Molecular investigation of tick-borne haemoparasite infections among transhumant zebu cattle in Karamoja Region, Uganda

Byaruhanga, Charles; Collins, Nicola E.; Knobel, Darryn L.; Chaisi, Mamohale E.; Vorster, Ilse; Steyn, H.C.; Oosthuizen, Marinda C.

doi:10.1016/j.vprsr.2016.06.004

Cited by 26 publications

(39 citation statements)

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“…Since the sequence differences targeted by the qPCR primers and probes were highly conserved in all A. centrale and A. marginale groEL sequences examined, the groEL gene is, therefore, a good marker for the detection of A. centrale infections in cattle in South Africa. However, in a recent study on the occurrence of tick-borne infections in cattle samples from Uganda [ 53 ], RLB assay detected more A. centrale infections than the qPCR assay, indicating the possibility of groEL gene variants which cannot be detected by the qPCR assay. This highlights the necessity for testing the assay in each region in which it is to be deployed.…”

Section: Discussionmentioning

confidence: 99%

“…This is the first comprehensive study on the occurrence of A. centrale in cattle in all nine provinces of South Africa using a nucleic acid-based method, although we recently reported on the occurrence of this species in cattle in Bergville, KwaZulu-Natal province, South Africa [ 47 ]. Mixed infections of A. centrale and A. marginale have been reported in cattle and wildlife in South Africa [ 47 ] and in cattle elsewhere [ 20 , 53 , 57 ]. Although multiplex qPCR assays are recommended for detecting tick-borne pathogens, competitive PCR suppression may occur if infection levels are similar between two or more target species, or are higher in one species/target [ 58 ].…”

Section: Discussionmentioning

confidence: 99%

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Co-infections with multiple genotypes of Anaplasma marginale in cattle indicate pathogen diversity

et al. 2018

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BackgroundOnly a few studies have examined the presence of Anaplasma marginale and Anaplasma centrale in South Africa, and no studies have comprehensively examined these species across the whole country. To undertake this country-wide study we adapted a duplex quantitative real-time PCR (qPCR) assay for use in South Africa but found that one of the genes on which the assay was based was variable. Therefore, we sequenced a variety of field samples and tested the assay on the variants detected. We used the assay to screen 517 cattle samples sourced from all nine provinces of South Africa, and subsequently examined A. marginale positive samples for msp1α genotype to gauge strain diversity.ResultsAlthough the A. marginale msp1β gene is variable, the qPCR functions at an acceptable efficiency. The A. centrale groEL gene was not variable within the qPCR assay region. Of the cattle samples screened using the assay, 57% and 17% were found to be positive for A. marginale and A. centrale, respectively. Approximately 15% of the cattle were co-infected. Msp1α genotyping revealed 36 novel repeat sequences. Together with data from previous studies, we analysed the Msp1a repeats from South Africa where a total of 99 repeats have been described that can be attributed to 190 msp1α genotypes. While 22% of these repeats are also found in other countries, only two South African genotypes are also found in other countries; otherwise, the genotypes are unique to South Africa.ConclusionsAnaplasma marginale was prevalent in the Western Cape, KwaZulu-Natal and Mpumalanga and absent in the Northern Cape. Anaplasma centrale was prevalent in the Western Cape and KwaZulu-Natal and absent in the Northern Cape and Eastern Cape. None of the cattle in the study were known to be vaccinated with A. centrale, so finding positive cattle indicates that this organism appears to be naturally circulating in cattle. A diverse population of A. marginale strains are found in South Africa, with some msp1α genotypes widely distributed across the country, and others appearing only once in one province. This diversity should be taken into account in future vaccine development studies.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Co-infections with multiple genotypes of Anaplasma marginale in cattle indicate pathogen diversity

et al. 2018

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“…We recently reported the detection of the two Anaplasma spp. in cattle from Karamoja Region in north-eastern Uganda (Byaruhanga et al, 2016). In other African countries, varying prevalences of A. marginale were reported: 6.1% in Sudan (Awad et al, 2011), 25.4% in Tunisia (Belkahia et al, 2015), 89.7% in Madagascar (Pothmann et al, 2016) and 65% to 100% in South Africa (Mutshembele et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Molecular detection and phylogenetic analysis of Anaplasma marginale and Anaplasma centrale amongst transhumant cattle in north-eastern Uganda

