Detection and differentiation of ovine Theileria and Babesia by reverse line blotting in China

A reverse line blot (RLB) assay was developed for detection and specific identification of the different ovine Theileria and Babesia parasites. In a polymerase chain reaction (PCR), the hypervariable region 4 (V4 region) of the 18S ribosomal DNA gene was amplified with a set of general primers specific for members of the genera Theileria and Babesia. Meanwhile, specific oligonucleotide probes were designed and bound on membrane. After one single-PCR amplification, the amplified fragment was hybridized against different generic and species-specific probes. It was able to detect four species, i.e., Babesia motasi (Chengde, Lintan, Ningxian, Tianzhu), Babesia sp. (Kashi), Theileria luwenshuni (Lintan, Madang, Ningxian), Theileria uilenbergi (Longde, Zhangjiachuan) as defined previously. All probes bound to their respective target sequence only; therefore, no cross-reaction was observed, resulting in clear recognition of either individual strains, species, or groups in normal positive tests. Meanwhile, no signal was observed when ovine genomic DNA and water were used as a control, demonstrating that the signals are due to the presence of parasite DNA in the samples. Furthermore, the sensitivity of RLB could be considerably enhanced to detect a parasitemia level between10(-3)% and 10(-8)%. Finally, 117 samples from field were tested with RLB, PCR, and enzyme-linked immunosorbent assay (ELISA). The positive rate of RLB was higher than that of PCR and ELISA, and furthermore, RLB could determinate the species of piroplasms, the samples were infected with. Samples, 1,117, from five areas in Gannan Tibet Autonomous Region have been examined with RLB assay and compared with ELISA assay for corresponding samples. The results showed that the positive rate of RLB was higher than that of ELISA test obviously, and both T. luwenshuni and T. uilenbergi were widely distributed in these areas. RLB developed here could be used for differentiation of Babesia and Theileria infection and for epidemiological survey, which was difficult to achieve by classical methods. In conclusion, the RLB is a versatile technique for simultaneous detection and identification of all ovine piroplasms.

A perspective on Theileria equi infections in donkeys

The donkey population has remained unchanged in the last two decades despite a decrease in the overall population of equids, emphasizing the usefulness of the donkey as a draught and pack animal. Piroplasmosis in donkeys, caused by Theileria equi and Babesia caballi, has been recognized as a serious problem of major economic importance as the affected animals manifest decreased working capacity, loss of appetite, etc. In tropical countries, T. equi infections are more wide-spread and pathogenic than those caused by B. caballi. Donkeys usually remain asymptomatic carriers with positive antibody titres throughout life. Transmission of infection occurs from animal to animal through ticks such as Hyalomma spp. Rhipicephalus spp. and Dermacentor spp. The clinical form of the disease is diagnosed by peripheral blood smear examination, but in carrier donkeys it is very difficult to demonstrate the parasite in stained blood smears as the parasitaemia is extremely low. For diagnosis of such low grade infection or carrier animals, serological tests and DNA-based molecular diagnostic techniques, which are discussed in the present review, have become mandatory. Currently, there is no suitable pharmacotherapy available to clear the T. equi infection from affected donkeys, though some new drugs and drug combinations used against this disease condition have been discussed. In the present situation, there is an urgent need for international cooperation and coordination for development of sensitive molecular diagnostic tools and effective pharmacotherapies for curtailment of the disease condition. Hence, it is imperative to develop and exchange reagents and technology developed through human resource sharing in the interest of sustainability of donkey husbandry.

Development of multiplex polymerase chain reaction for detection of Ehrlichia canis, Babesia spp and Hepatozoon canis in canine blood

A multiplex polymerase chain reaction (PCR) has been developed for simultaneous detection of canine blood parasites, Ehrlichia canis, Babesia spp and Hepatozoon canis, from blood samples in a single reaction. The multiplex PCR primers were specific to E. canis VirB9, Babesia spp 16S rRNA and H. canis 16S rRNA genes. Specificity of the amplicons was confirmed by DNA sequencing. The assay was evaluated using normal canine and infected blood samples, which were detected by microscopic examination. This multiplex PCR offers scope for simultaneous detection of three important canine blood parasites and should be valuable in monitoring parasite infections in dogs and ticks.

