Improvement of Polymyxin–Egg Yolk–Mannitol–Bromothymol Blue Agar for the Enumeration and Isolation of Bacillus cereus in Various Foods

2017 ◽  
Vol 80 (3) ◽  
pp. 502-505
Author(s):  
Il-Byeong Kang ◽  
Jung-Whan Chon ◽  
Dong-Hyeon Kim ◽  
Dana Jeong ◽  
Hong-Seok Kim ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Bacillus Cereus ◽  
Egg Yolk ◽  
Bromothymol Blue ◽  
Food Samples ◽  
Red Pepper ◽  
Soybean Paste ◽  
Contaminated Food ◽  
Pepper Powder ◽  
Red Pepper Powder

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.

Improvement of Mannitol–Yolk–Polymyxin B Agar by Supplementing with Trimethoprim for Quantitative Detection of Bacillus cereus in Foods

2012 ◽  
Vol 75 (7) ◽  
pp. 1342-1345 ◽  
Author(s):  
JUNG-WHAN CHON ◽  
JI-YEON HYEON ◽  
JUN-HO PARK ◽  
KWANG-YOUNG SONG ◽  
JONG-HYUN KIM ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Polymyxin B ◽  
Food Samples ◽  
Red Pepper ◽  
High Background ◽  
Fermented Soybean ◽  
Soybean Paste ◽  
Radish Sprouts ◽  
Pepper Powder ◽  
Red Pepper Powder

Mannitol–yolk–polymyxin B agar (MYPA) was modified by supplementation with trimethoprim. The ability of the supplemented medium to select for and recover Bacillus cereus from pure cultures and food samples with high background microflora was compared with MYPA. For evaluation of the modified MYPA (mMYPA) in food samples with high background microflora, B. cereus was experimentally spiked into red pepper powder, fermented soybean paste, vegetable salad, and radish sprouts, and then it was recovered on MYPA and mMYPA for comparison. In all food samples, there was no difference in recoverability (P >0.05) between mMYPA (red pepper powder, 3.34 ± 0.24 log CFU/g; fermented soybean paste, 3.52 ± 0.47 log CFU/g; vegetable salad, 3.51 ± 0.23 log CFU/g; radish sprouts, 3.32 ± 0.40 log CFU/g) and MYPA (red pepper powder, 3.18 ± 0.20 log CFU/g; fermented soybean paste, 3.33 ± 0.43 log CFU/g; vegetable salad, 3.36 ± 0.19 log CFU/g; radish sprouts, 3.33 ± 0.31 log CFU/g). However, mMYPA exhibited better selectivity than MYPA, because additional trimethoprim made the differentiation of suspected colonies easier by inhibiting competing flora. The addition of trimethoprim to conventional media could be a useful option to improve selectivity in foods with high background microflora.

scholarly journals Synergistic Effects of Mild Heating and Dielectric Barrier Discharge Plasma on the Reduction of Bacillus Cereus in Red Pepper Powder

Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 171 ◽  
Author(s):  
Eun Bi Jeon ◽  
Man-Seok Choi ◽  
Ji Yoon Kim ◽  
Shin Young Park
Keyword(s):  
Bacillus Cereus ◽  
Dielectric Barrier Discharge ◽  
Barrier Discharge ◽  
Synergistic Effects ◽  
Combined Treatment ◽  
Red Pepper ◽  
Dbd Plasma ◽  
Dielectric Barrier ◽  
Pepper Powder ◽  
Red Pepper Powder

The synergistic efficacy of a combined treatment of mild heat (MH) and dielectric barrier discharge (DBD) plasma in Bacillus cereus-contaminated red pepper powder was tested. A cocktail of three strains of B. cereus (NCCP 10623, NCCP 14579, ATCC 11778) was inoculated onto red pepper powder and then treated with MH (60 °C for 5–20 min) and DBD plasma (5–20 min). Treatment with MH and DBD plasma alone for 5–20 min resulted in reductions of 0.23–1.43 and 0.12–0.96 log CFU/g, respectively. Combined treatment with MH and DBD plasma was the most effective at reducing B. cereus counts on red pepper powder, and resulted in log-reductions of ≥6.0 log CFU/g. The largest synergistic values (4.24–4.42 log) against B. cereus in red pepper powder were obtained by the combination of 20 min MH and 5–15 min DBD plasma. The values of Hunter color ‘‘L’’, ‘‘a’’, and ‘‘b’’, were not significantly different from those of the untreated sample and that with the combination of MH (60 °C for 5–20 min) and DBD plasma (5–20 min). Also, no significant (p > 0.05) differences in pH values between samples were observed. Therefore, these results suggest that the combination of MH treatment and DBD plasma can be potentially utilized in the food industry to effectively inactivate B. cereus without incurring quality deterioration of red pepper powder.

scholarly journals Synergistic Effects of Mild Heating and Dielectric Barrier Discharge Plasma on Reduction of Bacillus cereus in Red Pepper Powder

