67 research outputs found
Occurrence of <i>Coxiella burnetii</i>, <i>Ehrlichia canis</i>, <i>Rickettsia</i> species and <i>Anaplasma phagocytophilum</i>-like bacterium in ticks collected from dogs and cats in South Africa
No full textTicks are major vectors of arthropod-borne infections and transmit a wide variety of zoonotic pathogens. This study was conducted mainly to determine the occurrence of canine tick-borne bacterial and rickettsial pathogens especially those with zoonotic potential. We examined 276 Rhipicephalus sanguineus, 38 Haemaphysalis elliptica and 4 Amblyomma hebraeum ticks from 90 dogs and 4 cats from the Free State, KwaZulu-Natal, North West and Mpumalanga provinces. DNA of Coxiella burnetii (41%), Ehrlichia or Anaplasma (18%), Rickettsia spp. (37%), Anaplasma phagocytophilum-like bacterium (18%) and Ehrlichia canis (19%) was detected by polymerase chain reaction (PCR) from a total of 147 pooled DNA samples. All samples were negative for the presence of Borrelia burgdorferi DNA. Ehrlichia canis was detected in samples from all the provinces except the North West; A. phagocytophilum was absent in KwaZulu-Natal samples, whereas Rickettsia species and C. burnetii were detected in all sampled provinces. The PCRpositive samples were confirmed by direct sequencing of the product. Data from this study calls for a joint effort by both veterinary and medical sectors to conduct epidemiological studies of the zoonotic pathogens in both animals and humans.</jats:p
Using detergent-enhanced LAMP for African trypanosome detection in human cerebrospinal fluid and implications for disease staging
No full textObjective
Where human African trypanosomiasis (HAT) patients are seen, failure to microscopically diagnose infections by Trypanosoma brucei gambiense in blood smears and/or cerebrospinal fluid (CSF) in the critical early stages of the disease is the single most important factor in treatment failure, a result of delayed treatment onset or its absence. We hypothesized that the enhanced sensitivity of detergent-enhanced loop-mediated isothermal amplification (LAMP) will allow for point of care (POC) detection of African trypanosomes in the CSF of HAT patients where the probability for detecting a single parasite or parasite DNA molecule in 1 μL of CSF sample is negligible by current methods.
Methodology
We used LAMP targeting the multicopy pan-T. brucei repetitive insertion mobile element (RIME LAMP) and the Trypanosoma brucei gambiense 5.8S rRNA-internal transcribed spacer 2 gene (TBG1 LAMP). We tested 1 μL out of 20 μL sham or Triton X-100 treated CSFs from 73 stage-1 and 77 stage-2 HAT patients from the Central African Republic and 100 CSF negative controls.
Results
Under sham conditions, parasite DNA was detected by RIME and TBG1 LAMP in 1.4% of the stage-1 and stage-2 gambiense HAT CSF samples tested. After sample incubation with detergent, the number of LAMP parasite positive stage-2 CSF’s increased to 26%, a value which included the 2 of the 4 CSF samples where trypanosomes were identified microscopically. Unexpected was the 41% increase in parasite positive stage-1 CSF’s detected by LAMP. Cohen’s kappa coefficients for RIME versus TBG1 LAMP of 0.92 (95%CI: 0.82–1.00) for stage-1 and 0.90 (95%CI: 0.80–1.00) for stage-2 reflected a high level of agreement between the data sets indicating that the results were not due to amplicon contamination, data confirmed in χ2 tests (p<0.001) and Fisher’s exact probability test (p = 4.7e-13).
