Adult Ixodid Ticks Research Articles

MOLECULAR CHARACTERIZATION OF ANAPLASMA PHAGOCYTOPHILUM IN IXODID TICKS IN KAYSERİ REGION IN TURKEY

The study was conducted to investigate the presence of Anaplasma phagocytophilum in ixodid ticks collected from cattle in Kayseri region of Turkey using Real Time PCR and to characterize positive isolates based on 16S rRNA gene region. DNA was extracted from 265 adult ticks. Nested PCR analyses were performed using Anaplasma phagocytophilum-specific primers amplifying a 641 bp fragment of 16S rRNA gene region. Real Time PCR analysis revealed positive results in one H. marginatum and R. turanicus sample. DNA sequences were submitted to GenBank and analyzed by pairwise and multiple sequence alignments with other A. phagocytophilum strains in GenBank to investigate the phylogeny. The phylogenetic analysis revealed that A. phagocytophilum isolates collected from H. marginatum and R. turanicus samples in Kayseri region clustered into three main groups (A, B, and C) with previously reported isolates from the world. A and B groups showed high homology, whereas C group had an average genetic variation of 0.2%. The average genetic differences between A and B groups were 10.8±2.0 and 13.0±2.7% between A and C groups, while the average genetic difference between B and C groups was 13.8±2.8%. In conclusion, this study provides scientific data on molecular prevalence and genetic characteristics of A. phagocytophilum in tick samples in Turkey.

Study on distribution of Ixodid ticks of cattle in Bedele District, South Western Ethiopia

BackgroundTicks cause substantial losses in cattle production, in terms of diseases, and reduced productivity, and are economically the most important ectoparasites of cattle. MethodsA cross-section study was conducted from January 2022 to August 2022 in the Bedele district to identify genera and species of Ixodid ticks infesting cattle and determine the prevalence concerning host-related factors. Adult ixodid ticks were collected from 384 randomly selected cattle by using forceps and preserved in separate collecting bottles with 70% ethyl alcohol. The collected ticks were identified under stereomicroscope into species based on their morphology. ResultsOut of the 384 cattle examined, 276 (71.9%) were found with being infested by one or more tick species. A total of 3192 ticks were collected and identified. Three genera; namely Amblyomma, Boophilus and Rhipicephalus, and four species (Amb. cohaerence, Boophilus decoloratus, Amb. variegatem, and Rhip. evertsi evertsi) were identified with a prevalence rate of 44.8%, 26.8%, 14.1%, and 14% respectively. The respective prevalence for assessed risk factors was: 71.32%, 68.75%, 74.72%, 72.72%, 82.02%, 68.81%, 72.97%, 69.19%, 75.25%, 72.25%, 71.34%, 72.93%, 67.65%, 75.00% Bedele Town, Haro, Ilike Kararo, Obolo Bachara, Cross Breed, Local Breed, Young, Adult, Old, Male, Female, Poor, Medium, and Good, respectively. Only the association between the breed of cattle is statistically significant in terms of the prevalence of ticks (p < 0.05), and others risk factors (Kebele, age, sex, and body condition) were statistically insignificant (p > 0.05). Tick species were highly distributed on the udder part with a prevalence of (26.3%) and least in the vulva body region of the cattle (2.3%). ConclusionsThe present study indicated there is a high prevalence of ixodid tick infestation, especially in local cattle breeds, adults, males, poor body condition, and Bedele town. In line with this, further studies on factors affecting tick burden and tick control strategies are recommended.

Prevalence, seasonal dynamics and associated variables of ixodid tick cattle infestation in Gondar, northwestern Ethiopia

