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1.
This study is designated to assess the effect of the severity of Babesia ovis infection on sialic acid concentration in blood sera in naturally infected sheep. Infected animals (diseased group) comprised 38 Iranian fat-tailed sheep, about 1–3 years old, naturally infected with B. ovis, divided into four subgroups with respect to parasitemia rates (low 0.1–0.3 %, moderate 0.4–0.9 %, high 1–2.5 %, and very high >2.5 %). The parasitological diagnosis was confirmed using PCR analysis. As a control group, ten clinically healthy sheep reared under the same management and environmental conditions were also sampled. Hematological parameters and the concentrations of total sialic acid (TSA), lipid-bound sialic acid (LBSA), and protein-bound sialic acid (PBSA) were measured in both groups. Compared to controls, sialic acid concentrations showed significant increase (p?Parasitemia rate was positively correlated with sialic acid concentrations. This study demonstrated that B. ovis infection induced marked and persistent elevations of serum sialic acid concentrations. It seems that increase of serum sialic acid concentrations during parasitemia alter receptor-ligand interactions, which are known to play important role in immune response. Furthermore, sialic acid would indirectly inhibit the action of leukocytes and consequently promote the evasion of the immune response and persistence of the parasite in the host. This factor could influence the parasite-host cell adhesion, but further detailed biochemical investigations are needed to precisely explain the exact role of sialic acid in invasion process of the parasite to the host cells.  相似文献   

2.
Aegyptianellosis, eperythrozoonosis, grahamellosis and haemobartonellosis are diseases caused by procaryotic microorganisms which parasitize the erythrocytes of a variety of animals. Differentiation between Eperythrozoon and Haemobartonella is difficult. The parasites are similar in the living state, being small cocci or rods. In stained preparations Eperythrozoon may appear to be annular. The major criterion for differentiation is the relation of the parasite to the erythrocyte. Haemobartonellae are tightly attached to the erythrocyte and are rarely seen free in the plasma. Eperythrozoa are loosely attached to the erthrocyte, can be readily disloded and are often seen free in the plasma. Aegyptianella which occurs intracellularly in an inclusion is easily differentiated from the others while Grahamella, which is rod shaped, is always intracellular and is not in an inclusion but is scattered throughout the erythrocyte's cytoplasm. These organisms are not generally pathogenic. A slight parasitemia, mild anemia and slight fever may follow infection in the intact animal. Most infected animals remain nonclinical carriers. Splenectomy of a carrier animal or infection of a splenectomized animal will produce high parasitemia; even then, the physiological disturbance is mild. The only exceptions to the general rule that infection with these organisms produces a mild disease in intact animals are infections with Aegyptianella pullorum, Eperythrozoon suis and Haemobartonella felis. Aegyptianella pullorum produces aegyptianellosis of fowl, a disease characterized by anemia, E. suis produces “icteroanemia of swine” and H. felis produces “filine infectious anemia”.  相似文献   

3.
Reduced glutathione (GSH) and methaemoglobin were measured in sheep blood during an infection cycle of Eperythrozoon ovis and in uninfected control blood. The GSH levels in infected erythrocytes were significantly lower in the latter half of the infection cycle. Incubation with acetylphenylhydrazine (APH) resulted in negligible leves in infected cells whereas control cells were approximately 45% normal. Infection with E. ovis had little effect on methaemoglobin levels. However, incubation with APH caused a marked increased of the methaemoglobin levels in both infected and control blood; the control methaemoglobin levels were significantly higher.It was concluded from these observations that E. ovis interfered with maintenance of GSH within erythrocytes to an extent that when challenged with an oxidizing chemical erythrocyte membrane integrity could be lost. In addition E. ovis may bave provided some protection against oxidative damage for the heme portion of the haemoglobin molecule or the amount of oxidative damage to haemoglobin was further advanced in the infected cells.  相似文献   

