首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
The present work describes the detection and first molecular characterization of Babesia vogeli in dogs, naturally infected in Brazil and even in South America. Microscopic examination of Giemsa-stained peripheral blood smears collected from dogs originating from four different locations in Brazil revealed the presence of large Babesia merozoites and trophozoites (>2.5 microm). DNA was extracted from infected blood samples and PCR amplifications of the 18S rDNA were carried out. As a reference, DNA from an isolate of B. vogeli originated from Egypt was used. PCR products were purified and sequenced. The DNA sequences demonstrated 100% identity among the Brazilian isolates. Comparisons with the 18S rDNA sequence of the B. vogeli isolate from Egypt and with other B. vogeli sequences from Spain, France, Japan, Australia and South Africa confirmed the affiliation of all Brazilian isolates to the species B. vogeli.  相似文献   

2.
Canine babesiosis represents an important veterinary medical problem. This study describes the molecular characterization of babesial parasites detected in eight clinically suspected dogs from northern Portugal, affected by lethargy, muscle tremors, weight loss, pale mucous membranes, hyperthermia or red-coloured urine. Microscopic examination of peripheral blood smears showed large intraerythrocytic piroplasms morphologically compatible with Babesia canis in all eight animals. DNA was extracted from blood on filter paper, and a Babesia spp. infection confirmed by polymerase chain reaction (PCR) amplification of a 408bp fragment of the 18S rRNA gene. Analysis of PCR-derived sequences revealed that seven dogs were infected with B. canis canis and one with B. canis vogeli. This is the first molecular identification report of both the species B. canis and the subspecies B. canis canis and B. canis vogeli in dogs from Portugal.  相似文献   

3.
The prevalence of hematozoan infections (Hepatozoon canis and Babesia sp., particularly Babesia canis vogeli) in canids from Venezuela, Thailand and Spain was studied by amplification and sequencing of the 18S rRNA gene. H. canis infections caused simultaneously by two different isolates were confirmed by RFLP analysis in samples from all the geographic regions studied. In Venezuela, blood samples from 134 dogs were surveyed. Babesia infections were found in 2.24% of the dogs. Comparison of sequences of the 18S rRNA gene indicated that protozoan isolates were genetically identical to B. canis vogeli from Japan and Brazil. H. canis infected 44.77 per cent of the dogs. A representative sample of Venezuelan H. canis isolates (21.6% of PCR-positives) was sequenced. Many of them showed 18S rRNA gene sequences identical to H. canis Spain 2, albeit two less frequent genotypes were found in the sample studied. In Thailand, 20 dogs were analyzed. No infections caused by Babesia were diagnosed, whereas 30 per cent of the dogs were positive to hematozoan infection. Two protozoa isolates showing 99.7-100% identity to H. canis Spain 2 were found. In Spain, 250 dogs were studied. B. canis vogeli infected 0.01% of the animals. The sequence of the 18S rRNA gene in Spanish isolates of this protozoa was closely related to those previously deposited in GenBank (> 99% identity). Finally, 20 red foxes were screened for hematozoans employing semi-nested PCR and primers designed to detect Babesia/Theileria. Fifty percent of the foxes were positive to Theileria annae. In addition, it was found that the PCR assay was able as well to detect Hepatozoon infections. Thirty five percent of the foxes were infected with two different H. canis isolates showing 99.8-100% identity to Curupira 1 from Brazil.  相似文献   

