RESUMO
Ehrlichia minasensis is a new pathogenic bacterial species that infects cattle, and Borrelia theileri causes bovine borreliosis. We detected E. minasensis and B. theileri DNA in cattle from southwestern Colombia by using PCR. E. minasensis and B. theileri should be considered potential etiologies of febrile syndrome in cattle from Colombia.
Assuntos
Infecções por Borrelia , Doenças dos Bovinos , Animais , Infecções por Borrelia/veterinária , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Colômbia/epidemiologia , DNA , Reação em Cadeia da PolimeraseRESUMO
The Anaplasmataceae family is composed of obligatory intracellular Gram-negative bacteria transmitted by arthropod vectors. In Brazil, with the exception of Anaplasma marginale, little is known about the occurrence of other Anaplasma and Ehrlichia species infecting cattle. The present study aimed at investigating the occurrence of Anaplasma spp. and Ehrlichia spp. in beef cattle (Bos indicus) sampled in the Brazilian Pantanal, an area prone to periodic flooding and endemic for bovine trypanosomiasis. Blood samples from 400 cattle were collected and screened by PCR assays based on rrs and dsb genes from Anaplasma spp. and Ehrlichia spp., respectively. Positive samples for Anaplasma spp. were subjected to qPCR assays based on the msp-2 gene and nPCR based on the groEL gene. As a result, 4.75% (19/400) and 48.12% (167/347) were positive for Anaplasma platys and Ehrlichia minasensis, respectively. Besides, positivity of 56.75% (227/400) for A. marginale and seropositivity of 90.75% (363/400) for Trypanosoma vivax were found. A high rate of co-infection was observed (67.25%), from which the co-infection by A. marginale and E. minasensis was more frequently found in calves than cows. Interestingly, none of the animals presenting co-infection showed anemia or other clinical signs. The present study showed, for the first time, the occurrence of A. platys and E. minasensis in beef cattle in the southern Pantanal, as well as a high rate of co-infection by A. marginale, E. minasensis and T. vivax in the sampled animals.
Assuntos
Anaplasmose/epidemiologia , Anemia/veterinária , Coinfecção/veterinária , Ehrlichiose/veterinária , Anaplasma/fisiologia , Anaplasma marginale/fisiologia , Anaplasmose/complicações , Anaplasmose/microbiologia , Anemia/complicações , Anemia/epidemiologia , Anemia/etiologia , Animais , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Coinfecção/epidemiologia , Coinfecção/microbiologia , Ehrlichia/fisiologia , Ehrlichiose/complicações , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologiaRESUMO
The genus Ehrlichia is composed of tick-borne obligate intracellular gram-negative alphaproteobacteria of the family Anaplasmataceae. Ehrlichia includes important pathogens affecting canids (E. canis, E. chaffeensis, and E. ewingii), rodents (E. muris), and ruminants (E. ruminantium). Ehrlichia minasensis, an Ehrlichia closely related to E. canis, was initially reported in Canada and Brazil. This bacterium has now been reported in Pakistan, Malaysia, China, Ethiopia, South Africa, and the Mediterranean island of Corsica, suggesting that E. minasensis has a wide geographical distribution. Previously, E. minasensis was found to cause clinical ehrlichiosis in an experimentally infected calf. The type strain E. minasensis UFMG-EV was successfully isolated from Rhipicephalus microplus ticks and propagated in the tick embryonic cell line of Ixodes scapularis (IDE8). However, the isolation and propagation of E. minasensis strains from cattle has remained elusive. In this study, the E. minasensis strain Cuiabá was isolated from an eight-month-old male calf of Holstein breed that was naturally infected with the bacterium. The calf presented clinical signs and hematological parameters of bovine ehrlichiosis. The in vitro culture of the agent was established in the canine cell line DH82. Ehrlichial morulae were observed using light and electron microscopy within DH82 cells. Total DNA was extracted, and the full genome of the E. minasensis strain Cuiabá was sequenced. A core-genome-based phylogenetic tree of Ehrlichia spp. and Anaplasma spp. confirmed that E. minasensis is a sister taxa of E. canis. A comparison of functional categories among Ehrlichia showed that E. minasensis has significantly less genes in the 'clustering-based subsystems' category, which includes functionally coupled genes for which the functional attributes are not well understood. Results strongly suggest that E. minasensis is a novel pathogen infecting cattle. The epidemiology of this Ehrlichia deserves further attention because these bacteria could be an overlooked cause of tick-borne bovine ehrlichiosis, with a wide distribution.