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When lambs born to and suckling Eperythrozoon ovis carrier ewes were inoculated with heparinised blood containing large numbers of E. ovis organisms, the lambs were either sterilised of the infection or patent infection was suppressed till the lambs were weaned. In vitro infection, transplacental transfer of antibodies or soluble antigens could not be demonstrated.
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Cell-wall-less uncultivated parasitic bacteria that attach to the surface of host erythrocytes currently are classified in the order Rickettsiales, family Anaplasmataceae, in the genera Haemobartonella and Eperythrozoon. Recently 16S rRNA gene sequences have been determined for four of these species: Haemobartonella felis and Haemobartonella muris and Eperythrozoon suis and Eperythrozoon wenyonii. Phylogenetic analysis of these sequence data shows that these haemotrophic bacteria are closely related to species in the genus Mycoplasma (class Mollicutes). These haemotrophic bacteria form a new phylogenetic cluster within the so-called pneumoniae group of Mycoplasma and share properties with one another as well as with other members of the pneumoniae group. These studies clearly indicate that the classification of these taxa should be changed to reflect their phylogenetic affiliation and the following is proposed: (i) that Haemobartonella felis and Haemobartonella muris should be transferred to the genus Mycoplasma as 'Candidatus Mycoplasma haemofelis' and 'Candidatus Mycoplasma haemomuris' and (ii) that Eperythrozoon suis and Eperythrozoon wenyonii should be transferred to the genus Mycoplasma as 'Candidatus Mycoplasma haemosuis' and 'Candidatus Mycoplasma wenyonii'. The former Haemobartonella and Eperythrozoon species described here represent a new group of parasitic mycoplasmas that possess a pathogenic capacity previously unrecognized among the mollicutes. These haemotrophic mycoplasmas have been given the trivial name haemoplasmas. These results call into question the affiliation of the remaining officially named species of Haemobartonella and Eperythrozoon which should be considered species of uncertain affiliation pending the resolution of their phylogenetic status.
A strain of Eperythrozoon coccoides was maintained in a pure state for 16 months in unsplenectomized Princeton mice by the intraperitoneal injection of parasitized blood, at intervals of 1 to 3 weeks. In the 39th passage three out of five mice developed marked ascites with innumerable neoplastic cells in the peritoneal fluid. By passage of this fluid the tumor cells and the eperythrozoon were transferred together, with the rapid development of ascites and early death of the animals. On continued passage of ascitic fluid and blood from the mice of the 39th successive group both the tumor and the eperythrozoon were ultimately obtained in a pure state. Development of the passaged tumor was uninfluenced by the eperythrozoon but growth of the latter appeared enhanced in the presence of the neoplastic cells. Throughout 50 passages in mice the ascites tumor has not altered in character. The intraperitoneal injection of ascitic fluid was irregularly followed by the appearance of tumor cells in the blood, the rate of the carriage being 26 per cent in sixty-five animals. The subcutaneous and intramuscular injection of the fluid resulted in solid, highly invasive, local growths which did not metastasize. The solid growths proved transferable in series yet after 20 passages still produced the ascites tumor on intraperitoneal injection of their cells.
Eperythrozoon suis is an extracellular red blood cell parasite that causes icteroanemia and poor growth performance in feeder pigs and has been associated with anemias in baby pigs and reproductive failures in sows. At present, few efficient tests are available for the diagnosis and study of E. suis infection in swine. This report discusses how a recently developed recombinant DNA probe (KSU-2) specific to E. suis DNA was utilized in in situ DNA hybridizations that couple biotinylated TaqI digested products of KSU-2 DNA with an immunogold detection system allowing the visualization by transmission electron microscopy of the gold particles within eperythrozoon organisms. Specific labelling by the probe of eperythrozoon organisms demonstrated a pattern that changed with the various stages of the eperythrozoon life cycle.
Eperythrozoon is an obligate parasitic bacteria found in many species of animals. A large scale investigation of the prevalence of Eperythrozoon spp. in humans, was conducted in a developing country using light, electron microscope and animal inoculation. Samples were collected in undeveloped areas of Inner Mongolia in China over a 2-year period of 1994-6. Of the 1529 investigated samples, 35.3% were found to be Eperythrozoon spp. positive. The prevalence of infection was associated with occupation and seasonal variations. The infections were mainly mild, in 89.6% of cases (excluding pregnant women and their children). Of 74 pregnant women tested in the areas of high prevalence, 44 were confirmed Eperythrozoon spp. positive. Similarly, eperythrozoa were found in all 44 umbilical cords tested and in the neonatal peripheral blood samples taken at birth. These data suggest that eperythrozoa can be transmitted via the placenta.