Conclusion
This study detected genomic trypanosome DNA in the CSF independent of the HAT stage and may be consistent with early CNS entry and other scenarios that identify critical knowledge gaps for future studies. Detergent-enhanced LAMP could be applicable for non-invasive African trypanosome detection in human skin and saliva or as an epidemiologic tool for the determination of human (or animal) African trypanosome prevalence in areas where chronically low parasitemias are present
Molecular occurrence of trypanosomes, erythrocyte and serum sialic acid concentrations of Muturu and Bunaji cattle in Benue State, Nigeria
No full textOne hundred each, of Muturu and Bunaji cattle were screened, using polymerase chain reaction (PCR), for trypanosomes in Makurdi and Gboko Local Government Areas of Benue State, Nigeria. Erythrocyte surface sialic acid (ESSA) and free serum sialic acid (FSSA) concentrations were determined and compared in both breeds with the aim of providing baseline data for research and diagnostic purposes. Five per cent (5%) and 23% of the Muturu and Bunaji cattle, respectively, were positive for trypanosomes. The result at p = 0.005 was significantly different, with p value of 0.0002 and odd ratio of 0.1762. The Trypanosoma species circulating in Benue State, as detected in the two breeds of cattle, were Trypanosoma congolense, T. vivax, T. brucei and T. evansi. This study, therefore, reports for the first time a natural infection of cattle with T. evansi and the use of a novel PCR in the diagnosis of trypanosome infections in cattle in Benue State, Nigeria. The determination of the ESSA and FSSA concentrations in Muturu cattle in Nigeria is also reported for the first time. The Muturu cattle have a significantly higher ESSA than the Bunaji cattle, this may be responsible for their relative trypanotoleranc
Molecular detection and characterization of tick-borne haemoparasites among cattle on Zanzibar Island, Tanzania
No full textTick-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 strategie
Molecular detection and characterization of tick-borne protozoan and rickettsial pathogens isolated from cattle on Pemba Island, Tanzania
No full textTick-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 Tanzani
Molecular survey for tick-borne pathogens in sheep and goats in Kano Metropolis, Nigeria
No full textTick-borne pathogens (TBPs) pose an increased health and productivity risk to livestock in sub-Saharan Africa. Information regarding TBPs infecting small ruminants in Kano metropolis is scarce. Therefore, we investigated the molecular epidemiology of tick-borne pathogens of economic importance from sheep and goats in Kano, Nigeria using Polymerase chain reaction (PCR). A total of 346 blood DNA samples were collected from small ruminants and analyzed for TBPs using PCR and sequencing. Risk of infection was determined for age, sex, breed and animal species. Our results indicate the absence of piroplasmids (Babesia/Theileria) and Rickettsia spp. infections. The overall prevalence for Anaplasma spp. was 9.25% (32/346) with a higher prevalence in goats 13.59% (25/184) compared with sheep 4.32% (7/162). With respect to age of animals, goats >4 years had the highest prevalence of 32.45% (11/37) which differs significantly (P = 0.0059) compared with other age categories. Cross breed goats had a prevalence of 15.63% (5/32) compared with Kano brown breed 14.08 (20/142). Sex significant difference (P = 0.029) was observed in the goats with females having the highest prevalence 20.89% (14/67) compared with males 9.40% (11/117). Furthermore, with regards to sheep, no significant difference (P > 0.05) was observed with respect to age and breed. Finally, no significant difference (P > 0.05) was observed with the prevalence of Anaplasma spp. due to Body condition score (BCS) in both sheep and goats. Conclusively, the occurrence of TBPs in small ruminants is low. Continuous efforts in tick control must be sustained to ensure high productive yield and reduced disease burden associated with TBPs of sheep and goats in Kano metropolis
Molecular analysis of tick-borne protozoan and rickettsial pathogens in small ruminants from two South African provinces
No full textTick-borne protozoan and rickettsial diseases are a major threat to livestock in tropical and sub-tropical regions of Africa. In this study we investigated the presence and distribution of Theileria spp., Babesia ovis, Anaplasma ovis, Anaplasma phagocytophilum, Ehrlichia ruminantium and SFG Rickettsia in sheep and goats from Free State and KwaZulu-Natal provinces. A total of 91 blood samples were screened in this study, 61 from goats and 30 from sheep. PCR assay was conducted using primers based on Theileria spp. 18S rRNA, Babesia ovis (BoSSU rRNA), Anaplasma ovis (AoMSP4), Anaplasma phagocytophilum epank1, Ehrlichia ruminantium pCS20 and SFG Rickettsia OmpA. Overall infection rates of Theileria spp., Anaplasma ovis and Ehrlichia ruminantium were 18 (19.8%), 33 (36.3%) and 13 (14.3%), respectively. The co-infection of two pathogens were detected in 17/91 (18.7%) of all samples, goats having higher rates of co-infection compared to sheep. Phylogenetic tree analysis sequence of pCS20 gene of E. ruminantium of this study was found to be in the same clade with Kumm2 and Riverside strains both from South Africa. The phylogram of SSU rRNA of Theileria ovis had longer branch length compared to all other sequences most of which were from Asia and Middle East. This study provides important data for understanding the tick-borne diseases occurrence in the study area and it is expected to improve the approach for the diagnosis and control of these disease
Prevalence and molecular characterization of ticks and tick-borne pathogens of one-humped camels (Camelus dromedarius) in Nigeria
No full textBackground
Ticks are hematophagous arthropods responsible for maintenance and transmission of several pathogens of veterinary and medical importance. Current knowledge on species diversity and pathogens transmitted by ticks infesting camels in Nigeria is limited. Therefore, the aim of this study was to unravel the status of ticks and tick-borne pathogens of camels in Nigeria.
