Lipid Metabolism of the Rickettsialike Microorganism Wolbachia Persica: II. Studies with Labeled Nonlipid Substrates

Neptune, E. M.; Weiss, Erik D.; Davies, John

doi:10.1093/infdis/114.1.45

Cited by 3 publications

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“…Proc., p. 116-117, 1965). The same is true of Wolbachia persica (16), which is an obligate intracellular parasite, but has a very active independent metabolism (13,20). Glutamate may well be an important metabolite for a number of obligate intracellular parasites, but similarities between the metabolisms of chlamydiae and rickettsiae are only superficial.…”

Section: Discussionmentioning

confidence: 99%

Transaminase Activity and Other Enzymatic Reactions Involving Pyruvate and Glutamate in Chlamydia (Psittacosis-Trachoma Group)

Weiss

1967

J Bacteriol

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The agents of meningopneumonitis (MN) and of trachoma (TR) purified from chick embryo allantoic fluids and yolk sacs, respectively, were shown to produce CO2 from the Cl positions of pyruvate and glutamate, but not from the other carbon atoms. The reaction with pyruvate did not require the addition of cofactors, but was stimulated to a small extent by a-lipoic acid and, in the case of TR, also by diphosphothiamine, and nicotinamide adenine dinucleotide (NAD). The reaction of MN with glutamate was greatly stimulated by the addition of NAD and pyruvate, and resulted in the accumulation of alanine. The reaction of TR with glutamate was also greatly enhanced by added NAD, but was not affected by added pyruvate. When eight intermediates of the citric acid cycle were added to MN cells incubated with glutamate-C14, plus NAD and pyruvate, they reduced to varying degrees the evolution of C'402. It was shown by chromatography that the C14 label extended to a-ketoglutarate and succinate, but not to fumarate and malate. A net gain in adenosine triphosphate could not be demonstrated in MN cells incubated with combined glutamate, pyruvate, oxaloacetate, and various cofactors. These results furnish additional examples of real or apparent gaps in enzyme sequences in Chlamydia. Previous work from this laboratory (18, 19) has shown that purified suspensions of members of the genus Chlamydia [psittacosis-trachoma group (14)] degraded glucose with production of CO2 and pyruvate. This reaction had cofactor and other requirements that were highly unusual for intact microorganisms. For example, the addition of stoichiometric amounts of adenosine triphosphate (ATP) relative to glucose was required for the liberation of CO2 from the Cl position, and the reaction was greatly enhanced by the addition of stoichiometric amounts of nicotinamide adenine dinucleotide phosphate (NADP). The requirement for ATP was eliminated when glucose-6-phosphate was substituted for glucose as the substrate. Moulder et al. (10) demonstrated the presence of glucose-6-phosphate and 6-phosphogluconate dehydrogenases in cellfree extracts of the agent of meningopneumonitis (MN). These enzymes could be differentiated by starch-gel electrophoresis from the corresponding ones derived from uninfected chick embryos.

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Section: Discussionmentioning

confidence: 99%

Transaminase Activity and Other Enzymatic Reactions Involving Pyruvate and Glutamate in Chlamydia (Psittacosis-Trachoma Group)

Weiss

1967

J Bacteriol

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Aegyptianella pullorumCarpano 1928—fine structure and taxonomy

Bird

Garnhám

1969

Parasitology

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Intraerythrocytic granules in the blood of Sudanese fowls first seen by Balfour (1908) were named Aegyptianella pullorum by Carpano (1928).Electron microscopy of a Rhodesian strain of A. pullorum indicated the similarity between these organisms and the Rickettsia-PLT group of organisms, also their dissimilarity to Sporozoa which we have studied. The organism was coccoid or coccobacillary, measuring up to 0·6 μm in diameter, and in longitudinal sections 1·5–3 μm. Pleomorphic and dividing forms were observed. Each organism was surrounded by two unit membranes with short internal invaginations from the inner membrane only. A layer of ribosome-like particles varying in density and depth gave the impression of an outer cortex. Irregular extensions of this layer towards the centre of the organism followed the lines of fine DNA-like filaments forming a web lattice throughout the substance of the organism. There was no well-defined nucleus as seen in Protozoa. Single as well as groups of organisms were situated in vacuoles lined by a membrane similar to the erythrocytes' own outer membrane. No intranuclear organisms were seen.The similarity of these organisms to symbionts studied by Roshdy and Bird in both adult and immature stages of A. persicus is illustrated. From this evidence, and its apparent likeness to the tick-borne fever agent, there is good reason for including A. pullorum among the Rickettsiaceae. The position suggested for it is between the Rickettsia and PLT group of organisms, closely allied to Wolbachia, the agent of tick-borne fever (Cytoecetes sp.) and the agent of bovine heart water disease (Cowdria ruminantium).We thank Mr R. Jacobson, F.I.M.L.T. for his willing assistance in conducting the sensitivity test, also Miss L. Lanigan and Mr D. Day for their technical and photographic assistance.

