1
|
Chon JW, Seo KH. Development of a new chromogenic medium for the enumeration of Bacillus cereus in various ready-to-eat foods. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.108188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
2
|
Chon JW, Seo KH. Evaluation of Ceftazidime as an Antibiotic Supplement in Mannitol-Yolk-Polymyxin B Agar Used for Enumeration of Bacillus cereus in Ready-to-Eat Vegetables. J Food Prot 2021; 84:1698-1703. [PMID: 33793795 DOI: 10.4315/jfp-20-405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 04/01/2021] [Indexed: 11/11/2022]
Abstract
ABSTRACT The Bacillus cereus group of bacteria, which causes foodborne diseases, can be detected by culture on selective media. However, the presence of competing flora is the most common factor preventing the accurate enumeration of B. cereus on selective agars. In this study, we improved the selectivity of mannitol-yolk-polymyxin B agar (MYPA) and its modified version containing trimethoprim (mMYPA) developed in our previous study by supplementation with ceftazidime (16 μg/mL). Ceftazidime-supplemented MYPA (C-MYPA16) and mMYPA (C-mMYPA16) were evaluated for bacteria recovery and selectivity with three types of ready-to-eat vegetables. Four B. cereus and one Bacillus thuringiensis strains were mixed and artificially inoculated into vegetable salad, radish sprouts, and sprout mix and then recovered on MYPA, mMYPA, C-MYPA16, and C-mMYPA16. In all tested vegetables, mMYPA, C-MYPA16, and C-mMYPA16 culture resulted in similar recovery of B. cereus and B. thuringiensis (P > 0.05), whereas radish sprout and sprout mix colonies grown on MYPA were undistinguishable. C-mMYPA16 was the most selective medium because it eliminated most of the competing flora, especially that in sprouts, without negatively affecting the recovery of B. cereus and B. thuringiensis. Our results indicate that supplementation of mMYPA with ceftazidime may improve the selectivity of this medium for B. cereus and B. thuringiensis in food testing. HIGHLIGHTS
Collapse
Affiliation(s)
- Jung-Whan Chon
- Department of Pet Total Care, Division of Nursing and Welfare, Kyung-in Women's University, Incheon 21041, Republic of Korea
| | - Kun-Ho Seo
- Center for One Health, College of Veterinary Medicine, Konkuk University, Seoul 05029, Republic of Korea
| |
Collapse
|
3
|
Talahmeh N, Abu-Rumeileh S, Al-Razem F. Development of a selective and differential media for the isolation and enumeration of Bacillus cereus from food samples. J Appl Microbiol 2020; 128:1440-1447. [PMID: 31867800 DOI: 10.1111/jam.14561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 12/15/2019] [Accepted: 12/17/2019] [Indexed: 11/29/2022]
Abstract
AIM Identification and enumeration of foodborne pathogens in food stuffs are valuable concerns. In the present study, starch-blood-egg yolk-polymyxin B-trimethoprim-ceftazidime (SBYPTC) agar was established to isolate and specify the number of Bacillus cereus in food products. METHODS AND RESULTS The effectiveness of the developed medium in selecting for B. cereus from pure cultures and food matrixes naturally contaminated by high levels of microbiota was estimated, and the results were compared with that of two commercially available MYPA and PMBA media. In pure cultures, there were no significant differences in the recoverability of B. cereus among the three media, however, SBYPTC agar showed a greater exclusivity. To examine SBYPTC performance in food, B. cereus were artificially inoculated into lettuce and potato samples with high background microbiota in two separated experiments. There were no significant differences between MYPA and PEMBA. However, SBYPTC manifested greater selectivity and exclusivity and made the differentiation easier by allowing growth of B. cereus in separated colonies and inhibiting competing microflora. CONCLUSION Our results showed that SBYPTC has high selective properties in comparison with MYPA and PEMBA. Thus, it can be considered as a useful tool to monitor the existence and the number of B. cereus in foods especially those contaminated with high levels of microflora. SIGNIFICANCE AND IMPACT OF THE STUDY In the food industry, SBYPTC can be employed for food quality assurance to monitor B. cereus in food products contaminated with high levels of microbiota.
