Efficient Isolation and Identification of Bacillus cereus Group

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.

Eksplorasi Bakteri Endofitik Dan Potensinya Dalam Penghambatan Jamur Akar Putih (Rigidoporus Microporus)

“…Berbeda dengan hasil pengujian reaksi gram dengan KOH 3% yang menunjukkan bahwa isolat A10 termasuk gram negatif, Bacillus cereus pada umumnya termasuk bakteri gram positif (Senesi & Ghelardi, 2010;Tallent et al, 2012). B. cereus tersebar luas pada berbagai lingkungan, terutama di dalam tanah, dan dapat bertahan lama dalam berbagai kondisi l i n g k u n g a n .…”

“…cereus dapat memiliki siklus hidup sebagai saprofit seumur hidupnya, tetapi bakteri ini juga berpotensi sebagai patogen yang menyebabkan sakit pada manusia, terutama sebagai penyebab keracunan makanan yang ditandai dengan diare, gangguan perut, mual atau muntah, yang sebagian besar terjadi pada orang yang kurang sehat, memiliki penyakit kritis atau memiliki kekebalan tubuh yang lemah (McIntyre et al, 2008;Senesi & Ghelardi, 2010;Tallent et al, 2012;). Hasil pengujian Bacillus cereus isolat A10 pada medium skim milk menunjukkan adanya aktivitas enzim protease yang sangat lemah ditandai dengan adanya zona bening yang tipis di sekitar koloni, dibandingkan dengan kontrol positif (Gambar 4).…”

Methodology for accelerated monitoring and assurance of sanitary quality and food safety

“…The presence of B. cereus or its toxins in food products is identified by morphological, biochemical, serological (ELISA), chemo-taxonomic and molecular genetic (PCR) methods [43]. It is possible to detect a toxin that causes vomiting, with the help of animal models (cats, monkeys) and cellular ones.…”

Optimized Culture Conditions for the Detection of Selected Strains of Bacillus in Eye Creams

“…This is the best criteria to distinguish B. thuringiensis from other related species in the Bacillus cereus group. The strain of Bacillus labeled B. megaterium ATCC 6258 grew on the chromogenic plate BACARA [36] but also on MYP with typical B. cereus features suggesting the strain actually was a member of the cereus group (Figure 2). Further investigation, including staining of this suspect strain using Brilliant Blue R250 and TB carbofuchsin (FDA-BAM method) revealed the presence of parasporal bodies indicating that the strain had been mislabeled.…”