4.
Babesia bigemina infection (also known as Texas fever) is reported as the most prevalent and main causative agent of bovine babesiosis, worldwide. The current study was undertaken to assess indicators of oxidative stress including activities of antioxidant enzymes and total antioxidant capacity (TAC), oxidation status of biomolecules and serum levels of trace elements as well as indicators of inflammation including sialic acid (SA) contents and cholinesterase activity in cattle naturally infected with B. bigemina. An infected group comprised of 20 crossbred Holstein cattle (3–4 years old) were diagnosed to be positive by both microscopy and nested PCR assay. The infected animals were subdivided into two groups according to their parasitemia rates (<20 % and>20 %). Furthermore, 10 healthy cattle were included as the control. The infection caused severe anemia in a parasitemia-burden dependent fashion. The activities of catalase and glucose-6-phosphate dehydrogenase as well as the levels of TAC, zinc, selenium, copper and manganese were significantly decreased as the parasitemia increased, accordingly. However, the activity of superoxide dismutase as well as the levels of malondialdehyde, protein carbonylation, DNA damage and iron, were significantly elevated in a parasitemeia-burden dependent manner. Additionally, glutathione peroxidase activity was significantly elevated with the lower rate of parasitemia, but the higher rate had no significant effect as compared to control. Moreover, total, protein and lipid binding SA contents were significantly increased but the activities of acetylcholinesterase and butyrylcholinesterase were significantly reduced, parasitemia dependently. Conclusively, the infection was remarkably associated with the induction of anemia, oxidative stress and inflammation.  相似文献   

5.
Anaplasma species are transmitted by ticks and cause diseases in humans and animals. These pathogens infect sheep, an economically important domestic animal worldwide. The current study was designed to characterize in 200 animals the infection with Anaplasma phagocytophilum and Anaplasma ovis and the genetic diversity of A. ovis strains collected from a naturally infected sheep flock with poor health condition. Sheep had 98% seroprevalence to Anaplasma spp. antibodies. PCR results confirmed the presence of A. phagocytophilum and A. ovis DNA in 11.5% and 37% of the sheep, respectively. Concurrent infections were detected in 6.5% of the sheep. Seventy-one adult ticks were collected from 45 sheep with infestations ranging from one to 15 ticks per animal. The analysis of A. ovis msp4 sequences demonstrated a previously unreported polymorphism for this pathogen with 17 different haplotypes in infected sheep. These results demonstrated that, although A. ovis msp4 haplotypes may be less variable when compared with Anaplasma marginale and A. phagocytophilum strains on a global scale, genetic polymorphisms occur in this locus in strains obtained from an infected sheep flock with poor health condition.  相似文献   

6.
Malaria is a serious infectious disease caused by parasites of the Plasmodium genus that affect different vertebrate hosts. Severe malaria leads to host death and involves different pathophysiological phenomena such as anemia, thrombocytopenia and inflammation. Nitric oxide (NO) is an important effector molecule in this disease, but little is known about its role in avian malaria models. Plasmodium gallinaceum- infected chickens were treated with aminoguanidine (AG), an inhibitor of inducible nitric oxide synthase, to observe the role of NO in the pathogenesis of this avian model. AG increased the survival of chickens, but also induced higher parasitemia. Treated chickens demonstrated reduced anemia and thrombocytopenia. Moreover, erythrocytes at different stages of maturation, heterophils, monocytes and thrombocytes were infected by Plasmodium gallinaceum and animals presented a generalized leucopenia. Activated leukocytes and thrombocytes with elongated double nuclei were observed in chickens with higher parasitemia; however, eosinophils were not involved in the infection. AG reduced levels of hemozoin in the spleen and liver, indicating lower inflammation. Taken together, the results suggest that AG reduced anemia, thrombocytopenia and inflammation, explaining the greater survival rate of the treated chickens.  相似文献   

