Molecular identification of tick-borne pathogens in Nigerian ticks

A molecular epidemiology investigation was undertaken in two Nigerian states (Plateau and Nassarawa) to determine the prevalence of pathogens of veterinary and public health importance associated with ticks collected from cattle and dogs using PCR, cloning and sequencing or reverse line blot techniques. A total of 218 tick samples, Amblyomma variegatum (N=153), Rhipicephalus (Boophilus) decoloratus (N=45), and Rhipicephalus sanguineus (N=20) were sampled. Pathogens identified in ticks included piroplasmids (Babesia spp., Babesia bigemina and Babesia divergens), Anaplasma marginale and Rickettsia africae. Piroplasmids were identified in A. variegatum, A. marginale was found in R. decoloratus, while R. africae was detected in all tick species examined. Ehrlichia spp. and Theileria spp. were not identified in any of the ticks examined. Of the 218 ticks examined, 33 (15.1%) contained pathogen DNA, with the presence of B. divergens and R. africae that are zoonotic pathogens of public health and veterinary importance. The variety of tick-borne pathogens identified in this study suggests a risk for the emergence of tick-borne diseases in domestic animals and humans, especially amongst the Fulani pastoralists in Plateau and Nassarawa states of Nigeria.     

Survey of ixodid ticks and two tick-borne pathogens in African buffaloes, Syncerus caffer, from the Caprivi Strip, Namibia

A capture operation to ascertain health status in free-ranging buffaloes from six different areas in the Caprivi Strip in the northeast corner of Namibia was conducted in October 2009. Basic information on the ticks and tick-borne pathogens normally found in wildlife from this area are scarce. The objective of this study was to assess the host status of African buffaloes, Syncerus caffer, for ixodid ticks and two selected tick-borne pathogens in the Caprivi Strip, a key area bordering Angola, Zambia, Botswana, and Zimbabwe. Four different tick species have been identified among the 233 collected specimens, and, of 95 tested buffaloes, 54 (57%) were positive for Theileria parva, whereas only 3 (3%) showed evidence of being infected with Ehrlichia ruminantium.     

Prevalence of ixodid ticks on cattle and sheep southeast of Iran

A survey was carried out to investigate the prevalence of hard tick species (Acari: Ixodidae) on cattle and sheep southeast of Iran. A total of 972 ticks were collected from 280 infested cattle and 1,207 ticks were collected from 632 infested sheep during activating seasons of ticks in 2008–2009. The species collected from cattle were Hyalomma marginatum marginatum (50.92%), Hyalomma anatolicum excavatum (25.61%), Hyalomma anatolicum anatolicum (8.12%), Hyalomma asiaticum asiaticum (1.85%), and Rhipicephalus sanguineus (13.47%) while the species collected from sheep were R. sanguineus (36.37%), H. marginatum marginatum (30.65%), H. anatolicum excavatum (19.05%), H. asiaticum asiaticum (10.52%), Hyalomma detritum (3.14%), and Dermacentor marginatus (0.24%). The results show that, H. marginatum marginatum, H. anatolicum excavatum, and R. sanguineus are dominant tick species in the surveyed area.     

A molecular survey of bovine Theileria parasites among apparently healthy cattle and with a note on the distribution of ticks in eastern Turkey

A survey of Theileria parasites in cattle in eastern Turkey was carried out using specific polymerase chain reaction. A total of 252 blood samples were collected from clinically healthy cattle between June and July 2004. Of 252 blood samples examined, 41 (16%) were positive for piroplasms by microscopy, whereas 114 (45%) were positive for the presence of at least one species of Theileria by PCR. The percentages of positive animals for Theileria annulata and benign Theileria species (Theileria sergenti/buffeli/orientalis) were 39% (99/252) and 7% (18/252), respectively. By allele-specific PCR examination of 18 field isolates which were positive for benign Theileria parasites, 8 samples were only amplified by B-type specific primers and 10 samples were amplified by both of the B and C-type specific primers, indicating a mixed infection with B and C-type of the parasite. None of the field isolates was amplified by I-type specific primers. Three samples were co-infected with T. annulata and benign Theileria parasites. Two of them which were infected with B-type parasite were also infected with T. annulata, the other sample which was infected both of B and C-type parasites was also infected with T. annulata. A total of 724 ixodid ticks were collected from the cattle. Hyalomma anatolicum anatolicum was the dominant species with 32% (230/724) in the region. H. a. excavatum, Boophylus annulatus and Rhipicephalus bursa represented 25% (183/724), 19% (140/724) and 15% (112/724) of the total number of ticks, respectively. R. sanguineus was the minor species and represented 8% (59/724) of the tick population.     

