In developed countries including Japan, malignant tumor (cancer), heart disease and cerebral apoplexy are major causes of death, but infectious diseases are still responsible for a high number of deaths in developing countries, especially among children aged less than 5 years. World Health Statistics published by WHO reports a high percentage of mortality from infectious diseases in children, and many of these diseases may be subject to transmission across borders and could possibly invade Japan.
　Given this situation, the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan initiated Phase I of the Program of Founding Research Centers for Emerging and Reemerging Infectious Disease, which ran from FY 2005 to 2009, and involved 8 Japanese universities and 2 research centers. The program was established for the following purposes: 1) creation of a domestic research structure to promote the accumulation of fundamental knowledge about infectious diseases, 2) establishment of 13 overseas research collaboration centers in 8 countries at high risk of emerging and reemerging infections and at which Japanese researchers are stationed and conduct research in partnership with overseas instructors, 3) development of a network among domestic and overseas research centers, and 4) development of human resources.
　The program was controlled under MEXT and managed by the RIKEN Center of Research Network for Infectious Diseases (Riken CRNID). Phase II of the program was set up as the Japan Initiative for Global Research Network on Infectious Diseases (J-GRID), and has been running in FY 2010-2014.
　Phase III will start in April 2015, and will be organized by the newly established Japanese governmental organization “Japan Agency for Medical Research and Development (AMED)”, the so-called Japanese style NIH.
　The Collaborative Research Center of Okayama University for Infectious Diseases in India (CRCOUI) was started up in 2007 at the National Institute of Cholera and Enteric Disease, Kolkata, India. Major projects of CRCOUI are concerned with diarrheal diseases such as, 1) active surveillance of diarrheal patients, 2) development of dysentery vaccines, 3) viable but nonculturable (VBNC) Vibrio cholerae, and 4) pathogenic mechanisms of various diarrhogenic microorganisms.
　This review article outlines project of J-GRID and CRCOUI which the authors carried out collaboratively with NICED staff members.

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　The killing effect of peppermint vapor (PMV) against pink-slime forming microorganisms, Methylobacterium mesophilicum as a bacterium and Rhodotorula mucilaginosa as a yeast, was investigated by the agar vapor assay. In this method, microbial cells were spread over the agar surface exposed to PMV in a petri dish, and then transferred into a recovery liquid. When 60μl of the peppermint liquid was added to a paper disc, a marked killing effect of PMV was observed after 48h against M. mesophilicum and after 168h against R. mucilaginosa. M. mesophilicum and R. mucilaginosa were found to be more resistant to PMV than Escherichia coli and Candida albicans, used as reference microorganisms, respectively. With the addition of 0.03% sodium pyruvate as a hydrogen peroxide scavenger in agar, the killing effect of PMV against E. coli and C. albicans was decreased, whereas it was little changed against M. mesophilicum and R. mucilaginosa. In fact, the properties of the killing effect of hydrogen peroxide solution at 0.2-1.0mM was in accord with those of PMV. M. mesophilicum and R. mucilaginosa were more resistant to the oxidant than E. coli and C. albicans, respectively. Results obtained suggested that reactive oxygen species (ROS) may be involved in the killing action of PMV and therefore pink-slime formers are more resistant to PMV than non-pink-slime formers because of the presence of carotenoids as an antioxidant in cells. We also suggest that the use of PMV appeared to be a potential tool for the control of pink-slime forming microorganisms occurring in wet areas of houses such as the bathroom and washing room.

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　In this study, a bacteriophage-based method for the colorimetric detection of E. coli O157:H7 in apple juice was investigated. Firstly, a gene encoding Cytochrome c Peroxidase (CCP) chromogenic enzyme was inserted into a wild type PP01 phage genome to construct the recombinant PP01ccp phage that was used in the production of the chromogenic enzyme through specific infection into E. coli O157:H7. The method was then examined in the colorimetric detection of E. coli O157:H7 in broth, and the appearance of E. coli O157:H7 in broth was confirmed by the color change after a few minutes of the enzyme assay. Secondly, the method was investigated in the colorimetric detection of E. coli O157:H7 in apple juice. A low E. coli O157:H7 concentration as 1 CFU mL^-1 was detected in 15 h that was in a shorter time than in previous bioluminescence phage-based methods. Moreover, the method is much simpler compared to other previous phage-based methods since it enables detection without the need for expensive apparatus.

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　Our previous studies indicated that extracellular glycoproteins produced by some white-rot and brown-rot basidiomycetous fungi reduce Fe(III) to Fe(II) and O₂ to H₂O₂ and produce hydroxyl radicals. The continuous generation of hydroxyl radicals requires a constant supply of O₂ and an electron donor for the reduction of oxidized forms of the glycoproteins to the reduced forms. However, electron donors for this reaction, such as NADH, have not been identified. In this study, the amounts of the extracellular pyridine coenzymes, NAD^＋ and NADH, were measured in agar cultures of four white-rot fungi, one brown-rot fungus, and three soft-rot fungi. The sums of NAD^＋ and NADH detected in wood-containing cultures of all five basidiomycetes were greater than those in glucose cultures. The amounts of NAD^＋ were higher than those of NADH in all wood-containing cultures except that of Irpex lacteus, and NAD^＋ was greater than NADH in all glucose cultures except that of Fomitopsis palustris. Significant amounts of pyridine coenzymes were present in glucose and wood-containing cultures of the three soft-rot fungi. The non-wood-degrading fungus, Penicillium funiculosum, did not produce NAD^＋ or NADH in either glucose or wood-containing cultures. The extracellular pyridine coenzyme levels were relatively high compared to the rates of extracellular hydroxyl radical generation in wood-degrading fungal cultures. Thus, white-, brown-, and soft-rot fungi produce pyridine coenzymes that could serve as electron donors for the production of hydroxyl radicals during wood degradation.

