Molecular identification and characterisation of ticks of one humped Camels (camelus dromedarius) from camel rearing counties in Kenya

Abstract

Ticks are economically significant ectoparasites of livestock due to their ability to maintain and transmit various pathogens of medical and veterinary importance. Currently, knowledge of the diversity of ticks affecting camels in Kenya is scanty. This study aimed to assess the diversity of ticks infesting camels and the genetic diversity of Hyalomma tick species, the major tick species infesting camels. Adult ticks (n =1517) were collected from one-humped camels (Camelus dromedarius) from five counties in Kenya at the Athi-River abattoir and identified to the species level using taxonomical and molecular methods. Ticks comprised three genera (Rhipicephalus, Hyalomma, and Amblyomma). Rhipicephalus pulchellus was the most abundant tick species (n =739; 48.71%), while Hyalomma albiparmatum (n = 11; 0.73%) was the least abundant. Other tick species included Hyalomma rufipes (n = 306; 20.17%), Amblyomma gemma (n = 201; 13.28%), Hyalomma dromedarii (n = 97; 6.39%), Hyalomma truncatum (n = 70; 4.61%), Amblyomma lepidum (n = 45; 2.97%), Hyalomma impeltatum (n = 30; 2.01%), and Rhipicephalus pravus (n = 18; 1.18%). The nucleotide diversity (π) and haplotype diversity values of Hyalomma species were 0.095±0.005 and 0.953±0.020, respectively, and the average number of nucleotide differences (k) was 58.003. Tajima‘s D, Fu and Li's D, and Fu and Li's F test statistics were all non-significant with values of 1.008 (p > 0.10), 1.320 (0.10 > p > 0.05) and 1.440 (p > 0.10) respectively. Wright‘s F statistics for genetic differentiation between all population species was also non-significant (p > 0.05). This study found the existence of various tick species in camels. Awareness of the impact of these ticks on camels, plus limited veterinary infrastructure, poses a challenge to the tick control measures. In conclusion, this study recommends further detailed investigations on the population genetics of Hyalomma tick species to identify the presence of introgression and hybridisation and which species is driving the gene flow. The findings of this study might provide insights about hybridisation among other tick species on the possibility that it could introduce new alleles that alter the vector competence, capacity to utilize various microhabitats, or even host use.