Toxin Gene Profiling of Bacillus cereus Food Isolates by PCR

Bacillus cereus is an opportunistic foodborne pathogen causing food intoxication and infectious diseases. Different toxins and pathogenic factors are responsible for diarrheal syndrome, like nonhemolytic enterotoxin Nhe, hemolytic enterotoxin Hbl, enterotoxin FM and cytotoxin K, while emetic syndrome is caused by the depsipeptide cereulide toxin. The traditional method of B. cereus detection is based on the bacterial culturing onto selective agars and cells enumeration. In addition, molecular and chemical methods are proposed for toxin gene profiling, toxin quantification and strain screening for defined virulence factors. Finally, some advanced biosensors such as phage-based, cell-based, immunosensors and DNA biosensors have been elaborated to enable affordable, sensitive, user-friendly and rapid detection of specific B. cereus strains. This review intends to both illustrate the state of the B. cereus diagnostic field and to highlight additional research that is still at the development level.

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Further Insights into the Toxicity of Bacillus cytotoxicus Based on Toxin Gene Profiling and Vero Cell Cytotoxicity Assays

Toxins ◽

10.3390/toxins13040234 ◽

2021 ◽

Vol 13 (4) ◽

pp. 234

Author(s):

Johanna Burtscher ◽

Danai Etter ◽

Michael Biggel ◽

Janine Schlaepfer ◽

Sophia Johler

Keyword(s):

Bacillus Cereus ◽

Vero Cell ◽

Diarrheal Disease ◽

Foodborne Pathogen ◽

Food Poisoning ◽

Gene Profiling ◽

Toxin Gene ◽

Cell Cytotoxicity ◽

Cytotoxic Potential ◽

Cytotoxicity Assays

Bacillus cytotoxicus belongs to the Bacillus cereus group that also comprises the foodborne pathogen Bacillus cereus sensu stricto, Bacillus anthracis causing anthrax, as well as the biopesticide Bacillus thuringiensis. The first B. cytotoxicus was isolated in the context of a severe food poisoning outbreak leading to fatal cases of diarrheal disease. Subsequent characterization of the outbreak strain led to the conclusion that this Bacillus strain was highly cytotoxic and eventually resulted in the description of a novel species, whose name reflects the observed toxicity: B. cytotoxicus. However, only a few isolates of this species have been characterized with regard to their cytotoxic potential and the role of B. cytotoxicus as a causative agent of food poisoning remains largely unclear. Hence, the aim of this study was to gain further insights into the toxicity of B. cytotoxicus. To this end, 19 isolates were obtained from mashed potato powders and characterized by toxin gene profiling and Vero cell cytotoxicity assays. All isolates harbored the cytK1 (cytotoxin K1) gene and species-specific variants of the nhe (non-hemolytic enterotoxin) gene. The isolates exhibited low or no toxicity towards Vero cells. Thus, this study indicates that the cytotoxic potential of B. cytotoxicus may be potentially lower than initially assumed.

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Toxin gene profiling of enterotoxic and emetic Bacillus cereus

FEMS Microbiology Letters ◽

10.1111/j.1574-6968.2006.00320.x ◽

2006 ◽

Vol 260 (2) ◽

pp. 232-240 ◽

Cited By ~ 107

Author(s):

Monika Ehling-Schulz ◽

Marie-HÃ©lÃ¨ne Guinebretiere ◽

Amanda MonthÃ¡n ◽

Odile Berge ◽

Martina Fricker ◽

...

Keyword(s):

Bacillus Cereus ◽

Gene Profiling ◽

Toxin Gene

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Psychrotrophic properties, toxigenic characteristics, and PFGE profiles of Bacillus cereus isolated from different foods and spices

Ciência Rural ◽

10.1590/0103-8478cr20210166 ◽

2022 ◽

Vol 52 (4) ◽

Author(s):

Hayriye Yeşim Can ◽

Mehmet Elmalı ◽

Alper Karagöz ◽

Hüseyin Burak Dişli

Keyword(s):

