کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4366778 1616587 2015 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Characteristics and phylogeny of Bacillus cereus strains isolated from Maari, a traditional West African food condiment
ترجمه فارسی عنوان
مشخصات و فیلوژنی سویه های باسیلوس سرئوس جدا شده از ماری، ادویه غذای سنتی غرب آفریقا
کلمات کلیدی
ماری، باسیلوس سرئوس، باسیلوس سرئوس بیووار آنتراسیس، تخمیر غذا
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش تغذیه
چکیده انگلیسی


• A Maari (fermented baobab tree seeds) production harboured high B. cereus counts.
• Three different B. cereus types by M13-PCR typing showed clear succession patterns.
• The B. cereus of M13-PCR groups 1, 2 and 3 were of PanC types III, III and IV.
• The M13-PCR gr. 1 isolates harboured capA, capB and capC genes.

Maari is a spontaneously fermented food condiment made from baobab tree seeds in West African countries. This type of product is considered to be safe, being consumed by millions of people on a daily basis. However, due to the spontaneous nature of the fermentation the human pathogen Bacillus cereus occasionally occurs in Maari. This study characterizes succession patterns and pathogenic potential of B. cereus isolated from the raw materials (ash, water from a drilled well (DW) and potash), seed mash throughout fermentation (0-96 h), after steam cooking and sun drying (final product) from two production sites of Maari. Aerobic mesophilic bacterial (AMB) counts in raw materials were of 105 cfu/ml in DW, and ranged between 6.5 × 103 and 1.2 × 104 cfu/g in potash, 109–1010 cfu/g in seed mash during fermentation and 107 – 109 after sun drying. Fifty three out of total 290 AMB isolates were identified as B. cereus sensu lato by use of ITS-PCR and grouped into 3 groups using PCR fingerprinting based on Escherichia coli phage-M13 primer (M13-PCR). As determined by panC gene sequencing, the isolates of B. cereus belonged to PanC types III and IV with potential for high cytotoxicity. Phylogenetic analysis of concatenated sequences of glpF, gmk, ilvD, pta, pur, pycA and tpi revealed that the M13-PCR group 1 isolates were related to B. cereus biovar anthracis CI, while the M13-PCR group 2 isolates were identical to cereulide (emetic toxin) producing B. cereus strains. The M13-PCR group 1 isolates harboured poly-γ-D-glutamic acid capsule biosynthesis genes capA, capB and capC showing 99-100% identity with the environmental B. cereus isolate 03BB108. Presence of cesB of the cereulide synthetase gene cluster was confirmed by PCR in M13-PCR group 2 isolates. The B. cereus harbouring the cap genes were found in potash, DW, cooking water and at 8 h fermentation. The “emetic” type B. cereus were present in DW, the seed mash at 48–72 h of fermentation and in the final product, while the remaining isolates (PanC type IV) were detected in ash, at 48–72 h fermentation and in the final product. This work sheds light on the succession and pathogenic potential of B. cereus species in traditional West African food condiment and clarifies their phylogenetic relatedness to B. cereus biovar anthracis. Future implementation of GMP and HACCP and development of starter cultures for controlled Maari fermentations will help to ensure a safe product.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Food Microbiology - Volume 196, 2 March 2015, Pages 70–78
نویسندگان
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