Eperythrozoon infection can be diagnosed clinically and hematologically only during acute attacks. In the febrile phase it is possible to detect the eperythrozoon organisms in the blood smear. The best method for staining is that by acridine-orange and examination by fluorescence microscopy. Serological identification (IHA, KBR, ELISA) is suitable for herd diagnosis only, because of the undulating level of the titre. In the individual case only positive results are regarded as significant. The best method to diagnose a latent infection of eperythrozoon suis is to splenectomize a suspected pig. The infection with eperythrozoon suis is a herd problem, therefore an examination should be made whenever there are pale pigs with fever, or a reduction of efficiency or an increased susceptibility to other infections.
On nine separate occasions, Babesia bovis microaerophilus stationary phase (MASP) cultures were initiated with blood from calves with concurrent infections of B. bovis and Theileria buffeli, Eperythrozoon wenyoni or Anaplasma spp. In each case B. bovis became established in culture and was maintained for 30-49 days. Culture material was inoculated into susceptible splenectomised calves to test for persistence of the other organisms. No haemoparasites other than B. bovis were detected in Giemsa-stained blood films of recipient calves and no antibodies to T. buffeli or Anaplasma were detected using indirect fluorescent antibody and card agglutination tests, respectively. The method provides a practical way of removing contaminants such as Theileria, Eperythrozoon and Anaplasma spp. from B. bovis isolates without the use of drugs, tick passage or repeated syringe passage in cattle.
The 16S rRNA gene of Eperythrozoon (Haemobartonella) wenyonii, a wall-less hemotrophic prokaryote currently classified as a rickettsia, was sequenced to determine the relationship of this organism to other wall-less prokaryotes. Comparison to the GenBank data base showed that this hemotrophic organism is a Mycoplasma (family Mollicutes). Phylogenetic analysis of 16S rRNA genes indicated that this and other recently sequenced 16S rRNA genes of hemotrophic bacteria form a new, separate branch which shares a node in common with the pneumoniae group of mycoplasmas. This result will require that Eperythrozoon wenyonii be reclassified as a Mycoplasma. A main point of this study is that this and related hemotrophic bacteria represent an entirely new group of pathogens among the mycoplasmas.
A total of 126 lamb carcases, of which 80 were jaundiced and 46 were grossly normal at routine meat inspection, were examined. Two specific diseases were demonstrated to be associated with jaundiced carcases. Eperythrozoon infection was demonstrated in 65% of jaundiced, and 12% of non-jaundiced carcases from jaundice-affected lots, but not in 5 normal carcases from unaffected killing lots. Copper poisoning was demonstrated in 2 of the jaundiced carcases. Infection with Eperythrozoon ovis was therefore the condition most commonly associated with, and presumably the major cause of jaundice in these lamb carcases. Copper poisoning was a less common cause of jaundice.
Tanaka, H. (The Rockefeller University, New York, N.Y.), W. T. Hall, J. B. Sheffield, and D. H. Moore. Fine structure of Haemobartonella muris as compared with Eperythrozoon coccoides and Mycoplasma pulmonis. J. Bacteriol. 90:1735-1749. 1965.-Thin sections of filterable hemolytic anemia agent of rat, now identified as Haemobartonella muris, revealed (i) that the agent is spherical or ellipsoidal and 350 to 700 mmu in size, (ii) that it has a single limiting membrane enclosing granules and some filaments (neither cell wall nor nucleoid was found), and (iii) that it is found preferentially at the surface and sometimes within the cytoplasmic vacuoles of erythrocytes in the circulating blood and bone marrow, and multiplies there through binary fission. No specific structure suggestive of motility was found. From the morphological point of view, Eperythrozoon coccoides was found to be very similar to H. muris, whereas Mycoplasma pulmonis, also covered with a single limiting membrane, differs in its pleomorphism and multiplication. These and some other microorganisms taxonomically between bacteria and viruses were compared morphologically, and their possible classification is discussed.