4.
The aims of this study were to determine the presence of Babesia spp. in blood samples from Italian dogs with clinical signs compatible with tick-borne diseases by means of PCR-restriction fragment length polymorphism (RFLP) and describe the clinicopathological findings of dogs with Babesia infection. We evaluated the majority of canine babesiosis cases by means of clinical history, physical examination, hematological, biochemical, serum electrophoresis, urinalysis and hemostatic tests. Forty-five out of 164 canine blood samples studied were positive to Babesia PCR-RFLP with the following results: Babesia canis canis (n=34) and Babesia canis vogeli (n=11). The majority of B. c. canis infections were detected in Northern Italy (29.1%; 30/103). B. c. vogeli cases were detected mainly in Central and Southern Italy (16.3%; 10/61). Only one B. c. vogeli was detected in Northern Italy (0.9%; 1/103). Three positive samples to B. c. canis and four positive samples to B. c. vogeli were selected for sequencing of a fragment of the 18S rRNA gene (410bp) for further molecular characterization. The sequence obtained from all seven dogs was 99/100% homologous to sequences from B. c. canis and B. c. vogeli, respectively, present in GenBank. Sixty-two percent of dogs infected with B. c. canis had recently travelled on a hunting trip to East European countries. The main acute clinical signs were dehydration, apathy, anorexia and fever. The majority of dogs infected with B. c. canis presented at initial clinical examination mild to severe thrombocytopenia, hyperfibrinogenemia, mild to moderate normocytic-normochromic non-regenerative anemia, hemolysis and neutropenia. The urinalysis showed hemoglobinuria in 13/19 dogs suggesting intravascular hemolysis. Dogs with B. c. canis infection had high levels of C-reactive protein. Hypoalbuminemia was present in 17/26 dogs. The 11 cases of B. c. vogeli infection did not present a homogenous clinicopathological pattern. B. c. vogeli infections were observed in young dogs causing hemolytic anemia and in adult/old does that frequently presented predisposing factors such as splenectomy or immunocompromised conditions. In conclusion, this study demonstrates the presence of B. c. canis and B. c. vogeli in Italian sick dogs and differences in clinicopathological pattern in these two species of B. canis.  相似文献   

5.
The heat shock protein 70 (hsp70) genes of Babesia gibsoni, B. canis canis, B. canis vogeli, and B. canis rossi isolated from infected dogs were cloned by polymerase chain reaction (PCR) and sequenced. In the nucleotide sequence and the predicted amino acid sequence of the gene, the parasites were very similar to each other. The nucleotide sequences of the hsp70 gene had more variety than those of 18S nuclear subunit ribosomal DNA (18S rDNA). A phylogenetic analysis of these sequences and comparisons with sequences from other Babesia and Theileria species revealed that all canine babesial isolates analyzed in the present study were closely related to each other and formed one cluster. Additionally, a phylogenetic analysis of Babesia and Theileria species showed that these parasites could be divided into three groups: group A including canine babesial isolates, B. divergens, B. odocoilei, B. bovis, B. caballi, and B. ovis; group B including Theileria annulata, T. orientalis, and T. cervi; and group C including B. microti and B. rodhaini. These results suggested that a phylogenetic analysis of the hsp70 gene sequence might be helpful in classifying Babesia and Theileria species, and that canine babesial isolates might be closely related to each other, indicating their evolution from the same ancestry.  相似文献   

6.
A total of 80 free-roaming dogs on Okinawa Island, Japan, were examined for Babesia infection using the polymerase chain reaction (PCR) and sequence analysis. Of 80 samples, 12 were positive in a Babesia genus-specific PCR. Consequent species-specific PCR for B. canis and B. gibsoni revealed that 5 (6.3%) and 7 (8.8%) dogs were infected with B. canis and B. gibsoni, respectively. Sequence analysis of the PCR products revealed that the 18S rRNA gene sequence of B. canis detected from dogs in Okinawa was very close to B. canis vogeli with sequence similarity of 99.94%.  相似文献   

7.
Ehrlichiosis and babesiosis are tick-borne diseases, caused mainly by Ehrlichia canis and Babesia canis, respectively, with a worldwide occurrence in dogs, whose main vector is the brown-dog tick, Rhipicephalus sanguineus. The present work aimed to detect the presence of E. canis and Babesia sp. in 91 dog blood samples in Colombia, by molecular and serological techniques. We also performed sequence alignment to indicate the identity of the parasite species infecting these animals. The present work shows the first molecular detection of E. canis and B. vogeli in dogs from Colombia. Immunoglobulin-G (IgG) antibodies to E. canis and Babesia vogeli were found in 75 (82.4%) and 47 (51.6%) sampled dogs, respectively. Thirty-seven (40.6%) and 5 (5.5%) dogs were positive in PCR for E. canis and Babesia sp., respectively. After sequencing, amplicons showed 99% of identity with isolates of E. canis and B. vogeli. The phylogenetic trees based on 16S rRNA-Anaplasmataceae sequences and 18S rRNA-piroplasmid sequences supported the identity of the found E. canis and B. vogeli DNAs, respectively. The present work shows the first molecular detection of E. canis and B. vogeli in dogs in Colombia.  相似文献   

