scholarly journals Ticks and Tick-Borne Pathogens Associated with Dromedary Camels (Camelus dromedarius) in Northern Kenya

2021 ◽  
Vol 9 (7) ◽  
pp. 1414
Author(s):  
Dennis Getange ◽  
Joel L. Bargul ◽  
Esther Kanduma ◽  
Marisol Collins ◽  
Boku Bodha ◽  
...  
Keyword(s):  
Q Fever ◽  
Epidemiological Data ◽  
Dromedary Camels ◽  
Ehrlichia Ruminantium ◽  
Northern Kenya ◽  
Pastoralist Communities ◽  
Rickettsia Africae ◽  
Pcr Products ◽  
Melting Analysis ◽  
Rickettsia Aeschlimannii

Ticks and tick-borne pathogens (TBPs) are major constraints to camel health and production, yet epidemiological data on their diversity and impact on dromedary camels remain limited. We surveyed the diversity of ticks and TBPs associated with camels and co-grazing sheep at 12 sites in Marsabit County, northern Kenya. We screened blood and ticks (858 pools) from 296 camels and 77 sheep for bacterial and protozoan TBPs by high-resolution melting analysis and sequencing of PCR products. Hyalomma (75.7%), Amblyomma (17.6%) and Rhipicephalus (6.7%) spp. ticks were morphologically identified and confirmed by molecular analyses. We detected TBP DNA in 80.1% of blood samples from 296 healthy camels. “Candidatus Anaplasma camelii”, “Candidatus Ehrlichia regneryi” and Coxiella burnetii were detected in both camels and associated ticks, and Ehrlichia chaffeensis, Rickettsia africae, Rickettsia aeschlimannii and Coxiella endosymbionts were detected in camel ticks. We also detected Ehrlichia ruminantium, which is responsible for heartwater disease in ruminants, in Amblyomma ticks infesting camels and sheep and in sheep blood, indicating its endemicity in Marsabit. Our findings also suggest that camels and/or the ticks infesting them are disease reservoirs of zoonotic Q fever (C. burnetii), ehrlichiosis (E. chaffeensis) and rickettsiosis (R. africae), which pose public health threats to pastoralist communities.

scholarly journals Ticks and tick-borne pathogens associated with dromedary camels (Camelus dromedarius) in northern Kenya

2021 ◽  
Author(s):  
Dennis Getange ◽  
Joel L. Bargul ◽  
Esther Kanduma ◽  
Marisol Collins ◽  
Boku Bodha ◽  
...  
Keyword(s):  
Q Fever ◽  
Epidemiological Data ◽  
Dromedary Camels ◽  
Ehrlichia Ruminantium ◽  
Northern Kenya ◽  
Pastoralist Communities ◽  
Rickettsia Africae ◽  
Pcr Products ◽  
Melting Analysis ◽  
Rickettsia Aeschlimannii

Ticks and tick-borne pathogens (TBPs) are major constraints to camel health and production, yet epidemiological data on their diversity and impact on dromedary camels are limited. We sur-veyed the diversity of ticks and TBPs associated with camels and co-grazing sheep at 12 sites in Marsabit County, northern Kenya. We screened blood and ticks (858 pools) collected from 296 camels and 77 sheep for bacterial and protozoan TBPs by high-resolution melting analysis and sequencing of PCR products. Hyalomma (75.7%), Amblyomma (17.6%) and Rhipicephalus (6.7%) spp. ticks were morphologically identified and confirmed by molecular analyses. We detected TBP DNA in 80.1% of blood samples from 296 healthy camels. “Candidatus Anaplasma camelii”, “Candidatus Ehrlichia regneryi” and Coxiella burnetii were detected in both camels and associ-ated ticks, and Ehrlichia chaffeensis, Rickettsia africae, Rickettsia aeschlimannii and Coxiella endo-symbionts were detected in camel ticks. We also detected Ehrlichia ruminantium, responsible for heartwater disease in ruminants, in Amblyomma ticks infesting camels and sheep and in sheep blood, indicating its endemicity in Marsabit. Our findings also suggest that camels and/or the ticks infesting them are reservoirs of zoonotic Q fever (C. burnetii), ehrlichiosis (E. chaffeensis), and rickettsiosis (R. africae), which pose a public health threat to pastoralist communities.

