Molecular prevalence of emerging Anaplasma and Ehrlichia pathogens in apparently healthy dairy cattle in peri-urban Nairobi, Kenya

Abstract

Background Anaplasma and Ehrlichia species are tick-borne pathogens of both veterinary and public health importance. The current status of these pathogens, including emerging species such as Ehrlichia minasensis and Anaplasma platys, infecting cattle in Kenya, remain unclear, mainly because of limitation in the diagnostic techniques. Therefore, we investigated the Anaplasma and Ehrlichia species infecting dairy cattle in Nairobi, Kenya using molecular methods. Results A total of 306 whole blood samples were collected from apparently healthy dairy cattle. Whole blood DNA was extracted and tested for presence of Anaplasma and Ehrlichia DNA through amplification and sequencing of the 16S rDNA gene. Sequence identity was confirmed using BLASTn analysis while phylogenetic reconstruction was performed to determine the genetic relationship between the Kenyan isolates and other annotated genotypes available in GenBank. Anaplasma and Ehrlichia species were detected in 19.9 and 3.3% of all the samples analyzed, respectively. BLASTn analysis of the sequences against non-redundant GenBank nucleotide database revealed infections with A. platys (44.8%), A. marginale (31%) and A. bovis (13.8%). All four sequenced Ehrlichia spp. were similar to Ehrlichia minasensis. Nucleotide polymorphism was observed for A. platys, A. bovis and E. minasensis. The Anaplasma species clustered in four distinct phylogenetic clades including A. marginale, A. platys, A. bovis and some unidentified Anaplasma spp. The Kenyan Ehrlichia minasensis clustered in the same clade with isolates from America and Australia but distant from E. ruminantium. Conclusion This study provides the first report of infection of dairy cattle in Kenya with A. platys and E. minasensis, which are emerging pathogens. We conclude that cattle in peri-urban Nairobi are infected with various species of Anaplasma and E. minasensis. To understand the extent of these infections in other parts of the country, large-scale screening studies as well as vector identification is necessary to inform strategic control.

Anaplasma and Theileria Pathogens in Cattle of Lambwe Valley, Kenya: A Case for Pro-Active Surveillance in the Wildlife–Livestock Interface

“…Matei et al [39] confirmed that dogs roaming rural communities in islands off the Kenyan coast were infected with A. platys. This study, however, found A. platys-like DNA in 16.9% of cattle in the study area, a prevalence notably higher than reported in cattle in China (4.35%) [40], Tunisia (3.5%) [41], Brazil (4.75%) [42], and Kenya [43]. However, as there was considerable sequence variation among A. platys clade sequences, our findings may represent an unknown diversity of A. platys-like pathogens circulating in the region as found in Tunisia [41].…”

Development of a Multiplex PCR and Magnetic DNA Capture Assay for Detecting Six Species Pathogens of the Genera Anaplasma and Ehrlichia in Canine, Bovine, Caprine and Ovine Blood Samples from Grenada, West Indies

“…The application of the xMAP six-plex PCR assay to 455 field samples detected 30.1% (137/455) of positives, where amongst these positive samples we found 34.3% (11/32) cattle for A. marginale, 16.4% (59/358) dogs for A. platys, and 13.9% (50/358) dogs for E. canis. These results are consistent with prior published reports from other endemic regions for bovine anaplasmosis and canine rickettsial pathogens of the world, including the Caribbean region [62][63][64][65][66]. Co-infection with E. canis and A. platys in the Grenadian dog population was 1.1% (4/358) and this observation is also similar to previous reports from the Caribbean islands of St. Kitts and Republic of Haiti [67,68].…”

Screening and Analysis of Anaplasma marginale Tunisian Isolates Reveal the Diversity of lipA Phylogeographic Marker and the Conservation of OmpA Protein Vaccine Candidate

“…However, this rate is lower than that reported in Algeria (11.1%) ( 56 ), Pakistan (16.3%) ( 57 ), Morocco (21.9%) ( 58 ), and other regions from Tunisia (31.5%) ( 11 ). Compared with other studies from African countries, A. marginale prevalence rates were significantly higher in cattle from Zambia (47.9%) ( 59 ), Kenya (31–96.2%) ( 60 , 61 ), South Africa (60%) ( 62 ), Nigeria (75.9%) ( 63 ), and Madagascar (89.7%) ( 64 ). Indeed, these variations in A. marginale prevalence rate between the different countries and regions of the same country could be due to several factors, in particular the sampling seasons and bioclimatic zones, the type of used molecular assays and associated genes, the variation of incriminated arthropod vectors, the susceptibility of animal breeds, and/or other risk factors related to herd management ( 2 , 15 ).…”