Molecular detection of Theileria sp. in ticks and naturally infected sheep

Current Status of Trypanosoma grosi and Babesia microti in Small Mammals in the Republic of Korea

Small mammals, such as rodents and shrews, are natural reservoir hosts of zoonotic diseases, including parasitic protozoa. To assess the risk of rodent-borne parasitic protozoa in the Republic of Korea (ROK), this study investigated the status of parasitic protozoa, namely Trypanosoma, Babesia, and Theileria, in small mammals. In total, 331 blood samples from small mammals were analyzed for parasites using PCR and sequenced. Samples were positive for Trypanosoma grosi (23.9%; n = 79) and Babesia microti (10%; n = 33) but not Theileria. Small mammals from Seogwipo-si showed the highest infection rate of T. grosi (48.4%), while the highest B. microti infection rate was observed in those from Gangneung-si (25.6%). Sequence data revealed T. grosi to be of the AKHA strain. Phylogenetic analysis of B. microti revealed the US and Kobe genotypes. B. microti US-type-infected small mammals were detected throughout the country, but the Kobe type was only detected in Seogwipo-si. To our knowledge, this is the first nationwide survey that confirmed T. grosi and B. microti infections at the species level in small mammals in the ROK and identified the Kobe type of B. microti. These results provide valuable information for further molecular epidemiological studies on these parasites.

Detection of Bhanja Bandavirus in Patients with Neuroinvasive Disease of Unknown Etiology in Croatia

BACKGROUND

Although the Bhanja bandavirus (BHAV) is widely distributed in some European countries, human infections are rarely reported. This study analyzed the prevalence of BHAV antibodies in patients with neuroinvasive diseases of unsolved etiology.

METHODS

A total of 254 Croatian patients who developed neurological symptoms during the four consecutive arbovirus transmission seasons (April 2017-October 2021) were tested. Cerebrospinal fluid (CSF) and urine samples were tested using RT-qPCR. In addition, CSF and serum samples were tested using a virus neutralization test.

RESULTS

BHAV RNA was not detected in any samples, while neutralizing (NT) antibodies were detected in serum samples of 53/20.8% of patients (95% CI = 16.0-26.3). In two patients, BHAV NT antibodies were detected in the CSF, indicating a recent infection. Both patients were inhabitants of rural areas in continental Croatia, and one reported a tick bite two weeks before symptoms onset. The seropositivity was high in all age groups (15.2-29.1%). The majority of seropositive patients (94.3%) resided at altitudes less than 200 m above sea level. The prevalence rates correlated positively with population density and negatively with certain climate parameters (temperature, number of hot/warm days).

CONCLUSIONS

The presented results indicate that BHAV is distributed in Croatia. Further studies are needed to determine the clinical significance of this neglected arbovirus.

Molecular detection of Babesia and Theileria species/genotypes in sheep and ixodid ticks in Erzurum, Northeastern Turkey: First report of Babesia canis in sheep

Piroplasmosis is a tick-borne protozoan disease caused by Babesia and Theileria species in ruminants. This study sought to determine the presence and prevalence of the agents causing piroplasmosis among sheep in Erzurum province, Turkey. It also sought to identify the tick species infesting the sheep and investigate the possible role of the ticks in the transmission of piroplasmosis. A total of 1621 blood samples and 1696 ixodid ticks from infested sheep were collected. Each blood sample and 115 tick pools were subjected to PCR assay. A total of 307 blood samples were found to be positive for Babesia spp. and Theileria spp. according to molecular analysis. The sequence analysis was revealed the presence of B. ovis (0.4%), B. crassa (0.4%), B. canis (0.4%), T. ovis (69.3%), Theileria sp. (26.6%), and Theileria sp. OT3 (2.9%) in 244 samples. The collected ticks were identified as D. marginatus (62.5%), Hae. parva (36.2%), Hae. punctata (1.1%), Rh. turanicus (0.1%), and H. marginatum (0.1%). The molecular analysis of the adult tick samples revealed T. ovis and T. annulata positivity in the D. marginatus pools, B. crassa and T. ovis positivity in the Hae. parva pools, and T. ovis positivity in the Hae. punctata pools. These results provide up-to-date data concerning tick-borne protozoan diseases of sheep and tick species infesting sheep in the region. The sheep breeding industry is an important livelihood for the region so it is essential to perform repeated studies on these pathogens in order to prevent disruptions to animal husbandry.