2019 ◽  
Author(s):  
Eun Bi Jeon ◽  
Man-Seok Choi ◽  
Ji Yoon Kim ◽  
Shin Young Park
Keyword(s):  
Bacillus Cereus ◽  
Dielectric Barrier Discharge ◽  
Barrier Discharge ◽  
Synergistic Effects ◽  
Combined Treatment ◽  
Red Pepper ◽  
Dbd Plasma ◽  
Dielectric Barrier ◽  
Pepper Powder ◽  
Red Pepper Powder

The synergistic efficacy of combined treatment mild heat (MH) and dielectric barrier discharge (DBD) plasma in Bacillus cereus-contaminated red pepper powder was tested. A cocktail of three strains of B. cereus (NCCP 10623, NCCP 14579, ATCC 11778) was inoculated onto red pepper powder and then treated with MH (60 ℃ for 5-20 min) and DBD plasma (5-20 min). Treatment with MH and DBD plasma alone for 5~20 min resulted in reductions of 0.23~1.43 and 0.12~0.96 log CFU/g, respectively. Combined treatment with MH and DBD plasma was the most effective at reducing B. cereus counts on red pepper powder and resulted in log-reductions of ≥ 6.0 log CFU/g. The largest synergistic values (4.24-4.42 log) against B. cereus in red pepper powder were obtained by the combination of 20 min MH and 5~15 min DBD plasma. Hunter color ‘‘L’’, ‘‘a’’, and ‘‘b’’ values of the combination-treated samples were not significantly different from those of non-treated samples. Also, no significant (p > 0.05) differences in pH values between samples were observed. Therefore, these results suggest that the combination of MH treatment and DBD plasma can be potentially utilized in the food industry to effectively inactivate B. cereus without incurring quality deterioration of red pepper powder.

An improved selective and diagnostic medium for the isolation and enumeration of Bacillus cereus in foods

1980 ◽  
Vol 26 (7) ◽  
pp. 753-759 ◽  
Author(s):  
R. Holbrook ◽  
Judith M. Anderson
Keyword(s):  
Bacillus Cereus ◽  
Egg Yolk ◽  
Bromothymol Blue ◽  
Food Samples ◽  
Selective Medium ◽  
Confirmatory Test ◽  
Staining Procedure ◽  
Complete Agreement ◽  
Phenol Red ◽  
Biochemical Tests

The use and performance of an improved diagnostic and selective medium, PEMBA (polymyxin pyruvate egg yolk mannitol bromothymol blue agar), for the detection of Bacillus cereus in foods is described. The distinct colonial appearance of B. cereus on PEMBA permitted the recognition of both strains: those that do precipitate egg yolk and those that do not react with egg yolk. A staining procedure, used to demonstrate microscopically both the presence of lipid globules in vegetative cells and spore morphology of isolates, proved a rapid and reliable confirmatory test which gave complete agreement with a battery of biochemical tests used for this purpose. The quantitative recovery of B. cereus on PEMBA from 143 food samples was not significantly different from counts on KG (Kim and Goepfert), MYP (mannitol egg yolk phenol red), and McClung's media, and the selectivity of PEMBA was generally superior.

Efficient Isolation and Identification of Bacillus cereus Group

2012 ◽  
Vol 95 (2) ◽  
pp. 446-451 ◽  
Author(s):  
Sandra M Tallent ◽  
Kristin M Kotewicz ◽  
Errol A Strain ◽  
Reginald W Bennett
Keyword(s):  
Bacillus Cereus ◽  
Dairy Products ◽  
Egg Yolk ◽  
Bromothymol Blue ◽  
Foodborne Illnesses ◽  
Isolation And Identification ◽  
Bacillus Cereus Group ◽  
Gram Positive ◽  
Contaminated Food ◽  
Chromogenic Agar

Abstract Bacillus cereus is a group of ubiquitous facultative anaerobic sporeforming Gram-positive rods commonly found in soil. The spores frequently contaminate a variety of foods, including produce, meat, eggs, and dairy products. Foodborne illnesses associated with toxins produced by B. cereus can result in self-limiting diarrhea or vomiting. Plate enumeration methods recommended by recognized food authorities to detect the presence of B. cereus in potentially contaminated food products do not inhibit other Gram-positive competitive bacteria. This study evaluated the use of Bacara, a new chromogenic agar, as an efficient method to identify and enumerate B. cereus group from food matrixes, even in the presence of background flora. Inclusivity and exclusivity testing was performed using four different selective and differential media for B. cereus, including Mannitol Egg Yolk Polymyxin (MYP), Polymyxin Pyruvate Egg-Yolk Mannitol Bromothymol Blue Agar, Bacillus Chromogenic Media, Brilliance, and Bacara. MYP and Bacara were also used in plate enumeration studies to isolate B. cereus from artificially contaminated foods.

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