The clinical course of babesiosis in 76 dogs infected with protozoan parasites Babesia canis canis

The aim of the study was to trace the clinical course of babesiosis in 76 dogs infected with Babesia canis protozoa and to assess the usefulness of PCR method in the routine diagnosis of the disease. The investigations were conducted in three successive seasons of the biological activity of ticks on dogs displaying possible clinical signs of babesiosis, the latter assigned individual numbers from 001 to 076. All the animals underwent routine clinical examinations and blood was collected for haematological, biochemical, parasitological and molecular tests for babesiosis. The most frequent clinical signs observed in the course of the disease were changes in urine colour and xanthosis or paleness of mucous membranes, whereas in the haematological and biochemical examinations, the most frequent laboratory findings were thrombocytopenia, leucopoenia, anaemia and an increase in levels of urea and bilirubin. In all blood smears stained with the May-Grunwald and Giemsa methods, from the 76 dogs, the presence of Babesia canis protozoa was observed in erythrocytes, and their DNA was detected in 69 blood samples by means of PCR technique. The course of the disease and the results of molecular examinations suggested the haemolytic form of babesiosis. The previous genetic analysis of isolates of Babesia canis canis from the eastern areas of Poland helped to distinguish two specific groups, A and B, within the species (Adaszek and Winiarczyk 2008a). The present study revealed a certain interrelation between the intensification of thrombocytopenia and the fact that protozoa belong to either group A or B. The mean number of thrombocytes in dogs infected with protozoa from group A was 61.11 thousand/mm3, whereas the mean number of thrombocytes in the blood of dogs infected with protozoa from group B was 27.47 thousand/mm3. A strong correlation was also observed between the low level of thrombocytes and the increase in the internal body temperature (p = 0.02), accelerated pulse rate (p = 0.01) and discoloration of urine (p = 0.04). As a result of the treatment of dogs with imidocarb, recovery was observed in 73 out of the 76 dogs brought to the clinic.

Transmission of Babesia caballi by Dermacentor nitens (Acari: Ixodidae) is restricted to one generation in the absence of alimentary reinfection on a susceptible equine host

The tropical horse tick, Dermacentor nitens, is a natural vector of Babesia caballi in the Americas. B. caballi, one of the etiologic agents of equine piroplasmosis, occurs widely throughout the world, but the United States and a few other countries are considered to be free of infection. B. caballi is transovarially transmitted by the one-host tick D. nitens; we tested the hypothesis that B. caballi can persist in multiple generations of D. nitens in the absence of opportunity to reacquire infection from a susceptible equine host. Partially engorged female D. nitens were collected from a B. caballi-infected horse in Puerto Rico and allowed to reattach and feed on an uninfected horse, successfully transmitting the infection. Three subsequent generations of ticks were reared on calves (nonsusceptible hosts for B. caballi), testing for B. caballi infection in each generation by feeding a sample of the larvae on naive horses. The first generation ofD. nitens reared on a nonsusceptible host transmitted B. caballi, whereas the second and third failed to transmit to naive horses, showing that D. nitens infection with B. caballi was restricted to one generation in the absence of alimentary reinfection. These results imply that, in the event of the introduction of this pathogen into areas of the continental United States where D. nitens occurs, the tick could become a short-term reservoir of B. caballi, making control of introduced infections more complex.

Biometrical and genetical characterization of large Babesia ovis in Iran

One species of Babesia was identified on the blood smear of 20 different naturally infected sheep in the Northwest of Iran. It was polymorphic, including double pyriform with acute or obtuse angle, single pyriform, and ring form. The size of typical paired pyriforms with acute angle was 2.7 x 0.4 microm (n=10) and with obtuse angle was 3.5 x 0.6 microm (n=10). Although the morphological and biometrical parameters resembled the Babesia motasi, the results of seminested polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism using primers specific for small subunit of 18S rRNA confirmed this species as Babesia ovis. Furthermore, the sequence analysis of hypervariable region of small subunit of 18S rRNA revealed the corresponding sequences for B. ovis as well. Experimental infection of healthy lambs with the morphological larger B. ovis showed a milder clinical signs compared to the small one.