Ticks are ectoparasites that impact the health and productivity in farm animals. They are also important vectors for pathogens transmitted to animals and humans. A cross-sectional study was conducted from November 2018 to April 2019 with the objectives of determining the prevalence, identifying genera and seasonal dynamics of adult ixodid ticks infesting cattle in and around Gondar, northwestern Ethiopia. Pearson Chi-square Test was used to evaluate the association of tick prevalence with explanatory variables. One way analysis of variance was used to compare mean tick density of cattle with the explanatory variables. The overall prevalence of cattle ixodid tick infestation was found to be 65.8% (95% CI = 60.0–71.2%). The effect of breed, sex, age and body condition score on tick prevalence was investigated. However, only the body condition score of study animals was found to have statistically significant effect on the prevalence of tick infestation. Monthly analysis of tick infestation showed statistically significant variation (χ2 = 36.17, p = 0.00) during the study period (November 2018 – April 2019). The highest monthly prevalence was recorded in March (85.0%), and the least in February (42.0%). A comparison of the tick prevalence across seasons showed statistically significant differences (χ = 34.10, p = 0.00), being highest (82.5%) during the short rainy season. During the study period, a total of 3796 adult ixodid ticks were collected from different body regions of the study animals. Three ixodid tick genera were identified, with the genus Rhipicephalus being the most prevalent (n = 2122 (55.9%) of the total adult ticks (3796). The overall mean tick density per host for all genera was 12.78 ticks, with a marked difference in tick density during the three study seasons. The highest MTD was recorded during the short rainy season (MTD = 18.58), (F = 19.71, p < 0.05). The present study has shown that ticks are highly prevalent in the study area. Therefore, an appropriate tick control program should be designed and implemented.

Study on Identification and Prevalence of Ixodid Ticks Genera Infestation in Cattle in the Case of Areka District, Wolaita Zone, and Southern Ethiopia.

A cross-sectional study was conducted from November 2021 to July 2022 to determine the prevalence and identify major ixodid ticks of cattle and associated risk factors in the case of Areka District, Woliata Zone, and Southern Ethiopia. Standard physical and direct stereomicroscopy techniques were employed for identification of tick genera. Descriptive statistics and chi-squared test analyses were used for data analysis and P < 0.05 was considered as significant. During the study period, a sample of 384 local breed cattle's were taken by random selection and a total of 683 adult ixodid ticks were collected from different body parts of infested animals. Among 384 examined animals, 275 (71.6%; 95% CI: 62.8-80.4) animals were infested with one or more ixodid tick genera. In current study, the major ixodid tick genera infesting cattle were Ambylomma (32.2%), Rhipicephalus (Boophilus) (30%), Haylomma (16.8%), and Rhipicephalus (21%), and most of the genera preferred dewlap and sternum body part of animal for attachment. Out of 184 male and 200 female cattle examined, 144 males (78.3%) and 131 females (65.5%) were positive for one or more adult ixodid tick genera. The difference also found statically significant (P < 0.05). The overall prevalence of hard tick's infestation was statistically significant (P < 0.05) across the age, origin, and body condition of cattle. In conclusion, the high level of prevalence of hard ticks infestation in the present study represent the most important problems of cattle and detrimental to production. According to this finding, it is recommended that owners who keep cattle should practice good management and regular deworming using acaricides and it is also important to create awareness among livestock owners about the veterinary importance of ticks for the integrated tick control.

Infestation of Ixodidae Ticks in Cattle: Prevalence and Associated Risk Factors in Ambo District, Western Ethiopia

In Ethiopia, ticks cause serious economic loss particularly in ruminants. A cross sectional study was conducted in Ambo district, Western Ethiopia from October, 2018 to June, 2019 with the objectives of determining the prevalence, identifying the associated risk factors and the tick species of cattle in the area. From five purposively selected kebeles (the smallest administrative unit of Ethiopia) of the district, a total of 384 cattle were selected by systematic random sampling method. Adult Ixodid ticks were collected from different body parts of infested cattle, preserved in 10% formalin and transported to Ambo University Veterinary Parasitology Laboratory for stereomicroscopic identification to species level. Among 384 cattle examined, 201 (52.34%) cattle were infested with one or two tick species. A higher prevalence of tick infestation was recorded in Degele Gatira kebele (53.25%), followed by Abebe Doyo (50.65%), Gosu Kora (50.65%), Kisose Liban (50.65%), and Senkele Faris (56.59%). The study investigated three genera of Ixodid ticks namely Rhipicephalus (41.7%), Boophilus (0.8%) and Amblyomma (2.60%). Mixed infestations were common including Rh. Boophilus and Amblyomma 24(6.25%) and Rh. Boophilus and Rhipicephalus 4(1.04%). The study identified four species of ticks; namely Rh. (Bo.) decoloratus 109 (28.40%), Rhipicephalus (Boophilus) annulatus 43(11.20%), Amblyomma vareigatum 3(0.80%) and Rhipicephalus evertsi evertsi 11(2.90%). The difference in tick infestation was found to be statistically insignificant (P &gt;0.05) between different age groups and kebeles but statistically significant (P &lt;0.05) among sex groups, breeds, and different body condition scores (P &lt;0.05). In conclusion, this study indicated a high prevalence of tick infestation and identified the most important ticks that can transmit various livestock diseases. A proper tick eradication campaign should be conducted to reduce the tick burden in the study area, and concomitantly reduce tick-borne diseases and associated economic losses.

