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| Registros recuperados: 10 | |
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| Sivakumar, Thillaiampalam; Kothalawala, Hemal; Weerasooriya, Gayani; Seekkuge Susil Priyantha Silva; Puvanendiran, Sumathy; Munkhjargal, Tserendorj; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Throughout the world, infections with the Babesia and Theileria parasites often result in economically significant clinical disease in cattle. We conducted a longitudinal survey of Babesia and Theileria infections in cattle from the Polonnaruwa (n?=?75; dry zone) and Nuwara Eliya (n?=?161; wet zone) districts of Sri Lanka. DNA from blood samples collected in June, September, and December 2014 and March 2015 was screened for Babesia bovis, Babesia bigemina, Theileria annulata and Theileria orientalis using specific polymerase chain reactions (PCRs). Additionally, serum samples collected from the animals were screened using enzyme-linked immunosorbent assays (ELISAs) to detect B. bovis- and B. bigemina-specific antibodies. All of the animals surveyed in... |
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Palavras-chave: Babesia; Cattle; Longitudinal study; Sri Lanka; Theileria. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4567 |
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| Musinguzi, Simon Peter; Suganuma, Keisuke; Asada, Masahito; Laohasinnarong, Dusit; Sivakumar, Thillaiampalam; Yokoyama, Naoaki; Namangala, Boniface; Sugimoto, Chihiro; Suzuki, Yasuhiko; Xuan, Xuenan; Inoue, Noboru. |
| We screened cattle and goats from the districts of Chama, Monze and Mumbwa in Zambia for animal African trypanosomes, Babesia bigemina and Theileria parva using PCRs; 38.1% of the samples tested positive for at least one of the parasite species. The most common parasite was Trypanosoma vivax (19.8%). Its incidence was significantly higher in goats than in cattle, (P<0.05). B. bigemina was found in samples from all the three areas, making it the most widespread of the parasites in Zambia. Among the tested samples, 12.0% of the positive samples were mixed infections. There were significant differences in the infection rates of T. vivax (Mumbwa had a significantly higher infection rate [39.6%, P<0.0001]), Th. parva (Monze had the only cases... |
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Palavras-chave: Animal African trypanosomosis; Cattle; Goat; Piroplasmosis; Zambia. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4389 |
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| Sivakumar, Thillaiampalam; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Babesia ovata, which is transmitted by Haemaphysalis longicornis, is an intraerythrocytic protozoan parasite of cattle. Based on its morphology, B. ovata is classified as a large-type Babesia. The developmental stages of B. ovata have been described both in cattle and the tick vector. In infected adult female ticks, the parasite is transovarially transmitted to the tick eggs. The sexual reproduction of B. ovata has been demonstrated in the tick midgut. The diagnostic tools that are currently available for the specific detection of B. ovata in cattle include microscopy and polymerase chain reaction assays. The development of improved molecular and serological diagnostic tools has been constrained by the limited availability of genetic data. B. ovata has... |
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Palavras-chave: Babesia ovata; Cattle; Epidemiology; Phylogeny; Taxonomy. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4555 |
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| Tattiyapong, Muncharee; Sivakumar, Thillaiampalam; Takemae, Hitoshi; Simking, Pacharathon; Jittapalapong, Sathaporn; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Babesia bovis, an intraerythrocytic protozoan parasite, causes severe clinical disease in cattle worldwide. The genetic diversity of parasite antigens often results in different immune profiles in infected animals, hindering efforts to develop immune control methodologies against the B. bovis infection. In this study, we analyzed the genetic diversity of the merozoite surface antigen-1 (msa-1) gene using 162 B. bovis-positive blood DNA samples sourced from cattle populations reared in different geographical regions of Thailand. The identity scores shared among 93 msa-1 gene sequences isolated by PCR amplification were 43.5-100%, and the similarity values among the translated amino acid sequences were 42.8-100%. Of 23 total clades detected in our... |
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Palavras-chave: Antigenicity variation; Babesia bovis; Msa-1; Genetic diversity; Thailand. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4490 |
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| Munkhjargal, Tserendorj; AbouLaila, Mahmoud; Mohamad Alaa Terkawi; Sivakumar, Thillaiampalam; Ichikawa, Madoka; Davaasuren, Batdorj; Nyamjargal, Tserendorj; Yokoyama, Naoaki; Igarashi, Ikuo; 横山, 直明; 五十嵐, 郁男. |