Molecular detection of Theileria and Babesia infections in cattle

This study was carried out to determine the presence and distribution of tick-borne haemoprotozoan parasites (Theileria and Babesia) in apparently healthy cattle in the East Black Sea Region of Turkey. A total of 389 blood samples were collected from the animals of various ages in six provinces in the region. Prevalence of infection was determined by reverse line blot (RLB) assay. The hypervariable V4 region of the 18S ribosomal RNA (rRNA) gene was amplified with a set of primers for members of the genera Theileria and Babesia. Amplified PCR products were hybridized onto a membrane to which generic- and species-specific oligonucleotide probes were covalently linked. RLB hybridization identified infection in 16.19% of the samples. Blood smears were also examined microscopically for Theileria and/or Babesia spp. and 5.14% were positive. All samples shown to be positive by microscopy also tested positive with RLB assay. Two Theileria (T. annulata and T. buffeli/orientalis) and three Babesia (B. bigemina, B. major and Babesia sp.) species or genotypes were identified in the region. Babesia sp. genotype shared 99% similarity with the previously reported sequences of Babesia sp. Kashi 1, Babesia sp. Kashi 2 and Babesia sp. Kayseri 1. The most frequently found species was T. buffeli/orientalis, present in 11.56% of the samples. T. annulata was identified in five samples (1.28%). Babesia infections were less frequently detected: B. bigemina was found in three samples (0.77%), B. major in two samples (0.51%) and Babesia sp. in five samples (1.28%). A single animal infected with T. buffeli/orientalis was also infected with B. bigemina.

Plasma levels of zinc, copper, copper/zinc ratio, and activity of carbonic anhydrase in equine piroplasmosis

We have determined the plasma concentrations of copper, zinc, copper/zinc ratio, and carbonic anhydrase activity in horses infected with Babesia equi. The study was conducted in 14 horses with the disease and 10 healthy animals that served as controls. The infection was confirmed by the clinical manifestations of the disease and by Giemsa staining of thin blood smears showing the parasites inside red blood cells. The horses with piroplasmosis had lower plasma levels of zinc, elevated copper, and increased activity of carbonic anhydrase. Consequently, the copper/zinc ratio was also higher than in the healthy controls.

[Occurrence and molecular characterization of Babesia species in a canine hospital population in the Londrina Region, Parana State, Brazil]

Canine babesiosis is a worldwide disease caused by the protozoan of Babesia genus. Babesia canis and B. gibsoni are both species that naturally infect dogs. The objective of this study was to evaluate the infection of Babesia species in dogs attended at the Londrina State University Veterinary Teaching Hospital (HV-UEL). It was selected 282 dogs seen at the Londrina State University Veterinary Teaching Hospital (HV-UEL) between April of 2005 and May of 2006. They presented anemia (Packed Cell Volume<25%), thrombocytopenia (Platelet count <150000/mm3), leukopenia (White blood cell count<5000/mm3) or a combination of two or three of these alterations at the moment of the consultation. The presence of Babesia sp was determined by the amplification of a specific fragment of DNA of the Babesia genus by PCR. Microscopic examination of Giemsa-stained blood smears detected 38 (13.5%) positive samples against 105 identified by PCR from 282 dogs. The positive samples were submitted to PCR-RFLP by Hinf I that allows distinguishing the species of B. canis vogeli and B. gibsoni. From 282 dogs, Babesia sp infection was identified in 105 (37.2%). From these 105 positive samples, the PCR-RFLP identified 66 (23.4%) samples with a profile compatible to B. canis vogeli and 39 (13, 8%) to B. gibsoni. As conclusions, the results obtained allow to affirm that the babesiose is an important differential for dogs that present anemia, leukopenia and thrombocytopenia and, B. canis vogeli is the subspecies that is present in the most of the cases of babesiose in the population of dogs studied and, that B. gibsoni is also present causing babesiosis in dogs of the Londrina region, Parana State, Brazil.

[Seroepidemiological studies on Babesia equi in horses from the State of Rio Grande do Sul determined by indirect immunoflourecence test and Elisa]

This research was performed to study the prevalence of antibodies against Babesia equi in horses of the northern region of Rio Grande do Sul state, using ELISA and indirect immunofluorescence antibody test (IFA). The total sera sample was 380, this number was considered as statistically representative of the population, as determined by mathematical model. The prevalence of B. equi was 31.6% and 35.8% by ELISA and IFA, respectively. The concordance between the assays was 0.87 (indices kappa), which is considered an optimal result. The results did not show any significant statistical difference (P < 0.05) between sex, age and horses breed. The results of this study allowed the characterization of the northern region of Rio Grande do Sul as an instable enzootic area for B. equi, which indicates a potential risk of economic losses caused by babesiosis outbreaks, especially for sensible horses from non enzootic areas or even born is the studied region.

