Eperythrozoon ovis infection of sheep

Fitzpatrick, J. L.; Barron, Ronnie; Andrew, Linda; Thompson, H.

doi:10.1007/bf02752854

Cited by 4 publications

(6 citation statements)

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“…It is well known from former studies that RBC precursors can be found in the circulation of patients with chronic and acute anemia (48) and in animals infected with HM (11). However, the presence of M. suis-infected reticulocytes and normoblasts in the bloodstream is a novel finding for the pathogenesis of HM (data not shown).…”

Section: Discussionmentioning

confidence: 78%

Mycoplasma suis Invades Porcine Erythrocytes

et al. 2009

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Mycoplasma suis belongs to the hemotrophic mycoplasma group and causes infectious anemia in pigs. According to the present state of knowledge, this organism adheres to the surface of erythrocytes but does not invade them. We found a novel M. suis isolate that caused severe anemia in pigs with a fatal disease course. Interestingly, only marginal numbers of the bacteria were visible on and between the erythrocytes in acridine orange-stained blood smears for acutely diseased pigs, whereas very high loads of M. suis were detected in the same blood samples by quantitative PCR. These findings indicated that M. suis is capable of invading erythrocytes. By use of fluorescent labeling of M. suis and examination by confocal laser scanning microscopy, as well as scanning and transmission electron microscopy, we proved that the localization of M. suis was intracellular. This organism invades erythrocytes in an endocytosis-like process and is initially surrounded by two membranes, and it was also found floating freely in the cytoplasm. In conclusion, we were able to prove for the first time that a member of the hemotrophic mycoplasma group is able to invade the erythrocytes of its host. Such colonization should protect the bacterial cells from the host's immune response and hamper antibiotic treatment. In addition, an intracellular life cycle may explain the chronic nature of hemotrophic mycoplasma infections and should serve as the foundation for novel strategies in hemotrophic mycoplasma research (e.g., treatment or prophylaxis).Mycoplasma suis is a member of the family Mycoplasmataceae. This organism belongs to a group of uncultivable highly specialized bacteria which parasitize the surface of erythrocytes of a variety of mammals (34). These species represent a distinct new cluster in the genus Mycoplasma and have been given the trivial name hemotrophic mycoplasmas (HM). Infections with HM are identified clinically by overt life-threatening hemolytic anemia or by subtle chronic anemia characterized by infertility, immune suppression, and greater susceptibility to infections (34). It is noteworthy that organisms that morphologically resemble HM have also been detected in the blood of humans (1,8,42,50).M. suis causes febrile acute icteroanemia in pigs (IAP), which is accompanied by high numbers of M. suis cells in the blood, as confirmed by microscopy as well as by PCR (18,21,34). Clinical symptoms are successfully cured by treatment with tetracycline. Nevertheless, once pigs are infected with M. suis, they remain lifelong carrier animals and therefore are epidemiologically important (19). Chronic M. suis infections result in reproductive disorders in sows, growth retardation in piglets, and increased susceptibility to respiratory and enteric infections in feeder pigs. M. suis occurs worldwide, and chronic IAP, in particular, is of major economic importance (19).Contrary to the well-established clinical picture of IAP (i.e., high morbidity and low mortality), we recently observed an increased incidence of acute IAP in feed...

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Section: Discussionmentioning

confidence: 78%

Mycoplasma suis Invades Porcine Erythrocytes

et al. 2009

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“…However, severe haemolytic anaemia and concurrent infections may occur during acute field outbreaks (Jesse et al 2015 ) and immunocompromised states (Boes and Durham, 2016 ). Also, acute infection of small ruminants causes severe haemolytic anaemia, weakness, decreased exercise tolerance and concurrent chronic infections (Fitzpatrick et al 1998 ). Abed and Alsaad ( 2017 ) observed anaemia and anorexia in more than 80%, respiratory distress and lymphadenopathy in less than 80%, haemoglobinuria in 42% and decreased milk production in 39% of acutely infected sheep under field conditions.…”

Section: Clinicopathological Aspects Of Mycoplasma Ovis mentioning

confidence: 99%

“…Abed and Alsaad ( 2017 ) observed anaemia and anorexia in more than 80%, respiratory distress and lymphadenopathy in less than 80%, haemoglobinuria in 42% and decreased milk production in 39% of acutely infected sheep under field conditions. Generally, mild anaemia, ill thrift, reduced weight gain, jaundice, exercise intolerance, decreased wool and milk production are the main features of chronic M. ovis infection in sheep and goats (Fitzpatrick et al 1998 ; Hornok et al 2009 ; Machado et al 2017 ).…”

Section: Clinicopathological Aspects Of Mycoplasma Ovis mentioning

confidence: 99%

“…On the other hand, infection is usually present as mild bacteraemia and less severe anaemia in older sheep and goats (Gulland et al 1987a ) due to the presence of acquired immunity (Hornok et al 2009 ). However, adult sheep may occasionally succumb to acute infection and develop haemolytic anaemia due to stress form pregnancy, parturition, handling, malnutrition and concurrent parasitic, viral or bacterial infections and other immunosuppressive conditions (Gulland et al 1987b ; Fitzpatrick et al 1998 ; Hornok et al 2009 ; Sykes et al, 2010 ).…”