Molecular detection of piroplasms in ixodid ticks infesting cattle and sheep in western Oromia, Ethiopia

In Ethiopia, ticks and tick-borne diseases are widely distributed and contribute to important economic losses. Several studies investigated the prevalence and species composition of ticks infesting ruminants; however, data on tick-borne pathogens are still scarce. During the study period from October 2010 to April 2011, a total of 1,246 adult ticks and 264 nymphs were collected from 267 cattle and 45 sheep in Bako District, western Oromia, Ethiopia. The study showed infestation of 228/267 (85.4 %) cattle and 35/45 (77.8 %) sheep with adult ticks. Overall, eight tick species, belonging to three genera (Amblyomma, Rhipicephalus, Hyalomma), were identified and Amblyomma cohaerens (n?=?577), Rhipicephalus evertsi evertsi (n?=?290), Rhipicephalus (Boophilus) decoloratus (n?=?287), and Amblyomma variegatum (n?=?85) were the more prevalent species. A statistically significant host preference in A. cohaerens for cattle and R. evertsi evertsi for sheep was noticed. Molecular detection of piroplasms, performed only for adult ticks of two species of the genus Rhipicephalus (R. evertsi evertsi and R. decoloratus), revealed an overall prevalence of 4 % (8/202) Theileria buffeli/sergenti/orientalis, 0.5 % (1/202) Theileria velifera, and 2 % (4/202) Theileria ovis. The study showed that tick infestation prevalence is considerably high in both cattle and sheep of the area, but with a low intensity of tick burden and a moderate circulation of mildly pathogenic piroplasm species.     

Anti-chemokine activities of ixodid ticks depend on tick species,developmental stage,and duration of feeding

Ixodid ticks require comparatively large bloodmeals for their development and survival. Blood-feeding elicits signaling events in the host leading to wound healing responses (hemostasis, inflammation, and tissue repair) and immunity. Bioactive molecules present in tick saliva sabotage these host responses at several levels. One of them is neutralization of cellular communication by binding of specific saliva molecules to cytokines that have important roles in innate and adaptive immunity. Chemokines are a subset of cytokines having chemotactic activities. We show anti-chemokine activities in salivary gland extracts (SGE) of adult Rhipicephalus appendiculatus ticks against human chemokines CXCL8, CCL2, CCL3, CCL5, and CCL11. At comparable protein concentrations, male Ixodes ricinus SGE showed activity against all the chemokines; SGE of female I. ricinus had comparatively lower levels of activity against all the chemokines but no detectable activity against CCL5 and CCL11. However, when the equivalent of a single pair of salivary glands was tested, male I. ricinus showed little or no activity against CCL3 and CCL5. No fundamental differences in activity were observed against mouse compared with human chemokines. A comparison with previously published data for Dermacentor reticulatus and Amblyomma variegatum indicates that the level of anti-cytokine activity depends on the species, developmental stage (adult or nymph), and amount of SGE used, as well as on the number of days the tick has been feeding.     

Molecular identification of tick-borne bacteria in wild animals and their ticks in Central Anatolia,Turkey