Byaruhanga

Collins

Knobel

et al. 2018

Ticks and Tick-borne Diseases

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There is little molecular data from Anaplasma marginale and Anaplasma centrale isolates from cattle in Uganda. Between November 2013 and January 2014, blood was collected from 240 cattle in 20 randomly-selected herds in two districts of the Karamoja Region in north-eastern Uganda. A duplex quantitative real-time polymerase chain reaction (qPCR) assay was used to detect and determine the prevalence of A. marginale (targeting the msp1β gene) and A. centrale (targeting the groEL gene). The qPCR assay revealed that most cattle (82.9%; 95% confidence interval [CI] 78.2-87.7%) were positive for A. marginale DNA, while fewer cattle (12.1%; 95% CI 7.9-16.2%) were positive for A. centrale DNA. A mixed effects logistic regression model showed that the age of cattle was significantly associated with A. centrale infection, while the prevalence of A. marginale varied significantly according to locality. The near full-length 16S ribosomal RNA (16S rRNA) gene and the heat shock protein gene, groEL, for both Anaplasma species were amplified from a selection of samples. The amplicons were cloned and the resulting recombinants sequenced. We found three novel A. marginale 16S rRNA variants, seven A. marginale groEL gene sequence variants and two A. centrale groEL gene sequence variants. Phylogenetic trees were inferred from sequence alignments of the 16S rRNA gene and GroEL amino acid sequences determined here and published sequences using maximum likelihood, Bayesian inference and parsimony methods Phylogenetic analyses classified the 16S rRNA gene and GroEL amino acid sequences into one clade for A. marginale and a separate clade for A. centrale. This study reveals a high prevalence and sequence variability of A. marginale and A. centrale, and is the first report on the phylogenetic characterisation of A. marginale and A. centrale from cattle in Uganda using molecular markers. Sequence variation can be attributed to mobile pastoralism, communal grazing and grazing with wildlife. These data support future epidemiological investigations for bovine anaplasmosis in Uganda.

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“…The RLB hybridization assay has been used extensively for the routine screening of cattle and wildlife samples in South Africa and has the ability to detect up to 32 pathogens in one reaction. This technique has been used in the discovery of novel pathogens or genetic variants of known pathogens [ 55 , 56 ]. Its utility lies in its ability to detect Anaplasma , Ehrlichia , Babesia and Theileria parasites in a single reaction [ 46 , 57 ], and it is therefore a good screening tool to establish what pathogens might be in a sample.…”

Section: Detection Of a Marginale And mentioning

confidence: 99%

“…It was concluded that duplex qPCR is the most sensitive of these three methods, as it detected more A. marginale and A. centrale positive samples. The duplex qPCR assay has been used in our laboratory for detection and quantification of A. marginale and A. centrale infections in cattle and wildlife [ 20 , 54 , 55 ]. Using the qPCR assay, we determined the prevalence of 57% and 17%, respectively, for A. marginale and A. centrale infections in South African cattle, as well as a co-infection rate of 15%.…”

Section: Detection Of a Marginale And mentioning

confidence: 99%

Detection and Characterisation of Anaplasma marginale and A. centrale in South Africa

Hove

Khumalo

Chaisi

et al. 2018

Veterinary Sciences

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Bovine anaplasmosis is endemic in South Africa and it has a negative economic impact on cattle farming. An improved understanding of Anaplasma marginale and Anaplasma marginale variety centrale (A. centrale) transmission, together with improved tools for pathogen detection and characterisation, are required to inform best management practices. Direct detection methods currently in use for A. marginale and A. centrale in South Africa are light microscopic examination of tissue and organ smears, conventional, nested, and quantitative real-time polymerase chain reaction (qPCR) assays, and a reverse line blot hybridisation assay. Of these, qPCR is the most sensitive for detection of A. marginale and A. centrale in South Africa. Serological assays also feature in routine diagnostics, but cross-reactions prevent accurate species identification. Recently, genetic characterisation has confirmed that A. marginale and A. centrale are separate species. Diversity studies targeting Msp1a repeats for A. marginale and Msp1aS repeats for A. centrale have revealed high genetic variation and point to correspondingly high levels of variation in A. marginale outer membrane proteins (OMPs), which have been shown to be potential vaccine candidates in North American studies. Information on these OMPs is lacking for South African A. marginale strains and should be considered in future recombinant vaccine development studies, ultimately informing the development of regional or global vaccines.

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Molecular investigation of tick-borne haemoparasite infections among transhumant zebu cattle in Karamoja Region, Uganda

Cited by 26 publications

References 49 publications

Co-infections with multiple genotypes of Anaplasma marginale in cattle indicate pathogen diversity

Co-infections with multiple genotypes of Anaplasma marginale in cattle indicate pathogen diversity

Molecular detection and phylogenetic analysis of Anaplasma marginale and Anaplasma centrale amongst transhumant cattle in north-eastern Uganda

Detection and Characterisation of Anaplasma marginale and A. centrale in South Africa

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