[Molecular diagnostic of congenital babesiosis in neonates foals from State of Rio de Janeiro, Brazil]

The aim of this study was to demonstrate, through nested PCR (nPCR) method, the occurrence of congenital babesiosis in two foals born of carrier mares. All mares were positive for T. equi based in visualization of intraerytrocytic parasites in blood smears, in indirect fluorescent antibody test (IFAT) and nPCR reactions. Just one mare was nPCR-positive for B. caballi. After the birth, all foals presented nPCR-positive for T. equi, while just one foal presented nPCR-positive for B. caballi. The present study prove the occurrence of congenital babesiosis in new-born foals, however, new studies are necessary to elucidate if the infection occur for transplacental transmission or in parturition moment.

An unusual form of canine babesiosis

An Akita Inu, living in Belgium, was presented with unusual clinical manifestations of acute babesiosis that included neurological signs and pancytopenia. Diagnosis was made by identifying Babesia canis in the blood smear. Neurological signs resolved after treatment with imidocarb diproprionate. Normalization of hematological abnormalities was gradual over 5 months.

Flow cytometry to evaluate the level of Babesia gibsoni parasitemia in vivo and in vitro by using the fluorescent nucleic acid stain SYTO16

In the present study, we employed flow cytometry to evaluate the level of parasitemia of Babesia gibsoni infecting canine erythrocytes in vivo and in vitro by using fluorescent nucleic acid staining. Peripheral blood samples from a B. gibsoni-infected dog and cultured B. gibsoni parasitizing in canine erythrocytes were stained with a membrane-permeable fluorescent nucleic acid stain, SYTO16. In this study, we utilized normal canine erythrocytes (LK erythrocytes) and canine erythrocytes containing high concentrations of potassium, reduced glutathione, and some free amino acids (HK erythrocytes) as host cells for culture. Parasitized cells in vive were discriminated completely from unparasitized cells and a correlation (r = 0.998) between the percentage of SYTO16-positive cells and parasitemia in vivo was observed. On the other hand, erythrocytes in vitro could not be divided clearly into parasitized and unparasitized cells. However, when LK erythrocytes were used as host cells, the percentage of SYTO16-positive cells was almost the same as, and was well correlated (r = 0.932) with, the level of parasitemia. When HK erythrocytes were used as host cells, the percentage of SYTO16-positive cells was almost half of, but was correlated (r = 0.982) with, the level of parasitemia. Therefore, we attempted to observe the changes in the percentage of parasitized cells after treatment with antiprotozoal drug or mitochondria inhibitors by using flow cytometry. The changes in the percentage of SYTO16-positive cells corresponded well with the changes of the level of parasitemia when the parasites in HK erythrocytes were cultured with each compound. The present results suggest that flow cytometric detection using SYTO16 is a rapid and reliable method for monitoring parasitemia both in vive and in vitro.

A Possible treatment strategy and clinical factors to estimate the treatment response in Bebesia gibsoni infection

The effectiveness of combination therapy using clindamycin, metronidazole and doxycycline against canine babesiosis, and the usefulness of platelet count and the plasma C-reactive protein (CRP) concentration as an estimation factor for treatment, were evaluated in four dogs experimentally infected with Babesia gibsoni. The combination therapy successfully eliminated B. gibsoni in peripheral blood in 3 of 4 dogs, however the remaining dog showed obvious uncontrolled relapse after a temporary recovery. In addition, it was shown that CRP levels decreased in an inverse relationship to the recovery of packed cell volume and therefore CRP levels could be used as an optional clinical marker to estimate the response to treatment.

Babesia gibsoni: Identification of an immunodominant, interspersed repeat antigen

In this report, an immunodominant antigen called BgIRA from Babesia gibsoni is identified and described. A highly repetitive antigen was screened from a cDNA library. The genomic BgIRA gene exists as single cope gene and contains 10 introns. BgIRA plays a dominant role in the immune response in dogs infected with B. gibsoni. The specificity and sensitivity of the rBgIRA in an ELISA indicated that this antigen might be useful in a diagnostic test.