Methods
Blood samples (n = 176) and adult ticks (n = 593) were collected from one-humped camels (Camelus dromedarius) of both sexes in three locations (Kano, Jigawa and Sokoto states) in north-western Nigeria and screened for the presence of Rickettsia spp., Babesia spp., Anaplasma marginale, Anaplasma spp. and Coxiella-like organisms using molecular techniques. All ticks were identified to species level using a combination of morphological and molecular methods.
Results
Ticks comprised the three genera Hyalomma, Amblyomma and Rhipicephalus. Hyalomma dromedarii was the most frequently detected tick species (n = 465; 78.4%) while Amblyomma variegatum (n = 1; 0.2%) and Rhipicephalus evertsi evertsi (n = 1; 0.2%) were less frequent. Other tick species included H. truncatum (n = 87; 14.7%), H. rufipes (n = 19; 3.2%), H. impeltatum (n = 18; 3.0%) and H. impressum (n = 2; 0.3%). The minimum infection rates of tick-borne pathogens in 231 tick pools included Rickettsia aeschlimannii (n = 51; 8.6%); Babesia species, (n = 4; 0.7%) comprising of B. occultans (n = 2), B. caballi (n = 1) and Babesia sp. (n = 1); Coxiella burnetii (n = 17; 2.9%); and endosymbionts in ticks (n = 62; 10.5%). We detected DNA of “Candidatus Anaplasma camelli” in 40.3% of the blood samples of camels. Other tick-borne pathogens including Anaplasma marginale were not detected. Analysis of risk factors associated with both tick infestation and infection with Anaplasma spp. in the blood indicated that age and body condition scores of the camels were significant (P < 0.05) risk factors while gender was not.
Conclusions
This study reports low to moderate prevalence rates of selected tick-borne pathogens associated with camels and their ticks in north-western Nigeria. The presence of zoonotic R. aeschlimannii emphasizes the need for a concerted tick control programme in Nigeri
Importance of bovine mastitis in Africa
No full textAbstractBovine mastitis is an important animal production disease that affects the dairy industry globally. Studies have estimated the prevalence of this disease in approximately 30% of African countries, with the highest prevalence found in Ethiopia. This is despite the wide cattle distribution in Africa, and the largest number of dairy farms and herds in countries such as South Africa, Kenya and Uganda. Furthermore, the estimated financial losses due to direct and indirect impacts of bovine mastitis are lacking in this continent. Therefore, intensive research efforts will help determine the continent-wide economic impacts and advance careful monitoring of disease prevalence and epidemiology. Here, published cases supporting the occurrence and importance of bovine mastitis in certain regions of Africa are outlined.</jats:p
Molecular characterization of horse flies (Diptera : Tabanidae) and determination of their role in transmission of haemoparasites in southern Africa
No full textPhD (Zoology), North-West University, Potchefstroom Campus, 2017Tabanids are biting flies commonly referred to as horse flies, deer flies or clegs. They belong to the family Tabanidae composed of more than 4 400 species belonging to 114 genera with a cosmopolitan distribution. Tabanids are of economic importance worldwide due to their ability to transmit various pathogens including bacteria, viruses and protozoa. In southern Africa little has been done to characterize tabanid flies to species level using molecular techniques, and there is insufficient knowledge on the role played by tabanid flies in transmission of haemoparasites. As a result the current study was aimed at characterizing tabanid flies (Tabanidae) in selected study sites in Lesotho, South Africa and Zambia. Morphological identification and molecular techniques were used to characterize tabanid flies found in the three countries to species level. Furthermore, this study sought to detect protozoan parasites of veterinary importance harboured by the sampled tabanid species. Lastly, metagenomic analysis was conducted to determine the gut microbiota of the sampled tabanid flies in order to identify genera of medical or veterinary importance and genera involved in symbiotic associations with arthropods.