Ticks and Tick-Borne Pathogens Abound in the Cattle Population of the Rabat-Sale Kenitra Region, Morocco.

Tick-borne pathogens cause the majority of diseases in the cattle population in Morocco. In this study, ticks were collected from cattle in the Rabat-Sale-Kenitra region of Morocco and identified morphologically, while tick-borne pathogens were detected in cattle blood samples via polymerase chain reaction assay and sequencing. A total of 3394 adult ixodid ticks were collected from cattle and identified as eight different tick species representing two genera, Hyalomma and Rhipicephalus. The collected ticks consisted of Hyalomma marginatum, Hyalomma anatolicum excavatum, Rhipicephalus sanguineus sensu lato, Rhipicephalus bursa, Hyalomma detritum, Hyalomma lusitanicum, Hyalomma dromedarii, and Hyalomma impeltatum. The overall prevalence of tick-borne pathogens in blood samples was 63.8%, with 29.3% positive for Babesia/Theileria spp., 51.2% for Anaplasma/Ehrlichia spp., and none of the samples positive for Rickettsia spp. Sequencing results revealed the presence of Theileria annulata, Babesia bovis, Anaplasma marginale, Theileria buffeli, Theileria orientalis, Babesia occultans, Anaplasma phagocytophilum, Anaplasma capra, Anaplasma platys, Anaplasma bovis, Ehrlichia minasensis, and one isolate of an unknown bovine Anaplasma sp. Crossbreeds, females, older age, and high tick infestation were the most important risk factors for the abundance of tick-borne pathogens, which occurred most frequently in Jorf El Melha, Sidi Yahya Zaer, Ait Ichou, and Arbaoua locations.

Analysis of laboratory methods for monitoring of tick-borne encephalitis natural foci

Introduction. Ixodid ticks simultaneously are hosts and vectors of tick-borne encephalitis virus (TBEV), presenting a high risk to humans. Monitoring of the vectors part of TBEV population is usually held by means of express analysis methods (ELISA and PCR), but only isolation and identification of infectious virus is reliable evidence of TBEV circulation in the natural foci. Objectives — to demonstrate the TBEV infection rates of Ixodid ticks from natural TBE foci of Baikal Region, based on comprehensive study, including ELISA, PCR and isolation of virus on laboratory mice (LM) model. Methods. Questing adult Ixodid ticks (n = 20 111, mainly — Ixodes persulcatus Schulze, 1930), were collected in TBE natural foci of Baikal Region during 2013–2020. The suspension on saline solution was prepared from the each tick and analyzed by ELISA first. The samples with positive ELISA results were verified in PCR-RT. Furthermore, randomly selected samples with negative ELISA results were analyzed by PCR. Suspensions with positive ELISA and PCR results have been inoculated to suckling LM intracerebrally. Results. The samples with positive PCR results have been divided into two groups: group 1 — all suspensions with positive ELISA results, group 2 — randomly selected samples with negative ELISA results. The positive PCR results in group 1 made up 70.5 % with average Ct rate 24.9. The positive PCR results in group 2 have been obtained in 2.2 % of cases with average Ct rate 30.7. The isolation on LM model was more successful in group 1 (25.8 vs 13.0 %; р &lt; 0.01; df = 69). Conclusion. ELISA is more useful for study of large amounts of ticks during monitoring of natural TBE foci, offering insight into the epidemically important vectors rate. To get the more full assessment of the ticks’ infection rate one must use ELISA and PCR simultaneously, and sum the results into general rate. For high strains isolation results the LM should be inoculated with the suspensions, which had shown positive both ELISA and PCR results.

