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At least 19 recordsLinked to original sources

PubMed1991

An Anaplasma centrale DNA probe that differentiates between Anaplasma ovis and Anaplasma marginale DNA.

An Anaplasma centrale genomic library was constructed in pUC13. Two clones pAC5 and pAC137 hybridising to A. centrale and A. marginale DNA were isolated from this library. One of these, pAC5, also hybridised to DNA from A. ovis. The total insert of pAC5 was subcloned into pBR322. This subclone, pAC5-12, could detect 1 ng A. centrale, 0.5 ng A. marginale and 3.9 ng A. ovis DNA. The hybridisation pattern obtained with pAC5-12 on digests of A. centrale, A. marginale and A. ovis DNA suggests that this probe detects EcoR1 and Hind111-polymorphisms. Probe pAC5-12 could detect A. ovis DNA in 36% of blood samples tested compared to the 33% detectability obtained with microscopy.

Anaplasma↗

PubMed1980

Characterization of immune responses of cattle to erythrocyte stroma, Anaplasma antigen, and dodecanoic acid-conjugated Anaplasma antigen: humoral immunity.

Normal erythrocyte antigen (sonically disrupted erythrocyte stroma; SES) and two anaplasma antigens (sonically disrupted anaplasma antigen; SAA, and French pressure cell-disrupted anaplasma antigen; FAA) were prepared from normal and Anaplasma marginale-infected blood. Portions of SAA and FAA antigens were chemically modified by conjugation with dodecanoic acid (SAADA and FAADA). Eleven cattle were vaccinated with SES, SAA, SAADA, or FAADA. Five weeks later, the 11 cattle, together with 3 controls, were challenge exposed with A marginale. The anti-anaplasma antibody response and the antierythrocyte-antibody response (including the blood group isoantibody response) were evaluated. Only SAA-vaccinated cattle developed anti-anaplasma antibody before challenge exposure. Isoantibodies were developed by 1 of the 3 SAADA-vaccinated cows and 1 of the 2 FAADA-vaccinated cows, as well as by all 3 SAA-vaccinated cows. After challenge exposure, all cattle developed anti-anaplasma antibody and antierythrocyte autoantibody.

Agglutination Tests↗

PubMed2026

Molecular epidemiology and phylogenetic analysis of Anaplasma ovis and Anaplasma marginale in Ixodidae infesting livestock in northwestern Iran.

BACKGROUND: Anaplasma marginale and Anaplasma ovis are tick-borne obligate intracellular bacteria causing anaplasmosis in cattle and small ruminants, respectively, with considerable economic losses worldwide. Given the favorable ecological conditions for tick survival and the limitation of data on Anaplasma spp. in local tick populations in northwestern Iran, this study aimed to molecular and phylogenetic analysis of A. ovis and A. marginale in Ixodidae infesting livestock in northwestern Iran. METHODS: In this cross-sectional study, a total of 780 ixodid ticks were collected from livestock across 198 herds in 11 counties of Ardabil Province during 2025. Ticks were morphologically identified and grouped into pools based on species and host type. Genomic DNA was extracted using a commercial kit and molecular detection of A. ovis and A. marginale was performed using PCR assays targeting the 16 S rRNA and groEL genes. Positive samples were submitted for Sanger sequencing to confirm the identity of Anaplasma spp., phylogenetic analysis was conducted using reference sequences from GenBank (NCBI) using MEGA software (version 12). Statistical analyses were conducted using SPSS (version 25), and associations between categorical variables were assessed using Fisher's exact test (p < 0.05). RESULTS: Eight tick species belonging to three genera were identified. Among the hosts, sheep exhibited the highest infestation rate (49.3%). Hyalomma anatolicum anatolicum was the most prevalent species (25.3%) and was present in all sampled counties. Tick distribution varied significantly among host species (p = 0.003) and geographic locations (p = 0.002). PCR analysis detected A. ovis DNA in 16.6% (4/24) and A. marginale DNA in 8.3% (2/24) of tick pools. Positive pools were primarily associated with Rhipicephalus spp. and Dermacentor marginatus. According to the results of the statistical analysis a significant association was found between tick species and host type (χ² = 13.87, p = 0.0031), with Hyalomma anatolicum anatolicum more prevalent in sheep (p = 0.001). Tick abundance varied across counties (χ² = 16.42, p = 0.002), with highest densities in Nir, Khalkhal, and Kowsar (χ² = 14.21, p = 0.0028). No significant association was observed between Anaplasma positivity and tick species (p = 0.21) or host type (p = 0.09). CONCLUSIONS: The detection of A. ovis and A. marginale DNA in ixodid tick pools indicates their circulation in Ardabil Province. However, due to pooled sampling and the limited number of positive samples, the infection rate at the individual tick level could not be determined. These findings also highlight the importance of a One Health approach, considering the interconnected roles of animal health, tick vectors, and the environment in the transmission and control of tick-borne diseases.