A light and electron microscopic study was carried out on pigs experimentally infected with Eperythrozoon (E.) suis during the acute and chronic phase of infection. During the acute phase Eperythrozoon organisms can be recognised by light microscopy as bright to dark orange points or circles. In contrast, in the chronically infected pigs E. suis appear as bright yellow or green small dots on the edge of the erythrocytes or in the plasma. By scanning electron microscopy, immature, juvenile and mature forms of E. suis could be seen on the same erythrocyte during the acute phase. In chronically infected pigs ring-shaped, rounded resting-stage forms, measuring about 1 micron in diameter, can be observed.
This paper reported an epidemiological investigation on human and animal Eperythrozoons infection in five districts from three provinces in China. The results showed that Eperythrozoon infection appeaned in human as well as in swines, sheep and cats. Due to geographical variations, the infectious rates showed significantly difference both in human and in animals. The infection rate in human was not associated with sex, age or occupation. Some questions related to the epidemiology of Eperythrozoonosis were discussed in this article.
After infection with Eperythrozoon suis, pigs began to produce cold agglutinins of immunoglobulin type IgM, that because of the similarity between the pathogenic antigen and antigen on the erythrocyte membrane caused agglomeration. The progression of this cold agglutinin was measured with an enzyme immunoassay especially invented for this purpose, and compared with serum-IgM, agglutination strength, pathogenic effect as well as number of erythrocytes in the blood. The cold agglutinin extracted from the erythrocyte membrane at 40 degrees C showed, in comparison to the initial figures, a higher level (1259 micrograms/ml) at 6 days after the illness peak, reaching its maximum (2435 micrograms/ml) at 12 days. Similar results were achieved at lower extraction temperatures (22 degrees C, 0 degree C). A high correlation could be shown between the levels of IgM and of cold agglutinin, as well as the parallel increase in the agglutination strength of the blood. At the time of maximal pathogenic effect, no agglutination of blood was observed. The number of erythrocytes decreased in acute phases of an attack to a constant mean of 2.32 Mill./microliters of blood and then increased, at the same rate as the cold agglutinin level decreased, almost reaching normal values. These experiments confirm the fact that an organism following an infection with Eperythrozoon suis, begins to produce cold agglutinins. Due to structural similarities between the pathogen and the erythrocyte antigen the cold agglutinin causes temperature dependent agglutination.(ABSTRACT TRUNCATED AT 250 WORDS)
Eperythrozoon was detected in suckling mice inoculated with a suspension of nymphal Ixodes ricinus ticks. The organism was filterable through 220 nm Millipore membranes, moderately sensitive to diethyl ether, pathogenic to suckling but not to adult mice when given intracerebrally, intraperitoneally or subcutaneously, and mimicked an arbovirus. Eperythrozoon should be considered as an agent potentially interfering with experiments performed on laboratory mice.
A 16-month-old Charolais bull was examined because of acute onset of scrotal and hind limb edema, fever, tachycardia, tachypnea, anorexia, and lethargy. Scrotal circumference on initial examination was 48 cm. Clinicopathologic abnormalities included microcytic, normochromic anemia and numerous Eperythrozoon organisms in blood smears. Results of immunohistochemical staining of a skin biopsy specimen suggested that the edema was the result of an Arthus-type reaction. Semen quality deteriorated rapidly, and the bull was aspermic within 7 days. The bull was treated with oxytetracycline, and the anemia and edema gradually subsided. Eperythrozoon organisms were not detected in blood smears after 3 days. Six months after initial examination, results of physical examination and semen evaluation were normal. We hypothesize that scrotal edema caused failure of testicular thermoregulation, resulting in transient production of abnormal sperm and infertility.
This paper reported an epidemiological investigation on human and animals infection of eperythrozoon in 1 provinces. The results showed that eperythrozoon infection appeared in human as well as in swines, sheep, cats, donkeis and chickens. Due to geographical variations, the infection rates showed a significant difference, both in human and animals. The infection rate was not associated with sex, age or occupation in human, but was associated with seasons in animals. High peak of infection rates in animals was in May, June, July and August.
This paper reported an epidemiological investigation on human and animal infection to Eperythrozoon in 5 provinces. The results showed that Eperythrozoon infection existed in human as well an in animals in those provinces. Due to geographical variation, the infection rates were different. The infection rate was not associated with sex and age in human. The overall infection rate of different Eperythrozoonoses was higher than in healthy humans. The cases of Eperythrozoonoses among human and pig-herd were reported in this paper.