8.
Babesiosis is an emerging tick-borne disease of animals and humans caused by intraerythrocytic protozoa of the genera Babesia and Theileria. In France canine babesiosis has a high prevalence with Babesia canis thought to be the main aetiological agent of the disease. Babesia vogeli has already been reported to occur in Europe and in other countries around the Mediterranean Sea. The tick Rhipicephalus sanguineus, the main known vector of B. vogeli, occurs in southern France. However, only one case of a B. vogeli infected dog has been reported to date in France. To gain further insight into the prevalence of Babesia and Theileria infections in dogs and ticks of the R. sanguineus complex, a study was conducted in a veterinary practice in the south of France from January to September 2010. Twelve bloods from dogs and 36 R. sanguineus ticks were analyzed using PCR and sequencing. For the analysis of ticks, a new primer was designed to specifically amplify the B. vogeli 18S rRNA gene. Four dogs (33.3%) and 8 ticks (22.2%) were found to be infected with B. vogeli. This approach has thus revealed for the first time a cluster of cases of canine babesiosis caused by B. vogeli in France and highlights the need to systematically screen for pathogens potentially responsible for canine babesiosis at the species level using suitable molecular tools.  相似文献   

9.
Canine babesiosis, caused by intra-erythrocytic Babesia, is a tick-borne disease of worldwide importance. No information on canine babesiosis has been documented in Tunisia. Detection and analysis of Babesia species from naturally infected dogs and ticks recovered from dogs were attempted by reverse line blot hybridization and nucleotide sequence analysis based on 18S rRNA gene. Out of 180 blood samples collected from domestic dogs in 4 villages situated in different bioclimatic zones, 12 were positive for Babesia canis vogeli. In addition, a total of 160 Rhipicephalus sanguineus were analysed; only one male was infected by B. canis vogeli. This is the first report on the detection of DNA belonging to B. canis vogeli in domestic dogs and in R. sanguineus in Tunisia.  相似文献   

10.
Large piroplasms (>2.5microm) were detected by direct microscopical investigation in 34 out of 16,767 (0.20%) canine blood smears in the Southern region of Greater Buenos Aires. Genomic DNA was extracted from two parasitemic dogs and the hypervariable 18S RNA gene region of the pathogen was specifically amplified, sequenced, and aligned with corresponding gene sequences available in the GenBank. Phylogenetic trees were constructed and compared. 18S RNA gene sequences reliably segregated in three clearly distinguishable clades representing Babesia canis, Babesia vogeli and Babesia rossi isolates, respectively. The 18S RNA gene sequences of both Babesia isolates from Argentina affiliated to the B. vogeli branch. This finding represents the first molecular evidence of the existence of B. vogeli in Argentina.  相似文献   

11.
Canine babesiosis, caused by intraerythrocytic Babesia spp., is a tick-borne disease of worldwide importance. No information on canine babesiosis has been documented in Slovenia. Therefore, 238 dogs admitted to the Small animal clinic in Ljubljana from the years 2000 to 2002 were tested for the presence of babesial parasites in the blood. Based on clinical, microscopic and molecular investigations, 14 dogs (5.9%) were determined as being infected with babesiae. Clinical signs relating to acute haemolysis, fever, anorexia, depression and haematological abnormalities such as anaemia and thrombocytopenia were noticed in most of the 14 infected dogs. The morphology of the parasites was indicative of Babesia canis infection. Two subspecies were detected, namely B. canis canis (11 dogs, 4.6%) and B. canis vogeli (3 dogs, 1.3%) using PCR and subsequent sequence analysis of portions of nns rRNA gene. In addition, based on nucleotide sequence analysis, the 11 isolates of B. c. canis could be subdivided into three groups, whereas the three B. c. vogeli isolates were genetically identical. The results of this study demonstrate the presence of canine babesiosis due to B. c. canis and B. c. vogeli in Slovenia.  相似文献   

12.
Babesia canis has generally been considered the only large Babesia to infect dogs. In this study, we used PCR to detect and characterize B. canis canis isolated from naturally infected dogs in Poland by amplifying and sequencing a portion of the 18S ribosomal RNA (rRNA) gene. Venous blood samples were collected from 76 Babesia-symptomatic dogs. A 559-bp fragment of the B. canis canis 18S rRNA gene was amplified by PCR. The PCR products were then digested with HincII restriction enzyme, and isolates were classified according to whether they were cut (group A) or not (group B) by this endonuclease. Sequencing of the PCR products from the isolates led to the identification of seven sequence variants (four in group A, and three in group B). Sequences were compared with GenBank sequences, and alignments showed that all B. canis canis isolates from Europe may be classified into groups A or B as defined in our study.  相似文献   

