Molecular detection and characterization of tick-borne haemoparasites among cattle on Zanzibar Island, Tanzania.

Tick-borne diseases (TBDs) are serious constraints to livestock production in Tanzania and other tropical and subtropical countries and impact the livelihoods of resource-poor farming communities in the region. In Tanzania, detailed studies on tick-borne pathogens (TBPs) in cattle using sensitive molecular detection methods are scarce. The objective of this study was to investigate the occurrence and species composition of bovine TBPs in cattle kept in Zanzibar Island. A total of 236 blood samples were randomly collected in cattle population in June and July 2019. We used polymerase chain reaction (PCR) and gene sequencing to detect and identify pathogens. PCR screening of all 236 samples revealed that 64.5% of animals were infected by TBPs, including Theileria parva (34.3%), T. mutans (38.1%), T. taurotragi (30.9%), Anaplasma marginale (10.2%), Babesia bigemina (5.1%), T. velifera (3.4%) and B. bovis (2.1%). Overall a total of 86 animals (36.4%) were co-infected with up to five pathogens including T. parva, T. mutans, T. taurotragi, A. marginale and B. bigemina. The pathogens mostly involved in the co-infection were T. parva, T. taurotragi and T. mutans. Sequence analysis indicated that T. parva p104 and B. bigemina RAP1a genes are diverse among the sampled animals in Zanzibar Island, with 99.64%-100% and 99.51%-100% nucleotide sequence identity value respectively. In contrast, the A. marginale MSP-5, T. mutans 18S rRNA V4 region and B. bovis SBP-2 genes are conserved, with 100%, 99.05%-100% and 99.66%-100% nucleotide sequence identity values respectively. The phylogenetic analyses revealed that T. parva p104 and B. bigemina RAP1a gene sequences showed significant differences of genotypes, as they appear in different clades. Meanwhile, A. marginale MSP-5, T. mutans 18S rRNA V4 region and B. bovis SBP-2 gene sequences appear in the same clade with other sequences extracted from the NCBI GenBank. The epidemiological findings revealed in this study will provide important information on tick-borne diseases in Tanzania and will be used as scientific basis for planning future control strategies.

Ringo AE ，Rizk MA ，Adjou Moumouni PF ，Liu M ，Galon EM ，Li Y ，Ji S ，Tumwebaze M ，Byamukama B ，Thekisoe O ，Xuan X ... -  《-》

Molecular detection and characterization of tick-borne protozoan and rickettsial pathogens isolated from cattle on Pemba Island, Tanzania.

Tick-borne diseases cause significant losses to livestock production in tropical and subtropical regions. In Tanzania, detailed studies on tick-borne pathogens in cattle using sensitive molecular detection methods are scarce. In this study, we investigated the occurrence of Theileria spp., Babesia spp., Anaplasma spp. and Ehrlichia spp. in 245 blood samples collected from cattle on Pemba Island, Tanzania. We used polymerase chain reaction (PCR) and gene sequencing to detect and identify pathogens. PCR screening revealed overall infection rates of 62.4% for Theileria spp., 17.6% for Babesia bigemina, 15.9% for Anaplasma marginale, 7.4% for Ehrlichia ruminantium and 4.5% for Babesia bovis. Further analysis using sequences of Theileria spp. 18S rRNA revealed infection of cattle with Theileria mutans (68.6%), Theileria taurotragi (48.4%), Theileria parva (41.2%), and Theileria ovis (1.9%). Co-infections of cattle, with up to six tick-borne pathogens, were revealed in 46.9% of the samples. Sequence analysis indicated that T. parva p104, E. ruminantium pCS20 and A. marginale MSP-5 genes are conserved among cattle blood samples in Pemba, with 99.3%-100%, 99.6%-100% and 100% sequence identity values, respectively. In contrast, the B. bigemina RAP-1a and B. bovis SBP-2 gene sequences were relatively diverse with 99.5%-99.9% and 66.4%-98.7% sequence identity values respectively. The phylogenetic analyses revealed that T. parva p104, E. ruminantium pCS20 and A. marginale MSP-5 gene sequences clustered in the same clade with other isolates from other countries. In contrast, the B. bigemina RAP-1 and B. bovis SBP-2 gene sequences showed significant differences in the genotypes, as they appeared in separate clades. This study provides important data for understanding the epidemiology of tick-borne diseases, and is expected to improve the approach for diagnosis and control of tick-borne diseases in Tanzania.

