Kyushu University Academic Staff Educational and Research Activities Database
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Takahisa Miyamoto Last modified date:2018.09.19

Professor / Division of Food Science & Biotechnology
Department of Bioscience and Biotechnology
Faculty of Agriculture


Graduate School
Undergraduate School


Homepage
http://www.agr.kyushu-u.ac.jp/lab/foodhygienicchemistry/eindex.html
Web site of Lab. of Food Hygienic Chemistry, Kyushu University, Japan .
Academic Degree
Ph.D.
Field of Specialization
Food Hygienic Chemistry, Food Microbiology, Food Preservation
Outline Activities
Development of Simple and Rapid Detection Method of Food Poisoning Bacteria

Salmonella spp., Escherichia coli, Staphylococcus aureus, Campylobacter spp., and Vibrio spp. are the major causes of food poisoning in the developed world. Conventional methods for the detection of these food poisoning bacteria in foods require 2 to 4 days to obtain presumptive results after initiation of sample analysis. The needs for more rapid and simple methods for the detection of food poisoning bacteria are growing in food industries and government agencies. In recent years, new methods have been developed to increase the efficiency and speed of food microorganism detection while reducing the labor. We have developed the rapid detection method for Salmonella by combination of a new selective enrichment and ELISA using monoclonal antibodies against dulcitol 1-phosphate dehydrogenase, a random amplified polymorphic DNA (RAPD) analysis for Salmonella. and fluorogenic assay for rapid detection of Vibrio parahaemolyticus in foods.
We have developed and are developing,

(1) Application of random amplified polymorphic DNA analysis for detection of Salmonella in foods.
(2) Rapid detection of Salmonella spp. by PCR amplification of Salmonella specific region in gat D gene.
(3) PCR assay for detecting Escherichia coli O157:H7 and O157:H-
(4) Rapid detection method of food poisoning bacteria by the combination of PCR and quartz crystal microbalance.
(5) Rapid detection method for viable bacteria and food poisoning bacteria by using a photon- counting TV camera.
(6) Immunomagnetic-flow cytometric detection of staphylococcal enterotoxin B in raw and dry milk
(7) Development of Rapid and Simple Method for Total Viable Bacterial Counts by Flow Cytometry


Sporulation of Bacillus cereus

Bacillus cereus is one of the food poisoning bacteria which produces heat resistant enterotoxin and spores. The presence of its spore in food is one of the biggest problems in food industry because the spore is resistant to heating, ultraviolet light and drugs. It is very difficult to sterilize these foods contaminated with spores of B. cereus.
The formation of an asymmetrically sited division septum is an early event of sporulation of Bacillus. The asymmetric division results in two distinct cells, that have radically different developmental fates. This sporulation division contrasts with division during vegetative growth of Bacillus, in which the septum is symmetrically situated with respect to the ends of the dividing cell.
The penicillin-binding proteins (PBPs) are membrane bound enzymes required for peptidoglycan synthesis and septum formation. At least seven PBPs are reported in Escherichia coli. There are various beta-lactam antibiotics and the target sites of them have been studied in detail on E. coli. Some of these antibiotics have specific target PBPs, for example, cefaloridine specifically binds to and inhibits PBP 1, mecillinam is specific for PBP 2 and cephalexin for PBP 3 of E. coli. The studies on the mechanism of action of penicillin on B. subtilis have shown the presence of PBPs that increase or decrease during sporulation. However, the mechanism of the gene expression for these PBPs at the initial stage of sporulation is not clear.
We have studied the mechanism of sporulation of B. cereus. We previously showed the presence of chromosomal proteins that seem to be involved in the initiation of sporulation of B. cereus. We identified one of the proteins as IMP dehydrogenase. In B. cereus, the enzyme activity was the largest in the cells that were induced to sporulate by nutritional shift down at 40 min from the initiation of chromosome replication, the sensitive stage for sporulation. The result suggests that high IMP dehydrogenase activity is necessary for the induction of sporulation of B. cereus. We are studying the involvement of IMP dehydrogenase in induction of sporulation of B. cereus. We have also shown that cephalexin inhibits the sporulation of B. cereus which has been induced to sporulate by nutrient downshift and that the presence of PBPs that has high affinity to cephalexin. We are also studying the mechanism of expression of the PBPs sensitive to cephalexin in B. cereus.