[Dogs babesiosis--still actually problem]

Babesiosis (piroplasmosis) is a tick-borne disease with a symptoms of hemolytic anemia. For the first time babesiosis was described in dogs in United States in 1934. The etiological factor of this disease in Poland is protozoa Babesia canis, and its vector--Dermacentor-tick. The most common symptoms of babesiosis are: icterus, hemoglobinuria, occasionally vomits and diarrhea. The biochemical examination of blood serum from sick animals can reveal the increase of activity of AST, ALT, the increase of total bilirubine, urea and creatynine concentrations. The results of hematological examinations can show anemia, leucopenia and thrombocytopenia. The diagnosis of babesiosis bases on anamnesis, clinical examinations of dogs, microscopical examinations of blood smears from sick animals; IF-assay and PCR can also be helpful for the diagnosis of babesiosis. Till now does not exist the effective immunoprophylaxis against this disease. Babesiosis is well-known disease, however there are still problems with therapy of infected animals. Most effective drug in therapy of dog piroplasmosis is imidocarb, but sometimes can be observed side effects after it application. It is possible that the genetically differences which are detected in subspecies may have an influence on the severity of disease and the effectiveness of therapy.

[A babesiosis case in February in Ankara]

Bovine babesiosis is a widespread disease occurring throughout tropical and subtropical regions and causes serious economical losses. Transmitted by ticks, Babesia species attract attention as the cause of disease and parallel the seasonal activity of ticks, in spring-summer months when temperatures increase. Ticks, that transmit the disease, belong to the Ixodidae family (pasture ticks-hard ticks) and affect cattle that go out to pasture during the warm season. In this case, babesiosis was reported from a barn in Ankara, the temperatures had decreased to under 0 degrees C and it was snowing in February. The cattle hadn't been in a pasture for the past 3 months.

Development of a rapid immunochromatographic test for simultaneous serodiagnosis of bovine babesioses caused by Babesia bovis and Babesia bigemina

With the objective of developing a simpler diagnostic alternative, a rapid immunochromatographic test (BoiICT) was constructed for the simultaneous detection of Babesia bovis- and Babesia bigemina-specific antibodies using B. bovis recombinant merozoite surface antigen-2c and B. bigemina recombinant rhoptry-associated protein-1. The BoiICT selectively detected specific antibodies to B. bovis and B. bigemina. All sera from cattle infected with other protozoan parasites (i.e., Cryptosporidium parvum, Neospora caninum, and Theileria orientalis) showed negative results in the BoiICT. The relative sensitivity and specificity for detecting antibody to B. bovis were 96.7% (29 of 30) and 91.3% (73 of 80), respectively. The relative sensitivity and specificity for detecting antibody to B. bigemina were 96.7% (29 of 30) and 92.5% (74 of 80), respectively. These findings indicate that the BoiICT is useful for fast field diagnostic assessment of bovine babesioses without any laboratory equipment.

The case of babesiosis in farmed wolf (Canis lupus L)

There was recognised the case of canine babesiosis in farmed wolf (Canis lupus) in Białowieza, northeastern Poland. The typical symptoms were observed in animal--depression, asitia, and haematocyturia. The treatment with antibiotics gave positive results. It was the first observation of babesiosis in wolf in Poland.

Assessment of primers designed for the subspecies-specific discrimination among Babesia canis canis, Babesia canis vogeli and Babesia canis rossi by PCR assay

Canine babesiosis is an infectious disease caused by either Babesia gibsoni or Babesia canis protozoans. The latter is also classified under three different phylogenetic groups, referred to as subspecies B. canis canis, B. canis vogeli and B. canis rossi. The objective of the present study was to validate and standardize a PCR assay to discriminate the organisms at the subspecies level. First, the reference sequences of the 18S rRNA, 5.8S rRNA and 28S rRNA genes, including the internal transcribed spacer 1 (ITS1) and 2 (ITS2) of the most common species and subspecies of the genus Babesia were retrieved from the GenBank database. Subspecies-specific primers (BAB3, BAB4 and BAB5) and one genus-specific primer were designed from the alignment of the sequences. The PCR assays were evaluated in three different combinations of primer pairs in order to assure complete specificity for each reaction. The results of the tests had demonstrated effectiveness of the novel primer pairs BAB1/BAB3, BAB1/BAB4 and BAB1/BAB5 for the amplification of the subspecies-specific target fragments of 746 bp (B. c. canis), 546 bp (B. c. vogeli) and 342 bp (B. c. rossi) by PCR. The original enzymatic amplification assays with novel primers reported in this paper were confirmed to be a reliable tool for the specific discrimination among B. canis subspecies by single-step PCR assays.