7.
One splenectomized and 6 intact coyotes (Canis latrans), and 2 coydogs were experimentally inoculated with a recent isolate of Babesia gibsoni. The disease was mild in intact animals, was fatal in the splenectomized coyote, and was characterized by a regenerative hemolytic anemia with the PCV decreasing to 16% in intact animals and to 6% in the splenectomized coyote. Peak parasitemia ranged from 3% to 21% of erythrocytes infected and was inversely correlated to PCV. Serum lactate dehydrogenase, bilirubin, and globulin concentrations were increased in all infected animals. Three weeks after inoculation, specific antibody titers increased to 1:65,536 and remained elevated in the chronically infected animals. The splenectomized coyote had progressive weakness until death, 24 days after inoculation. Intact animals had splenomegaly and anorexia at the height of infection. The splenectomized coyote had generalized edema, omental petechiae, renal and hepatic degeneration, membrano-proliferative glomerulonephritis and congestion, extramedullary hematopoiesis, lymphoid hyperplasia, and severe hemosiderosis in an accessory spleen. The only consistent change in the intact animals was splenomegaly.  相似文献   

8.
African trypanosomosis is a potentially fatal disease that is caused by extracellular parasitic protists known as African trypanosomes. These parasites inhabit the blood stream of their mammalian hosts and produce a number of pathological features, amongst which is anemia. Etiology of the anemia has been partly attributed to an autoimmunity-like mediated erythrophagocytosis of de-sialylated red blood cells (dsRBCs) by macrophages. Lactose infusion to infected animals has proven effective at delaying progression of the anemia. However, the mechanism of this anemia prevention is yet to be well characterized. Here, the hypothesis of a likely induced further modification of the dsRBCs was investigated. RBC membrane galactose (RBC m-GAL) and packed cell volume (PCV) were measured during the course of experimental trypanosomosis in mice infected with Trypanosoma congolense (stb 212). Intriguingly, while the membrane galactose on the RBCs of infected and lactose-treated mice (group D) decreased as a function of parasitemia, that of the lactose-untreated infected group (group C) remained relatively constant, as was recorded for the uninfected lactose-treated control (group B) animals. At the peak of infection, the respective cumulative percent decrease in PCV and membrane galactose were 30 and 185 for group D, and 84 and 13 for group C. From this observed inverse relationship between RBCs membrane galactose and PCV, it is logical to rationalize that the delay of anemia progression during trypanosomosis produced by lactose might have resulted from an induction of galactose depletion from dsRBCs, thereby preventing their recognition by the macrophages.  相似文献   

9.
A survey was carried in North Khorasan Province, Iran in 2010–2011, designed to identify Theileria spp. infections of both sheep and ticks. The tick species were also examined. Ninety sheep from different flocks were clinically examined, and blood samples and ixodid ticks were collected. Light microscopy of blood smears revealed Theileria spp. infection in 37 (41.1 %), while 74 (82.2 %) of blood samples were positive using semi-nested PCR. Theileria ovis, Theileria lestoquardi, and mixed infection were detected in 63/90 (70 %), 5/90 (5.5 %), and 6/90 (6.6 %) of samples, respectively. Of the 434 ticks that were collected, the most prevalent species was Rhipicephalus turanicus (69.3 %) followed by Hyalomma marginatum turanicum (18.4 %), Dermacentor marginatus (6.4 %), and Rhipicephalus bursa (5.7 %). The ticks were separated into 42 tick pools, and the salivary glands were dissected out in 0.85 % (w/v) saline under a stereomicroscope and examined using semi-nested PCR. Three pools of H. marginatum turanicum salivary glands were infected with T. ovis and T. lestoquardi, and one pool of R. turanicus was infected with T. ovis. Based on these results, it is concluded that the prevalence of T. ovis is higher than T. lestoquardi and that H. marginatum turanicum and R. turanicus are likely vectors of T. lestoquardi and T. ovis in this area.  相似文献   