Enhancement of Freezing Tolerance in Plants

Some plant species develop freezing tolerance when exposed to low, non-freezing temperatures. If freezing tolerance could be provided to cold-sensitive plants, the contribution to stable production of crops would be significant. In our laboratory, we found that hardened cells of Chlorella vulgaris C-27 survive slow freezing to -196 C. Freezing tolerance of the cells were developed by expression of hardening-induced Chlorella (hiC) genes. We have isolated 17 cDNA clones corresponding to hiC genes. Out of them, hiC6 accounted for 75% of hiC clones and was shown to be siginificantly involved in the development of freezing tolerance.
In order to investigate whether the HIC6 protein will confer freezing tolerance to plants, the coding region of the hiC6 gene was introduced into tobacco plant. However, the aquired level of freezing tolerance of the transgenic tobacco leaves was relatively low and not satisfactory. Now, we are trying to enhance the level of freezing tolerance by increasing the expression level of the HIC6 protein and by introducing additional genes encoding stress-inducible proteins such as fatty acid desaturase and scavenging enzymes, superoxidase dismutase and ascorbate peroxidase etc.
Research
Research Interests
  • Study on mechanism for heat injury and recovery in Salmonella
    keyword : Salmonella, heating, injury, recovery, water activity
    2008.04.
  • Studies on inactivation of toxins from foodborne pathogen
    keyword : vero toxin、 food additives, secretion inhibition, production inhibition, activity inhibition、cytotoxity
    2009.10.
  • Control of food borne pathogens by bacteriophage
    keyword : bacteriophage, EHEC, Salmonella, Campylobacter
    2014.04.
  • Basic study on the reduction of risk for foodborne illness due to fresh produce
    keyword : foodborne illness fresh produce, Salmonella, O157, Listeria
    2013.04~2017.04.
  • Basic study on rapid detection and control of pathogenic Listeria monocytogenes
    keyword : Listeria monocytogenes MLST real-time PCR hlyA
    2007.04~2015.03.
  • Simultaneous detection of foodborne pathogens
    keyword : foodborne pathogen toxin rapid detection
    2007.05~2015.03.
  • Studies on inactivation of toxins from foodborne pathogen
    keyword : vero toxin、, cereulide, food additives, food color, food extracts, secretion inhibition, production inhibition, activity inhibition、cytotoxity
    2009.10~2010.09.
  • Control and classification of verotoxigenic E. coli
    keyword : E.coli pathogenic verotoxin classificartion genotyping
    2008.04.
  • Development of non-thermal sterilization and elimination method of food-borne pathogens in fresh produce
    keyword : fresh produce, food-borne pathogen, slightly acidic hypochlorous water, chlorine dioxide
    2007.04~2012.03.
  • Development of cultivation condition decrease the contamination of vegetables with Salmonella
    keyword : tomato lettuce Salmonella internalization
    2007.04~2012.03.
  • Antibacterial activity of catechins
    keyword : catechin foodborne illness green tea extracts food additive detergent mechanism
    2006.04The antibacterial activity of the green tea extracts containing catechins was investigated on various kinds of bacteria at different pH’s. The antibacterial activity of GTE was determined after incubation in 50% L broth containing various concentrations of GTE for 48 h at 30 or 37℃. The tests were performed on 19 strains of gram-negative bacteria and 27 strains of gram-positive bacteria. At pH 6.5, GTE effectively inhibited the growth of Staphylococcus aureus, Bacillus brevis, B. cereus, B. subtilis except B.subtilis IFO12113, Vibrio alginolyticus, V. cholerae, V. parahaemolyticus and V. vulnifivus at less than 250 ppm. On the other hand, E. coli O157:H7, Salmonella spp, Listeria monocytogenes, Lactobachillus spp. were resistant to GTE. The antibacterial activity of GTE increased at pH 5.0 on B. cereus, L. monocytogenes, L.plantarum, and V. parahaemolyticus. In contrast, the activity increased more than 4 times at pH 8.0 on S. Enteritidis, E. coli O157:H7, and P. aeruginosa etc compared with those at pH 6.5. The antibacterial activity of GTE was the highest on S. Typhimurium ΔkatG mutant among wild type and deletion mutants ( ΔkatG, ΔahpC, and ΔahpF), suggesting H2O2 generated from catechins is one of the important factors for the antibacterial action. .