A total of 529 tabanid flies comprising of 2 from Lesotho, 307 from South Africa and 157 from Zambia, were collected. Morphological analysis revealed a total of 5 different genera collected from the sampled areas namely: Ancala, Atylotus, Haematopota, Philoliche and Tabanus. The overall number of members from the genus Tabanus was greater than all other genera combined. Morphological identification was further supported by amplification of mitochondrial cytochrome oxidase 1 (CO1) gene whereby the PCR products were sequenced and the retrived sequences matched with the above mentioned genera from the NCBI database. Phylogeny of southern African tabanid flies using CO1 gene sequences supported monophyly in Tabanidae when compared to other tabanid flies from the NCBI database. In addition, tabanid flies from the Afrotropic region were found to be genetically distinct from those found in the Nearctic and the Neotropical regions. This is probably due to influence of variable environmental factors in different geographical areas which are probably affecting genetic makeup of the flies.
Deoxyribonucleic acid extracted from South African Tabanus par and T. taeniola tested positive for the presence of Trypanosoma congolense and T. theileri whilst one member from T. par was positive for the presence of Trypanozoon species. Deoxyribonucleic acid extracted from Zambian tabanid flies tested positive for the presence of Besnoitia besnoiti, Babesia bigemina, Theileria parva and for Trypanozoon species at 1.27% (2/157), 5.73% (9/157), 30.11% (30/157) and 9.82% (14/157) respectively.
Analysis of gut microbes from the seven South African tabanid flies produced a total of 407 689 assembled sequences and a total of 505 operational taxonomic units (OTUs). The most abundant phylum was Proteobacteria (44.55%), followed by unclassified bacteria with 37.08%. The other important detected phyla included Tenericutes (8.91%), Firmicutes (7.33%) and Bacteroidetes (1.98%). Analysis of gut microbes associated with twelve tabanid flies from Zambia revealed 2 524 727 assembled sequences and 2 285 OTUs per fly species. A total of 12 phyla were recovered from the produced OTUs. The abundant bacterial phyla were Proteobacteria (57.81%), followed by Tenericutes with 22.67% and the least phyla detected included Planctomycetes, Gemmatimonadetes, WS3 as well as Chlamydiae. The Spiroplasma was the genus detected amongst all tabanid species and is suspected to be a mutual or commensal symbiont in the gut of tabanid flies. Furthermore, the following genera which has species of medical or veterinary or environmental importance were detected from the gut of tabanid flies by means of metagenomics analyses: Enterobacter, Serratia, Klebsiella, Shigella, Escherichia, Proteus, Providencia, Acinetobacter, Zymobacter, Vibrio, Comamonas, Pseudomonas, Brochothrix, Bacillus, Staphylococcus and Enterococcus. This is study has pioneered detection of bacterial genera of medical, veterinary and invironmental significance by metagenomics in tabanid flies.
This is the first report of detection of Besnoitia besnoiti, Babesia bigemina, Theileria parva and various trypanosome species by PCR from southern African tabanid flies. Additionally, it is for the first time gut microbes associated with tabanid flies are explored by metagenomic analysis. This study has demonstrated that there is a high abundance of different tabanid fly species in South Africa and Zambia. However, not much can be said regarding tabanid flies from Lesotho due to the fact that in the current study only 2 specimens were captured during a 3 months sampling period. Nonetheless, this study has not determined the vectorial capacity of tabanid flies for the detected protozoan parasites and bacteria. It has been reported that tabanid flies mechanically transmit some Trypanosoma species as well as bacterial species such as Anaplasma marginale, Bacillus anthracis and Listeria monocytogenes. Further studies to determine if tabanids are capable of transmitting tick-borne parasites such as Babesia species and Theileria species are required. Transmission of Besnoitia species by tabanid flies is not clarified, and their association with tabanid flies needs to be further explored. Whilst a lot of research and control strategies are focused on tsetse flies and ticks, it is evident that tabanid flies need to be considered for inclusion in such efforts as well. The findings obtained in this study open doors for future studies, particularly in identifying candidate microbes that can be used in the control of tabanid flies as well as in determining the actual role played by symbiotic microbes inside the tabanid fliesNational Research Foundation (NRF)
Department of Science and Technology (DST)Doctora
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