On October 17, 2006, the Sakai City Public Health Center received a report of acute gastroenteritis among 4 members from the same company who had eaten raw meat dish called “

: Korean-style beef tartar” and raw liver at a rotisserie in Sakai City on October 7. Based on information from interviews, the median incubation period was 5.5 (range, 5 - 7 days), and the median length of illness was 7 days (range, 4 - 10 days). The illness was characterized by a prolonged incubation period, non-bloody watery diarrhea, reduced vomiting, and light fever, which led us to suspect an enteric protozoan infection. Stool specimens obtained from 3 of the 4 symptomatic patients were positive for Cryptosporidium oocysts. They, along with 2 food workers, were negative for food poisoning bacteria or Norovirus. Genotyping of the Cryptosporidium isolates by direct sequencing of PCR products revealed that all the isolates were the C. parvum genotype II (bovine) and the subgenotype of IIa with 100 % homology with respective 18S rRNA and Cpgp40/15 genes. Positive implementation of tests for enteric protozoa including Cryptosporidium is necessary in the differential diagnosis of suspected foodborne gastroenteritis, particularly when it is characterized by a prolonged incubation period and severe watery diarrhea. In fact, we were able to diagnose the illness as cryptosporidiosis without waiting for the results of bacteriological and virological examinations, and thus prevented the possible occurrence of a secondary infection through an ill patient who works as cooking personnel in the company.

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We describe a case of infective endocarditis caused by Campylobacter fetus accompanied by pulmonary emboli. A 52-year-old man was referred to our hospital due to febrile temperatures with a history of dental treatment followed by eating raw meat. Computed tomography revealed multiple infiltrations and a nodule with low attenuation area and feeding vessels. A mobile mass, possible vegetation, attached to the tricuspid valve was detected by transthoracic echocardiography. Two blood cultures disclosed Campylobacter fetus. Long-term antibiotic therapy was given, curing the infection with valvuloplasty. We presented the possibility that infective Campylobacter fetus endocarditis after dental treatment was caused by eating raw meat.

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In this study, we evaluated the applicability of cytolethal distending toxin (cdt) gene-based species-specific multiplex PCR for the direct detection and identification of Campylobacter jejuni, C. coli and C. fetus from stool specimens of patients with gastroenteritis in comparison to culture methods. A total of 711 stool specimens were examined for the isolation or detection of campylobacters by using Skirrow's selective agar culture plates, a filtration method and the multiplex PCR assay. Forty-one and 36 C. jejuni strains were isolated by culture and filtration methods, respectively. In addition, 2 and 3 C. coli strains were isolated by Skirrow and the filtration methods, respectively. However, when the multiplex PCR was employed, the cdtB genes of C. jejuni and C. coli were detected in 45 and 4 stool samples, respectively, and 9 C. jejuni PCR-positive samples by multiplex PCR were negative by culture method. Sequence analysis of the PCR products obtained from 8 stool specimens from which campylobacters were not isolated by culture method but the sequences exactly matched with that of the cdtB gene of C. jejuni strain 81–176. None of the remaining stool samples which were culture negative for campylobacters produced any amplicon. Stool samples were defined as Campylobacter-positive if detected by any method. The sensitivity of the multiplex PCR was 83%, which was higher than Skirrow (74%) and filtration method (66%). These data indicate that cdtB gene-based multiplex PCR is a rapid and more sensitive method to identify the most important species of Campylobacter for human diseases. (248)

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Campylobacter-induced diarrhea is increasingly recognized worldwide. However, little information is available regarding the Campylobacter strains associated with diarrheal patients in Thailand. In this study, we attempted to isolate Campylobacter strains from diarrheal patients in Thailand and to characterize the species using a cytolethal distending toxin (cdt) gene-based C. jejuni, C. coli, and C. fetus-specific multiplex PCR assay. Campylobacter species were also confirmed using 16S rRNA gene sequencing and hipO gene detection. From 2,500 diarrheal stool specimens, 76 Campylobacter-like organisms were isolated and identified via conventional culture methods. Among these 76 organisms, 73 were identified as Campylobacter species (43 C. jejuni, 29 C. coli, and 1 C. fetus) via multiplex PCR, whereas 3 remained unidentified. Two Campylobacter-like organisms yielded 2 amplicons corresponding to cdt genes from C. jejuni and C. coli. Subsequently, C. jejuni and C. coli were re-isolated from each sample. The third isolate was identified as C. hyointestinalis via 16S rRNA gene sequencing. To our knowledge, this is the first report on the isolation of C. hyointestinalis from a diarrheal patient in Thailand. These data indicate that C. jejuni (58%) and C. coli (40%) are prevalent among diarrheal patients in Thailand.