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Substrate utilization by Ehrlichia sennetsu and Ehrlichia risticii separated from host constituents by renografin gradient centrifugation

et al. 1988

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The in vitro metabolic activities of two monocytic species of Ehrlichia were investigated. The Miyayama strain of Ehrlichia sennetsu and two strains of Ehrlichia risticii, isolated in Illinois and Maryland, were cultivated in a P388D1 mouse macrophage cell line. The ehrlichia particles from heavily infected cultures were separated from host constituents by a Renografin gradient centrifugation procedure modified from those employed for rickettsiae and chlamydiae. The metabolic activities of the isolated ehrlichiae were measured by their formation of CO2 after incubation for 1 h or longer at 34°C with 14C-labeled substrates. Of the substrates tested, glutamine was utilized most vigorously. The greatest activity was obtained at pH 7.2 to 8.0, while the activity rapidly declined at pH below 7. The most favorable buffer was one that contained 0.05 M potassium phosphate as well as 0.2 M sucrose, thus affording some osmotic protection. Glutamate was utilized to a much lesser extent than glutamine, and glucose was not utilized at all. No consistent differences in metabolic activities among the three strains were observed.During the past several years there has been a resurgence of veterinary, medical, and biological interest in the genus Ehrlichia, previously believed to include only veterinary pathogens. In 1981 Ristic et al. (21) observed that there was a serological relationship between Rickettsia sennetsu and Ehrlichia canis. This was quickly followed by a report by Hoilien et al. (10), who illustrated the pronounced similarity in the developmental cycles of the two agents. This led to the reclassification of R. sennetsu as Ehrlichia sennetsu by Ristic and Huxsoll (20). E. sennetsu is a human pathogen isolated in 1953 in Japan (15), and until recently it was believed to be confined to a small region of that country (19). E. canis has been recognized for over 50 years as a worldwide pathogen of dogs (20).Cole et al. (3) greatly facilitated the investigation of E. sennetsu by demonstrating that this agent can be cultivated readily in an established cell line, P388D1, derived from murine macrophages. When Potomac horse fever, a disease that made its first appearance in Maryland about a decade ago, was investigated, it became obvious that the etiologic agent was an ehrlichia related to E. canis but more closely related to E. sennetsu (11). The agent was named Ehrlichia risticii (12), and the disease was renamed equine monocytic ehrlichiosis. These findings raise many questions about the ecology and phylogeny of E. sennetsu and E. risticii, which are widely separated geographically and are pathogenic for different mammalian hosts. The possibility that E. canis is the common link and that the dog is the common reservoir was raised by the discovery that E. canis can infect humans and produce a disease that is somewhat similar to Rocky Mountain spotted fever (7,14).Information on the biological properties of Ehrlichia spp. is quite limited. No detailed studies of the metabolic properties of any of the ehrlichiae have been r...

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Lipid Metabolism of the Rickettsialike Microorganism Wolbachia Persica: II. Studies with Labeled Nonlipid Substrates

Cited by 3 publications

References 0 publications

Transaminase Activity and Other Enzymatic Reactions Involving Pyruvate and Glutamate in Chlamydia (Psittacosis-Trachoma Group)

Transaminase Activity and Other Enzymatic Reactions Involving Pyruvate and Glutamate in Chlamydia (Psittacosis-Trachoma Group)

Aegyptianella pullorumCarpano 1928—fine structure and taxonomy

Substrate utilization by Ehrlichia sennetsu and Ehrlichia risticii separated from host constituents by renografin gradient centrifugation

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