10.
Equine theileriosis due to Theileria equi is probably the most widespread and pathogenic disease of equines, which comes with major cardiac and renal complications. This study was undertaken to investigate the biomarkers of cardiac and renal functions in horses infected with T. equi and determine the association between these parameters and the level of parasitemia. Giemsa-stained blood smears from 300 horses with ages of 3–4 years old were examined for detection of T. equi on erythrocytes. Moreover, multiplex PCR was employed for confirmation of the diagnosis in the 28 positive cases. Based on the rate of red blood cell infection, the infected animals were subdivided into horses with low (n = 9), moderate (n = 13) and high (n = 6) parasitemia. The concentrations of urea, creatinine, cystatin-C, cardiac troponin I (cTn-I), homocysteine (Hcy), myocardial fractions of creatine kinase (CK-MB) and d-dimer were determined in control (healthy) horses (n = 20) and the infected animals. The results revealed that both the renal (urea, creatinine and cystatin-C) and the cardiac (cTn-I, Hcy, CK-MB and d-dimer) biomarkers increased in a parasitemia burden-dependent pattern. However, urea, creatinine, cTn-I and d-dimer levels were not significantly influenced in the horses infected with low rate (<1 %) of parasitemia (p> 0.05). Moreover, all of the biomarkers were significantly and positively associated with the parasitemia (R2> 0.5). In conclusion, T. equi infection was related to cardiac and renal complications evidenced by increase in the levels of biomarkers and evaluation of these indices may have promise for early diagnosis of the complications.  相似文献   

11.
Intraerythrocytic piroplasms, morphologically indistinguishable from Cytauxzoon felis, were identified in stained blood films from more than one third of free-ranging cougars (Puma concolor couguar) in southern Florida in a study that failed to demonstrate negative effects of piroplasm infection on measured hematologic parameters. However, a recent study with a nested 18s rRNA polymerase chain reaction (PCR) assay identified only 9% of the free-ranging cougars in southern Florida as infected with C. felis but found 83% of these animals were infected with an unnamed small Babesia sp. In this study, hematology and clinical chemistry parameters were determined during the initial appearance of piroplasms in stained blood films of three western cougars housed in northern Florida. One animal became ill, but the remaining two animals did not exhibit clinical signs of disease. The hematocrit decreased in all three cougars concomitant with the first recognized parasitemia. A regenerative response to anemia (increased polychromasia, increased mean cell volume, and increased red cell distribution width) was recognized in two cougars that were examined twice during the following 2 weeks. Thrombocytopenia and probable leukopenia occurred in one animal. The most consistent clinical chemistry findings were increased serum bilirubin concentrations and increased alanine aminotransferase and aspartate aminotransferase activities at the time of initial recognition of parasitemia. Serum protein findings were not consistent in these cougars. The use of PCR and determination of 18S rRNA gene sequences in the blood from these three animals revealed infection with C. felis, but not with the Babesia sp. In this report, we demonstrate that mild hemolytic anemia, and probably liver injury, occurs concomitant with the initial discovery of C. felis piroplasms in stained blood films.  相似文献   

12.
Eleven 6-month-old calves were tsetse fly challenged with a stock of Trypanosoma vivax (IL 2337) that causes hemorrhagic infection. The calves were randomly euthanatized every 4 to 6 days; two other calves served as controls. Peripheral blood changes included anemia, thrombocytopenia, and an initial leukopenia. Later in the course of infection, leukocytosis associated with lymphocytosis and neutropenia developed. Moderate reticulocytosis (highest mean count 3.6 +/- 3.7%, maximum count 9.4%) accompanied the first wave of parasitemia, but poor response (highest mean 0.4 +/- 0.0%) occurred during the second wave, despite the persistence of severe anemia. Light microscopic examination of bone marrow samples showed a drop in the myeloid: erythroid ratio with a decrease in granulocytes, particularly metamyelocytes, bands, and segmenters. Increase in lymphocyte counts corresponded with the appearance of lymphoid nodules within the marrow. Megakaryocytic volume increased significantly in infected animals, and some megakaryocytes showed emperipolesis of red cells, neutrophils, and lymphocytes. Transmission electron microscopic examination of the bone marrow revealed that trypanosomes had crossed the sinusoidal endothelium into the hematopoietic compartment as early as the second day of parasitemia. Macrophages proliferated in the bone marrow; and from the second day of parasitemia until the end of the experimental infection, on day 46, the macrophages had phagocytosed normoblasts, eosinophil and neutrophil myelocytes, metamyelocytes, bands, and segmenters, as well as reticulocytes, erythrocytes, and thrombocytes. Therefore, dyserythropoiesis and dysgranulocytopoiesis were responsible, in part, for the observed anemia and granulocytopenia, respectively.  相似文献   

