Publications by authors named "Hajime Honma"

Malarial parasites exhibit extensive genomic plasticity, which induces the antigen diversification and the development of antimalarial drug resistance. Only a few studies have examined the genome maintenance mechanisms of parasites. The study aimed at elucidating the impact of a mutation in a DNA mismatch repair gene on genome stability by maintaining the mutant and wild-type parasites through serial cultures for approximately 400 days and analysing the subsequent spontaneous mutations.

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There has been some controversy about the evolutionary origin of Plasmodium vivax, particularly whether it is of Asian or African origin. Recently, a new malaria species which closely related to ape P. vivax was found in chimpanzees, in addition, the host switches of P.

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Background: The malaria parasite Plasmodium falciparum is a protozoan that develops in red blood cells (RBCs) and requires various host factors. For its development in RBCs, nutrients not only from the RBC cytosol but also from the extracellular milieu must be acquired. Although the utilization of host nutrients by P.

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Article Synopsis
  • Scientists found that the malaria parasite Plasmodium vivax infects both humans and African apes.
  • They studied the DNA of several types of malaria parasites from Asia and Africa to understand where P. vivax came from.
  • The research shows that P. vivax likely originated in Africa, rather than being closely related to Asian primate parasites as previously thought.
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is a primate parasite whose natural host is the African Old World monkeys. Here, we report the draft genome sequence for The data are useful not only for understanding the evolution of malaria but also for allowing the comparative genomics of malaria parasites.

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In this study, we investigated the mutation tendency of a mutator rodent malaria parasite, Plasmodium berghei, with proofreading-deficient DNA polymerase δ. Wild-type and mutator parasites were maintained in mice for over 24 weeks, and the genome-wide accumulated mutations were determined by high-throughput sequencing. The mutator P.

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Plasmodium falciparum malaria imposes a serious public health concern throughout the tropics. Although genetic tools are principally important to fully investigate malaria parasites, currently available forward and reverse tools are fairly limited. It is expected that parasites with a high mutation rate can readily acquire novel phenotypes/traits; however, they remain an untapped tool for malaria biology.

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Genetic diversity of Plasmodium falciparum is intimately associated with morbidity, mortality and malaria control strategies. It is therefore imperative to study genetic makeup and population structure of this parasite in endemic areas. In Kong Mong Tha, an isolated village in western Thailand, the majority of P.

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The geographical distribution of single nucleotide polymorphism (SNP) in the mitochondrial genome of the human malaria parasite Plasmodium falciparum was investigated. We identified 88 SNPs in 516 isolates from seven parasite populations in Africa, Southeast Asia and Oceania. Analysis of the SNPs postulated a sub-Saharan African origin and recovered a strong negative correlation between within-population SNP diversity and geographic distance from the putative African origin over Southeast Asia and Oceania.

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The Apicomplexan Cryptosporidium andersoni, is a species of gastric Cryptosporidium, is frequently detected in older calves and adult cattle. Genotyping analyses based on 18S ribosomal RNA gene sequences have been performed on a novel C. andersoni genotype, namely the Kawatabi type, and the oocysts were classified into two distinct groups genotypically: Type A (the sequence in GenBank) and Type B (with a thymine nucleotide insertion not in Type A).

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P. cynomolgi, a malaria-causing parasite of Asian Old World monkeys, is the sister taxon of P. vivax, the most prevalent malaria-causing species in humans outside of Africa.

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We investigated the prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam. A total of 740 single fecal samples collected from diarrheic and non-diarrheic pigs on 89 farms were screened by the modified Ziehl-Neelsen staining method. Prevalence at the animal and the farm levels were 18.

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SERA5 is regarded as a promising malaria vaccine candidate of the most virulent human malaria parasite Plasmodium falciparum. SERA5 is a 120 kDa abundantly expressed blood-stage protein containing a papain-like protease. Since substantial polymorphism in blood-stage vaccine candidates may potentially limit their efficacy, it is imperative to fully investigate polymorphism of the SERA5 gene (sera5).

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Background: The reemergence of Plasmodium vivax in South Korea since 1993 represents a serious public health concern. Despite the importance in understanding genetic diversity for control strategies, however, studies remain inconclusive with the general premise that due to low rate of malaria transmission, there is generally low genetic diversity with very few strains involved. In this study, the genetic diversity and population structure of P.

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Eimeria gruis and E. reichenowi cause coccidiosis, a major parasitic disease of cranes. By non-invasive molecular approaches, we investigated the prevalence and genetic characterization of pathogens in two Japanese crane habitats; one is Hokkaido inhabited by the endangered red-crowned crane, and the other is Izumi in Kyushu where populations that consist mainly of vulnerable hooded and white-naped cranes migrate in winter.

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Apicomplexan parasites of the genus Plasmodium, pathogens causing malaria, and the genera Babesia and Theileria, aetiological agents of piroplasmosis, are closely related. However, their mitochondrial (mt) genome structures are highly divergent: Plasmodium has a concatemer of 6-kb unit and Babesia/Theileria a monomer of 6.6- to 8.

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Cryptosporidium parvum is a ubiquitous zonootic parasite causing enteritis in man and animals. Cryptosporidium infection was confirmed microscopically in neonatal calves (less than 6 weeks of age) at Kafr El Sheikh Province, Egypt. Multilocus analysis using a wide array of genetic markers was carried out to assess genetic diversity of C.

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Triplumaria selenicaLatteur, Tuffrau and Wespes, 1970 was redescribed from pyridinated silver carbonate-impregnated specimens. Triplumaria selenica has a slit of the vestibular opening extending posteriorly along the left side of the vestibulum. The wide C-shaped adoral polybrachykinety extends along the ventral side of the vestibular opening.

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Neonatal calves are prone to Cryptosporidium infection resulting in economic loss as well as a significant source for zoonotic infection. This study was devoted to ascertain the prevalence and molecular analysis of Cryptosporidium in dairy calves at Kafr El Sheikh Province, Egypt. Twenty-nine out of 96 faecal specimens collected from calves, less than 6 weeks of ages, microscopically showed cryptosporidia oocysts (prevalence 30.

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Bacterial populations in epilithic biofilms collected from two distinct oligotrophic rivers of Japan were studied using denaturing gradient gel electrophoresis (DGGE). PCR-DGGE of the 16S rRNA gene and subsequent sequencing analysis suggested that in freshwater biofilms, members of the Cytophaga-Flavobacterium-Bacteroides (CFB) group were the most dominant, followed by those of alpha, beta, gamma, and delta-Proteobacteria; Leptospiraceae; and unidentified bacteria. Members of the CFB group, alpha-Proteobacteria, and cyanobacteria/plastid DNA were also detected from the biofilms collected from the estuary site, but the species in these samples differed from those detected in biofilms in the freshwater areas of the rivers.

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The general perception is that cattle are major reservoirs for Cryptosporidium parvum infections in humans and that C. parvum is a major cause of diarrhea and production loss in cattle. Adult cattle may play an important role as cryptic carrier of the infection.

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We investigated the prevalence of Cryptosporidium infection in relation to age and clinical status in cattle in the central region of Viet Nam. A total of 266 fecal samples from diarrheic and non-diarrheic cattle were examined by the modified Ziehl-Neelsen staining method. Prevalence of Cryptosporidium parvum type infections, those of the Cryptosporidium andersoni type, and mixed infection of both types was 33.

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We genetically analyzed eimerian oocysts isolated from the red-crowned crane (Grus japonensis) in Hokkaido, a northern island of Japan. Two types of oocysts of which shapes were similar to Eimeria gruis and E. reichenowi were found.

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