Collapse
Affiliation(s)
- N Talahmeh
- Applied Biology Program, College of Applied Sciences, Palestine Polytechnic University, Hebron, Palestine
| | - S Abu-Rumeileh
- Applied Biology Program, College of Applied Sciences, Palestine Polytechnic University, Hebron, Palestine
| | - F Al-Razem
- Applied Biology Program, College of Applied Sciences, Palestine Polytechnic University, Hebron, Palestine
| |
Collapse
|
4
|
Wei S, Chelliah R, Park BJ, Kim SH, Forghani F, Cho MS, Park DS, Jin YG, Oh DH. Differentiation of Bacillus thuringiensis From Bacillus cereus Group Using a Unique Marker Based on Real-Time PCR. Front Microbiol 2019; 10:883. [PMID: 31114555 PMCID: PMC6503103 DOI: 10.3389/fmicb.2019.00883] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 04/05/2019] [Indexed: 11/13/2022] Open
Abstract
The efficiency of a novel biomarker (the transcriptional regulator, XRE) was tested and evaluated in differentiating Bacillus thuringiensis from Bacillus cereus group species in environmental and spiked samples based on PCR and real-time PCR. Totally 120 strains, representing two bacterial groups, B. cereus group and non-Bacillus sp., were used to evaluate the performance of XRE and crystal protein (cry2, an existing biomarker). Further, three diverse samples (kimbap, lettuce, and spinach) were inoculated with B. thuringiensis and prominent biomarkers XRE and cry2 were used as targets. Direct analysis of the detection results for the pure cultures of B. cereus group wild-types, references and type strains revealed an accuracy rate of 97.5% targeting XRE, and 83.3% targeting cry2. The real-time PCR was constructed with a R 2-value of 0.993. For the artificially contaminated samples, a concentration of 103 CFU/g of B. thuringiensis in spiked food samples could be detected using real-time PCR targeting XRE. A good performance was obtained with XRE in discriminating B. thuringiensis from B. cereus groups, as well as detecting B. thuringiensis in spiked food samples with PCR or real-time PCR. Therefore, this real-time PCR targeting XRE can be used as a dependable and promising tool to identify B. thuringiensis in foods.
Collapse
Affiliation(s)
- Shuai Wei
- Department of Medical Biomaterials Engineering, Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, South Korea
| | - Ramachandran Chelliah
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon, South Korea
| | - Byung-Jae Park
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon, South Korea
| | - Se-Hun Kim
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon, South Korea
| | - Fereidoun Forghani
- Center for Food Safety, College of Agricultural and Environmental Sciences, University of Georgia, Griffin, GA, United States
| | - Min Seok Cho
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju, South Korea
| | - Dong-Suk Park
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju, South Korea
| | - Yong-Guo Jin
- National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Deog-Hwan Oh
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon, South Korea
| |
Collapse
|
5
|
Chon JW, Kim DH, Bae D, Song KY, Kim H, Sung K, Seo KH. Comparison of Direct Syringe Filtration and Membrane Filtration for the Selective Isolation of Campylobacter jejuni from Ready-to-Eat Sprouts. Foodborne Pathog Dis 2019; 16:371-375. [PMID: 30864872 DOI: 10.1089/fpd.2018.2546] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Culture method using enrichment broth and selective agar is one of the most common isolation methods for detecting Campylobacter jejuni from food. However, the overgrowth of competing bacteria in enrichment culture complicates the selective isolation of C. jejuni. In this study, we compared an enrichment/plating method for the isolation of C. jejuni from sprout samples with an enrichment/plating method with syringe or membrane filtration when transferring enriched broths to plates. Four types of sprout samples were artificially contaminated with various levels of C. jejuni and incubated in 100 mL of Bolton broth for 48 h. Enrichment broths were either directly transferred onto modified charcoal-cefoperazone-deoxycholate agar or filtered through membrane or with a syringe. A significantly higher (p < 0.05) isolation rate of Campylobacter positives was obtained with both filtration methods (58-61%) than with the method without filtration (10%). Membrane filtrations yielded 61%, whereas syringe yielded 58% positives. In most cases of unfiltered samples (98%), high competing flora covered most of the plate, making differentiation and picking of suspicious colonies difficult. However, less plates were contaminated with competing flora in both filtration methods. Only 5% of plates were contaminated in the syringe filtration method, whereas no competing flora was observed in membrane filtration (0%).