| We evaluated the inhibitory effects of pepstatin A and mefloquine on the in vitro and in vivo growths of Babesia parasites. The in vitro growth of Babesia bovis, B. bigemina, B. caballi, and B. equi was significantly inhibited (P < 0.05) by micromolar concentrations of pepstatin A (50% inhibitory concentrations = 38.5, 36.5, 17.6, and 18.1 μM, respectively) and mefloquine (50% inhibitory concentrations = 59.7, 56.7, 20.7, and 4 μM, respectively). Furthermore, both reagents either alone at a concentration of 5 mg/kg or in combinations (2.5/2.5 and 5/5 mg/kg) for 10 days significantly inhibited the in vivo growth of B. microti in mice. Mefloquine treatment was highly effective and the combination treatments were less effective than other treatments.... |
| Ano: 2012 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3829 |
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| Altangerel, Khukhuu; Sivakumar, Thillaiampalam; Inpankaew, Tawin; Jittapalapong, Sathaporn; Terkawi, Mohamad Alaa; Ueno, Akio; Xuan, Xuenan; Igarashi, Ikuo; Yokoyama, Naoaki; 玄, 学南; 五十嵐, 郁男; 横山, 直明. |
| Here we report on an epidemiological study regarding the molecular prevalence of different genotypes of Theileria orientalis present among domestic cattle and water buffalo populations bred in Thailand. A phylogenetic analysis based on the parasitic gene encoding a major piroplasm surface protein revealed the presence of 5 genotypes (Types 1, 3, 5, 7, and N-3) in cattle and 7 genotypes (Types 1, 3, 4, 5, 7, N-2, and N-3) in water buffaloes. Types 4, 7, and N-3 of T. orientalis were reported for the first time in water buffaloes. The previously reported C and Thai types from Thailand clustered as types 7 and 6, respectively, in the present analysis. Great similarities were observed among nucleotide sequences of isolates of the same genotype from cattle and... |
| Ano: 2011 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3592 |
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| Ishizaki, Takahiro; Sivakumar, Thillaiampalam; Hayashida, Kyoko; Tuvshintulga, Bumduuren; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Babesia bovis is an apicomplexan hemoprotozoan that can invade bovine red blood cells (RBCs), where it multiplies asexually. RBC invasion assays using free viable merozoites are now routinely used to understand the invasion mechanism of B. bovis, and to evaluate the efficacy of chemicals and antibodies that potentially inhibit RBC invasion by the parasite. The application of high-voltage pulses (high-voltage electroporation), a commonly used method to isolate free merozoites from infected RBCs, reduces the viability of the merozoites. Recently, a cold treatment of B. bovis in vitro culture was found to induce an effective release of merozoites from the infected RBCs. In the present study, we incubated in vitro cultures of B. bovis in an ice bath to... |
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Palavras-chave: Babesia bovis; Cold treatment; Invasion-inhibition assay; Merozoite isolation; RBC invasion. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4488 |
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| Tuvshintulga, Bumduuren; Sivakumar, Thillaiampalam; Battsetseg, Badgar; Narantsatsaral, Sandag-ochir; Enkhtaivan, Batsaikhan; Battur, Banzragch; Hayashida, Kyoko; Okubo, Kazuhiro; Ishizaki, Takahiro; Inoue, Noboru; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Babesia microti is a tick-transmitted zoonotic hemoprotozoan parasite. In the present study, we investigated B. microti infection in questing ticks in Mongolia. A total of 219 questing ticks were collected from three different Mongolian provinces (Bayan-Olgii, Khovsgol, and Selenge). Of these, 63 from Selenge were identified as Ixodes persulcatus, while the remaining 156 (from all three provinces) were identified as Dermacentor nuttalli. When the tick DNA samples were screened using a B. microti-specific nested PCR, 19 (30.2%) of the 63 I. persulcatus ticks were found to be B. microti-positive. The parasite was not detected in D. nuttalli. Subsequently, the 18S rRNA, cox1, and tufA sequences of B. microti were amplified, sequenced, and subjected to... |
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Palavras-chave: 18S rRNA; B. microti; Cox1; Mongolia; Ticks; TufA. |
| Ano: 2015 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4554 |
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| Liyanagunawardena, Nilukshi; Sivakumar, Thillaiampalam; Kothalawala, Hemal; Silva, Seekkuge Susil Priyantha; Battsetseg, Badgar; Dinh Thi Bich Lan; Inoue, Noboru; Igarashi, Ikuo; Yokoyama, Naoaki. |
| Babesia bovis is the most virulent Babesia organism, resulting in a high mortality rate in cattle. The genetic diversity of B. bovis merozoite surface antigens (MSAs), such as MSA-1, MSA-2b, and MSA-2c, might be linked to altered immune profiles in the host animals. The present study aimed to develop type-specific PCR assays for Asian msa-1 genotypes, thereby re-analyzing the genetic diversity of msa-1 in Sri Lanka, Mongolia, and Vietnam. Specific primers were designed for nine Asian msa-1 genotypes, which had been detected based on the phylogeny constructed using msa-1 gene sequences retrieved from the GenBank database. Specificity of the type-specific PCR assays was confirmed using plasmids containing the inserts of msa-1 gene fragments that represent... |
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Palavras-chave: Asia; Babesia bovis; Genetic diversity; Msa-1; Type-specific PCR. |
| Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4489 |
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| Registros recuperados: 10 | |
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