Prevalence of ixodid ticks infesting Raya cattle breeds in Semi-arid areas of Raya Azebo district, northern Ethiopia

A cross-sectional study was conducted from January to December, 2016 in Semi-arid areas of Raya Azebo District with the objectives to estimate the prevalence of ixodid ticks and assessing the difference in infestation among the different host risk factors such as age, sex and body condition scores. A total of 2697 adult ixodid ticks were collected from 488 Raya cattle breed selected randomly. Tick species were identified morphologically and the prevalence of the infested animals was estimated in relation to sex, age and body condition score. The study revealed that cattle in the study area were infested with atleast one or more ticks with an overall prevalence of 90% (405/448). Six tick species that belongs to the genera of Rhipicephalus (54%), subgenus Boophilus (5%), Amblyomma (3%) and Hyalomma (2.7%) were also identified. The overall prevalence of ticks on cattle with the age from 6 months to 2 years, 3-5 years and greater than 5 years was 90%, 90%, and 92% respectively. A prevalence of 91% in female and 90% in male cattle was also observed. Similarly, the prevalence of ticks was 100 %, 90.7% and 70% in poor, medium and good body conditioned animals, respectively. The high prevalence and presence of many species of ticks may damage the hide and skins of the cattle and thereby contribute to reduced income from cattle. Hence, appropriate control measures using acaricides, improved cattle management practices and community awareness creation are recommended.Keywords: Body condition; Cattle; Prevalence; Semi-arid; Tick

Molecular detection of Rickettsia conorii and other zoonotic spotted fever group rickettsiae in ticks, Romania

The diverse tick fauna as well as the abundance of tick populations in Romania represent potential risks for both human and animal health. Spotted fever group (SFG) rickettsiae are recognized as important agents of emerging human tick-borne diseases worldwide. However, the epidemiology of rickettsial diseases has been poorly investigated in Romania. In urban habitats, companion animals which are frequently exposed to tick infestation, play a role in maintenance of tick populations and as reservoirs of tick-borne pathogens. Therefore, the aim of the present study was to investigate the occurrence of SFG rickettsiae in ticks infesting dogs in a greater urban area in South-eastern Romania. Adult ixodid ticks (n=205), including Rhipicephalus sanguineus sensu lato (n=120), Dermacentor reticulatus (n=76) and Ixodes ricinus (n=9) were collected from naturally infested dogs and were screened for SFG rickettsiae using conventional PCR followed by sequencing. Additionally, ticks were screened for DNA of Babesia spp., Hepatozoon spp., Ehrlichia canis, and Anaplasma platys. Four zoonotic SFG rickettsiae were identified: Rickettsia raoultii (16%) and Rickettsia slovaca (3%) in D. reticulatus, Rickettsia monacensis (11%) in I. ricinus, and Rickettsia conorii (0.8%) in Rh. sanguineus s.l. Moreover, pathogens of veterinary importance, such as B. canis (21%) in D. reticulatus and E. canis (7.5%) in Rh. sanguineus s.l. were identified. The findings expand the knowledge on distribution of SFG rickettsiae as well as canine pathogens in Romania. Additionally, this is the first report describing the molecular detection of R. conorii in ticks from Romania.

Influence of altitude on tick-borne encephalitis infection risk in the natural foci of the Altai Republic, Southern Siberia

The Altai Republic is a highly endemic area as far as tick-borne encephalitis (TBE) is concerned. The aim of the research was to study the effect of altitude on the risk of tick-borne encephalitis infection in the Altai Republic. The paper analyzes the following data: the study of ixodid ticks collected from the vegetation in 116 sites at the 200–2383m elevation above sea level in 2012–2014, TBE virus prevalence of these vectors, tick-bite incidence rate, and TBE incidence rate of the population.Species identification of 4503 specimens has shown that the most common species are Dermacentor nuttalli (45.3%), Ixodes persulcatus (33.1%), Dermacentor silvarum (9.4%), Dermacentor reticulatus (8.9%), and Haemaphysalis concinna (5.0%).A total of 2997 adult ixodid ticks were studied for the presence of the TBE virus; 2163 samples were examined by ELISA, while 834 specimens were tested by PCR. The TBE virus prevalence of Dermacentor spp. ticks in both reactions was significantly higher than of Ixodes persulcatus ticks (p<0.001).The work shows that the altitude is an important factor in the development of the epidemiological situation of tick-borne encephalitis: the higher the elevation of the area above sea level, the smaller the range of vectors. There is also a change of a leading species: in middle altitude (800–1700m above sea level) the virus is transmitted by ticks of D. nuttalli along with I. persulcatus, and in high mountains (above 1700m above sea level) D. nuttalli becomes an absolute dominant species. However, these species of ticks are less effective vectors than I. persulcatus. With the increase of altitude the tick-bite incidence rate decreases (r=−0.78, p<0.05), and TBE incidence also reduces (r=−0.67, p<0.05).