Collapse
Affiliation(s)
- Jung-Whan Chon
- 1 Center for One Health, College of Veterinary Medicine, Konkuk University, Seoul, Korea
| | - Dong-Hyeon Kim
- 1 Center for One Health, College of Veterinary Medicine, Konkuk University, Seoul, Korea
| | - Dongryeoul Bae
- 2 Arkansas Regional Laboratory, Office of Regulatory, U.S. Food and Drug Administration, Jefferson, Arkansas
| | - Kwang-Young Song
- 1 Center for One Health, College of Veterinary Medicine, Konkuk University, Seoul, Korea
| | - Hyunsook Kim
- 3 Department of Food and Nutrition, College of Human Ecology, Hanyang University, Seoul, Korea
| | - Kidon Sung
- 4 Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas
| | - Kun-Ho Seo
- 1 Center for One Health, College of Veterinary Medicine, Konkuk University, Seoul, Korea
| |
Collapse
|
6
|
Chon JW, Kim YJ, Kim DH, Song KY, Kim H, Seo KH. Supplementation of Modified Mannitol-Yolk-Polymyxin B Agar with Cefuroxime for Quantitative Detection of Bacillus cereus in Food. J Food Sci 2018; 84:133-137. [PMID: 30557913 DOI: 10.1111/1750-3841.14393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/19/2018] [Indexed: 12/26/2022]
Abstract
The presence of unwanted competing flora has been the most common confounding factor in the enumeration of Bacillus cereus (B. cereus) using selective media such as mannitol-yolk-polymyxin B agar (MYPA). The objective of this study was to improve MYPA selectivity for B. cereus by supplementation with a second-generation cephalosporin, cefuroxime. The performance of cefuroxime-supplemented MYPA (cefu-MYPA) was evaluated by comparison with original MYPA in 60 food products with established microbiological standards for B. cereus contamination. Cefu-MYPA demonstrated superior recoverability and selectivity for B. cereus compared with original MYPA in most tested foods. B. cereus numbers on MYPA and cefu-MYPA were 363.5 and 462.0 CFU/g, respectively. Competing flora on cefu-MYPA was detected in significantly less samples (70%) compared to original MYPA (93%). In addition, the detection and isolation of suspected colonies were significantly improved in cefu-MYPA because of the reduction or elimination of competing flora in all tested foods except fruit juice, indicating superior selectivity of the modified medium. Our findings suggest that cefuroxime supplementation of MYPA would markedly improve the detection rate of B. cereus, particularly in foods with high levels of indigenous flora.
Collapse
Affiliation(s)
- Jung-Whan Chon
- the Konkuk Univ., Hwayang-dong, Gwangjin-gu, Seoul, The Republic of Korea
| | - Young-Ji Kim
- the Konkuk Univ., Hwayang-dong, Gwangjin-gu, Seoul, The Republic of Korea
| | - Dong-Hyeon Kim
- the Konkuk Univ., Hwayang-dong, Gwangjin-gu, Seoul, The Republic of Korea
| | - Kwang-Young Song
- the Konkuk Univ., Hwayang-dong, Gwangjin-gu, Seoul, The Republic of Korea
| | - Hyunsook Kim
- Dept. of Food & Nutrition, College of Human Ecology, Hanyang Univ., 222 Wangsimni-ro, Seongdong-gu, Seoul, Republic of Korea
| | - Kun-Ho Seo
- the Konkuk Univ., Hwayang-dong, Gwangjin-gu, Seoul, The Republic of Korea
| |
Collapse
|
7
|
Chon JW, Seo KH, Bae D, Park JH, Khan S, Sung K. Prevalence, toxin gene profile, antibiotic resistance, and molecular characterization of Clostridium perfringens from diarrheic and non-diarrheic dogs in Korea. J Vet Sci 2018; 19:368-374. [PMID: 29486533 PMCID: PMC5974518 DOI: 10.4142/jvs.2018.19.3.368] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 01/18/2018] [Accepted: 02/10/2018] [Indexed: 11/20/2022] Open
Abstract