13.
The prevalence of Hepatozoon canis infections in dogs in Nigeria was surveyed using molecular methods. DNA was extracted from blood samples obtained from 400 dogs. A primer set that amplified the Babesia canis 18S rRNA gene, which has high similarity to the H. canis 18S rRNA gene, was used for the PCR. As a result, samples from 81 dogs (20.3%) produced 757 bp bands, which differed from the 698 bp band that corresponded to B. canis infection. The sequence of the PCR products of 10 samples were determined, all of which corresponded with the H. canis sequence.  相似文献   

14.
Babesia canis canis in dogs from Hungary: detection by PCR and sequencing   总被引：1，自引：0，他引：1  
Canine babesiosis in Hungary has always been a severe and frequent disease, attributed to infection with Babesia canis transmitted by Dermacentor reticulatus. Identification of the disease agent has been based merely on size and morphology of the intraerythrocytic parasites and no evidence has been found concerning the subspecies (genotype) of B. canis. Therefore, a molecular survey on natural Babesia infection of dogs in Hungary using PCR and sequence analysis was attempted to clarify the subspecies (genotype) and to obtain information on the occurrence of B. canis. A total of 44 blood samples from dogs showing clinical signs of babesiosis were collected. A piroplasm-specific PCR amplifying the partial 18S rRNA gene yielded an approximately 450 bp PCR product in 39 (88.6%) samples. Thirteen positive samples originated from Budapest and 26 from 21 other locations. Five PCR products were chosen randomly for sequencing. The partial 18S rDNA sequences were submitted to GenBank (accession numbers AY611729; AY611730; AY611731; AY611732 and AY611733). The sequences showed 100% homology to one another or differed by one nucleotide. BLAST search against GenBank revealed the highest similarity (99.8 or 100%) with Babesia canis canis. The implication of these data, for the further study and diagnosis of canine babesiosis is discussed.  相似文献   

15.
Babesia canis has generally been considered the only large Babesia to infect dogs. Here we describe the molecular characterization of a large Babesia species that was detected in the blood and bone marrow of a dog with clinical and hematological abnormalities consistent with babesiosis. Analysis of the 18S rRNA genes revealed a unique sequence that shared 93.9% sequence identity with B. bigemina and 93.5% sequence identity with B. caballi, compared to 91.2-91.6% identity with B. canis canis, B. c. vogeli, and B. c. rossi. Cross-reactive antibodies against B. canis, B. gibsoni (Asian genotype), or B. gibsoni (California genotype) antigens were not detected in acute or convalescent serum samples. The dog was treated with imidocarb diproprionate, which resulted in the resolution of clinical signs, and subsequently Babesia DNA was not detectable by PCR in post-treatment samples. The organism described in this report represents a genetically unique large Babesia sp. and is the eighth genetically distinct piroplasm capable of infecting the domestic dog.  相似文献   

16.
OBJECTIVE: To detect Anaplasma platys and Babesia canis vogeli infection, using polymerase chain reaction (PCR)-based assays, in free-roaming dogs associated with eight Aboriginal communities in remote areas of Australia and to determine the impact of infection through the assessment of platelet numbers. PROCEDURES: Blood samples from 215 dogs were screened by PCR for A platys and B canis vogeli using established genus-specific DNA primers for the 16S and 18S rRNA genes respectively. Both A platys DNA and B canis vogeli DNA were confirmed from the screening PCR either by sequencing or by the use of species-specific primers. Peripheral blood films from 92 of the 215 dogs were used to estimate platelet numbers through an indirect method. RESULTS: Of 215 dogs, 69 (32%) were positive for A platys, 22 (10%) for B canis vogeli and 24 (11%) for both. The two organisms were detected singularly and as coinfection in all communities. For the 92 dogs in which peripheral blood films were examined, the mean estimated platelet counts for the non-infected dogs was 318 x 10(9)/L, those infected with A platys alone was 256 x 10(9)/L, those with B canis vogeli alone was 276 x 10(9)/L and those infected with both parasites was 169 x 10(9)/L. In young dogs, infection produced significantly decreased mean platelet counts when compared to uninfected dogs. Thrombocytopenia (< 200 x 10(9)/L) was detected in 18 (51%) dogs infected with A platys alone, 3 (33%) dogs infected with B canis vogeli alone, 13 (72%) dogs coinfected, and 8 (27%) uninfected dogs. CONCLUSIONS: A platys and B canis vogeli infection, either singularly or together, was widespread in free roaming dogs associated with remote Aboriginal communities in the Northern Territory and north-western New South Wales. Moreover, both A platys and B canis vogeli infections were associated with a reduction in mean platelet numbers in dog populations, particularly in young dogs. The fact that 51% of dogs infected with A platys alone and 72% dogs coinfected were thrombocytopenic compared to 27% of uninfected dogs suggests that the organism alone or in combination with B canis vogeli has the potential to cause thrombocytopenia and perhaps contribute to a clinical bleeding disorder in infected dogs.  相似文献   

