Search Results (10)

Amblyomma hebraeum is a tick species of veterinary importance because it is a major vector of Ehrlichia ruminantium, the causative agent of heartwater disease. This species infests livestock in southern African regions and is a three-host species of veterinary importance. Maximum entropy algorithm (MaxEnt) modeling was used to predict the potential distribution of A. hebraeum. The MaxEnt model performed better than random with an average test area under the curve (AUC) value of 0.94, and model predictions were significantly better than random, giving AUC ratios above the null expectations in the partial receiver operating characteristic (pROC) analyses (p < 0.001). A set of five variables was selected for the species from 19 bioclimatic variables based on correlation analysis. The study showed that the current distribution of A. hebraeum is estimated to occur across coastal regions of the Eastern Cape and KwaZulu-Natal provinces in South Africa, Swaziland, southern Mozambique, eastern Zimbabwe, and eastern Botswana. Temperature seasonality (Bio 4) had the highest effect on the distribution of this species. The environmentally suitable habitat for A. hebraeum increased with decreasing temperature seasonality (Bio 4). Transferring the models to future conditions showed a decrease in suitable habitats for this species under changing climate. These results have public health implications and can be used for making control planning decisions in areas suitable for this vector across its geographical distribution. Full article

Generally, ixodid ticks are important ectoparasites of cattle, including those in smallholder production systems in the Eastern Cape Province, where varying environmental conditions influence their distribution and feeding behaviour. This study investigated ecological variation in tick species composition and attachment site preferences in Bos taurus cattle across coastal and inland areas of the Eastern Cape Province, South Africa. Ticks were collected from cattle of different ages, sexes, breeds, and body condition scores. Sampling was conducted prior to acaricide treatment, and ticks were manually removed from standard predilection sites on each animal. Specimens were preserved in 70% ethanol and later identified morphologically at the Döhne Agricultural Development Institute Laboratory. Data were analysed using generalized linear mixed models with a negative binomial distribution to assess the effects of host and environmental factors on tick burden. Descriptive statistics were used to summarise species composition, while inferential statistics were applied to evaluate differences in infestation levels across host-related and spatial variables. A total of 3250 adult ixodid ticks were collected from cattle. The most prevalent species was Rhipicephalus (Boophilus) decoloratus (39.7%), followed by Rhipicephalus evertsi evertsi (21.0%), Amblyomma hebraeum (17.7%), Hyalomma rufipes (5.8%), Ixodes pilosus (5.8%), Rhipicephalus (Boophilus) microplus (4.5%), R. appendiculatus (3.0%), and R. simus (2.5%). Tick burdens were significantly higher in the coastal zone (85 ± 7.5) than in semi-arid inland areas (62 ± 5.9). Attachment site analysis showed significantly higher infestation levels (p < 0.05) on the udder/scrotum compared to other body regions. This study provides baseline information on tick species composition and attachment site ecology in cattle, contributing to improved understanding of host–parasite interactions and supporting the development of targeted, region-specific tick control strategies. Full article