Clostridium perfringens causes diarrhea and other diseases in animals and humans. We investigated the prevalence, toxin gene profiles, and antibiotic resistance of C. perfringens isolated from diarrheic dogs (DD) and non-diarrheic dogs (ND) in two animal hospitals in Seoul, Korea. Fecal samples were collected from clinically DD (n = 49) and ND (n = 34). C. perfringens was isolated from 31 of 49 DD (63.3%) and 21 of 34 ND dogs (61.8%). All C. perfringens strains were positive for the α toxin gene, but not for the β, ε, or ι toxin genes; therefore, all strains were identified as type A C. perfringens. All isolates were cpe-negative, whereas the β2 toxin gene was identified in 83.9% and 61.9% of isolates from DD and ND, respectively. Most isolates were susceptible to ampicillin (94%), chloramphenicol (92%), metronidazole (100%), moxifloxacin (96%), and imipenem (100%). However, 25.0% and 21.2% of isolates were resistant to tetracycline and clindamycin, respectively. Molecular subtyping of the isolated strains was performed by using pulsed-field gel electrophoresis. Fifty-two isolates were classified into 48 pulsotypes based on more than 90% similarity of banding patterns. No notable differences were observed among the isolates from DD and ND.
Collapse
Affiliation(s)
- Jung-Whan Chon
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Kun-Ho Seo
- KU Center for One Health, College of Veterinary Medicine, Konkuk University, Seoul 05029, Korea
| | - Dongryeoul Bae
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Ji-Hee Park
- Joy Animal Hospital, Ansan 15388, Korea.,Veterinary Clinical Pathology, College of Veterinary Medicine, Chonbuk National University, Jeonju 54896, Korea
| | - Saeed Khan
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Kidon Sung
- Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| |
Collapse
|
8
|
Chon JW, Kim YJ, Kim YJ, Jung JY, Bae D, Khan S, Seo KH, Sung K. Addition of Rifampicin to Bolton Broth to Inhibit Extended-Spectrum β-Lactamase-ProducingEscherichia colifor the Detection ofCampylobacter. J Food Sci 2017. [DOI: 10.1111/1750-3841.13761] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jung-Whan Chon
- Div. of Microbiology, Natl. Center for Toxicological Research; US Food and Drug Administration; Jefferson AR 72079 U.S.A
| | - Young-Ji Kim
- KU Center for One Health, College of Veterinary Medicine; Konkuk Univ.; Hwayang-dong Gwangjin-gu Seoul 05029 Republic of Korea
| | - Young-Jo Kim
- Ministry of Food and Drug Safety; Osong 28159 Republic of Korea
| | - Ji Young Jung
- Div. of Microbiology, Natl. Center for Toxicological Research; US Food and Drug Administration; Jefferson AR 72079 U.S.A
| | - Dongryeoul Bae
- Div. of Microbiology, Natl. Center for Toxicological Research; US Food and Drug Administration; Jefferson AR 72079 U.S.A
| | - Saeed Khan
- Div. of Microbiology, Natl. Center for Toxicological Research; US Food and Drug Administration; Jefferson AR 72079 U.S.A
| | - Kun-Ho Seo
- KU Center for One Health, College of Veterinary Medicine; Konkuk Univ.; Hwayang-dong Gwangjin-gu Seoul 05029 Republic of Korea
| | - Kidon Sung
- Div. of Microbiology, Natl. Center for Toxicological Research; US Food and Drug Administration; Jefferson AR 72079 U.S.A
| |
Collapse
|
9
|
Kang IB, Chon JW, Kim DH, Jeong D, Kim HS, Kim H, Seo KH. Improvement of Polymyxin-Egg Yolk-Mannitol-Bromothymol Blue Agar for the Enumeration and Isolation of Bacillus cereus in Various Foods. J Food Prot 2017; 80:502-505. [PMID: 28207304 DOI: 10.4315/0362-028x.jfp-16-206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A modified polymyxin-egg yolk-mannitol-bromothymol blue agar (mPEMBA) was developed by supplementing polymyxin-egg yolk-mannitol-bromothymol blue agar (PEMBA) with trimethoprim to improve the selectivity for and recoverability of Bacillus cereus from naturally and artificially contaminated food samples. The number of B. cereus in mPEMBA was significantly higher than in PEMBA, indicating better recoverability (P < 0.05) in red pepper powder (PEMBA 0.80 ± 0.22 log CFU/g versus mPEMBA 1.95 ± 0.17 log CFU/g) and soybean paste (PEMBA 2.19 ± 0.18 log CFU/g versus mPEMBA 3.09 ± 0.13 log CFU/g). In addition, mPEMBA provided better visual differentiation of B. cereus colonies than PEMBA, which is attributable to the reduced number of competing microflora. We conclude that the addition of trimethoprim to PEMBA could generate a synergistic effect to improve selectivity for B. cereus .