  • Studies on development of rapid detection and control of Norovirus
    keyword : Norovirus RTーPCR SPR decontamination
    2007.04~2014.03Norovirus is highly infectious and is the major cause of food poisoning worldwide. Rapid and accurate detection of norovirus is a critical issue for the prevention of the disease and epidemiological investigation. Although RT-PCR assay is widely used for the detection of norovirus, the detection rate of the assay is still limited. By aligning the conserved regions of various strains of norovirus, we have designed a new primer set for RT-PCR with high detection rate. The whole genomic RNA sequences (approx. 7.7 kb) of 46 human-infectious norovirus were obtained from GenBank. Stool specimens from norovirus-infected patients were kindly provided from Fukuoka City Institute for Hygiene and Environment (Fukuoka, Japan). Forty-six genomic RNA sequences of norovirus were aligned by using ClustalW program for the screening of conserved regions among the strains. And primer sets were designed to amplify the conserved regions. The newly designed primer sets were used in RT-PCR assay for 150 patient-derived fecal samples. The PCR products amplified by the primer sets were sequenced and conserved region of 196 strains of norovirus were aligned by ClustalW program to screen highly conserved region. Finally, a primer set for RT-PCR assay was designed according to the alignment. The detection rate of the primer set was assessed for 150 stool specimens. Alignment of 196 norovirus strains revealed that a junction region of ORF1 and ORF2 was highly conserved irrespective of the genotype. Newly designed primer was able to detect norovirus from 148 out of 150 stool specimens, on the other hands, previously reported primer set detected 136. Further investigation includes the detection of norovirus from food samples, which contains variety of interfering substances. The efforts will also made to develop more simple, rapid and accurate assay by gene amplification in combination with biosensor..
  • Study on adhesion inhibition of bacteria on agricultural produce
    keyword : Salmonella SPR food additive detergent adhesion
    2002.04.
  • Studies on sporulation of Bacillus cereus
    keyword : Bacillus cereus, spore, PBP, IMPDH
    1986.04~2008.03Bacillus cereus is one of the food poisoning bacteria which produces heat resistant enterotoxin and spores. The penicillin-binding proteins (PBPs) are membrane bound enzymes required for peptidoglycan synthesis and septum formation. However, the mechanism of the gene expression for these PBPs at the initial stage of sporulation is not clear. We have studied the mechanism of sporulation of B. cereus. We previously showed the presence of chromosomal proteins that seem to be involved in the initiation of sporulation of B. cereus. We identified one of the proteins as IMP dehydrogenase. In B. cereus, the enzyme activity was the largest in the cells that were induced to sporulate by nutritional shift down at 40 min from the initiation of chromosome replication, the sensitive stage for sporulation. The result suggests that high IMP dehydrogenase activity is necessary for the induction of sporulation of B. cereus. We are studying the involvement of IMP dehydrogenase in induction of sporulation of B. cereus. We have also shown that cephalexin inhibits the sporulation of B. cereus which has been induced to sporulate by nutrient downshift and that the presence of PBPs that has high affinity to cephalexin. We are also studying the mechanism of expression of the PBPs sensitive to cephalexin in B. cereus..
Academic Activities
Reports
1. Mechanism for antibacterial action of catechin.
2. Growth characteristics and control of bacterial spore in foods.
3. Development of method eliminating bacteria from fresh produce to secure food safety.
4. Study on rapid and sensitive detection of Salmonella.
5. Biosensor.
6. T. Miyamoto, Overview of food-borne disease in Japan,, Food Science and Industry, 37(2): 12-21, 2004.04.
7. Detection of food poisoning bacteria by using PCR and QCM.
8. Sensitive detection of bacterial toxin
T. Miyamoto
Seibutu-kogaku Kaishi, 81:442(2003).