Ringo AE ，Adjou Moumouni PF ，Lee SH ，Liu M ，Khamis YH ，Gao Y ，Guo H ，Zheng W ，Efstratiou A ，Galon EM ，Li J ，Tiwananthagorn S ，Inoue N ，Suzuki H ，Thekisoe O ，Xuan X ... -  《-》

Occurrence of tick-borne haemoparasites in cattle in the Mungwi District, Northern Province, Zambia.

Little is known about the occurrence of haemoparasites in cattle in communal grazing areas of Mungwi District of Northern Province, Zambia. Clinical signs and post mortem lesions are pathognomonic of mixed tick-borne infections especially babesiosis, anaplasmosis and East Coast fever. The main objective of this study was to screen selected communal herds of cattle for tick-borne haemoparasites, and identify the tick vectors associated with the high cattle mortalities due to suspected tick-borne diseases in the local breeds of cattle grazing along the banks of the Chambeshi River in Mungwi District, Northern Province, Zambia. A total of 299 cattle blood samples were collected from July to September 2010 from Kapamba (n = 50), Chifulo (n = 102), Chisanga (n = 38), Kowa (n = 95) and Mungwi central (n = 14) in the Mungwi District. A total of 5288 ticks were also collected from the sampled cattle from April to July 2011. DNA was extracted from the cattle blood and the hypervariable region of the parasite small subunit rRNA gene was amplified and subjected to the reverse line blot (RLB) hybridization assay. The results of the RLB assay revealed the presence of tick-borne haemoparasites in 259 (86.6%) cattle blood samples occurring either as single (11.0%) or mixed (75.6%) infections. The most prevalent species present were the benign Theileria mutans (54.5%) and T. velifera (51.5%). Anaplasma marginale (25.7%), Babesia bovis (7.7%) and B. bigemina (3.3%) DNA were also detected in the samples. Only one sample (from Kapamba) tested positive for the presence of T. parva. This was an unexpected finding; also because the tick vector, Rhipicephalus appendiculatus, was identified on animals from Kowa (14.0%), Chisanga (8.5%), Chifulo (6.0%) and Kapamba (1.4%). One sample (from Kapamba) tested positive for the presence of Ehrlichia ruminantium even though Amblyomma variegatum ticks were identified from 52.9% of the sampled animals from all study areas. There was significant positive association between T. mutans and T. velifera (p < 0.001) infections, and between A. marginale and B. bovis (p = 0.005). The presence of R. microplus tick vectors on cattle was significantly associated with B. bovis (odds ratio, OR = 28.4, p < 0.001) and A. marginale (OR = 42.0, p < 0.001) infections, while A. variegatum presence was significantly associated with T. mutans (OR = 213.0, p < 0.001) and T. velifera (OR = 459.0, p < 0.001) infections. Rhipicephalus decoloratus was significantly associated with B. bigemina (OR = 21.6, p = 0.004) and A. marginale (OR = 28.5, p < 0.001). Multivariable analysis showed a significant association between location and tick-borne pathogen status for A. marginale (p < 0.001), T. mutans (p = 0.004), T. velifera (p = 0.003) and T. taurotragi (p = 0.005). The results of our study suggest that the cause of cattle mortalities in Mungwi during the winter outbreaks is mainly due to A. marginale, B. bovis and B. bigemina infections. This was confirmed by the clinical manifestation of the disease in the affected cattle and the tick species identified on the animals. The relatively low prevalence of T. parva, B. bigemina, B. bovis and E. ruminantium could indicate the existence of endemic instability with a pool of susceptible cattle and the occurrence of disease outbreaks.

Tembo S ，Collins NE ，Sibeko-Matjila KP ，Troskie M ，Vorster I ，Byaruhanga C ，Oosthuizen MC ... -  《-》

Molecular detection of tick-borne pathogens in cattle from Southwestern Ethiopia.