Babesiosis in Southeastern, Central and Northeastern Europe: An Emerging and Re-Emerging Tick-Borne Disease of Humans and Animals

There is now considerable evidence that in Europe, babesiosis is an emerging infectious disease, with some of the causative species spreading as a consequence of the increasing range of their tick vector hosts. In this review, we summarize both the historic records and recent findings on the occurrence and incidence of babesiosis in 20 European countries located in southeastern Europe (Bosnia and Herzegovina, Croatia, and Serbia), central Europe (Austria, the Czech Republic, Germany, Hungary, Luxembourg, Poland, Slovakia, Slovenia, and Switzerland), and northern and northeastern Europe (Lithuania, Latvia, Estonia, Iceland, Denmark, Finland, Sweden, and Norway), identified in humans and selected species of domesticated animals (cats, dogs, horses, and cattle). Recorded cases of human babesiosis are still rare, but their number is expected to rise in the coming years. This is because of the widespread and longer seasonal activity of Ixodes ricinus as a result of climate change and because of the more extensive use of better molecular diagnostic methods. Bovine babesiosis has a re-emerging potential because of the likely loss of herd immunity, while canine babesiosis is rapidly expanding in central and northeastern Europe, its occurrence correlating with the rapid, successful expansion of the ornate dog tick (Dermacentor reticulatus) populations in Europe. Taken together, our analysis of the available reports shows clear evidence of an increasing annual incidence of babesiosis across Europe in both humans and animals that is changing in line with similar increases in the incidence of other tick-borne diseases. This situation is of major concern, and we recommend more extensive and frequent, standardized monitoring using a "One Health" approach.

Molecular identification of Theileria species in naturally infected sheep using nested PCR-RFLP

Ovine theileriosis is an important tick-borne haemoprotozoan disease of sheep in tropical and subtropical regions, causing severe productivity and economic loss. There is a paucity of information related to molecular studies of ovine theileriosis from India. The present study identified different Theileria spp. in naturally infected sheep using nested PCR-restriction fragment length polymorphism (nPCR-RFLP). Blood samples and ticks were collected from 204 sheep in different agro-climatic zones of Haryana state, India, during the tick active season. Microscopic examination of thin blood smears revealed 33.3% (68/204) infections with Theileria spp., while 44.6% (91/204) of blood samples were positive by nPCR assay. Different Theileria spp. were identified based upon RFLP patterns using four restriction enzymes: Hpa II, Bsh 1285I, Hae II and Rsa I. Out of 91 positive samples, 50.5% (46/91), 23.08% (21/91), 11% (10/91) and 2.2% (2/91) were positive for T. ovis, T. lestoquardi, T. luwenshuni (Theileria sp. China 1/Theileria sp. China) and T. annulata, respectively. Mixed infection was detected in 13.2% (12/91) of cases. Based upon HpaII enzymatic digestion pattern, two samples with T. lestoquardi and T. annulata, nine samples with T. lestoquardi and T. ovis and one sample with T. ovis and T. annulata were detected. The presence of these Theileria spp. was further confirmed by sequence analysis. The majority of ticks collected from sheep were identified as Rhipicephalus spp. followed by Hyalomma anatolicum and Hemaphysalis spp. The present investigation depicts the first comprehensive molecular report of naturally infected sheep with T. ovis, T. lestoquardi, T. annulata and T. luwenshuni from northern India.