scholarly journals Tick-borne pathogens of potential zoonotic importance in the southern African Region

2014 ◽  
Vol 85 (1) ◽  
Author(s):  
Simbarashe Chitanga ◽  
Holly Gaff ◽  
Samson Mukaratirwa
Keyword(s):  
Southern Africa ◽  
Case Reports ◽  
Babesia Microti ◽  
Rickettsia Conorii ◽  
Haemorrhagic Fever ◽  
African Region ◽  
Ehrlichia Ruminantium ◽  
Rickettsia Africae ◽  
Crimean Congo Haemorrhagic Fever ◽  
Rickettsia Aeschlimannii

The aim of this communication is to provide preliminary information on the tick-borne pathogens of potential zoonotic importance present in southern Africa, mainly focusing on their geographical distribution and host range, and to identify research gaps. The following tick-borne zoonoses have been reported to occur in southern Africa based mainly on case reports: Crimean–Congo haemorrhagic fever caused by Crimean–Congo haemorrhagic fever virus; ehrlichiosis caused by Ehrlichia ruminantium, Ehrlichia canis and Anaplasma phagocytophilum; babesiosis caused by Babesia microti; relapsing fever caused by Borrelia duttonii and rickettsioses caused by Rickettsia africae, Rickettsia aeschlimannii and Rickettsia conorii. The epidemiological factors influencing their occurrence are briefly reviewed.

scholarly journals Integrated Extreme Real-Time PCR and High-Speed Melting Analysis in 52 to 87 Seconds

2019 ◽  
Vol 65 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Joseph T Myrick ◽  
Robert J Pryor ◽  
Robert A Palais ◽  
Sean J Ison ◽  
Lindsay Sanford ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
High Speed ◽  
Dna Analysis ◽  
Point Of Care ◽  
Turnaround Time ◽  
Single Nucleotide Variants ◽  
Cycle Times ◽  
Pcr Products ◽  
Melting Analysis

Abstract BACKGROUND Extreme PCR in <30 s and high-speed melting of PCR products in <5 s are recent advances in the turnaround time of DNA analysis. Previously, these steps had been performed on different specialized instruments. Integration of both extreme PCR and high-speed melting with real-time fluorescence monitoring for detection and genotyping is presented here. METHODS A microfluidic platform was enhanced for speed using cycle times as fast as 1.05 s between 66.4 °C and 93.7 °C, with end point melting rates of 8 °C/s. Primer and polymerase concentrations were increased to allow short cycle times. Synthetic sequences were used to amplify fragments of hepatitis B virus (70 bp) and Clostridium difficile (83 bp) by real-time PCR and high-speed melting on the same instrument. A blinded genotyping study of 30 human genomic samples at F2 c.*97, F5 c.1601, MTHFR c.665, and MTHFR c.1286 was also performed. RESULTS Standard rapid-cycle PCR chemistry did not produce any product when total cycling times were reduced to <1 min. However, efficient amplification was possible with increased primer (5 μmol/L) and polymerase (0.45 U/μL) concentrations. Infectious targets were amplified and identified in 52 to 71 s. Real-time PCR and genotyping of single-nucleotide variants from human DNA was achieved in 75 to 87 s and was 100% concordant to known genotypes. CONCLUSIONS Extreme PCR with high-speed melting can be performed in about 1 min. The integration of extreme PCR and high-speed melting shows that future molecular assays at the point of care for identification, quantification, and variant typing are feasible.

scholarly journals Amblyomma hebraeum is the predominant tick species on goats in the Mnisi Community Area of Mpumalanga Province South Africa and is co-infected with Ehrlichia ruminantium and Rickettsia africae

2019 ◽  
Author(s):  
Frans Jongejan ◽  
Laura Berger ◽  
Suzanne Busser ◽  
Iris Deetman ◽  
Manon Jochems ◽  
...  
Keyword(s):  
South Africa ◽  
Tick Species ◽  
Amblyomma Hebraeum ◽  
Ehrlichia Ruminantium ◽  
Mpumalanga Province ◽  
Rickettsia Africae ◽  
Community Area

Abstract The authors have withdrawn this preprint from Research Square

scholarly journals Snapback Primer Genotyping with Saturating DNA Dye and Melting Analysis