Wild animals fulfill an important mission in the ecology of tick-borne diseases as both suitable hosts to tick vectors and reservoirs of the pathogens. However, current data regarding the role of wild animals in the ecology of tick-borne pathogens is insufficient and more investigations are required. In this study, we investigated tick-borne bacterial pathogens in wild boar, hare, and fox and their ticks in Turkey. A total of 102 tick pools comprised of 445 ticks and blood samples were analyzed for the presence of bacterial DNA by PCRs targeted rickettsial gltA and ompA genes, 5S-23S rDNA gene for Borrelia spp., and msp4 gene for Anaplasma spp. As a result of PCR and sequence analyses, three pathogenic spotted fever group (SFG) rickettsiae, two SFG rickettsiae with unknown pathogenicity and one pathogenic Borrelia burgdorferi sensu lato were detected in samples obtained from wild animals. Rickettsia slovaca was detected in ticks (13.7% of tick pools) collected from wild boars and blood of a wild boar. In addition, the presences of R. hoogstraalii (19.6% of tick pools), R. aeschlimannii (5.8% of tick pools), R. sibirica subsp. mongolitimonae (1.9% of tick pools) and Candidatus R. goldwasserii (0.9% of tick pools) were detected in ticks collected from wild animals. Furthermore, B. burgdorferi sensu stricto was detected in a tick pool collected from a wild boar. This is the first report on the presence of Candidatus R. goldwasserii in Turkey. Consequently, this study shows that pathogenic Rickettsia and Borrelia species are circulating in Turkish wildlife and these pathogens can pose a threat to human health. Also, it has been determined that the investigated wild animals play a role as maintenance host for vector ticks; therefore, these animals must also be considered in the ecology of the mentioned pathogens.     

A survey of free-living ixodid ticks on a commercial game farm in the Thabazimbi District, Limpopo Province, South Africa

Free-living stages of ticks on a commercial game farm in the Thabazimbi District, Limpopo Province, South Africa, were collected by drag-sampling with flannel strips during the period September 2003 to August 2004. A total of 5 tick species was collected from 4 sites. Boophilus decoloratus was the most abundant species, followed by Amblyomma hebraeum. Seasonal abundance of the ticks was quantified and an optimum time to implement control measures against the ticks is proposed.     

Seasonal prevalence of flies feeding on cattle in northern Nigeria

Summary A survey over a year of flies feeding on a tethered bull was carried out on a ranch in the north of Nigeria. Flies were netted on one day in each month for two hours in both morning and afternoon. Flies caught included surface feeders, blood suckers and those causing myiasis. The commonest genus caught wasMusca which was present in relatively large numbers throughout the year.Stomoxys calcitrans was by far the most abundant of the blood-sucking fly species caught.

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Résumé L'auteur a observé durant toute une année les mouches se nourrissant sur un taureau au piquet, dans un ranch de la Nigéria du Nord. Les captures au filet, ont eu lieu à raison d'un jour par mois et à raison de deux heures le matin, et le soir. Les mouches capturées comprenaient des mouches lécheuses, piqueuses et celles causant des myiases. Le genre le plus communément capturé a été le genreMusca, qui a été de loin le plus abondant parmi les espèces hématophages capturées.

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Sumario Se efectuó un reconocimiento de un a?o, sobre la prevalencia estacional de moscas, en un rancho localizado en el norte de Nigeria. Las moscas se alimentaron en un toro centinela. La recolección se hizo un día cada mes, dos horas en la ma?ana y dos en la tarde. Se colectaron moscas que sen alimentan en la superficie, moscas hematófogas y las que causan miasis. De todas las capturas, el géneromusca fue el más común y estuvo presente en abundancia todo el a?o. La especie hematófaga más abudante, de todas las atrapadas fue laStomoxys calcitrans.

     

Drag-sampling of free-living ixodid ticks in the Kruger National Park

Free-living ticks were collected by means of drag-sampling in 32 of the 35 landscape zones of the Kruger National Park during a period of 1 calendar month. Of the 18,199 specimens collected, 99.53% were larvae, 0.05% nymphs and 0.42% adults. Fourteen species were collected. Amblyomma hebraeum followed by Boophilus decoloratus, predominated, both in distribution and abundance. Large variations were encountered between drags. There was no correlation between the numbers of larvae collected and time of day, temperature, grass length, vegetation biomass estimates and subzone type.     