Section: Clinicopathological Aspects Of Mycoplasma Ovis mentioning

confidence: 99%

“…The pathological features of Mycoplasma ovis infection in sheep vary considerably depending on the degree of infection severity. At post-mortem, the carcase appears pale and wet with a gelatinous epicardial fat on the heart and moderate non-suppurative pneumonia in the lungs (Fitzpatrick et al 1998 ). The spleen is markedly enlarged (splenomegaly), congested and soft with a prominent white pulp.…”

Section: Clinicopathological Aspects Of Mycoplasma Ovis mentioning

confidence: 99%

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Review of clinical aspects, epidemiology and diagnosis of haemotropic Mycoplasma ovis in small ruminants: current status and future perspectives in tropics focusing on Malaysia

Paul

Jesse

Chung

et al. 2020

Trop Anim Health Prod

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Mycoplasma ovis (formerly Eperythrozoon ovis ) is an epierythrocytic parasitic bacterium of small ruminants known as haemotropic mycoplasma, which is transmitted mechanically by biting flies and contaminated instruments. Acute mycoplasmosis causes severe haemolytic anaemia and mortality in young animals. At the same time, chronic disease may produce mild anaemia and varying degrees of morbidity depending on several factors, including age, reproductive status, the plane of nutrition, immunological status and the presence of concurrent infection. Haemotropic Mycoplasma ovis is currently recognised as an emerging zoonotic pathogen which is widely distributed in the sheep and goat producing areas of tropics and subtropics, where the disease is nearly endemic. Human infection has been reported in pregnant women, immunocompromised patients and people exposed to animals and arthropods. The current diagnosis of haemoplasma relies on microscopic evaluation of Giemsa-stained blood smear and PCR. Although there are few published reports on the incidence of haemotropic Mycoplasma ovis infection of small ruminants in Malaysia, information on its prevalence, risk factors, severity and economic impacts is grossly inadequate. Therefore, a large-scale survey of small ruminant flocks is necessary to elucidate the current seroprevalence status and molecular characteristics of haemotropic M. ovis infection in Malaysia using ELISA and PCR sequencing technologies. In the future, surveillance programs, including vector forecast, quarantine, monitoring by periodic surveys and public enlightenment, will limit the internal and transboundary spread of M. ovis , enhance control efforts and mitigate production losses in Malaysia. Electronic supplementary material The online version of this article (10.1007/s11250-020-02357-9) contains supplementary material, which is available to authorized users.

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Chronic eperythrozoonosis in an adult ewe

2006

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April 25, and the ewe was treated with two doses of 20 mg/kg oxytetracycline (Engemycin 10 per cent) for suspected bacterial pneumonia. The illthrift and harsh lung sounds initially improved, but the ewe developed more severe anaemia; the organisms reappeared in blood smears, and the pneumonia recrudesced. The ewe was euthanased on June 18, 2002, and examined postmortem.Grossly, the ewe's carcase was pale and emaciated. There was 200 ml of clear, pale yellow fluid in the peritoneal cavity. Gelatinous oedema was evident in the mediastinal, mesenteric and perirenal tissues. Haemal nodes in the mesentery and sublumbar tissue were enlarged, with dimensions up to 10 mm x 5 mm x 5 mm. There was well demarcated, greybrown consolidation in the cranioventral portions of the left and right lungs, and brown, malodorous fluid exuded from cut surfaces.On histological examination, the lymphoid tissue of the haemal nodes was hyperplastic (Fig 2b), whereas there was little development of lymphoid follicles in the splenic white pulp or the cortices of the mesenteric and mediastinal lymph nodes. The medullae of the lymph nodes were oedematous, with a diffuse increase in polymorphonuclear leucocytes. Haemosiderosis was evident in Küpffer cells in the liver and in other cells of the monocyte-macrophage system in the spleen, lymph nodes, haemal nodes and lungs. There were accumulations of haemosiderin in the proximal convoluted tubular epithelial cells and interstitial macrophages in the kidney (Figs 2c, d). Erythrophagocytosis was evident in the spleen and haemal nodes. Bone marrow from the mid-diaphysis of the femur consisted of a loose, oedematous, fibrillary stroma of low cellularity. The liver had several small foci of periacinar necrosis associated with loss of hepatocytes and infiltration by macrophages containing brown, granular material. Suppurative bronchopneumonia was evident in the cranioventral portions of the lungs. Mild, non-suppurative epicarditis and interstitial myositis were evident. Small numbers of sarcocysts were scattered throughout the myocardium and skeletal muscle. There was hyperplasia of the zona fasciculata of the adrenal gland. A cyst was present in the thyroid gland. Mild chronic enteritis was evident. There were no significant findings in the rumen, reticulum, abomasum or pancreas.Faecal samples collected when the ewe was presented were negative for nematode eggs by the McMaster technique and negative for fluke eggs by the Boray flotation technique. Non-haemolytic Escherichia coli was isolated from faeces submitted for culture on February 13, but faecal cultures were negative for β-haemolytic E coli, as well as Salmonella, Campylobacter and Clostridium species. Faecal smears stained by the Ziehl-Neelsen technique were negative for acid-fast

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Eperythrozoon ovis infection of sheep

Cited by 4 publications

References 16 publications

Mycoplasma suis Invades Porcine Erythrocytes

Mycoplasma suis Invades Porcine Erythrocytes

Review of clinical aspects, epidemiology and diagnosis of haemotropic Mycoplasma ovis in small ruminants: current status and future perspectives in tropics focusing on Malaysia

Chronic eperythrozoonosis in an adult ewe

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