9. Measurement of viavle bacteria and toxins by FCM
T. Miyamoto
Center news of advanced instrumental analysis Kyushu University,22(2),p.1-4(2003).
10. Trends of Research and Development of rapid Detection method for Food microorganisms
T. Miyamoto
Shokuhinn to Gijutu, 384:1-11(2003).
11. Novel detection method for toxins in dairy products
T. Miyamoto
Kagaku to seibutu, 41(4):221-223 (2003).
12. Simple and Rapid detection method for food poisoning bacteria
T. Miyamoto
Shokuhin kougyou, 2000.7.30,45-51(2000).
13. Simple and Rapid detection method for food apoisoning
bacteria
T. Miyamoto
Nihon shokuhinn kagaku kougaku kaishi, 47(3):173-180(2000).
14. Clarification of mechanism for freezing injury of E. coli O157:H7 in foods.
T. Miyamoto, S. Hatano, K. Honjoh.
15. Development of rapid and simple method for detection of food poisoning and spoilage bacteria
T. Miyamoto
Kagaku to Seibutu,37(7),482-486 (1999).
16. Development of sensitive and rapid detection method for E. coli and coliform bacteria.
T. Miyamoto, S. Hatano, K. Honjoh..
17. Rapid detectio nf B .cereus emetic toxin and Clarification of mechanism for production of the toxin
T. Miyamoto, S. Hatano, M. Yoshimoto.
18. Studies on inhibition of sporulation of Bacillus
T. Miyamoto, S. hatano, M. Yoshimoto.
19. Rapid detection of salmonella by ELISA using monoclonal antibodies..
Papers
1. Takahisa Miyamoto, Xiaoguang Zhangb,, Development of novel monoclonal antibodies directed against catechins for investigation of antibacterial mechanism of catechins, Journal of Microbiological Methods, http://dx.doi.org/10.1016/j.mimet.2017.03.014, 137, 6-13, 2017.03, Catechins are major polyphenolic compounds of green tea. To investigate mechanism for antibacterial action of
catechins, 11 monoclonal antibodies (MAbs) were raised against a 3-succinyl-epicatechin (EC)-keyhole limpet
hemocyanin (KLH) conjugate. Amino acid sequences of variable regions determined for MAbs b-1058, b-1565,
and b-2106 confirmed their innovative character. MAb b-1058 strongly interacted with its target substances in
the following order of magnitude: theaflavin-3,3′-di-O-gallate (TFDG) > theaflavin-3-O-gallate
(TF3G) ≥theaflavin-3′-O-gallate (TF3’G) > gallocatechin gallate (GCg) > penta-O-galloyl-β-D-glucose
(PGG) > epigallocatechin gallate (EGCg), as determined using surface plasmon resonance (SPR) on MAbimmobilized
sensor chips. The affinity profiles of MAbs b-1058 and b-2106 to the various polyphenols tested
suggested that flavan skeletons with both carbonyl oxygen and hydroxyl groups are important for this
interaction to take place. S. aureus cells treated with EGCg showed green fluorescence around the cells after
incubation with FITC-labeled MAb b-1058. The fluorescence intensity increased with increasing concentrations
of EGCg. These MAbs are effective to investigate antibacterial mechanism of catechins and theaflavins..
2. Takahisa Miyamoto, Seiyo Toyofuyku, Motokzu Nakayama, Ken-ichi Honjoh, Specific inhibition of cytotoxicity of Shiga-like toxin 1 of enterohemorrhagic Escherichia coli by gallocatechin gallate and epigallocatechin gallate, Food Control, http://dx.doi.org/10.1016/j.foodcont.2014.02.017, 42, 263-269, 2014.08.
3. Miyamoto, T., Nakayama, M., Shigemune, N., Tokuda, H., Matsushita, T., Furuta, K., Mekada, Y., Honjoh, K. Application of green tea extract as food preservative to improve shelf life of overnight pickled cucumber, Nippon Shokuhin Kagaku Kogaku Kaishi, 56, 12, 660-664 (2009) .