Haemoparasites-Challenging and Wasting Infections in Small Ruminants: A Review

Haemoparasites include bacteria, mycoplasma, protozoa and flagellates inhabiting the bloodstream of living hosts. These infections occur worldwide and are transmitted by vectors, especially ticks and tsetse flies. Geographical distribution varies due to movements of animals and vectors between geographical areas, and even between countries and continents. These changes may be caused by climate change, directly and indirectly, and have a huge effect on the epidemiology of these microbes. Active and ongoing surveillance is necessary to obtain reliable maps concerning the distribution of these infections in order to do proper risk assessment and efficient prophylactic treatment. Genera Anaplasma, Ehrlichia, Mycoplasma, Babesia, Theileria and Trypanosoma include common haemoparasite species in small ruminants causing a variety of clinical manifestations from high fatality rates to more subclinical infections, depending on the species or strain involved. These infections may also cause ill-thift or long-lasting wasting conditions. Life-long infections are a common feature of these pathogens. The present review will focus on haemoparasites in small ruminants, especially related to challenging and wasting infections.

Molecular and Parasitological Survey of Ovine Piroplasmosis, Including the First Report of Theileria annulata (Apicomplexa: Theileridae) in Sheep and Goats from Turkey

Blood and tick samples were collected from 333 apparently healthy sheep and 257 goats as well as 10 sheep exhibiting clinical signs of babesiosis in Adana, Gaziantep, and Adiyaman Provinces in southern Turkey. Fully engorged female ticks were selected and maintained in an incubator until they oviposited. The tick carcasses and their egg masses were examined. Piroplasms compatible with Babesia spp. and Theileria spp. were observed in both symptomatic and asymptomatic small ruminants. Genomic DNA isolates from blood of ovine, tick samples, and egg masses were screened for piroplasms by utilizing 18S rRNA polymerase chain reaction and reverse line blotting (RLB) assays. Parasitemia ranged from 0.01% to 5.6% of erythrocytes in clinical cases. RLB showed positivity in 239 (40.5%) of the sampled apparently healthy sheep and goats and revealed the presence of three Theileria and one Babesia species. Theileria ovis was the most prevalent (35.4%), followed by Babesia ovis (5.4%), Theileria annulata (3.9%), and Theileria sp. MK (0.3%). Thirty-two small ruminants infected with T. ovis were also infected with B. ovis One animal infected with T. ovis was also infected with Theileria sp. MK. Ticks were identified as Rhipicephalus bursa, Rhipicephalus turanicus, Hyalomma excavatum, Haemaphysalis parva, and Hyalomma anatolicum Egg masses of two female R. bursa carcasses were infected with B. ovis This is the first report of theileriosis caused by T. annulata in sheep and goats in Turkey.

Establishment of an Artificial Tick Feeding System to Study Theileria lestoquardi Infection

The establishment of good experimental models for Theileria sp. infection is important for theileriosis research. Routinely, infection of ticks is accomplished by feeding on parasite-infected animals (sheep, cows and horses), which raises practical and ethical problems, driving the search for alternative methods of tick infection. Artificial tick feeding systems are based mainly on rearing ticks on host-derived or hand-made artificial membranes. We developed a modified feeding assay for infecting nymphal stages of Hyalomma anatolicum ticks with Theileria lestoquardi, a highly pathogenic parasite of sheep. We compared two different membranes: an artificial silicone membrane and a natural alternative using mouse skin. We observed high attachment rates with mouse skin, whereas in vitro feeding of H. anatolicum nymphs on silicone membranes was unsuccessful. We could infect H. anatolicum nymphs with T. lestoquardi and the emerging adult ticks transmitted infective parasites to sheep. In contrast, similar infections with Rhipicephalus bursa, a representative tick with short mouth-parts that was proposed as a vector for T. lestoquardi, appeared not to be a competent vector tick species. This is the first report of an experimentally controlled infection of H. anatolicum with T. lestoquardi and opens avenues to explore tick-parasite dynamics in detail.