Gastrointestinal parasites (GIPs) and tick infestations remain critical health challenges limiting cattle productivity in rural South Africa, particularly within communal farming systems. The Eastern Cape Province, characterized by high livestock densities and variable management practices, provides a unique context in which to examine parasitic burdens across systems. This study aimed to compare the prevalence, intensity, and diversity of GIPs and tick species in cattle raised under rural communal grazing versus communal feedlot systems in the Eastern Cape Province of South Africa. A total of 160 cattle (n = 80 per system) were randomly selected for fecal and tick examinations in community-based feedlots in Holela (Centane) and Gxwalibomvu (Tsomo), as well as from surrounding rural villages. Fecal samples were analyzed using the McMaster technique to determine fecal egg counts (FEC), while tick species were identified and counted from standardized body regions. Body condition scores (BCS) were recorded, and farmer practices related to parasite control were surveyed. Results showed significantly higher GI parasite prevalence and FEC in rural community cattle compared to feedlot cattle (p < 0.05), with Haemonchus contortus and Trichostrongylus spp. being the most prevalent. Similarly, rural cattle had significantly higher tick infestation rates, dominated by Rhipicephalus microplus and Amblyomma hebraeum. Logistic regression identified rural production system, poor body condition (BCS ≤ 2), and absence of recent deworming as significant risk factors for GI parasitism (p < 0.05). Strong negative correlations were found between BCS and both FEC (r = −0.63) and tick burden (r = −0.57). Additionally, rural farmers reported lower acaricide usage and greater reliance on traditional remedies. The study confirms that rural communal systems expose cattle to higher parasitic risks due to unmanaged grazing, limited veterinary support, and poor parasite control strategies. Communal feedlots, by contrast, offer more controlled conditions that reduce parasitic burden. Integrating strategic parasite management, farmer training, and expanded veterinary outreach is essential to improving cattle health and productivity in communal areas. Full article

Ticks are a significant threat to livestock globally, with certain species displaying distinct host preferences at various developmental stages. Accurate species-level identification is essential for studying tick populations, implementing control strategies, and understanding disease dynamics. This study evaluated ticks infesting cattle across six provinces in South Africa using morphological and molecular methods. Ticks were preserved, examined morphologically using an Olympus Digital Camera Microscope, and identified using the 16S rRNA gene. The study identified four genera, namely Amblyomma, Hyalomma, Ixodes, and Rhipicephalus, comprising 15 ixodid species. Amblyomma hebraeum was the most prevalent species, with an infestation rate of 54.4%. Molecular analysis revealed genetic relationships among tick species, with genetic distances ranging from 0.00 to 0.13, and phylogenetic analysis clustered species into distinct genera with high bootstrap support. Principal Component Analysis highlighted clear genetic relatedness among species. These findings enhance our understanding of tick diversity, morphology, and distribution in South Africa’s cattle populations, emphasizing their economic significance. The study provides critical baseline data for monitoring and developing effective strategies to manage tick-borne diseases, ensuring improved livestock health and productivity. Full article

Tick-borne rickettsioses are considered among the oldest known vector-borne zoonotic diseases. Among the rickettsiae, Rickettsia africae is the most reported and important in Africa, as it is the aetiological agent of African tick bite fever (ATBF). Studies describing the prevalence of R. africae in southern Africa are fragmented, as they are limited to small geographical areas and focused on Amblyomma hebraeum and Amblyomma variegatum as vectors. Amblyomma spp. ticks were collected in Angola, Mozambique, South Africa, Zambia and Zimbabwe during the sampling period from March 2020 to September 2022. Rickettsia africae was detected using the ompA gene, while characterisation was conducted using omp, ompA, ompB and gltA genes. In total, 7734 Amblyomma spp. ticks were collected and were morphologically and molecularly identified as Amblyomma eburneum, A. hebraeum, Amblyomma pomposum and A. variegatum. Low levels of variability were observed in the phylogenetic analysis of the R. africae concatenated genes. The prevalence of R. africae ranged from 11.7% in South Africa to 35.7% in Zambia. This is one of the largest studies on R. africae prevalence in southern Africa and highlights the need for the inclusion of ATBF as a differential diagnosis when inhabitants and travellers present with flu-like symptoms in the documented countries. Full article