4. Machida, T., Murase, H., Kato, E., Honjoh, K., Matsumoto, K., Miyamoto, T., and Iio, M., Isolation of cDNAs for hardening-induced genes from Chlorella vulgaris by suppression subtractive hybridization., Plant Science, 17(3): 238-246, 2008.09.
5. Miyamoto, T., Murata, Y., Kobayashi, H., Shimoyae, M., Kamikado, H., Noda, N., Maruyama, K., Honjoh, K., Iio, M., Enumeration of viable counts in raw milk using the automated fluorescence microscopic method, Biocontrol Science, 10, 4, 147-154, 10(4):147-154, 2005.12.
6. Miyamoto, T., Nakayama, M., Sasaki, C., Sadakari, K., Itoh, Y., Fujimoto, A., Honjoh, K., and Iio, M., Simple identification of some Bacillus species and related genera in food by RAPD analysis combined with morphological observation., Biocontrol Science, 10, 1,2, 45-53, 10(1): 45-53, 2005.06.
7. Kobayashi, H., Miyamoto, T., Hashimoto, Y., Kiriki, M., Motomatsu, A., Honjoh, K., and Iio, M., Identification of factors involved in recovery of heat-injured Salmonella Enteritidis., J. Food Prot., 68, 5, 932-941, 68 (5): 932-941, 2005.01.
8. Miyamoto, T., Kamikado, H., Sasaki, C., Sadakari, S., Honjoh, K. and Iio, M., An attempt to identify Bacillus cereus by PCR., Biocontrol Science, 9, 3, 69-75, 9(3): 69-75, 2004.01.
9. Miyamoto, T., Shimizu, Y., Kobayashi, H., Honjoh, K., and Iio, M., Studies of collagen binding with immobilized Salmonella enteritidis and inhibiton with synthetic and naturally occurring food additives by a surface plasmon resonance biosensor., Sensors and Materials., 15, 8, 453-466, 15(8): 453-466, 2003.12.
10. Miyamoto, T. and Iio, M., Detection of Bacillus cereus by PCR, Proceedings of the United States-Japan Cooperative Program in Natural Resources, Protein Resources Panel, 32nd Annual meeting, 2003.11.
11. Miyamoto, T., Kamikado, H., Kobayashi, H., Honjoh, K., and Iio, M., Immunomagnetic flow cytometric detection of staphylococcal enterotoxin B in raw and dry milk, J. Food Protection., 66, 7, 1222-1226, 66(7):1222-1226, 2003.07.
12. Miyamoto, T., Kamikado, H., Kobayashi, H., Iio, M., Immunomagnetic-flow cytometric detection of staphylococcal enterotoxin B in raw and dry milk, Proceedings of the United States-Japan Cooperative Program in Natural Resources, Protein Resources Panel, 31th Annual meeting, Monterey, California, I1-7, 2002.12.
13. Miyamoto, T., Sayed, Md. A., Sasahara, R., Sukimoto, K., Umezaki, A., Honjoh, K., Iio, M. and Hatano, S., Cloning and overexpression of Bacillus cereus penicillin-binding protein 3 gene in Escherichia coli, Biosci. Biotechnol. Biochem., 66, 1, 44-50, 66(1): 44-50, 2002.01.
14. Miyamoto, T., Ichioka, N., Sasaki, C., Kobayashi, H., Honjoh, K., Iio, M. and Hatano, S., Polymerase chain reaction assay for detection of Escherichia coli O157:H7 and Escherichia coli O157:H-, J. Food Protection, 65, 1, 5-11, 65(1): 5-11 (2002), 2002.01.
15. Miyamoto, T., Kobayashi, H., Iio, M., Recovery of Stressed Salmonella enteritidis, Proceedings of the United States-Japan Cooperative Program in Natural Resources, Protein Resources Panel, 30th Annual meeting, Tukuba, Ibaraki., 48-51, p. 48-51, 2001.11.
