RESUMEN
Haematological and molecular analysis of blood samples was carried out during an outbreak of bovine anaplasmosis in Hungary. Acute disease was observed in five animals, two of which died. Anaplasma-carrier state was diagnosed in 69 (92%) of cattle. Further evaluation of 24 blood samples revealed concurrent infections with Mycoplasma wenyonii and 'CandidatusM. haemobos' in 22 and 21 animals, respectively. In addition, two cows were identified with rickettsaemia. Regarding molecular investigation of potential hard tick vectors, Haemaphysalis inermis and Dermacentor marginatus males collected from the animals were PCR-negative. However, in one pool (out of 18) of Ixodesricinus males, and in six pools (out of 18) of D. reticulatus males the msp4 gene of Anaplasma marginale was detected. In the same I. ricinus pool Anaplasma ovis was also identified. All ticks were negative for haemoplasmas. Anaplasma sequences yielded 97-99% homology to sequences deposited in the Genbank. This is the first report of fatal bovine anaplasmosis associated with divergent A. marginale genotypes and concurrent 'CandidatusM. haemobos' infection, as well as of an A. ovis strain in ticks collected from cattle.
Asunto(s)
Anaplasma marginale/genética , Anaplasma ovis/genética , Anaplasmosis/microbiología , Enfermedades de los Bovinos/microbiología , Coinfección/veterinaria , Brotes de Enfermedades/veterinaria , Genotipo , Anaplasma marginale/aislamiento & purificación , Anaplasma ovis/aislamiento & purificación , Anaplasmosis/epidemiología , Anaplasmosis/transmisión , Animales , Vectores Arácnidos/microbiología , Proteínas Bacterianas/genética , Secuencia de Bases , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/transmisión , Coinfección/epidemiología , Coinfección/microbiología , ADN Bacteriano/análisis , ADN Bacteriano/genética , Dermacentor/microbiología , Hungría/epidemiología , Ixodes/microbiología , Masculino , Proteínas de la Membrana/genética , Datos de Secuencia Molecular , Mycoplasma/genética , Mycoplasma/aislamiento & purificación , Infecciones por Mycoplasma/microbiología , Infecciones por Mycoplasma/veterinaria , Filogenia , Reacción en Cadena de la Polimerasa/veterinaria , Prevalencia , Rickettsia/genética , Rickettsia/aislamiento & purificación , Infecciones por Rickettsia/microbiología , Infecciones por Rickettsia/veterinariaRESUMEN
The present study was carried out in a herd with concurrent infections of Mycoplasma wenyonii and 'Candidatus M. haemobos', to investigate if transplacental and/or vector-borne transmission is possible for one or both bovine haemoplasma species. For this purpose blood samples were collected from 38 mother animals and their newborn calves; as well as from 17 uninseminated cows twice three months apart. In addition, 311 mosquitoes and blood-sucking flies (Diptera: Culicidae, Tabanidae, Muscidae) were cought near the animals. DNA was extracted from all samples, followed by real-time PCR analysis. In 10.5% of neonate calves, that were born to cows harbouring both haemoplasmas, M. wenyonii and/or 'Candidatus M. haemobos' positivity was detected. Copy numbers in positive samples from cows and their calves indicated that - in comparison with M. wenyonii - 'Candidatus M. haemobos'-bacteraemia had usually lower levels. In samples of uninseminated cows the rate of infection with the latter species decreased. These findings may explain why M. wenyonii was significantly more frequently detected in blood-sucking flies, than 'Candidatus M. haemobos'. In conclusion, molecular evidence is provided for the first time on the transplacental transmission of bovine haemoplasmas. Regarding their spread by blood-sucking arthropods, new potential vectors were identified, i.e. the horn fly (Haematobia irritans), the stable fly (Stomoxys calcitrans) and two species of horse flies (Tabanus bovinus, T. bromius).