Abattoir-based survey of contagious bovine pleuropneumonia in cattle in Turkey

Blood samples collected from 945 cattle at four local abattoirs in Turkey were examined for contagious bovine pleuropneumonia (CBPP) by the complement fixation test (CFT) and competitive ELISA (cELISA). In addition, the carcases of the animals were examined macroscopically at the abattoirs and 62 lung samples which had lesions suggestive of CBPP were collected for bacteriological culture. To identify suspicious isolates the PCR was used in addition to the routine biochemical tests. By the CFT, two of the 945 serum samples were seropositive, and by the cELISA, four of them were seropositive. In the bacteriological culture of the lungs, growth was observed in 18 (29 per cent) of the samples by the observation of turbidity in the broths. However, when these broths were inoculated into an agar base, growth was observed in only three (4.8 per cent) samples. These isolates were identified as Mycoplasma species on the basis of biochemical tests. In the PCR analysis of DNA extracted from the broths, none of the isolates was identified as Mycoplasma mycoides subspecies mycoides small colony or one of the members of the M mycoides cluster, but amplification was obtained in only eight (44.4 per cent) of 18 samples, using Mycoplasma-genus specific primers. These DNA samples were examined further with primers specific to 16S rRNA and were then sequenced and compared with the databanks; DNA homologies at different levels were observed in five samples, with Mycoplasma alkalescens, Mycoplasma canadense, Mycoplasma bovis and Mycoplasma bovigenitalium.     

Cattle infestation by Hyalomma ticks and prevalence of Theileria in Hyalomma species in the east of Turkey

A total of 2388 cattle and 442 shelters, from two provinces (Elazig and Malatya) endemic for tropical theileriosis in the east of Turkey, were studied for Hyalomma tick populations from July 1993 to July 1995 in Elazig and from May 1998 to January 1999 in Malatya. Four thousand five hundred and eighty one of 7455 Hyalomma ticks were collected from cattle, the other ticks (2874) were collected from shelters. All of the ticks collected from shelters were Hyalomma anatolicum anatolicum. Two thousand eight hundred and ninety five (63.1%) of 4581 Hyalomma ticks collected from cattle were H.a. anatolicum. 23.8% (1047/4581), 11.7% (536/4581) and 0.6% (3/4581) of Hyalomma ticks were Hyalomma anatolicum excavatum, Hyalomma detritum and Hyalomma marginatum marginatum, respectively. A total of 5909 Hyalomma adult ticks collected from cattle (3362/5909) and shelters (2447/5909) were dissected and salivary glands were stained with Methylgreen/Pyronin method. Thousand one hundred and fifty (46.9%) of 2447 H.a. anatolicum collected from shelters and 412 (19.1%) of 2147 H.a. anatolicum collected from cattle were positive for Theileria infection. Twenty (2.4%) of 820 H.a. excavatum and 23 (4.6%) of 495 H. detritum collected from cattle were positive. The mean number of infected acini per infected male and female ticks collected from cattle were 11.3 and 22.4 in H.a. anatolicum, 4 and 6.8 in H.a. excavatum, 17.9 and 18.3 in H. detritum, respectively. In H.a. anatolicum collected from shelters, the above rates were 11.8 and 17.6 in male and female ticks, respectively. The prevalence and intensity of Theileria infection was greater in female ticks than in males.     

Seroprevalence of Fasciolosis in Equines of the Black Sea Region,Turkey

This study determined the seroprevalence of fasciolosis in equines (n = 140) by enzyme-linked immunosorbent assay and Western blot. Blood samples were collected from different locations of the Black Sea Region of Turkey. The overall seroprevalence of fasciolosis in equines was 19.3%: 18% of horses (15), 22.6% of donkeys (7), and 19.2% of mules (5). The seroprevalence rates across provinces were as follows: 25% (5/20) in Samsun, 21.9% (7/32) in Tokat, 31.4% (11/35) in Amasya, 7.4% (2/27) in Ordu, and 7.7% (2/26) in Sinop. Three protein bands with molecular weights of 13, 30-40, and 40-65 kDa were determined in antigen clusters in sera from Fasciola spp-infected equine animals.     

Boophilus microplus: passage of bovine immunoglobulins and albumin across the gut of cattle ticks feeding on normal or vaccinated cattle

Cattle were vaccinated with antigens from adult female Boophilus microplus and haemolymph was collected from female ticks which had engorged on these animals and on matched control cattle. Radio-immunoassay for bovine plasma proteins in haemolymph from ticks fed on control cattle showed low concentrations of IgG1 and albumin. There was a significant increase in bovine plasma proteins passing across the gut in ticks fed on vaccinated cattle, with an average of 150 times more albumin and four to five times more IgG1 in the haemolymph. Ticks with obviously damaged gut had the highest concentrations of bovine plasma proteins but apparently undamaged ticks from vaccinated cattle also had elevated protein concentrations.     