Molecular evidence of a new Babesia sp. in goats

In this study, a novel Babesia sp. infecting goats was detected and its phylogenetic relationship to related species was determined. A total of 200 blood samples collected from sheep (n=78) and goats (n=122) were examined in the study. The V4 hypervariable region of the 18S rRNA gene of the novel Babesia sp. was amplified by PCR and analysed using a reverse line blot hybridization assay adapted for small ruminants. Samples from seven goats hybridized to Theileria/Babesia catch-all and Babesia catch-all probes and did not hybridize to any species-specific probe tested, suggesting the presence of an unrecognized Babesia species or genotype. Sequencing results showed the isolate to clearly differ from ovine Babesia species and genotypes currently available in the GenBank database. The isolate showed 90.9%, 93.5%, and 93.4% identity to B. ovis, B. motasi, and B. crassa, respectively and 91-93% similarity to Babesia genotypes recently described in small ruminants. The highest homology (∼96-97%) observed was with Babesia odocoilei, Babesia sp. EU1, and Babesia divergens. The new isolate was provisionally designated Babesia sp. The study contributes to better insight into the distribution and phylogenetic diversity of piroplasms in small ruminants. The survey indicated a high prevalence of piroplasms in small ruminants (21.5%). Of those detected, T. ovis was the most prevalent (17%), followed by Babesia sp. (3.5%), and B. ovis (2%).

Piroplasmosis in wildlife: Babesia and Theileria affecting free-ranging ungulates and carnivores in the Italian Alps

BACKGROUND

Piroplasmosis are among the most relevant diseases of domestic animals. Babesia is emerging as cause of tick-borne zoonosis worldwide and free-living animals are reservoir hosts of several zoonotic Babesia species. We investigated the epidemiology of Babesia spp. and Theileria spp. in wild ungulates and carnivores from Northern Italy to determine which of these apicomplexan species circulate in wildlife and their prevalence of infection.

METHODS

PCR amplification of the V4 hyper-variable region of the 18S rDNA of Babesia sp./Theileria sp was carried out on spleen samples of 1036 wild animals: Roe deer Capreolus capreolus (n = 462), Red deer Cervus elaphus (n = 52), Alpine Chamois Rupicapra rupicapra (n = 36), Fallow deer Dama dama (n = 17), Wild boar Sus scrofa (n = 257), Red fox Vulpes vulpes (n = 205) and Wolf Canis lupus (n = 7). Selected positive samples were sequenced to determine the species of amplified Babesia/Theileria DNA.

RESULTS

Babesia/Theileria DNA was found with a mean prevalence of 9.94% (IC95% 8.27-11.91). The only piroplasms found in carnivores was Theileria annae, which was detected in two foxes (0.98%; IC95% 0.27-3.49). Red deer showed the highest prevalence of infection (44.23%; IC95% 31.6-57.66), followed by Alpine chamois (22.22%; IC95% 11.71-38.08), Roe deer (12.55%; IC95% 9.84-15.89), and Wild boar (4.67%; IC95% 2.69-7.98). Genetic analysis identified Babesia capreoli as the most prevalent piroplasmid found in Alpine chamois, Roe deer and Red deer, followed by Babesia bigemina (found in Roe deer, Red deer and Wild boar), and the zoonotic Babesia venatorum (formerly Babesia sp. EU1) isolated from 2 Roe deer. Piroplasmids of the genus Theileria were identified in Wild boar and Red deer.

CONCLUSIONS

The present study offers novel insights into the role of wildlife in Babesia/Theileria epidemiology, as well as relevant information on genetic variability of piroplasmids infecting wild ungulates and carnivores.