2008 ◽  
Vol 54 (10) ◽  
pp. 1648-1656 ◽  
Author(s):  
Luming Zhou ◽  
Roscoe J Errigo ◽  
Hongzhe Lu ◽  
Mark A Poritz ◽  
Michael T Seipp ◽  
...  
Keyword(s):  
Full Length ◽  
Stem Length ◽  
Clinical Samples ◽  
Physical Separation ◽  
Dna Hairpins ◽  
Pcr Products ◽  
Melting Analysis ◽  
Higher Temperature ◽  
Covalent Modifications ◽  
Lower Temperature

Abstract Background: DNA hairpins have been used in molecular analysis of PCR products as self-probing amplicons. Either physical separation or fluorescent oligonucleotides with covalent modifications were previously necessary. Methods: We performed asymmetric PCR for 40–45 cycles in the presence of the saturating DNA dye, LCGreen Plus, with 1 primer including a 5′ tail complementary to its extension product, but without any special covalent modifications. Samples were amplified either on a carousel LightCycler for speed or on a 96/384 block cycler for throughput. In addition to full-length amplicon duplexes, single-stranded hairpins were formed by the primer tail “snapping back” and hybridizing to its extension product. High-resolution melting was performed on a HR-1 (for capillaries) or a LightScanner (for plates). Results: PCR products amplified with a snapback primer showed both hairpin melting at lower temperature and full-length amplicon melting at higher temperature. The hairpin melting temperature was linearly related to the stem length (6–28 bp) and inversely related to the log of the loop size (17–135 bases). We easily genotyped heterozygous and homozygous variants within the stem, and 100 blinded clinical samples previously typed for F5 1691G>A (Leiden) were completely concordant by snapback genotyping. We distinguished 7 genotypes in 2 regions of CFTR exon 10 with symmetric PCR using 2 snapback primers followed by product dilution to favor intramolecular hybridization. Conclusions: Snapback primer genotyping with saturating dyes provides the specificity of a probe with only 2 primers that are free of special covalent labels in a closed-tube system.

scholarly journals Epidemiological features of Mediterranean spotted fever, murine typhus, and Q fever in Split-Dalmatia County (Croatia), 1982–2002

2007 ◽  
Vol 136 (7) ◽  
pp. 972-979 ◽  
Author(s):  
V. PUNDA-POLIĆ ◽  
B. LUKŠIĆ ◽  
V. ČAPKUN
Keyword(s):  
Incidence Rate ◽  
Q Fever ◽  
Spotted Fever ◽  
Epidemiological Data ◽  
Incidence Rates ◽  
Mediterranean Spotted Fever ◽  
Murine Typhus ◽  
Epidemiological Features ◽  
And Gender ◽  
Gender Specific

SUMMARYWe determined the epidemiological features of three zoonoses in hospitalized patients in southern Croatia. Patients were diagnosed by serological testing. Clinical and epidemiological data were also collected. Between 1982 and 2002, Mediterranean spotted fever (MSF) was diagnosed in 126 (incidence rate 1·27/100 000 per year), murine typhus (MT), in 57 (incidence rate 0·57/100 000 per year), and Q fever in 170 (incidence rate 1·7/100 000 per year) patients. MSF and Q fever were characterized by a marked seasonality. Incidences of Q fever and of MSF were higher for males than for females (P<0·0001 andP=0·0024, respectively). The most frequent of the three zoonoses in children was MSF. Q fever and MT cases were mostly seen in the 21–50 years age group. We found no statistically significant differences between season- and gender-specific incidence rates of MT. Whereas infections due to rickettsiae decreased, the incidence of Q fever increased over the last 12 years of the study.

scholarly journals Whole Blood Interferon γ Release Is a More Sensitive Marker of Prior Exposure to Coxiella burnetii Than Are Antibody Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Anja Scholzen ◽  
Margot de Vries ◽  
Hans-Peter Duerr ◽  
Hendrik-Jan Roest ◽  
Ann E. Sluder ◽  
...  
Keyword(s):  
Coxiella Burnetii ◽  
Whole Blood ◽  
Q Fever ◽  
Dominant Role ◽  
Epidemiological Data ◽  
Interferon Γ ◽  
Antibody Responses ◽  
Initial Exposure ◽  
Past Exposure ◽  
Release Assay