Preliminary survey of ticks (Acari: Ixodidae) on cattle in northern Sudan

In a cross sectional survey conducted during the period June 2001 to July 2002, the geographical distribution of ticks on cattle in the Sudan was determined. Seventeen locations were surveyed from Northern, Central, Eastern, Western, Blue Nile and White Nile Provinces. Total body collections of ticks were made from 20 cattle at each location. Four tick genera and 11 species were identified. The tick species collected included Amblyomma lepidum, Amblyomma variegatum, Boophilus decoloratus, Hyalomma anatolicum anatolicum, Hyalomma dromedarii, Hyalomma impeltatum, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus evertsi evertsi, Rhipicephalus sanguineus group and Rhipicephalus simus simus. Major ecological changes have occurred due to extensive animal movement, deforestation, desertification and establishment of large mechanized agricultural schemes. These factors have certainly affected the distribution of ticks and tick-borne diseases in the Sudan. The absence of A. variegatum and A. lepidum in northern Sudan was not surprising, since these tick species are known to survive in humid areas and not in the desert and semi-desert areas of northern Sudan. The absence of B. annulatus in northern and central Sudan is in accordance with the finding that this tick species is restricted to the southern parts of the central Sudan. The presence of H. anatolicum anatolicum in Um Benin in relatively high abundance is an interesting finding. The present finding may indicate that the southern limit of this species has changed and moved southwards to latitude 13 degrees N. It is concluded that major changes in tick distribution have taken place in the Sudan.     

Economic impact of ticks and tick-borne diseases on cattle production systems around Lake Mburo National Park in South Western Uganda

A longitudinal economic impact study of Ticks and Tick-Borne Diseases (TTBDs) in cattle around Lake Mburo National Park (LMNP) was done. Impact was valued using Uganda Shilling (Ug. Shs) (exchange rate of 1USD to Ug. Shs 1,420). The costs for controlling TTBDs was constituting 85.6 ± 3.2% (pastoral) and 73.8 ± 4.2% (ranches) to total disease control costs. The main costs were on tick control, constituting 83.1% (ranches) and 87.9% (pastoral). In pastoral herds, the costs were negatively correlated to herd size (r = −0.99). The mean annual cost per cattle for controlling TTBDs for ranch and pastoral herds was similar Ug. Shs 5,900 ± 545. The mean annual Economic Cost (EC) of TTBDs per cattle was not significantly different (p > 0.05) between pastoral (Ug. Shs 6,700 ± 580) and ranch herds (Ug. Shs 7,600 ± 970). The mean annual EC per cattle was negatively correlated (r = −0.99) with herd size in pastoral systems contrary to positive correlation (r = 0.99) observed among the ranches. The major component of EC of TTBDs of 88.2% (pastoral) and 78.6% (ranches) was due to their control. The other component was owed to mortality, which was positively correlated (p < 0.01) to the ranch herd size. The total annual EC of TTBDs around LMNP was Ug. Shs 437,754,600 (USD 308,144).     

Study on ticks and tick-borne zoonoses in public parks in Italy

A survey on tick density and on tick‐borne zoonoses was carried out in four public parks in the outskirts of Imola (northern Italy) from June to October 2006. All stages of Ixodes ricinus and only larvae of Riphicephalus sanguineus were recovered by dragging, performed on 100‐m transects. Almost all ticks (99%) were harvested in one park. I. ricinus density (nymphs/100 m²) ranged from 0 in park L to 6.3 in park F. Nymphs and adults of I. ricinus were subjected to PCR for Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi s. l. and Rickettsia spp. The observed prevalences were 38.3% for Bartonella henselae, 5.2% for Bartonella clarridgeiae, 10.4% for B. burgdorferi s. l., 2.6% for Rickettsia helvetica and 13% for Rickettsia monacensis, respectively. No DNA of A. phagocytophilum was found. Acarological risks (AR) were calculated as probabilities of collecting at least one infected nymph per transect. The AR values calculated for the various zoonotic agents were 11.4% for R. helvetica, 27.7% for B. clarridgeiae, 49.7% for B. burgdorferi s. l., 57.2% for R. monacensis and 90.4% for B. henselae, respectively. In this study, B. clarridgeiae was for the first time identified in I. ricinus ticks.