Ixodid ticks infesting cattle in three agroecological zones in central Oromia: species composition, seasonal variation, and control practices

A cross-sectional study was conducted to determine the species, prevalence, and seasonal variation of ticks on cattle in central Oromia. In addition, questionnaire survey was used to assess the control practices of ticks in central Oromia. During the study period from August 2008 through April 2009, a total of 10,440 adult ixodid ticks were collected from a total of 918 cattle (153 cattle during dry and wet seasons from each of three agroecologies) in three agroecological zones during wet and dry seasons. A total of seven species of ixodid ticks belonging to four genera were identified during the wet period, whereas similar numbers of genera but six species of ixodid ticks were recorded during the dry season. Amblyomma, Boophilus, Rhipicephalus, and Hyalomma tick genera were identified during the two seasons. Five different species of ticks were identified from the highland altitude. Significantly (p < 0.05) higher proportion of Boophilus decoloratus (88.2 %) was identified during the wet season, Hyalomma truncatum (1.5 %) was with the least proportion. Rhipicephalus evertsi evertsi (50.8 %) was the most abundant during the dry period, whereas Hyalomma marginatum rufipes (5 %) was with smallest proportion. In the midland, a total of six species of ticks were identified. Significantly (p < 0.05) higher proportion of Amblyomma variegatum (76.6 %) than the other species was recorded during the wet season in the midland. But Rhipicephalus pulchellus (0.05 %) was collected with the lowest proportion. R. e. evertsi (46.3 %) was the most abundant tick species during the dry season, whereas R. pulchellus (0 %) was with lowest proportion. In the lowland, a total of seven species of ticks during the wet and six during the dry season were identified. A significantly (p < 0.05) higher proportion of A. variegatum (30.3 %) was recorded during the wet season, whereas R. pulchellus (1.4 %) was identified with the lowest proportion in the lowland. R. e. evertsi (24.8 %) was the most abundant tick species during the dry season in the lowland, but R. pulchellus (0 %) was with the lowest proportion during the same season in the lowland. Results of the study revealed that the highest mean total tick burden was recorded during the early rainy season than the dry season from the end of March to April. And the lowest mean tick count was recorded during the early dry and the late dry season during December and February, respectively. The overall tick count across seasons showed significant variation (F = 114 and p = 0.000). The questionnaire survey on the tick control practices has revealed that (90 %) diazinon and (57.3 %) cypermethrin were the commonly used acaricides with a frequency of one to three times per year during the peak of tick infestation. In conclusion, this study demonstrated that ixodid ticks occur with high prevalence and burden and still play major roles in reducing productivity of cattle and cause health problems of cattle in central Oromia. Further studies on the role of ticks in the transmission of pathogens to cattle, other animals, and zoonotic pathogens to man in Oromia are urgently needed.

Theileria and Babesia Parasites in Ticks in Tunisia

A total 576 adult ixodid ticks, collected in seven sites in Northern Tunisia, were analysed for piroplasm infection. Reverse line blot analysis identified nine different piroplasms, with an overall prevalence of 22.7%. 17.8% were Theileria spp. positive, 8.5% were positive for Babesia spp. and 3.6% of ticks harboured both genera. Although, most of the positive ticks harboured a single infection (17%), mixed infections with two, three or four different piroplasm species were also detected (5.7%).

