) (Aikawa & Nussenzweig, 1972;Adams et al, 1984;Neimark et al, 2002a), pigs (Zachary & Basgall, 1985), an opossum (Messick et al, 2002), putative Haemobartonella-infected or Eperythrozoon-like-infected erythrocytes from an owl monkey (Aotus trivirgatus) (Peters et al, 1974) and cynomolgus monkeys (Macaca fascicularis) (Dillberger et al, 1994).…”

Section: Electron Microscopy (Em)supporting

confidence: 68%

Mycoplasma ovis comb. nov. (formerly Eperythrozoon ovis), an epierythrocytic agent of haemolytic anaemia in sheep and goats

Neimark

Hoff

Ganter³

2004

International Journal of Systematic and Evolutionary Microbiology

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102

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Eperythrozoon ovis, an erythrocytic agent that causes haemolytic anaemia in sheep and goats, occurs worldwide and is currently thought to be a rickettsia. To determine the relationship between this agent and other haemotrophic bacterial parasites, the 16S rRNA gene of this organism was sequenced. Phylogenetic analysis revealed that this wall-less bacterium is not a rickettsia, but a mycoplasma. This mycoplasma is related closely to several other uncultivated, epierythrocytic mycoplasmas that comprise a recently identified group, the haemotrophic mycoplasmas (haemoplasmas). The haemoplasma group is composed of former Eperythrozoon and Haemobartonella species, as well as newly identified epierythrocytic mycoplasmas. Haemoplasmas parasitize the surface of erythrocytes of a wide variety of vertebrate animal hosts and are transmitted mainly by blood-feeding arthropod vectors. Recognition that E. ovis is a mycoplasma provides a new approach to dealing with this bacterium. It is proposed that E. ovis should be reclassified as Mycoplasma ovis comb. nov.Eperythrozoon ovis is an uncultivated, wall-less bacterium that parasitizes the surface of sheep erythrocytes. This organism is transmitted by blood-feeding arthropods and parasitizes animals in sheep-rearing regions throughout the world. Signs of infection include mild to severe haemolytic anaemia, as well as icterus; animals may exhibit poor weight gain and depression, but death is rare in adults. Infections are frequently unapparent and chronic. E. ovis also infects goats, in which it results in more severe disease (Splitter et al., 1956;Kreier & Ristic, 1963;Daddow, 1979;Mason et al., 1989;Mason & Statham, 1991).As E. ovis has not been cultivated, diagnosis is made by detection of organisms on erythrocytes in Romanowskytype or acridine orange-stained blood smears and by serological methods. Parasitism of erythrocytes often occurs at a low level and is transient; detection requires examination of repeated blood smears. However, erythrocyte parasitaemia can be as high as 100 % in our experience; a high level of parasitaemia can occur even in subclinical infection and can persist for months (Overas, 1969;Brun-Hansen et al., 1997). E. ovis is completely resistant to penicillin and other antimicrobial agents that target the cell wall. Also, tetracycline treatment does not eliminate this agent from chronically infected animals. This organism has been thought to be a rickettsia because of its obligate parasitism, erythrocyte localization, small size, staining properties and transmission by arthropod vectors. E. ovis and a number of similar haemotrophic bacteria have been classified in the order Rickettsiales, family Anaplasmataceae, in the genera Haemobartonella and Eperythrozoon (Kreier & Ristic, 1984;Kreier et al., 1992). Recently, phylogenetic analysis of 16S rRNA gene sequences from four of these bacteria, Haemobartonella felis, Haemobartonella muris, Eperythrozoon suis and Eperythrozoon wenyonii, has demonstrated that these wallless bacteria are not rickettsiae, but tha...

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Section: Electron Microscopy (Em)supporting

confidence: 68%

Mycoplasma ovis comb. nov. (formerly Eperythrozoon ovis), an epierythrocytic agent of haemolytic anaemia in sheep and goats

Neimark

Hoff

Ganter³

2004

International Journal of Systematic and Evolutionary Microbiology

Self Cite

102

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“…The haemoparasites of M. arvalis comprised five species of which Haemobartonella sp. (more recently on the basis of molecular evidence reclassified as a mycoplasma; Neimark et al 2001Neimark et al , 2002 was clearly the dominant parasite because prevalence throughout the seasons and across all 4 years of the study was highest with this organism. Although infections with Haemobartonella sp.…”

Section: Discussionmentioning

confidence: 98%

Factors affecting the component community structure of haemoparasites in common voles ( Microtus arvalis ) from the Mazury Lake District region of Poland