16. Honjoh,K., Shimizu, H., Nagaishi, N., Matsumoto, H., Suga, K., Miyamoto, T., Iio, M., and Hatano, S., Improvement of freezing tolerance in transgenic tobacco leaves by expressing the hiC6 gene, Biosci. Biotechnol. Biochem., 10.1271/bbb.65.1796, 65, 8, 1796-1804, 65(8): 1796-1804, 2001.08.
17. Miyamoto, T., Iio, M., and Hatano, S., Freezing injury of E. coli O157:H7 and DNA region specific to E. coli O157, Proceedings of the United States-Japan Cooperative Program in Natural Resources, Protein Resources Panel, 29th Annual meeting,Waikiki, Hawaii, E- 1-12 (2000)., E- 1-12, 2000.11.
18. Kim, S.-I., Miyamoto, T., Honjoh, K., Iio, M., and Hatano, S., Molecular cloning, overproduction and characterization of the Bacillus cereus IMP dehydrogenase, Biosci. Biotechnol. Biochem., 10.1271/bbb.64.1210, 64, 6, 1210-1216, 64(6): 1210-1216, 2000.06.
19. Trevanich, S., Miyamoto, T., Harada, Y., Honjoh, K. and Hatano, S., Rapid detection of enterotoxigenic Escherichia coli O6 in water by using monoclonal antibody and a photon-counting TV camera, J. Food Protection, 63, 4, 534-538, 63(4): 534-538, 2000.04.
20. Miyamoto, T., Yoshida, Y., Etoh, S., Honjoh, K., Iio, M. and Hatano S., Studies on freezing injury of unwashed and washed cells of Escerichia coli O157:H7, Jpn. J. Food Microbiology, 17(2): 127-133(2000)..
21. Miyamoto, T., Trevanich, S., Hatano, S., Application of random amplified polymorphic DNA analysis and DNA sensor using quartz crystal microbalance for rapid detection of salmonella SPP. in foods, Proceedings of the United States-Japan Cooperative Program in Natural Resources, Protein Resources Panel, 28th Annual meeting, Tukuba, Ibaraki, 90-106, p. 90-106, 1999.12.
22. Miyamoto, T., Trevanich, S., Honjoh, K., Hatano, S., Rapid detection of Salmonella spp. by PCR amplification of Salmonella specific region in gatD gene, 日本食品微生物学会雑誌, 16, 2, 99-109, 16(2): 99-109, 1999.02.
23. Miyamoto, T., Trevanich, S., Okabe, T., Tomoda, S., Honjoh, K., Hatano, S., Rapid detection method of Salmonella-specific PCR product by DNA-immobilized quartz crystal microbalance., Jpn. J. Food Microbiol., 16(1): 57-63(1999)..
24. Miyamoto, T., Kuramitsu, Y., Ookuma, A., Trevanich, S., Honjoh, K., Hatano, S., Rapid detection of counting of viable bacteria in vegetables and environmental water using a photon-counting TV camera, J. Food Protection, 61, 10, 1312-1316, 61(10): 1312-1316, 1998.10.
25. Miyamoto, T., Tian, H.-Z., Okabe, T., Trevanich, S., Asoh, K., Tomoda, S., Honjoh, K., Hatano, S., Application of random amplified polymorphic DNA analysis for detection of Salmonella spp. in foods., J. Food Prot., 61, 7, 785-791, 61(7): 785-791, 1998.07.
26. Miyamoto, T., Matsuno, K., Imamura, M., Kim, S.-I., Honjoh, K., and Hatano, S., Purification and some properties of IMP dehydrogenase of Bacillus cereus., Microbiological Research , 153, 1, 23-27, 153(1), 23-27, 1998.01.
Presentations
1. Inhibition of adhesion of food-poisoning bacteria by food additives.
2. Miyamoto, T., Wen, H.-M., Kinoshita, Y., Kobayashi, H., Honjoh, K., Tashiro, K., BCAA promotes recovery from Heat-Injury in Salmonella Typhimurium, UJNR Food and Agricultural Panel 38th Annual Meeting, Epochal Tsukuba, Tsukuba, Ibaraki, Japan, (2009.10.06)..