Tick-borne diseases (TBDs) are emerging and re-emerging infections that have a worldwide impact on human and animal health. Lyme borreliosis (LB) is a severe zoonotic disease caused by the spirochete Borrelia burgdorferi sensu lato (s.l.) transmitted to humans by the bite of infected Ixodes ticks. Borrelia miyamotoi is a spirochete that causes relapsing fever (RF) and is genetically related to Borrelia burgdorferi s.l. However, there have been no reports of B. miyamotoi in Egypt, and the data on LB in camels is scarce. Thus, the present study was conducted to screen and genetically identify Borrelia spp. and B. miyamotoi in Egyptian camels and associated ticks using polymerase chain reaction (PCR). Methods: A total of 133 blood samples and 1596 adult hard ticks were collected from Camelus dromedaries at Cairo and Giza slaughterhouses in Egypt. Tick species were identified by examining their morphology and sequencing the cytochrome C oxidase subunit 1 (cox1) gene. Borrelia spp. was detected using nested PCR on the IGS (16S-23S) gene, and positive samples were genotyped using 16S rRNA and glpQ spp. genes specific for Borrelia burgdorferi and Borrelia miyamotoi, respectively. The positive PCR products were sequenced and analyzed by phylogenetic tree. Results: Analysis of the cox1 gene sequence revealed that the adult ticks belonged to three genera; Hyalomma (H), Amblyomma (Am), and Rhipicephalus (R), as well as 12 species, including H. dromedarii, H. marginatum, H. excavatum, H. anatolicum, R. annulatus, R. pulchellus, Am. testudinarium, Am. hebraeum, Am. lipidium, Am. variegatum, Am. cohaerens and Am. gemma. Borrelia spp. was found in 8.3% (11/133) of the camel blood samples and 1.3% (21/1596) of the ticks, respectively. Sequencing of the IGS (16S-23S) gene found that B. afzelii, detected from H. dromedarii and H. marginatum, and B. crocidurae, which belongs to the RF group, was detected from one blood sample. B. burgdorferi and B. miyamotoi were discovered in the blood samples and tick species. Phylogenetic analysis of the glpQ gene showed that the B. miyamotoi in this study was of the Asian and European types. Conclusions: These results suggest that the camels can be infected by Lyme borrelia and other Borrelia bacteria species. This study also provides the first insight into the presence of Borrelia miyamotoi and B. afzelii DNA in camels and associated ticks in Egypt. Full article

Ehrlichia ruminantium (E. ruminantium) is the causative agent of heartwater disease and it is mainly transmitted to livestock by Amblyomma hebraeum (A. hebraeum) tick in South Africa. This study investigated the occurrence of E. ruminantium and its genetic diversity in ticks within Ngaka Modiri Molema district of North West Province in South Africa. Genomic DNA was extracted from whole A. hebraeum ticks totaling 876 and resulted in a total of 292 pooled DNA samples. Firstly, conventional PCR was used to detect Ehrlichia spp. targeting the dsbA gene, followed by nested PCR targeting the Map1 gene performed on DNA pool samples that were positive from the first PCR. One hundred and six tick DNA pool samples were positive by dsbA gene PCR for the presence of Ehrlichia spp. with minimum infection rate (MIR) of 121, while 13/106 were positive by Map1 PCR with MIR of 15. Different E. ruminantium Map1 genotypes (NWUe1, NWUe2, NWUe3, NWUe5, and NWUe6) were detected from tick samples and were closely related to more than 13 gene sequences of E. ruminantium from the NCBI GenBank database. These findings suggest that there is a significant diversity of E. ruminantium infecting ticks in the study area. Full article

Deciphering the interactions between ticks and their microbiome is key to revealing new insights on tick biology and pathogen transmission. However, knowledge on tick-borne microbiome diversity and their contribution to drug resistance is scarce in sub–Saharan Africa (SSA), despite endemism of ticks. In this study, high-throughput 16S rRNA amplicon sequencing and PICRUSt predictive function profiling were used to characterize the bacterial community structure and associated antibiotic resistance markers in Amblyomma variegatum, A. hebraeum, and Hyalomma truncatum ticks infesting Nguni cattle (Bos spp.). Twenty-one (seven families and fourteen genera) potentially pathogenic and endosymbiotic bacterial taxa were differentially enriched in two tick genera. In H. truncatum ticks, a higher abundance of Corynebacterium (35.6%), Porphyromonas (14.4%), Anaerococcus (11.1%), Trueperella (3.7%), and Helcococcus (4.7%) was detected. However, Rickettsia (38.6%), Escherichia (7%), and Coxiellaceae (2%) were the major differentially abundant taxa in A. variegatum and A. hebraeum. Further, an abundance of 50 distinct antibiotic resistance biomarkers relating to multidrug resistance (MDR) efflux pumps, drug detoxification enzymes, ribosomal protection proteins, and secretion systems, were inferred in the microbiome. This study provides theoretical insights on the microbiome and associated antibiotic resistance markers, important for the design of effective therapeutic and control decisions for tick-borne diseases in the SSA region. Full article