Collapse
Affiliation(s)
- Il-Byeong Kang
- Center for One Health, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Jung-Whan Chon
- Center for One Health, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Dong-Hyeon Kim
- Center for One Health, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Dana Jeong
- Center for One Health, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Hong-Seok Kim
- Center for One Health, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Hyunsook Kim
- Department of Food & Nutrition, College of Human Ecology, Hanyang University, Seoul 04763, Republic of Korea
| | - Kun-Ho Seo
- Center for One Health, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea
| |
Collapse
|
10
|
Chon JW, Yim JH, Kim HS, Kim DH, Kim H, Oh DH, Kim SK, Seo KH. Quantitative Prevalence and Toxin Gene Profile of Bacillus cereus from Ready-to-Eat Vegetables in South Korea. Foodborne Pathog Dis 2015; 12:795-9. [DOI: 10.1089/fpd.2015.1977] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Jung-Whan Chon
- Department of Animal Science and Technology, Konkuk University, Seoul, Korea
| | - Jin-Hyeok Yim
- KU Center for Food Safety, College of Veterinary Medicine, Konkuk University, Seoul, Korea
| | - Hong-Seok Kim
- KU Center for Food Safety, College of Veterinary Medicine, Konkuk University, Seoul, Korea
| | - Dong-Hyeon Kim
- KU Center for Food Safety, College of Veterinary Medicine, Konkuk University, Seoul, Korea
| | - Hyunsook Kim
- Department of Food and Nutrition, Hanyang University, Seoul, Korea
| | - Deog-Hwan Oh
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon, Korea
| | - Soo-Ki Kim
- Department of Animal Science and Technology, Konkuk University, Seoul, Korea
| | - Kun-Ho Seo
- KU Center for Food Safety, College of Veterinary Medicine, Konkuk University, Seoul, Korea
| |
Collapse
|
11
|
Kim JB, Kim CW, Cho SH, No WS, Kim WJ. Proposal of statistical sampling plans for Bacillus cereus in Korean fermented soybean pastes. Food Sci Biotechnol 2015. [DOI: 10.1007/s10068-015-0099-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
12
|
Kim CW, Cho SH, Kang SH, Park YB, Yoon MH, Lee JB, No WS, Kim JB. Prevalence, genetic diversity, and antibiotic resistance of Bacillus cereus isolated from Korean fermented soybean products. J Food Sci 2015; 80:M123-8. [PMID: 25472031 DOI: 10.1111/1750-3841.12720] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 10/15/2014] [Indexed: 02/06/2023]
Abstract
Bacillus cereus contamination is a major food safety problem for Korean fermented soybean products, but few studies have assessed its potential to cause foodborne illness. The objectives of this study were to investigate the prevalence and characteristics of B. cereus isolated from Korean fermented soybean products. B. cereus was detected in 110 of 162 (67.9%) samples. The highest B. cereus frequency was observed in deonjang (68 of 93 samples, 73.1%) and cheonggukjang (18 of 25, 72.0%); however, nonhemolytic enterotoxin was detected only in 22 of 162 samples (13.6%). Although the tested B. cereus isolates showed diverse pulsotypes according to repetitive sequence-PCR banding patterns, they displayed similar antibiotic sensitivity spectra. The low frequency of enterotoxin detection suggests that the potential risk of B. cereus foodborne illness associated with Korean fermented soybean products is lower than generally presumed. However, considering the prevalence of B. cereus and the high content of fermented soybean products in the Korean diet, it is necessary to constantly monitor the level of contamination with B. cereus and its toxins in such Korean food products.