13.
A complement-fixation (CF) antigen which has been prepared from Theileria infected erythrocytes is capable of reacting to specific serum antibodies of deer acutely infected with Theileria.

No sera from 17 deer known to be free of Theileria infection reacted positively to the CF test. Of 35 tests on sera from 12 infected deer having a parasitemia of 2% or less and no accompanying anemia, only 10 (29%) were positive, 2 (6%) were suspicious, and 23 (66%) were negative. Of 65 tests on 8 acutely infected deer, 49 (75%) were positive, 4 (6%) were suspicious and 12 (18%) were negative. Of the 8 deer in which acute theileriasis occurred all reacted to Theileria antigen at one time or another.

A significant correlation was found between CF titers and the degree of parasitemia in acute infections.

Rabbits were hyperimmunized using erythrocytes from either normal or Theileria infected deer. Reciprocal absorption of the hyperimmune sera with Theileria and normal erythrocytic antigens demonstrated the presence of antibodies specific for Theileria.

  相似文献   

14.
OBJECTIVE: To characterize clinical and hematologic responses in dogs following experimental inoculation with Babesia gibsoni-like isolates from infected dogs in Oklahoma. DESIGN: Prospective study. ANIMALS: 6 mixed-breed dogs. PROCEDURE: 2 dogs were inoculated with organisms from a naturally infected dog, and 3 were inoculated with organisms from a second naturally infected dog (1 of these 3 dogs was splenectomized 1 week prior to inoculation). One dog was not inoculated. Complete blood counts were performed weekly. RESULTS: In the 5 dogs inoculated with organisms, parasites were initially detected 1 to 5 weeks after inoculation, and severity of parasitemia peaked with 1.9 to 6.0% of RBC infected by 4 to 6 weeks after inoculation. Parasitemia was easily detectable (> 0.1% of RBC infected) for 3 to 4 weeks. Clinical abnormalities included lethargy, fever, and pale mucous membranes but were mild to nearly inapparent in 2 dogs. All dogs developed regenerative anemia and marked thrombocytopenia. Thrombocytopenia developed before and lasted longer than the parasitemia. Profound but transient neutropenia was detected in some dogs. The splenectomized dog developed more severe parasitemia and anemia and more pronounced clinical abnormalities. Three dogs with intact spleens recovered without treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that 2 or more genotypically distinct, but morphologically identical, small Babesia parasites can infect dogs in the United States. Compared with infection with small Babesia parasites from California, infection with these isolates resulted in less severe parasitemia and clinical abnormalities. Parasitemia was transient, indicating that identification of organisms in blood smears may be difficult in some dogs.  相似文献   

15.
Although Mycoplasma ovis (formerly Eperythrozoon ovis) has been described in small ruminants worldwide, data on M. ovis in goats remain scarce. Accordingly, the aims of the present study were to i) determine the prevalence of hemoplasmas in goats, ii) identify the tick species parasitizing the animals, and iii) determine factors associated with infection in five dairy and three beef goat farms from the Paraíba State, northeastern Brazil. Blood samples were obtained from 402 goats. Samples were screened for hemoplasmas using a pan-hemoplasma PCR. The positive samples were confirmed by sequencing. An epidemiological questionnaire was given to each farm owner addressing age, gender, and presence of ticks. A total of 158/402 (39.3%) goats were positive for M. ovis by PCR. Sequencing of PCR positive samples has shown ≥99% identity with multiple M. ovis 16S rDNA sequences deposited in GenBank, including M. ovis isolates from humans. Dairy (OR = 2.15; 95% CI: 1.40–3.32%; P = 0.0004) and anemic goats (OR = 2.33; 95% CI: 1.51–3.71%; P = 0.0001) were more likely to be infected than beef and non-anemic animals, respectively. Amblyomma parvum (49/52, 94.23%) and Rhipicephalus microplus (3/52, 5.77%) were the tick species found parasitizing the animals, with no significant association between the presence of ticks and infection by M. ovis (P = 0.1164). This is the first reportedly molecular detection of M. ovis infection in goats from South America. In conclusion, M. ovis is highly prevalent in goats from northeastern Brazil, mainly in dairy animals.  相似文献   