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岩手県一関市にある74の農業用ため池において、2007年9月〜2009年9月にかけて、コイの在・不在が浮葉植物・沈水植物・抽水植物の被度に与えている影響を明らかにするための調査を行った。その結果、絶滅危惧種を含む浮葉植物と沈水植物の被度が、コイの存在により負の影響を受けている可能性が示された。一方、抽水植物の被度への有意な効果は認められなかった。コイの導入は、農業用ため池の生態系を大きく改変する可能性を示唆している。

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  The development of a carrier for the delivery of siRNA is a factor in the realization of RNA interference (RNAi) therapeutics. Modification of siRNA carriers with polyethylene glycol, i.e., PEGylation, is a general strategy for stabilizing a particle in the blood stream and delivering it to tissue or cells. However, it is well-known that, when a carrier is modified by PEGylation, it results in a significant inhibition of both cellular uptake and the endosomal escape process. In a previous study, we reported on the development of a multifunctional envelope-type nano device (MEND) for delivering siRNA and peptide-based functional devices for overcoming the effects conferred by PEGylation and succeeded in the delivery of siRNA to tumor tissue. In this study, we noticed that the pH-sensitive property, changing from neutral to cationic in response to a decrease in pH, could avoid the inhibition caused by PEGylation and succeeded in synthesizing a pH-sensitive cationic lipid, YSK05. The YSK05-MEND had a higher fusogenicity and potency for endosomal escape than other MENDs containing conventional cationic lipids. The PEGylated YSK05-MEND induced efficient gene silencing and avoided the inhibition of endosomal escape caused by PEGylation followed by optimization of the lipid composition. Furthermore, the intratumoral injection of the PEGylated YSK05-MEND resulted in a more efficient gene silencing compared with MENDs containing conventional cationic lipids. Thus, the YSK05-MEND is a promising siRNA carrier for avoiding the inhibition in intracellular trafficking caused by PEGylation both in vitro and in vivo.

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2010年6〜10月に、北海道渡島半島北部を流れる朱太川水系78地点において魚類相調査を行い、10科29種の魚類を記録した。通し回遊魚は、種の豊かさおよび存在量がともに高かったのに対して、止水環境利用魚類の存在量は低く、イトウは個体群絶滅が示唆された。これらは、朱太川における流程方向の生息場所間の連結性の高さと、氾濫原湿地の大規模な喪失による河川横断方向の生息場所間の連結性の低下を反映しているものと推察された。朱太川水系における魚類の保全のためには、通し回遊魚の保全には引き続き流程方向の連結性の維持が求められる一方で、止水環境利用魚類の保全・回復には氾濫原湿地の再生が必要なことが示唆された。

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朱太川水系の過去の魚類相を再構築することを目的として、博物館標本と聞き取り調査を行った。美幌博物館、北海道大学総合博物館水産科学館、市立函館博物館、国立科学博物館において、朱太川水系から採集された魚類標本の調査を行い、13種の魚類標本の所在を確認することができた。しかし、市立函館博物館の1923年以前の標本台帳に記されているイトウ標本の所在は不明であった。また、朱太川漁業協同組合の関係者18名に過去の朱太川水系の魚類相に関する聞き取り調査を行い、42種の魚類の採集・観察歴について情報を得た。同定の信頼性が高いと考えられるのはそのうちの34種であり、地域の漁業協同組合の保護・増殖の対象種であるかどうかと、聞き取り対象者が生息量の増減を認識していたかどうかは、有意に相関していた。カワヤツメなどの氾濫原湿地を利用する魚類の生息量の減少を指摘する回答者が12名いた。現在は見られないイトウが過去に確かに生息していたこと、カワヤツメの生息量が急減したことが聞き取りからほぼ確かであることが判明し、黒松内町の生物多様性地域戦略における自然再生の目標設定、すなわち「氾濫原湿地の回復」の妥当性が確認された。多くの人々が関心をもって観察・採集してきた生物種については、聞き取り調査によって量の変化に関する情報を得ることができる可能性が示唆された。

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Cryptosporidium species infect domestic animals, livestock, and humans. These protozoan parasites are frequently reported as major environmental contaminants in many countries despite their differing climatic, socioeconomic, and demographic factors. This review focuses on the research findings that relate to Cryptosporidium epidemiology, genetic diversity, and associated risk factors relating to animals, contaminated water sources, and humans in Japan. Adequate knowledge of these factors is essential for understanding the economic and public health importance of cryptosporidiosis in Japan so that effective control strategies against it are implemented. Cryptosporidium infections are highly prevalent in animals in Japan. Among the different animal species, cattle infections stand out because of their economic importance and zoonotic potential. Living circumstances in Japan restrain Cryptosporidium transmission between humans, but there is evidence to suggest that animals, especially those in close contact with humans, can be potential sources of human infections. Water sampling studies have provided clues about how environmental contamination with Cryptosporidium oocysts can cause infections in livestock and wild animals. There is some evidence of person-to-person transmission of cryptosporidiosis, but only occasionally and under certain circumstances. By identifying the major role played by animals in Cryptosporidium transmission to people in Japan, we highlight the urgent need for disease control against this pathogen.

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