Prevalence of Tick-Borne Zoonotic Bacteria in Questing Adult Ticks from Northern Spain

A total of 691 questing adult ixodid ticks of the genera Ixodes, Haemaphysalis, Dermacentor, and Rhipicephalus were tested by polymerase chain reaction (PCR) and reverse line blot (RLB) for the presence of Anaplasma phagocytophilum, Coxiella burnetii, Borrelia spp., and spotted fever group (SFG) rickettsiae. Ticks were collected by blanket dragging during 2 sampling years (2003-2005) in 10 recreational areas in the Basque Country (Northern Spain). Adult ticks were collected every month of the year and eight different species were identified among which Ixodes ricinus was the most abundant and widespread. Three pathogens for humans, Borrelia burgdorferi, A. phagocytophilum, and C. burnetii, as well as rickettsiae of unknown pathogenicity were detected. The latter were identified as Rickettsia sp. RpA4/DnS14 by sequencing of the citrate synthase (gltA) gene. The infection rates varied from 0.1%-6.9%. DNA of A. phagocytophilum was detected mainly in I. ricinus, but also in Haemaphysalis punctata, H. concinna, and Rhipicephalus bursa. Coxiella burnetii was detected in only one specimen of H. punctata, and Borrelia spp. in eight ticks. Furthermore, PCR-RLB analysis specific for B. burgdorferi sensu lato detected one H. punctata with positive hybridization with the B. burgdorferi sensu stricto probe, and two I. ricinus positive for B. afzelii and B. garinii. SFG rickettsiae were the pathogens most frequently found, present in 48 of 97 D. reticulatus analyzed. Mixed infections were not found in any of the analyzed ticks. These results are compared and discussed with data obtained in previous studies carried out in the same and other regions.

Distribution and molecular detection of Theileria and Babesia in questing ticks from northern Spain

A total of 562 questing adult ixodid ticks, collected during 2003-05 in 10 recreational mountain areas in northern Spain, were analysed for piroplasm infection. Reverse line blot (RLB) analysis using a panel of probes for 23 piroplasm species identified 16 different piroplasms, with an overall prevalence of 9.3%. Most were Theileria spp.-positive (7.7%), 3.0% were positive for Babesia spp. and 1.4% of ticks harboured both genera. Ixodes ricinus (Linnaeus, 1758), the most abundant tick in the vegetation, ranked third with regard to piroplasm infection prevalence (11.4%) after Rhipicephalus bursa (Canestrini & Fanzago, 1878) (16.0%) and Haemaphysalis punctata (Canestrini & Fanzago, 1878) (13.5%). Infection was detected in 6.2% of Dermacentor reticulatus (Fabricius, 1794) and in 1.1% of Haemaphysalis inermis (Birula, 1895), but was absent from Haemaphysalis concinna (Koch, 1844). Ixodes ricinus carried more piroplasm species (13), followed by H. punctata (10), D. reticulatus (8), R. bursa (3) and H. inermis (1). Although most of the positive ticks harboured a single infection (76.9%), mixed infections with two or three different piroplasm species were also detected (23.1%). The various tick-pathogen associations found are discussed and prevalences of infection in ticks are compared with previous results on piroplasms infecting animals in the same region.

In vitro splenocyte proliferation responses of BALB/c mice to salivary gland extracts of three ixodid tick species (Acari: Ixodidae)

In vitro proliferation and cytokine production were investigated in BALB/c mice splenic cell cultures that were stimulated with concanavalin A (ConA) and lipopolysaccharide (LPS) and simultaneously exposed to salivary gland extracts (SGE) of unfed and partially fed adult ixodid ticks (Ixodes ricinus, Rhipicephalus appendiculatus, Amblyomma variegatum). Generally, tick SGE enhanced proliferation of unstimulated splenocytes and SGE of unfed ticks suppressed mitogen induced proliferation. Partially fed R. appendiculatus and A. variegatum suppressed ConA responses, while partially fed I. ricinus stimulated both ConA and LPS induced proliferation. A. variegatum and R. appendiculatus females slightly enhanced LPS responses 2 days after attachment but suppressed them at the end of the slow feeding phase. In 72 h ConA induced cell cultures, interferon gamma (IFN-γ) production was suppressed by SGE of all ticks, interleukin (IL)-10 production was enhanced by unfed I. ricinus and partially fed A. variegatum males and IL-5 production was enhanced by feeding R. appendiculatus females and A. variegatum males. The study revealed variability in the responsiveness of murine splenocytes to SGE of different ixodid tick species, whereby patterns of host immunomodulation within one tick species differed between sexes and changed during feeding.