Pawełczyk¹,

Bajer²,

Behnke

et al. 2004

Parasitology Research

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The prevalence and abundance of infections with haemoparasites were studied over a 4-year period in Microtus arvalis (common vole, n =321) sampled from fallow grassland sites in north-eastern Poland. Total species richness was five (prevalence= Haemobartonella sp. 63.9%, Bartonella spp. 27.7%, Babesia microti 9.0%, Trypanosoma sp. 8.4% and and Hepatozoon lavieri 3.1%) with 76.9% of the voles carrying at least one species and a mean infracommunity species richness of 1.1. Variation in species richness was determined primarily by season and year, the interaction of these factors, and that of year with host age. The observed frequency distribution of infracommunity species richness did not differ from that predicted by a null model, suggesting that there were no marked associations between the species. Analyses of prevalence and abundance of infection with each species in turn, revealed that overall the principal causes of variation were temporal and seasonal, their interaction, and interactions with intrinsic factors (age and sex), the latter playing only a minor role in their own right. However, the relative importance of these combinations varied and was distinct for each of the species in the study. Prevalence data revealed eight sets of two- and three-way associations between species, mostly dependent to some extent on one of the intrinsic and extrinsic factors in the model. Analysis of quantitative associations suggested two sets of positive two-way interactions, none of which remained after controlling for the effect of extrinsic and intrinsic factors on the abundance of each species. These data are discussed in the context of the changing ecological profiles in this region of Eastern Europe and, in a wider context, in relation to current understanding of the factors that shape component community structures of haemoparasites in wild rodents.

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“…Healthy and splenectomized animals are susceptible to infection (19); the intact ones are able to keep parasitemia at lower levels for several days as a nonlethal pattern, but they develop complications such as severe anemia. Splenectomized monkeys develop higher levels of parasitemia and die (2,27). The therapeutic time window for intact or splenectomized monkey models of P. falciparum (4,29) infection is 0.4 to 3 days, with an average of about 2 days.…”

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confidence: 99%

New Potential Antimalarial Agents: Therapeutic-Index Evaluation of Pyrroloquinazolinediamine and Its Prodrugs in a Rat Model of Severe Malaria

Xie

Lin

et al. 2006

Antimicrob Agents Chemother

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Tetra-acetamide pyrroloquinazolinediamine (PQD-A4) and bis-ethylcarbamyl pyrroloquinazolinediamine (PQD-BE) are new derivatives of pyrroloquinazolinediamine (PQD) and are being investigated as potential chemotherapeutic agents for the treatment of malaria. Comparative studies to assess the therapeutic indices of PQD-A4, PQD-BE, and PQD were conducted in Plasmodium berghei-infected rats following daily intragastric dosing for three consecutive days. Artesunate (AS), a standard drug for treatment of severe malaria, was used as a comparator. The minimum doses required to clear malaria parasitemia were 156 mol/kg of body weight for AS and 2.4 mol/kg for PQD, PQD-4A, and PQD-BE. The maximum tolerated dose (MTD) of AS was 625 mol/kg, and its therapeutic index was calculated to be 4. The MTDs of PQD-A4, PQD-BE, and PQD were found to be 190, 77, and 24 mol/kg, respectively, yielding therapeutic indices of 80, 32, and 10, respectively. Although PQD-A4 and PQD-BE are only half as potent as PQD based on their curative effects, the two new derivatives, PQD-4A and PQD-BE, are 8.0-fold and 3.2-fold safer, respectively, than their parent compound when they are dosed for three consecutive days. Oral PQD-A4 and PQD-BE are 44 to 70 times more potent on an mg basis than intravenous AS. As assessed from the therapeutic index over 3 days, PQD-A4, PQD-BE, and PQD administered orally are 20.0, 8.0, and 2.5 times safer than AS given intravenously. The results indicate that PQD-4A is a promising candidate for antimalarial treatment.

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The putative haemobartonella that influences Plasmodium falciparum parasitaemia in squirrel monkeys is a haemotrophic mycoplasma

Cited by 40 publications

References 21 publications

Mycoplasma ovis comb. nov. (formerly Eperythrozoon ovis), an epierythrocytic agent of haemolytic anaemia in sheep and goats

Mycoplasma ovis comb. nov. (formerly Eperythrozoon ovis), an epierythrocytic agent of haemolytic anaemia in sheep and goats

Factors affecting the component community structure of haemoparasites in common voles ( Microtus arvalis ) from the Mazury Lake District region of Poland

New Potential Antimalarial Agents: Therapeutic-Index Evaluation of Pyrroloquinazolinediamine and Its Prodrugs in a Rat Model of Severe Malaria

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