16.
Seven, adult, female beagles were inoculated with a Swedish granulocytic Ehrlichia organism closely related to Ehrlichia equi and E. phagocytophila. Blood and bone marrow changes were evaluated throughout the acute phase of infection. All dogs developed moderate to severe thrombocytopenia during the parasitemic period. The mean platelet volume and platelet distribution width increased, and large platelets were seen on blood smears when platelet numbers were low. In bone marrow, absolute numbers of megakaryocytes and immature megakaryocytes were increased. These results suggested the thrombocytopenia was caused by increased platelet destruction. The dogs also developed mild, normocytic, normochromic anemia, with simultaneous decreases in serum iron concentration and total iron-binding capacity that resembled the anemia of inflammation. In bone marrow, there was a slight increase in immature erythroid cells and no erythroid hypoplasia; iron stores were normal to increased. Myeloid hyperplasia was seen in all infected dogs, despite neutropenia in peripheral blood. Lymphopenia occurred early in the parasitemic period, but lymphocytes responded strongly and numbers increased above baseline levels by the end of parasitemia. Blast-transformed lymphocytes (5% to 20%) were seen in peripheral blood for a few days. Experimentally-induced canine granulocytic ehrlichiosis caused cytopenias of short duration, coincident with the appearance of ehrlichial inclusions in neutrophils.  相似文献   

17.
An outbreak of trypanosomoasis caused by Trypanosoma evansi involving horses, camels and donkeys occurred in a farm in Israel. A longitudinal study of two outbreak phases was conducted which included clinical monitoring, blood smears, packed cell volume (PCV), serology and polymerase chain reaction (PCR) followed by reverse dot blot (RDB) for the molecular detection of infection. This was the first reported T. evansi outbreak in domestic animals in Israel. Most of the camels on the farm (8/10; 80%) were diagnosed with T. evansi infection whereas infection was less prevalent in the horses (3/7; 43%) and donkeys (6/13; 46%). Clinical disease was evident in 4 camels and 1 horse exhibiting characteristic clinical signs, anemia and parasitemia detected on blood smears and by positive RDB. Six other animals were diagnosed as asymptomatic latent carriers by positive RDB and 6 additional animals were only seropositive and were considered suspected carriers. A significant difference was found in the mean PCV between symptomatic and latent carriers with severe anemia observed only in the symptomatic animals. An anaphylactic-like reaction, fatal in one case, was observed in 2 camels diagnosed with severe trypanosome parasitemia immediately following treatment with melarsenoxide cysteamine. Furthermore, recurrence of infection was documented in one camel 4 months post treatment.  相似文献   

18.
The therapeutic efficacies of imidocarb and parvaquone were tested against Babesia equi of European origin in carrier horses and for induced acute infections in splenectomized ponies. Imidocarb, at a dosage of 4 mg/kg of body weight, given IM at 72-hour intervals 4 times, was ineffective in eliminating B equi-carrier infection in 9 mature geldings. A single IM administration of 4 mg/kg was not therapeutic in acutely infected splenectomized ponies. When given at 3 different dosages and treatment schedules, parvaquone was ineffective in clearing carrier infection. Parvaquone given IM once at a dosage of 20 mg/kg was effective for acute B equi infections in splenectomized ponies; parasitemia began to decrease within 24 hours after treatment. Infections were not eliminated however, and within 4 weeks, secondary parasitemia and anemia developed. Of 4 ponies, 3 died of acute piroplasmosis.  相似文献   

