RESUMO
Descriptions of Babesia occultans have previously been restricted to sub-Saharan Africa. Here, we report the finding, for the first time, of this low or non-pathogenic bovine Babesia species in Tunisia, northern Africa. B. occultans DNA was detected by molecular methods in Hyalomma marginatum unfed ticks collected in 3 bioclimatic regions of Tunisia. The near-full-length 18S rRNA gene was sequenced and compared with related sequences retrieved from GenBank. Phylogenetic analysis indicated that other sequences deposited as Babesia sp. could also correspond to B. occultans, suggesting that this species may have a wide distribution in Mediterranean and Asiatic regions, and not only in sub-Saharan Africa as previously described. A B. occultans-specific Reverse Line Blot (RLB) oligonucleotide probe was designed for future epidemiological studies that would help to clarify this possibility.
Assuntos
Vetores Aracnídeos/parasitologia , Babesia/isolamento & purificação , Babesiose/veterinária , Doenças dos Bovinos/parasitologia , Ixodidae/parasitologia , Animais , Babesia/classificação , Babesia/genética , Babesiose/parasitologia , Babesiose/transmissão , Sequência de Bases , Bovinos , Doenças dos Bovinos/transmissão , DNA de Protozoário/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Feminino , Doenças dos Cavalos/parasitologia , Cavalos , Masculino , Dados de Sequência Molecular , Sondas de Oligonucleotídeos/genética , Filogenia , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 18S/genética , Alinhamento de Sequência/veterinária , Especificidade da Espécie , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária , TunísiaRESUMO
Canine babesiosis, caused by intra-erythrocytic Babesia, is a tick-borne disease of worldwide importance. No information on canine babesiosis has been documented in Tunisia. Detection and analysis of Babesia species from naturally infected dogs and ticks recovered from dogs were attempted by reverse line blot hybridization and nucleotide sequence analysis based on 18S rRNA gene. Out of 180 blood samples collected from domestic dogs in 4 villages situated in different bioclimatic zones, 12 were positive for Babesia canis vogeli. In addition, a total of 160 Rhipicephalus sanguineus were analysed; only one male was infected by B. canis vogeli. This is the first report on the detection of DNA belonging to B. canis vogeli in domestic dogs and in R. sanguineus in Tunisia.
Assuntos
Vetores Aracnídeos/parasitologia , Babesia/isolamento & purificação , Babesiose/veterinária , Doenças do Cão/parasitologia , Rhipicephalus sanguineus/parasitologia , Animais , Babesia/classificação , Babesia/genética , Babesiose/epidemiologia , Babesiose/parasitologia , Sequência de Bases , Estudos Transversais , DNA de Protozoário/química , DNA de Protozoário/genética , Doenças do Cão/epidemiologia , Cães , Feminino , Amplificação de Genes , Masculino , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 18S/genética , Alinhamento de Sequência/veterinária , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária , Tunísia/epidemiologiaRESUMO
A total 576 adult ixodid ticks, collected in seven sites in Northern Tunisia, were analysed for piroplasm infection. Reverse line blot analysis identified nine different piroplasms, with an overall prevalence of 22.7%. 17.8% were Theileria spp. positive, 8.5% were positive for Babesia spp. and 3.6% of ticks harboured both genera. Although, most of the positive ticks harboured a single infection (17%), mixed infections with two, three or four different piroplasm species were also detected (5.7%).
Assuntos
Babesia/isolamento & purificação , Theileria/isolamento & purificação , Carrapatos/parasitologia , Animais , Babesia/classificação , DNA de Protozoário/genética , Especificidade da Espécie , Theileria/classificação , Carrapatos/classificação , TunísiaRESUMO
A seroepidemiological survey was conducted in five bioclimatic areas of Tunisia to determine the prevalence of antibodies to Ehrlichia canis and Anaplasma phagocytophilum antigens, surrogate markers of the agents of canine monocytic ehrlichiosis (CME) and canine granulocytic ehrlichiosis, respectively. Among 286 collected sera, 54.2% and 25.2% were seropositive for E. canis and A. phagocytophilum, respectively, by the indirect immunofluorescence antibody (IFA) test. Clinical and hematological tests were done only for 58 sick dogs from Tunis area. A reverse line blot (RLB) hybridization was then used to identify isolated Ehrlichia and Anaplasma species infecting dogs (n = 228). Among them, only two dogs were infected by A. phagocytophilum; ten sample dogs were demonstrated infected by E. canis and ten infected by Ehrlichia sp., from which one dog showed a mixed infection with A. phagocytophilum and E. canis and one with A. phagocytophilum and Ehrlichia sp. RLB findings were confirmed by sequencing; BLAST search against GenBank revealed high similarity of the sequence of Ehrlichia sp. PCR/RLB amplicons with Anaplasma platys 16S rRNA partial sequence.
Assuntos
Anaplasma phagocytophilum , Anaplasmose , Doenças do Cão , Ehrlichia canis , Ehrlichiose/veterinária , Anaplasma phagocytophilum/genética , Anaplasma phagocytophilum/imunologia , Anaplasma phagocytophilum/patogenicidade , Anaplasmose/epidemiologia , Anaplasmose/microbiologia , Anaplasmose/fisiopatologia , Animais , Anticorpos Antibacterianos/sangue , DNA Bacteriano/análise , Doenças do Cão/epidemiologia , Doenças do Cão/imunologia , Doenças do Cão/fisiopatologia , Cães , Ehrlichia canis/genética , Ehrlichia canis/imunologia , Ehrlichia canis/patogenicidade , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Tunísia/epidemiologiaRESUMO
Between October and November 2006, a total of 278 bovine blood samples were examined, and 104 (37.4%) were positive for piroplasms by microscopy. A reverse line blot hybridisation with polymerase chain reaction detected Theileria annulata, T. buffeli, Babesia bovis and B. bigemina in cattle accounting for 48.6% of positive samples. The most frequently found species was T. buffeli, which was present in 39.2% of the samples. T. annulata was found in 48 samples (17.3%). Babesia infections were less frequently detected: B. bovis was found in 6.8% of the samples and B. bigemina in 4.3%. Mixed infections were detected in 45 samples, accounting for seven different combinations of species. Seven Ixodid tick species (Boophilus annulatus, Ixodes ricinus, Hyalomma marginatum, Hyalomma excavatum, Hyalomma detritum, Haemaphysalis punctata and Haemaphysalis sulcata) were collected from examined cattle in the 23 visited farms. I. ricinus was the dominant species (36%), mainly collected in the humid zone, while it seemed to be very rare in the semi-arid zone (where only 15 specimens were collected), whereas B. annulatus was the most commonly collected species in the sub-humid area (68.5% of ticks collected in this zone).