Animals↗

PubMed1987

The persistence of colostral Anaplasma antibodies and incidence of in utero transmission of Anaplasma infections in calves under laboratory conditions.

Twenty-six calves, born from 25 Anaplasma-infected, intact and splenectomized cows, from a herd kept under strict tick-free laboratory conditions, were monitored for the presence of Anaplasma antibodies, using the rapid card agglutination test. Serum was collected at birth, weekly for 12 weeks, and then monthly for approximately 6 months. Specific antibodies passively acquired could be detected in calf sera for an average period of 8 weeks after birth. Calves that remained positive for longer than 12 weeks were suspected of having contracted in utero infections. Infection of the calves was confirmed by splenectomy. It was concluded that 4 calves in Group I contracted in utero infections. Two of the dams were chronically infected, whilst the other 2 underwent acute primary reactions during the 1st and 2nd trimesters of gestation, respectively. Subsequently all calves born from infected cows in this tick-free herd were serologically screened before being splenectomized at an average age of 8 months. Out of 50 cows, 8 in utero infected calves were identified serologically and this finding was confirmed through splenectomy or subinoculation of blood. Both Anaplasma centrale and Anaplasma marginale were carried transplacentally. Splenectomized and intact cows, chronically infected or undergoing primary reactions during the 1st, 2nd or 3rd trimester of gestation, produced infected calves. A 15,6% incidence of in utero transmitted infections were observed amongst 77 calves under these conditions. None of the 13 splenectomized cows, undergoing primary A. centrale infections during gestation, aborted. Clinical signs of disease were not observed in any of the 12 in utero infected calves prior to splenectomy. The implications of these findings are discussed.

Anaplasmosis↗

PubMed1977

Finite purification of Anaplasma marginale: serologic inactivity of the anaplasma body.

Anaplasma bodies finitely purified by affinity chromatography to eliminate all traces of erythrocytic stromata were not agglutinated by serum from calves having acute anaplasmosis. The stromata which were associated with the anaplasma bodies were also finitely purified and agglutinated with such serum. The evidence indicates that the antibody in anaplasmosis that is detected by agglutination tests is directed against the erythrocytic stromata and not against the finitely purified anaplasma bodies.

Anaplasma↗

PubMed1987

Vaccination with Anaplasma centrale: response after an experimental challenge with Anaplasma marginale.

The haematological and clinical responses to vaccination with Anaplasma centrale and to subsequent challenge with Anaplasma marginale were evaluated. Twenty Holstein steers 14 to 16 months of age were divided into two groups of 12 and eight animals respectively (groups I and II). Group I was inoculated on day zero with 10(7) A. centrale-infected erythrocytes and group II was kept as a control. On day 125 both groups were challenged with 5 X 10(7) A. marginale-infected erythrocytes. A. centrale inoculation produced low parasitaemias (maximum mean 2.7%), moderate packed cell volume (PCV) falls (minimum mean 20.5%) and no clinical symptoms. After the challenge group I had significantly lower parasitaemia (maximum mean 2.3%) and higher PCV (minimum mean 20.1%) than group II (7.5% and 14.5% respectively). Four steers from group II developed acute anaplasmosis and required treatment.

Anaplasma↗

PubMed1991

Identification of immunodominant polypeptides common between Anaplasma centrale and Anaplasma marginale.

High titered antibody from rabbits immunized with Anaplasma centrale or from cattle recovered from A. centrale infection bound predominantly to several 33-36 kDa polypeptides present in both A. centrale and the Israel-NT isolate of Anaplasma marginale. High titered bovine antibody against the Israel-NT isolate of A. marginale also reacted predominantly with A. centrale polypeptides in this size range. The immunodominance of the 33-36 kDa polypeptides and their cross-reactivity indicate that these shared epitopes may be primarily responsible for the cross-protective immunity between A. centrale and A. marginale.

Anaplasma↗

PubMed1992

The Anaplasma marginale msp5 gene encodes a 19-kilodalton protein conserved in all recognized Anaplasma species.