Collapse
Affiliation(s)
- Cheol-Woo Kim
- Dept. of Food Science & Biotechnology, Dongguk Univ, 30, Pildong-ro 1-gil, Joong-gu, Seoul, Republic of Korea
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Chon JW, Song KY, Kim H, Seo KH. Comparison of 3 Selective Media for Enumeration ofBacillus cereusin Several Food Matrixes. J Food Sci 2014; 79:M2480-4. [DOI: 10.1111/1750-3841.12594] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 07/24/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Jung-Whan Chon
- KU Center for Food Safety; Konkuk Univ; 1 Hwayang-dong, Gwangjin-gu Seoul 143-701 The Republic of Korea
| | - Kwang-Young Song
- KU Center for Food Safety; Konkuk Univ; 1 Hwayang-dong, Gwangjin-gu Seoul 143-701 The Republic of Korea
| | - Hyunsook Kim
- KU Center for Food Safety; Konkuk Univ; 1 Hwayang-dong, Gwangjin-gu Seoul 143-701 The Republic of Korea
| | - Kun-Ho Seo
- KU Center for Food Safety; Konkuk Univ; 1 Hwayang-dong, Gwangjin-gu Seoul 143-701 The Republic of Korea
| |
Collapse
|
14
|
Kim DH, Chon JW, Kim H, Hwang DG, Seo KH. Quantitative Validation of Two Novel Selective Media for the Enumeration of B
acillus cereus
in Naturally Contaminated Fermented Sauce Samples. J Food Saf 2014. [DOI: 10.1111/jfs.12133] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dong-Hyeon Kim
- KU Center for Food Safety; College of Veterinary Medicine; Konkuk University; Seoul 143-701 Korea
| | - Jung-Whan Chon
- KU Center for Food Safety; College of Veterinary Medicine; Konkuk University; Seoul 143-701 Korea
| | - Hyunsook Kim
- KU Center for Food Safety; College of Veterinary Medicine; Konkuk University; Seoul 143-701 Korea
| | - Dae-Geun Hwang
- KU Center for Food Safety; College of Veterinary Medicine; Konkuk University; Seoul 143-701 Korea
| | - Kun-Ho Seo
- KU Center for Food Safety; College of Veterinary Medicine; Konkuk University; Seoul 143-701 Korea
| |
Collapse
|
15
|
Kim DH, Kim H, Chon JW, Moon JS, Song KY, Seo KH. Development of blood-yolk-polymyxin B-trimethoprim agar for the enumeration of Bacillus cereus in various foods. Int J Food Microbiol 2013; 165:144-7. [PMID: 23732830 DOI: 10.1016/j.ijfoodmicro.2013.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 03/21/2013] [Accepted: 04/20/2013] [Indexed: 11/17/2022]
Abstract
Blood-yolk-polymyxin B-trimethoprim agar (BYPTA) was developed by the addition of egg yolk, laked horse blood, sodium pyruvate, polymyxin B, and trimethoprim, and compared with mannitol-yolk-polymyxin B agar (MYPA) for the isolation and enumeration of Bacillus cereus (B. cereus) in pure culture and various food samples. In pure culture, there was no statistical difference (p>0.05) between the recoverability and sensitivity of MYPA and BYPTA, whereas BYPTA exhibited higher specificity (p<0.05). To evaluate BYPTA agar with food samples, B. cereus was experimentally spiked into six types of foods, triangle kimbab, sandwich, misugaru, Saengsik, red pepper powder, and soybean paste. No statistical difference was observed in recoverability (p>0.05) between MYPA and BYPTA in all tested foods, whereas BYPTA exhibited higher selectivity than MYPA, especially in foods with high background microflora, such as Saengsik, red pepper powder, and soybean paste. The newly developed selective medium BYPTA could be a useful enumeration tool to assess the level of B. cereus in foods, particularly with high background microflora.
Collapse
Affiliation(s)
- Dong-Hyeon Kim
- KU Center for Food Safety, College of Veterinary Medicine, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea
| | | | | | | | | | | |
Collapse
|