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　Bactrocera cucurbitae (melon fruit fly) is one of the most detrimental vegetable-damaging pests in Bangladesh. The toxicity of Bacillus thuringiensis (Bt) has been reported against a few genera of Bactrocera in addition to numerous other insect species. Bt strains, harbouring cry1A-type genes were, therefore, assayed in vivo against the 3^rd instar larvae of B. cucurbitae in this study. The biotype-based prevalence of cry1 and cry1A genes was calculated to be 30.8% and 11.16%, respectively, of the test strains (n=224) while their prevalence was greatest in biotype kurstaki. Though three indigenous Bt strains from biotype kurstaki with close genetic relationship exhibited higher toxicity, maximum mortalities were recorded for Btk HD-73 (96%) and the indigenous Bt JSc1 (93%). LC₅₀ and LC₉₉ values were determined to be 6.81 and 8.32 for Bt JSc1, 7.30 and 7.92 for Bt SSc2, and 6.99 and 7.67 for Btk HD-73, respectively. The cause of toxicity and its variation among the strains was found to be correlated with the synergistic toxic effects of cry1, cry2, cry3 and cry9 gene products, i.e. relevant Cry proteins. The novel toxicity of the B. thuringiensis strains against B. cucurbitae revealed in the present study thus will help in developing efficient and eco-friendly control measures such as Bt biopesticides and transgenic Bt cucurbits.

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　The overproduction of enzymes was performed by manipulating the medium components. In our study, solvent-tolerant thermophilic lipase-producing Bacillus coagulans was isolated from soil samples and a stepwise optimization strategy was employed to increase the lipase production using coconut oil cake basal medium. In the first step, the influence of pH, temperature, carbon source, nitrogen source and inducers on lipase activity was investigated by the One-Factor-At-A-Time (OFAT) method. In the second step, the three significant factors resulted from OFAT were optimized by the statistical approach (CCD).The optimum values of olive oil (0.5%), Tween 80 (0.6%) and FeSO₄ (0.05%) was found to be responsible for a 3.2-fold increase in the lipase production identified by Central Composite Design.

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　No formation of N,N’-methylene dianiline (MDA) was observed in chain-extended thermoplastic polyurethane (PU) when sterilized by autoclaving or γ-ray irradiation. No formation of MDA was observed in nonchain-extended thermoplastic PU when sterilized by γ-ray irradiation. Less than 1 ppm of MDA was produced in nonchain-extended thermoplastic PU subjected to autoclave sterilization. Autoclave sterilization did not produce MDA in thermosetting PU potting material. MDA formation in potting material was promoted by γ-ray irradiation and increased with increasing irradiation doses at a quadratic equation of regression. MDA formation at 100 kGy irradiation amounted to a few ppm and less than one ppm at 25 kGy irradiation: therefore, the potential risk to human recipients was not significant. The elution of compounds other than MDA from potting material was more problematic. Solvent extracts from potting material showed mutagenicity in the absence of metabolic activity (S9Mix). MDA showed mutagenicity in the presence of metabolic activity, therefore MDA was not the major mutagenic candidate. The chemical and biological characteristics of the specific mutagens should be identified in a further study. The lack of MDA formation and a smaller presence of mutagens in autoclave-sterilized potting material indicated that autoclave sterilization was preferable if the material is able to tolerate heating.

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　We carried out a basic study in order to evaluate the bacterial contamination in water dispensers. Water samples were obtained from water dispensers from October 2012 to November 2013, and standard plate counts (at 36˚C, 24 h) of the samples, as well as heterotrophic plate counts (at 25˚C, 7 d), were estimated with the standard methods for the examination of drinking water in Japan. Standard plate counts exceeding the water-quality standard (1.0×10² CFU/ml) were observed in 42 of the 140 samples (30.0%), with a maximum detected bacterial count of 2.1×10⁵ CFU/ml. The rate of the standard plate counts exceeding the water quality standard tended to be higher when using a one-way type method or water dispensers with natural water. Ralstonia spp. was most commonly isolated, and Pseudomonas aeruginosa was isolated in a few cases. Some opportunistic pathogens were also isolated, suggesting that we should be more concerned about bacterial contamination in cold water supplied from water dispensers.

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　The ability of heated scallop-shell powder (HSSP) to work against Listeria sp. biofilm formed at a low temperature was investigated. A biofilm of L. innocua ATCC 33090 was grown on a glass plate at 15˚C for 15 days, then immersed in HSSP slurry. Following treatment, the disinfection ability of the HSSP against the biofilm was non-destructively quantified by conductimetric assay. The biofilm grown at 15˚C was less sensitive than that grown at 37˚C to HSSP treatment and alkaline treatment. The biofilm grown at 15˚C was completely deactivated by 30 min of HSSP treatment (10 mg/mL, pH 12.5). In contrast, after 30 min treatment with alkaline solution at pH 12.5 or sodium hypochlorite (100 ppm), the activity was reduced by only one order of magnitude. The disinfection efficacy of HSSP (10 mg/mL) against L. innocua is similar to or higher than that of sodium hypochlorite (200 ppm). Fluorescence microscopy validated the results of the conductimetric assay. Therefore, HSSP treatment is a potentially powerful alternative control agent against Listeria sp. biofilms that present hazards in the food industry.

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