Primary report on distribution of tick fauna in Iran

A tick survey was carried out in four different geographical areas of Iran, where the majority of the domestic ruminants in Iran exist. About 1,500 sheep, 1,200 goats and 500 cattle of 12 herds in different provinces lying in the corresponding zones were inspected for tick infestation. The occurrence of ticks on cattle, sheep and goats were 62, 55 and 57%, respectively, with no differences between the zones. The mean number of ticks on each animal was low (10-20 ticks per animal). Ixodid ticks were found throughout the year, whereas the soft tick Ornithodoros sp., which occurred in mountainous area with a significant difference in abundance, showed a clear pattern of seasonality, being generally present from November to March. The largest numbers of adult ixodid ticks were generally present from April to August. Rhipicephalus, Haemaphysalis and Dermacentor ticks occurred in the mountainous area, whereas Boophilus and Ixodes ticks were only present in the Caspian region. Hyalomma were very abundant in each zone but especially in the mountainous area, whereas Ixodes ticks were the minor genus.

Detection of human granulocytic ehrlichiosis agent and Borrelia burgdorferi in ticks by polymerase chain reaction.

Adult ixodid ticks were collected from Westchester County, New York, and Ipswich, Massachusetts, to determine the presence of infection with a human granulocytic ehrlichiosis (HGE) agent by using the polymerase chain reaction (PCR). The presence of Borrelia burgdorferi in ticks collected from New York was also determined by PCR. Of the 229 ticks from New York and 47 ticks from Massachusetts, 9% (22/229) and 25% (12/47) of ticks contained HGE agent, respectively. Fifty-four percent (123/229) of the ticks collected from New York were B. burgdorferi positive; 4% (9/229) of these ticks contained both HGE agent and B. burgdorferi. This finding indicates that animals with Lyme borreliosis may be also exposed to the etiologic agent of HGE. More extensive laboratory diagnosis may be necessary when multiple tick-borne diseases are suspected in animals.

Differences in Borrelia infections in adult Ixodes persulcatus and Ixodes ricinus ticks (Acari: Ixodidae) in populations of north-western Russia.

Dark-field microscopy was used to determine the number of Borrelia spirochetes in 630 standard preparations obtained from adult ixodid ticks (344 Ixodes persulcatus and 286 I. ricinus) collected in 1989-92 in the Leningrad region of Russia. The average numbers of Borrelia in I. persulcatus and I. ricinus preparations were 34.7 and 23.3 per 100 microscopic fields, respectively. The maximal individual values registered each year for ticks of both species were several hundred times greater than the minimal values. Ticks carrying relatively small numbers of Borrelia generally predominated. Proportions of more heavily infected ticks varied considerably from year to year. These parameters were significantly higher in foci with predominance of I. persulcatus ticks. As a consequence, risk to acquire Lyme borreliosis in such foci is considered greater than in foci where I. ricinus predominates.

Organization of ribosomal RNA genes in Borrelia burgdorferi sensu lato isolated from Ixodes ovatus in Japan.

Borrelia burgdorferi sensu lato was obtained from adult ixodid ticks, Ixodes ovatus, collected in Nagano, Japan, and was named NT112. The genomic DNA was digested with enzymes, electrophoresed, blotted and hybridized with rRNA gene probes obtained from B. burgdorferi sensu stricto B31. The results showed that the borrelial chromosome contains a single rrs (16S rRNA gene) sequence and two copies of rrl/rrf (23S/5S rRNA genes) sequences. The rrl/rrf genes were tandemly repeated at intervals of 3.2 kb and were located separately from the rrs gene on the genome. Our findings indicate that the organization of rRNA genes in Borrelia from I. ovatus ticks is identical to that of B. burgdorferi sensu stricto.

The identification of a shared immunogen present in the salivary glands and gut of ixodid and argasid ticks.

The identification of a 70-kDa immunogen present in salivary gland extracts of several ixodid species, namely Hyalomma truncatum (sweating-sickness-inducing (SS+) and non-inducing (SS-) strains), Hyalomma marginatum rufipes and Rhipicephalus evertsi evertsi, is reported. The immunogen was identified by Western blots using a monoclonal antibody of the IgM isotype directed against a 70-kDa immunogen present in the salivary glands of (SS-) female H. truncatum ticks. Cross-reactivity with the gut of unfed adult ixodid ticks, Amblyomma hebraeum, Rhipicephalus simus simus, R. evertsi evertsi, Rhipicentor nuttali, H.m. rufipes, and salivary glands of adult argasid species, Ornithodoros savignyi and Ornithodoros moubata, was demonstrated using ELISA.