A molecular study of tick-borne haemoprotozoan parasites (Theileria and Babesia) in small ruminants in Northern Tunisia

In this study, the frequency of Theileria and Babesia species in sheep and goats was assessed via reverse line blotting (RLB). A total of 263 apparently healthy sheep and goats, from 16 randomly selected flocks located in 9 localities situated in 3 bioclimatic zones in Tunisia, were investigated for the blood protozoans. RLB hybridization with polymerase chain reaction detected only Theileria ovis in sheep and goats, accounting for 22.4% (95% confidence interval [CI]: 17.6-27.1%) positive samples. The infection rate in sheep (28.1%; 95% CI: 23.8-32.3%) was higher than in goats (4.7%; 95% CI: -10.9 to 20.4%). Neither Babesia nor mixed infections were detected. Only two Ixodid tick species (Rhipicephalus turanicus and Rhipicephalus bursa) were collected from the examined sheep and goats in 5 localities. R. turanicus was the dominant species (95.5%) collected mainly in the humid zone, while apparently rare in the sub-humid zone. R. bursa was the only species collected in the semi-arid area. RLB analysis identified six different piroplasms in ticks, with an overall prevalence of 31.5% (95% CI: 28.1-34.9%). Twenty percent (95% CI: 14.4-25.5%) of the collected ticks tested positive for Theileria spp., 3% (95% CI: -5.6 to 11.6%) for Babesia spp. and 0.9% (95% CI: -8.1 to 9.9%) of the ticks harbored both genera; several of these species are not known to occur in small ruminants. This is the first report on the detection of Theileria and Babesia species DNA in small ruminants and ticks in Tunisia.

First molecular detection of Theileria ovis in Rhipicephalus sanguineus tick in Iran

OBJECTIVE

To determine tick infestation of domestic ruminants and their infection to ovine theileriosis in northern Iran.

METHODS

About 425 domestic ruminants in Ghaemshahr city in northern Iran were inspected for tick infestations. Twenty tick specimens (13 females and 7 males) of Rhipicephalus sanguineus (R. sanguineus), the most common tick in the study area, were tested by PCR amplification against 18s rRNA genome of Theileria spp using specie specific primers and then the PCR products were sequenced for species identification by comparison with data base available in GenBank.

RESULTS

About 323 ticks were collected from 102 animals (88 sheep, 12 goats and 2 cattle). The prevalence of ticks infesting animals was R. sanguineus (82.35%), Rhipicephalus bursa (R. bursa) (0.3%), Ixodes ricinus (I. ricinus) (15.2%), Boophilus annulatus (B. annulatus) (1.2%), Haemaphysalis punctata (H. punctata) (0.3%) and Haemaphysalis numidiana (H. numidiana) (0.6%). Eleven (55%) tick specimens were PCR positive against genome of Theileria ovis (T. ovis). Sequence analysis of the PCR products confirmed presence of T. ovis in one R. sanguinus.

CONCLUSIONS

This is the first report of tick infection to T. ovis in Iran. Due to dominant prevalence of R. sanguineus as well as its infection to T. ovis, it is postulated this tick is the main vector of ovine theileriosis in northern Iran.

Molecular phylogenetic studies on Theileria spp. isolates (China) based on small subunit ribosomal RNA gene sequences

Six Theileria spp. from cattle, buffalo and black goat were identified in the Hubei province of China. In order to study the taxonomic status of these parasites, phylogenetic analysis of 18S rRNA genes were carried out. The 18S rRNA genes from each isolate were amplified by the polymerase chain reaction and the approximate 1.75 kb products were cloned and sequenced. Phylogenetic analysis of these gene sequences revealed that the five parasites from buffalo and cattle belonged to the Theileria sergenti/buffeli/orientalis group. The parasite from the Chinese goat (Macheng-Hubei, DQ286802) was closely related to Theileria luwenshuni isolated from sheep in the north of China. This represent the first report on the use of molecular phylogeny to classify Theileria spp. obtained in the Hubei province, showing that Theileria spp. from ruminants found in Hubei province belongs to the benign group of Theileria spp.