Tick-borne diseases (TBDs) cause significant losses among livestock and impact the livelihoods of resource-poor farming communities worldwide. In Ethiopia, detailed studies on the epidemiology of tick-borne pathogens (TBPs) in cattle using sensitive molecular detection methods are scarce. The objective of this study was to determine the prevalence and species composition of bovine TBPs of veterinary significance in local cattle populations. A comprehensive cross-sectional epidemiological study was conducted in cattle populations of Illubabor zone in Southwestern Ethiopia from June to August 2013. For this purpose, blood samples were collected from 392 cattle. A combination of polymerase chain reaction (PCR) and a Reverse Line Blot (RLB) hybridization assay was employed for the detection of TBPs in these samples. The PCR/RLB results of the 392 blood samples indicated a high overall prevalence of 96.9% for TBPs, including Theileria mutans (66.1%), Theileria orientalis (51.8%), Anaplasma sp. Omatjenne (25.5%), Anaplasma marginale (14.5%), Babesia bigemina (14.0%) and Theileria velifera (13.0%) and minor occurrences of Ehrlichia ruminantium (0.5%) and Ehrlichia minasensis (0.26%). Moreover, three novel Anaplasma genotypes were detected in bovine blood samples. A phylogenetic analysis revealed that they most likely represent three, but at least two, new species. The prevalence of the three novel Anaplasma species, preliminary designated as Anaplasma sp. Hadesa, Anaplasma sp. Saso and Anaplasma sp. Dedessa, was 12.5%, 14.3% and 5.6%, respectively. Overall, a total of 227 cattle (57.9%) were found to be co-infected with two or more TBPs simultaneously and 86 different species combinations were observed. The findings show a very high burden of infection of cattle with TBPs in Ethiopia. The high frequency of co-infections suggests that clinical manifestations might be complex. Further research is required to determine the pathogenicity, host cell types and vector of the three novel Anaplasma species identified in this study.

Hailemariam Z ，Krücken J ，Baumann M ，Ahmed JS ，Clausen PH ，Nijhof AM ... -  《PLoS One》

Molecular detection and characterization of Babesia bovis, Babesia bigemina, Theileria species and Anaplasma marginale isolated from cattle in Kenya.

Infections with Babesia bovis, Babesia bigemina, Theileria species and Anaplasma marginale are endemic in Kenya yet there is a lack of adequate information on their genotypes. This study established the genetic diversities of the above tick-borne hemoparasites infecting cattle in Kenya. Nested PCR and sequencing were used to determine the prevalence and genetic diversity of the above parasites in 192 cattle blood samples collected from Ngong and Machakos farms. B. bovis spherical body protein 4, B. bigemina rhoptry-associated protein 1a, A. marginale major surface protein 5, Theileria spp. 18S rRNA, T. parva p104 and T. orientalis major piroplasm surface protein were used as the marker genes. B. bovis, B. bigemina, T. parva, T. velifera, T. taurotragi, T. mutans and A. marginale were prevalent in both farms, whereas T. ovis, Theileria sp. (buffalo) and T. orientalis were found only in Ngong farm. Co-infections were observed in more than 50 % of positive samples in both farms. Babesia parasites and A. marginale sequences were highly conserved while T. parva and T. orientalis were polymorphic. Cattle-derived T. parva was detected in Machakos farm. However, cattle and buffalo-derived Theileria were detected in Ngong farm suggesting interactions between cattle and wild buffaloes. Generally, the pathogens detected in Kenya were genetically related to the other African isolates but different from the isolates in other continents. The current findings reaffirm the endemicity and co-infection of cattle with tick-borne hemoparasites, and the role of wildlife in pathogens transmission and population genetics in Kenya.

Adjou Moumouni PF ，Aboge GO ，Terkawi MA ，Masatani T ，Cao S ，Kamyingkird K ，Jirapattharasate C ，Zhou M ，Wang G ，Liu M ，Iguchi A ，Vudriko P ，Ybanez AP ，Inokuma H ，Shirafuji-Umemiya R ，Suzuki H ，Xuan X ... -  《Parasites & Vectors》