3. Development of quantitative analysis of EGCg by using EGCg-specific binding peptide.
4. Trends in detection methods for food pathogens.
5. Isolation of cDNAs for hardening specific genes from Chlorella vulgaris by using suppression subtractive hybridization
Ken-ichi Honjoh, Takeshi Machida, Eri Kato, Hisako Murase, Masayoshi Iio, and Takahisa Miyamoto.
6. Cloning of hardening inducible NADPH-thioredoxin reductase gene of Chlorella.
7. Cloning and expression of torehalose synthetase gene of tobacco.
8. Studies on mechanism of antibacterial action of catechins.
9. Study on mechanism of attachment and control of Salmonella.
10. New technology on food safety

Kyushu University, Takahisa Miyamoto, Professor
In recent years, food-related issues have become increasingly more conspicuous in developed countries. This holds true for Japan as well, where food-related issues have been drawing attention as a socially significant topic. In general, a food-borne illness event can be caused by contamination of food with biological agents or pathogens (e.g., viruses, bacteria, parasites, prions), chemical agents (e.g., toxins, metals), or physical agents (e.g. glass fragments, bone chips). With more than 200 known diseases being transmitted through food, pathogens are the most significant cause. Conventional methods for the detection of these bacterial pathogens in foods require 2 to 4 days to obtain presumptive results after initiation of sample analysis. The needs for more rapid and simple methods for the detection of food poisoning bacteria are growing in food industries and government agencies. In recent years, new methods have been developed to increase the efficiency and speed of food microorganism detection while reducing the labor. We have developed several rapid detection methods for enumeration and detection of viable bacteria and bacterial pathogens in food. For rapid enumeration of viable bacteria in milk, an automated fluorescence microscopic method developed for measurement of viable bacterial counts was applied. In the automated analysis of viable bacteria, bacterial cells were recovered from milk after the treatments with EDTA and Triton X-100, stained with 6-CFDA and the stained cells were counted with the automated microscopic method. For rapid and simultaneous detection of 6 pathogens (Salmonella spp, Vibrio parahaemolyticus, enterohemorrhagic Escherichia coli, Staphylococcus aureus, Listria monocytogenes, and Bacillus cereus emetic strains), a method in combination of a new enrichment broth and real-time multiplex PCR using TaqMan probes was developed..
11. Food hygienic chemistry study to secure food safety and quality.
12. Method of detection for SNP specific to L. monocytogenes clinical strain.
13. Specific detection of B. cereus expressingcereulide synthetase gene.
14. FLUORESCENT MICROSCOPE WAS APPLIED FOR COUNTING VIABLE NUMBER IN MILK.
15. Genetic classification of Listeria monocytogenes based on DNA sequences of some specific genes.
16. Clarification of mechanism for recovery from heating stress in Salmonella.
17. Simultanious detection of 5 food poisoning bacteria in food.
Membership in Academic Society
  • Japan Association of Food Preservation Scientists
Awards
  • Bioscience, Biotechnology, and Biochemistry pp.845~854 (2015)
    Motokazu Nakayama, Kanami Shimatani, Tadahiro Ozawa, Naofumi Shigemune, Daisuke Tomiyama, Koji Yui, Mao Katsuki, Keisuke Ikeda, Ai Nonaka & Takahisa Miyamoto
    Mechanism for the antibacterial action of epigallocatechin gallate (EGCg) on Bacillus subtilis
Educational
Educational Activities
Applied Bioscience
Laboratory work of basic microbiology
Basic Biotechnology
Advanced Biotechnology
Food Hygienic Chemistry
Food Preservation
Laboratory Work of Food Hygienic Chemistry
Advanced Food Safety Evaruation
Advanced Food Biotechnology I and II
Food Biotechnology Seminar I and II
Advanced Studies Food Biotechnology I and II
Food Science & Food System
Food Science & Biotechnology
Bio-Engeneering
Other Educational Activities
  • 2008.04.
Social
Professional and Outreach Activities
Lecturer, Food borne Infection Prevention course, JICA, 2006, 2007, 2008, 2009, 2010, 2011.