Bacillus Cereus ◽

Food Poisoning ◽

Raw Milk ◽

Gene Profiling ◽

Poultry Meat ◽

Pcr Analysis ◽

Toxin Gene ◽

Raw Poultry ◽

Pfge Profiles ◽

Milk And Dairy Products

ABSTRACT: Bacillus cereus is an aerobic and facultatively anaerobic, spore-forming bacterium, and it is found naturally in soil and poses a risk factor for the contamination of food and foodstuffs including cereals, vegetables, spices, ready-to-eat (RTE) foods, meats, milk, and dairy products. This study determined the prevalence of B. cereus in raw poultry meat, raw cow’s milk, cheese, spices, and RTE foods in Hatay province. The study also analysed the psychrotrophic properties, toxigenic characteristics, and pulsed-field gel electrophoresis (PFGE) profiles of the isolates. The levels of contamination with B. cereus determined for cheese, raw milk, RTE foods, spices, and raw poultry meat were 16.6%, 34.2%, 42.8%, 49%, and 55.5%, respectively. B. cereus was isolated from 84 (42%) of the 200 samples analysed and the 84 isolates were verified by PCR analysis targeting the haemolysin gene specific for B. cereus. Of the total isolates, 64 (76.1%) were psychrotrophic. The toxin gene profiling of B. cereus isolates was determined by amplifying the four genes nhe, hbl, cytK, and ces. The nhe and cytK genes were most frequently detected in the isolates, while the hbl and ces genes were not found. In addition, a high genetic relationship between the isolates was detected at a 92% similarity level by PFGE analysis. In conclusion, the occurrence of both psychrotrophic and toxigenic B. cereus strains in this study indicated a potential risk for food spoilage and food poisoning.

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Analysis of enterotoxigenic Bacillus cereus strains from dried foods using whole genome sequencing, multi-locus sequence analysis and toxin gene prevalence and distribution using endpoint PCR analysis

International Journal of Food Microbiology ◽

10.1016/j.ijfoodmicro.2018.06.016 ◽

2018 ◽

Vol 284 ◽

pp. 31-39 ◽

Cited By ~ 9

Author(s):

Laurenda Carter ◽

Hannah R. Chase ◽

Charles M. Gieseker ◽

Nicholas R. Hasbrouck ◽

Cynthia B. Stine ◽

...

Keyword(s):

Sequence Analysis ◽

Bacillus Cereus ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Pcr Analysis ◽

Toxin Gene ◽

Whole Genome ◽

Dried Foods

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Toxin gene pattern in Bacillus cereus group strains isolated from sheep ricotta cheese

Veterinary Research Communications ◽

10.1007/s11259-008-9139-6 ◽

2008 ◽

Vol 32 (S1) ◽

pp. 323-326 ◽

Cited By ~ 7

Author(s):

E. P. L. De Santis ◽

A. Foddai ◽

S. Virdis ◽

P. Marongiu ◽

A. L. Pilo ◽

...

Keyword(s):

Bacillus Cereus ◽

Toxin Gene ◽

Bacillus Cereus Group

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Distribution and Toxin Gene Characteristic of Bacillus cereus Isolated from Foods in Busan

Journal of Food Hygiene and Safety ◽

10.13103/jfhs.2020.35.3.219 ◽

2020 ◽

Vol 35 (3) ◽

pp. 219-224

Author(s):

So-hyun Park ◽

Wi-Gyeong Gwon ◽

In-sook Lee ◽

Eun-ju Kim ◽

Su-jeong Hwang ◽

...

Keyword(s):

Bacillus Cereus ◽

Toxin Gene

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DETECTION OF HBLD TOXIN GENE BY BACILLUS CEREUS ISOLATED FROM MEAT CURRY FOOD SAMPLES IN MALAYSIAN RESTAURANTS

Environment & Ecosystem science ◽

10.26480/ees.02.2020.68.72 ◽

2020 ◽

Vol 4 (2) ◽

pp. 68-72

Author(s):

Marwan Msarah ◽

Ahmed Alsier ◽

Sahilah, A.M.

Keyword(s):

Bacillus Cereus ◽

Foodborne Pathogen ◽

Food Poisoning ◽

Egg Yolk ◽

Food Samples ◽

Blood Agar ◽

Toxin Gene ◽

Biochemical Tests ◽

Isolation Medium ◽

Hemolysin Bl

Bacillus cereus is a ubiquitous foodborne pathogen, can cause food poisoning, leading to infections, have two major types of food poisoning emetic and diarrheal. Foods rich in protein such as meat are associated with foodborne outbreaks of diarrhea caused by B. cereus. The aim of this study is to isolate and identify B. cereus from ready to eat (RTE) meat curry from restaurants in Malaysia and to detect hblD pathogenic gene of B. cereus isolates. Mannitol egg yolk polymyxin agar was used as a selective isolation medium. Commercially available kits and boiling methods were used for DNA extraction, samples acquired from restaurants were examined for the presence of Hemolysin BL gene by polymerase chain reaction (PCR). Among all isolates, twenty-four of B. cereus isolates detected for HBL enterotoxin production by the discontinuous pattern on HBL sheep blood agar then confirmed by biochemical tests. More than 58.33 % of the isolate showed discontinuous hemolysis pattern on HBl blood agar and 29.16% of the samples were shown positive for hblD gene that can cause diarrhea with the size of 807bp on gel. This study demonstrated that RTE meat curry was a potential source for entero-toxigenic B. cereus and the presence of the hblD toxin genes for the HBL complex in the isolates tested were highly associated. Therefore, these meat curry isolates should be regarded as potential toxin producers.

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