19.
The ovine brucellosis caused by Brucella ovis has tropism for reproductive tissues but until now the mechanism of bacterial persistence is not understood. Cytokine expression profiles were studied for 8 months in rams after being experimentally infected with the rough virulent strain of B. ovis (R-B. ovis) to study the pathogenesis of B. ovis and immune mechanism possibly associated to bacteria tropism and persistence. The messenger RNA (mRNA) expression levels of interleukin-1α (IL-1α), IL-1β, IL-6, IL-10, IL-12, interferon-γ (INF-γ) and tumour necrosis factor-α (TNF-α) cytokines were quantified by real-time quantitative RT-PCR (qRT-PCR) in reproductive tissues (epididymus, testicles, ampolae, vesicular glands and bulbourethral glands), and non-reproductive (liver, spleen and kidneys) tissues at 30, 60, 120 and 240 days post infection (dpi). During the acute phase of infection at 30 dpi, the host immune response was most notable demonstrating an up-regulation of several cytokines in reproductive tissues, including the epididymus (IL-6, IL-1β and IL-1α), testicles (INF-γ and IL-12), bulbourethral glands (IL-6 and TNF-α) and ampolae (INF-γ, IL-10, IL-1β and IL-1α). During the development of infection, cytokine gene expression levels decreased, providing evidence of immunosuppression and evidence of immune evasion that favoured persistence of chronic R-B. ovis infection. During the chronic phase of R-B. ovis infection (120 and 240 dpi), cytokine production was down-regulated in the epididymus (IL-1β and IL-1α), testicles (INF-γ and IL-12), and ampolae (INF-γ, IL-10, IL-1β and IL-1α), with the exception of the bulbourethral glands (IL-6 and TNF-α) and epididymus (IL-6); in these tissues, R-B. ovis infection resulted in up-regulation of the pro-inflammatory cytokine IL-6. Herein, we report cytokine expression profiles in tissues of rams experimentally infected with the rough strain of B. ovis, which are associated with bacterial persistence and macrophage activation.  相似文献   

20.
The role of macrophages in the erythrocyte membrane oxidative damage and the pathogenesis of anemia in Babesia gibsoni-infected dogs with low parasitemia were investigated. Macrophages derived from peripheral blood monocytes (PBM) from B. gibsoni-infected dogs produced significantly higher chemiluminescent responses, indicating the release of reactive oxygen intermediates, than those from non-infected dogs when the cells were subjected to non-specific stimulation with phorbol 12-myristate 13-acetate (PMA) and opsonized zymosan (OZ), or infected dog erythrocyte membranes opsonized with infected dog serum. These results indicate that PBM of B. gibsoni-infected dogs with low parasitemia were highly activated compared to those of non-infected dogs. Furthermore, the membrane lipid peroxidation of normal dog erythrocytes incubated with PBM from B. gibsoni-infected dogs was significantly higher (p<0.05) than that of erythrocytes incubated with PBM from non-infected dogs when the PBM were stimulated with the opsonized membranes. These results suggest that the oxidative damage of erythrocytes observed in B. gibsoni-infected dogs with low parasitemia might be induced, in part, by reactive oxygen species released from the activated PBM. On the other hand, the present study also showed a significant increase (p<0.001) of IgG-bound erythrocytes in B. gibsoni-infected dogs compared with such erythrocytes in non-infected dogs. The increase of IgG-bound erythrocytes in infected dogs might reflect the increase of erythrocytes with oxidative damage induced by the infection with B. gibsoni. The results of the present study suggest that the increase of IgG-bound erythrocytes in the circulation of infected dogs induce a high degree of erythrocyte loss via immunological phagocytosis by activated macrophages, resulting in severe anemia in spite of low parasitemia.  相似文献   

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