17.
The morphologically small Babesia species isolated from naturally infected dogs in Europe, Japan, and US are described as Babesia gibsoni despite the fact that molecular techniques show that they should be assigned to two or three separate taxons. The morphologically large Babesia isolated from dogs in Europe, Africa, and US were generally classified as B. canis until it was proposed to distinguish three related, albeit genetically distinct subspecies of this genus, namely B. canis canis, B. canis rossi, and B. canis vogeli. The insight into the molecular taxonomy of canine piroplasms is, however, limited because only partial small subunit ribosomal RNA (ssrRNA) sequence data exist for two species from the B. canis group. In this work, we molecularly characterised natural Babesia infections in 11 dogs from Croatia, France, Italy, and Poland. These infections were diagnosed as caused by B. canis canis and B. canis vogeli based on the analysis of the complete sequence of the ssrRNA genes. Phylogenetic analysis confirmed that the large Babesia species of dogs belong the to the Babesia sensu stricto clade, which includes species characterised by transovarial transmission in the tick vectors and by exclusive development inside the mammalian host erythrocytes. The new data facilitate the reliable molecular diagnosis of the subspecies of B. canis.  相似文献   

18.
The prevalence of Babesia infections in domestic dogs in South Africa was studied using reverse line blot hybridization and 18S sequence analysis. Babesia canis vogeli was confirmed for the first time in domestic dogs in South Africa. Out of a total of 297 blood samples collected from domestic dogs in Bloemfontein, East London, Johannesburg, Durban and from the Onderstepoort Veterinary Academic Hospital, 31 were positive for Babesia canis rossi, whereas B. c. vogeli was detected in 13 dogs. None of the dogs carried both parasites. The detection of B. c. vogeli has implications with regard to prevalence and varied clinical manifestation of canine babesiosis in South Africa.  相似文献   

19.
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.  相似文献   

20.
Luo J  Yin H  Liu Z  Yang D  Guan G  Liu A  Ma M  Dang S  Lu B  Sun C  Bai Q  Lu W  Chen P 《Veterinary parasitology》2005,133(1):1-6
The 18S small subunit ribosomal RNA (18S rRNA) gene of an unnamed Babesia species (designated B. U sp.) was sequenced and analyzed in an attempt to distinguish it from other Babesia species in China. The target DNA segment was amplified by polymerase chain reaction (PCR). The PCR product was ligated to the pGEM-T Easy vector for sequencing. It was found that the length of the 18S rRNA gene of all B. U sp. Kashi 1 and B. U sp. Kashi 2 was 1699 bp and 1689 bp. Two phylogenetic trees were, respectively, inferred based on 18S rRNA sequence of the Chinese bovine Babesia isolates and all of Babesia species available in GenBank. The first tree showed that B. U sp. was situated in the branch between B. major Yili and B. bovis Shannxian, and the second tree revealed that B. U sp. was confined to the same group as B. caballi. The percent identity of B. U sp. with other Chinese Babesia species was between 74.2 and 91.8, while the percent identity between two B. U sp. isolates was 99.7. These results demonstrated that this B. U sp. is different from other Babesia species, but that two B. U sp. isolates obtained with nymphal and adultal Hyalomma anatolicum anatolicum tick belong to the same species.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号