Immunization with Anaplasma marginale outer membranes induced immunity against clinical disease which correlated with antibody titer to outer membrane proteins, including a 19-kDa protein (N. Tebele, T. C. McGuire, and G. H. Palmer, Infect. Immun. 59:3199-3204, 1991). This 19-kDa protein, designated major surface protein 5 (MSP-5), was encoded by a single-copy 633-bp gene. The molecular mass of MSP-5, defined in immunoblots by binding to monoclonal antibody ANAF16C1, was conserved among all recognized species of Anaplasma: A. marginale, A. centrale, and A. ovis. Recombinant MSP-5, which absorbed the antibody reactivity of bovine immune serum to native MSP-5, was recognized by anti-A. marginale and anti-A. centrale immune sera in a competitive inhibition assay with monoclonal antibody ANAF16C1. The presence of antibody to the epitope defined by monoclonal antibody ANAF16C1 in all postinfection sera tested indicates that this epitope is a potential diagnostic antigen for use in identifying persistently infected cattle.

Amino Acid Sequence↗

PubMed1987

DNA probes for the detection of Anaplasma centrale and Anaplasma marginale.

Anaplasmosis can be diagnosed either by immunological techniques or by direct microscopic examination of blood smears. Both methods are time-consuming and labour intensive. The use of DNA probes in an hybridization assay may simplify the diagnosis of anaplasmosis in cattle and sheep. A genomic DNA library of Anaplasma centrale was constructed in an expression vector and screened to detect clones containing A. centrale DNA. Four probes which hybridized to A. centrale and Anaplasma marginale DNA were isolated. One of these (AC-1) hybridized only to A. centrale DNA, whereas AC-2, AC-3 and AC-4 could detect DNA from both A. centrale and A. marginale. Probes AC-1 and AC-2 could detect 127 ng and 8 ng DNA respectively, while AC-3 and AC-4 detected 64 ng A. centrale DNA.

Anaplasma↗

PubMed1990

An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to Anaplasma centrale and Anaplasma marginale.

An enzyme-linked immunoassay (ELISA) was applied to detect antibodies to A. centrale and A. marginale using homologous and heterologous antigens. The assay was compared with the indirect fluorescent antibody (IFA) test, and although a similar degree of sensitivity was obtained, the ELISA test had several advantages. Partially purified Anaplasma initial bodies used for antigen preparations contained negligible amounts of residual erythrocytic material, and did not interfere with the specificity of the ELISA. The antigenic similarity between A. marginale and A. centrale was further substantiated by cross-reactivity obtained with heterologous antigens in both ELISA and IFA tests, and antibodies produced during natural infection with A. marginale were indistinguishable in both tests from those produced following vaccination with A. centrale.

Anaplasma↗

PubMed1991

Analysis of protein compositions and surface protein epitopes of Anaplasma centrale and Anaplasma marginale.

Protein composition was compared and epitopes were analyzed among the isolates of Anaplasma centrale and A. marginale by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting using bovine antisera and monoclonal antibodies, and enzyme-linked immunosorbent assay. Common and unique proteins were found among the isolates. All isolates tested had a major surface protein with an apparent molecular weight of 38 to 40 kilodalton which had slight molecular size variations between species. This protein was also a dominant immunogen to the host. At least two species-common epitopes, one of which might contain carbohydrate(s), were present on the major surface protein. One species-specific epitope was identified on the major surface protein of A. marginale isolates.

Anaplasma↗

PubMed1990

Frozen and fresh Anaplasma centrale vaccines in the protection of cattle against Anaplasma marginale infection.

The immunity induced by frozen and fresh Anaplasma centrale vaccines against anaplasmosis caused by A. marginale was tested in 12-month old Friesian steers. A. centrale parasitaemia occurred in all cattle inoculated with both types of vaccine. The average maximal decrease in PCV for the frozen and fresh vaccines was 41.0 and 40.3% respectively. All cattle recovered spontaneously. Vaccinated and control steers of the same age were challenged six months later with doses of 10(6), 10(7) or 10(8) A. marginale organisms. Vaccinated cattle showed average maximal A. marginale parasitemia of 1.2-4.0 versus 10.3-12.0% in control cattle. The average maximal decrease in packed cell volume (PCV) was 33.1 and 30.0% for steers vaccinated with frozen or fresh vaccine, respectively, and 57.4% for the non-vaccinated steers. All vaccinated cattle recovered spontaneously from the A. marginale infection while 7 out of 8 control steers required specific treatment. It thus appears that both frozen and fresh A. centrale vaccines are equally capable of inducing partial protection against infection with A. marginale and of preventing severe red blood cell destruction.

Anaplasma↗

PubMed1983

Influence of a second Anaplasma exposure on the success of treatment to eliminate Anaplasma carrier infections in cattle.

Treatment of adult Anaplasma carrier cows, with long-acting oxytetracycline at dosage levels generally successful in eliminating infection, was unsuccessful when the treatment was preceded or accompanied by a 2nd exposure to A marginale on days 0, 7, or 14 before treatment. Noninfected calves exposed to A marginale 7 days before a similar treatment developed anaplasmosis and became carriers of infection.

Anaplasma↗

PubMed1988