For the zoonotic disease Q fever, serological analysis plays a dominant role in the diagnosis of Coxiella burnetii infection and in pre-screening for past exposure prior to vaccination. A number of studies suggest that assessment of C. burnetii-specific T-cell IFNγ responses may be a more sensitive tool to assess past exposure. In this study, we assessed the performance of a whole blood C. burnetii IFNγ release assay in comparison to serological detection in an area of high Q fever incidence in 2014, up to seven years after initial exposure during the Dutch Q fever outbreak 2007-2010. In a cohort of &gt;1500 individuals from the Dutch outbreak village of Herpen, approximately 60% had mounted IFNγ responses to C. burnetii. This proportion was independent of the Coxiella strain used for stimulation and much higher than the proportion of individuals scored sero-positive using the serological gold standard immunofluorescence assay. Moreover, C. burnetii-specific IFNγ responses were found to be more durable than antibody responses in two sub-groups of individuals known to have sero-converted as of 2007 or previously reported to the municipality as notified Q fever cases. A novel ready-to-use version of the IFNγ release assay assessed in a subgroup of pre-exposed individuals in 2021 (10-14 years post exposure) proved again to be more sensitive than serology in detecting past exposure. These data demonstrate that C. burnetii-induced IFNγ release is indeed a more sensitive and durable marker of exposure to C. burnetii than are serological responses. In combination with a simplified assay version suitable for implementation in routine diagnostic settings, this makes the assessment of IFNγ responses a valuable tool for exposure screening to obtain epidemiological data, and to identify previously exposed individuals in pre-vaccination screens.

scholarly journals Molecular identification and prevalence of tick-borne pathogens in zebu and taurine cattle in North Cameroon

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Babette Abanda ◽  
Archile Paguem ◽  
Mamoudou Abdoulmoumini ◽  
Manchang Tanyi Kingsley ◽  
Alfons Renz ◽  
...  
Keyword(s):  
Significant Risk ◽  
Significant Risk Factor ◽  
Control Measures ◽  
Correct Identification ◽  
Ehrlichia Ruminantium ◽  
Rickettsia Africae ◽  
High Prevalence ◽  
Northern Cameroon ◽  
Study Sites ◽  
High Level

Abstract Background Public interest for tick-borne pathogens in cattle livestock is rising due to their veterinary and zoonotic importance. Consequently, correct identification of these potential pathogens is crucial to estimate the level of exposition, the risk and the detrimental impact on livestock and the human population. Results Conventional PCR with generic primers was used to identify groups of tick-borne pathogens in cattle breeds from northern Cameroon. The overall prevalence in 1260 blood samples was 89.1%, with 993 (78.8%) positive for Theileria/Babesia spp., 959 (76.1%) for Anaplasma/Ehrlichia spp., 225 (17.9%) for Borrelia spp., and 180 (14.3%) for Rickettsia spp. Sanger sequencing of a subset of positively-tested samples revealed the presence of Theileria mutans (92.2%, 130/141), T. velifera (16.3%, 23/141), Anaplasma centrale (10.9%, 15/137), A. marginale (30.7%, 42/137), A. platys (51.1%, 70/137), Anaplasma sp. ‘Hadesa’ (10.9%, 15/137), Ehrlichia ruminantium (0.7%, 1/137), E. canis (0.7%, 1/137), Borrelia theileri (91.3%, 42/46), Rickettsia africae (59.4%, 19/32) and R. felis (12.5%, 4/32). A high level of both intra- and inter-generic co-infections (76.0%) was observed. To the best of our knowledge, B. theileri, T. mutans, T. velifera, A. platys, Anaplasma sp. ‘Hadesa’, R. felis and E. canis are reported for the first time in cattle from Cameroon, and for R. felis it is the first discovery in the cattle host. Babesia spp. were not detected by sequencing. The highest number of still identifiable species co-infections was up to four pathogens per genus group. Multifactorial analyses revealed a significant association of infection with Borrelia theileri and anemia. Whereas animals of older age had a higher risk of infection, the Gudali cattle had a lower risk compared to the other local breeds. Conclusion Co-infections of tick-borne pathogens with an overall high prevalence were found in all five study sites, and were more likely to occur than single infections. Fulani, Namchi and Kapsiki were the most infected breed in general; however, with regions as significant risk factor. A better-adapted approach for tick-borne pathogen identification in co-infected samples is a requirement for epidemiological investigations and tailored control measures.

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