Variation in tick microbiota may affect pathogen acquisition and transmission but for many vector species, including Amblyomma hebraeum, components and determinants of the microbiome are unidentified. This pilot study aimed to determine baseline microbial community within A. hebraeum nymphs infected- and non-infected with Rickettsia africae from the environment, and within adult ticks infected- and non-infected with R. africae collected from cattle sampled from two locations in the Eastern Cape province of South Africa. Adult A. hebraeum ticks (N = 13) and A. hebraeum nymph (N = 15) preliminary screened for R. africae were randomly selected and subjected to Illumina sequencing targeting the v3–v4 hypervariable regions of the 16S rRNA gene. No significant difference in microbial community composition, as well as rarefied OTU richness and diversity were detected between adults and nymphs. Nymphs showed a higher richness of bacterial taxa indicating blood-feeding could have resulted in loss of microbial diversity during the moulting stage from nymph to adult. Core OTUs that were in at least 50% of nymphs and adults negative and positive for Rickettsia at 1% minimum relative abundance were Rickettsia, Coxiella and Ruminococcaceae UCG-005 with a single genus Arsenophonus occurring only in nymphs negative for Rickettsia. Ehrlichia spp. was present in only four nymphal ticks positive for Rickettsia. Interestingly, Rickettsia aeschlimannii was found in one nymph and one adult, indicating the first ever detection of the species in A. hebraeum. Furthermore, A. hebraeum harboured a Coxiella-like endosymbiont, which should be investigated further as Coxiella may affect the viability and transmission of other organisms. Full article

Importation of tick-infected animals and the uncontrollable migration of birds and wild animals across borders can lead to geographical expansion and redistribution of ticks and pathogen vectors, thus leading to the emergence and re-emergence of tick-borne diseases in humans and animals. Comparatively, little is known about the occurrence of piroplasms in ixodid ticks in the Eastern Cape, South Africa, thus necessitating this study, which is aimed at detecting piroplasms (Theileria and Babesia) from feeding tick samples collected from cattle, sheep, and goats in selected sites in the Eastern Cape, South Africa. A total of 1200 feeding ixodid ticks collected from farm animals at selected homesteads were first subjected to molecular identification using mitochondrial 12S ribosomal RNA (rRNA) gene by PCR and were further tested for the presence of piroplasms through amplification of the 18S rRNA gene via nested-PCR followed by sequencing of the PCR products. The results indicated that 853 (71.1%) corresponded to the genus Rhipicephalus, 335 (27.9%) corresponded to genus Amblyomma, and 12 (1%) corresponded to genus Haemaphysalis. Amblyomma hebraeum and Rhipicephalus appendiculatus were the most common identified ticks from this study. The 18S rRNA nested-PCR revealed that 44 (3.7%) samples were confirmed positive for Theileria. A homology search for the generated sequences revealed a high percentage identity of 98–98.9% similarity to T. buffeli, T. orientalis, and T. sergenti in the GenBank. Based on the results obtained herein, we conclude that there is a big diversity of Theileria species; therefore, we suggest that this research should cover more geographical areas in order to reveal the true prevalence of this pathogen in the studied area because this will be a great step in the possible prevention of an outbreak that could have devastating effects on livestock production and human health in both the studied areas and South Africa at large. Full article