scholarly journals Discrimination of Psychrotrophic and Mesophilic Strains of the Bacillus cereus Group by PCR Targeting of Major Cold Shock Protein Genes

1998 ◽  
Vol 64 (9) ◽  
pp. 3525-3529 ◽  
Author(s):  
Kevin P. Francis ◽  
Ralf Mayr ◽  
Felix von Stetten ◽  
Gordon S. A. B. Stewart ◽  
Siegfried Scherer
Keyword(s):  
Bacillus Cereus ◽  
Dairy Products ◽  
Cold Shock ◽  
Food Poisoning ◽  
Cold Shock Protein ◽  
Pcr Assay ◽  
Specific Primers ◽  
Bacillus Cereus Group ◽  
Cold Adapted ◽  
Pcr Targeting

ABSTRACT Detection of psychrotrophic strains (those able to grow at or below 7°C) of the Bacillus cereus group (Bacillus cereus, Bacillus thuringiensis, and Bacillus mycoides) in food products is at present extremely slow with conventional microbiology. This is due to an inability to discriminate these cold-adapted strains from their mesophilic counterparts (those able to grow only above 7°C) by means other than growth at low temperature, which takes 5 to 10 days for detection. Here we report the development of a single PCR assay that, using major cold shock protein-specific primers and appropriate annealing temperatures, is capable of both rapidly identifying bacteria of the B. cereus group and discriminating between psychrotrophic and mesophilic strains. It is intended that this development help to more accurately predict the shelf life of refrigerated pasteurized food and dairy products and to reduce the incidence of food poisoning by psychrotrophic strains of the B. cereus group.

scholarly journals Multi-locus sequence typing and virulence profile in Bacillus cereus sensu lato strains isolated from dairy products

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Angelica Bianco ◽  
Loredana Capozzi ◽  
Angela Miccolupo ◽  
Simona Iannetti ◽  
Maria Luisa Danzetta ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Bacillus Cereus ◽  
Dairy Products ◽  
Virulence Genes ◽  
Food Poisoning ◽  
Important Food ◽  
Food Contaminants ◽  
Bacillus Cereus Group ◽  
Mlst Analysis ◽  
Sequence Types

Members of Bacillus cereus group are important food contaminants and they are of relevant interest in food safety and public heath due to their ability to cause two distinct forms of food poisoning, emetic and diarrhoeal syndrome. In the present study, 90 strains of B. cereus isolated from dairy products, have been typed using Multilocus Sequence Typing (MLST) analysis and investigated for the occurrence of 10 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, entFM, entS and bceT) and one emetogenic gene (ces), to determine their genetic diversity. A total of 58 sequence types were identified and among these 17 were signalled as new profiles. Among the virulence genes, the majority of our strains carried the entS (92%), entFM (86%), nhe (82%) and cytK (72%) genes. All remaining genes were identified in at least one strain with different prevalence, stressing the genetic diversity, how even the different grade of pathogenicity of B. cereus isolated from dairy products.

Development of Rapid Real-Time PCR and Most-Probable-Number Real-Time PCR Assays To Quantify Enterotoxigenic Strains of the Species in the Bacillus cereus Group

2007 ◽  
Vol 70 (12) ◽  
pp. 2774-2781 ◽  
Author(s):  
I-CHEN YANG ◽  
DANIEL YANG-CHIH SHIH ◽  
JAN-YI WANG ◽  
TZU-MING PAN
Keyword(s):  
Bacillus Cereus ◽  
Real Time ◽  
Real Time Pcr ◽  
Food Samples ◽  
Most Probable Number ◽  
Pcr Assay ◽  
Bacillus Cereus Group ◽  
Probable Number ◽  
Cooked Rice ◽  
Group Detection

Members of the Bacillus cereus group may produce diarrheal enterotoxins and could be potential hazards if they enter the food chain. Therefore, a method capable of detecting all the species in the B. cereus group rather than B. cereus alone is important. We selected nhe as the target and developed a real-time PCR assay to quantify enterotoxigenic strains of the B. cereus group. The real-time PCR assay was evaluated with 60 B. cereus group strains and 28 others. The assay was also used to construct calibration curves for different food matrices and feces. The assay has an excellent quantification capacity, as proved by its linearity (R2 > 0.993), wide dynamic quantification range (102 to 107 CFU/g for cooked rice and chicken, 103 to 107 CFU/ml for milk, and 104 to 107 CFU/g for feces), and adequate relative accuracy (85.5 to 101.1%). For the low-level contaminations, a most-probable-number real-time PCR assay was developed that could detect as low as 100 CFU/ml. Both assays were tested with real food samples and shown to be considerably appropriate for B. cereus group detection and quantification.

scholarly journals Exposure to Bacillus cereus in Water Buffalo Mozzarella Cheese

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1899
Author(s):  
Angela Michela Immacolata Montone ◽  
Federico Capuano ◽  
Andrea Mancusi ◽  
Orlandina Di Maro ◽  
Maria Francesca Peruzy ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Dairy Products ◽  
Water Buffalo ◽  
Diarrheal Disease ◽  
Food Poisoning ◽  
Mozzarella Cheese ◽  
Food Borne ◽  
Genes Encoding ◽  
Spoilage Bacterium ◽  
Hemolysin Bl

Bacillus cereus is a spoilage bacterium and is recognized as an agent of food poisoning. Two food-borne illnesses are caused by B. cereus: a diarrheal disease, associated with cytotoxin K, hemolysin BL, non-hemolytic enterotoxin and enterotoxin FM, and an emetic syndrome, associated with the cereulide toxin. Owing to the heat resistance of B. cereus and its ability to grow in milk, this organism should be considered potentially hazardous in dairy products. The present study assessed the risk of B. cereus poisoning due to the consumption of water buffalo mozzarella cheese. A total of 340 samples were analyzed to determine B. cereus counts (ISO 7932:2005); isolates underwent molecular characterization to detect the presence of genes encoding toxins. Eighty-nine (26.1%) samples harbored B. cereus strains, with values ranging from 2.2 × 102 to 2.6 × 106 CFU/g. Isolates showed eight different molecular profiles, and some displayed virulence characteristics. Bacterial counts and the toxin profiles of isolates were evaluated both separately and jointly to assess the risk of enteritis due to B. cereus following the consumption of buffalo mozzarella cheese. In conclusion, the results of the present study showed that the risk of poisoning by B. cereus following the consumption of this cheese was moderate.

scholarly journals The Genetically Remote Pathogenic Strain NVH391-98 of the Bacillus cereus Group Is Representative of a Cluster of Thermophilic Strains

2007 ◽  
Vol 74 (4) ◽  
pp. 1276-1280 ◽  
Author(s):  
Sandrine Auger ◽  
Nathalie Galleron ◽  
Elena Bidnenko ◽  
S. Dusko Ehrlich ◽  
Alla Lapidus ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Food Poisoning ◽  
Temperate Phage ◽  
Pathogenic Strain ◽  
Bacillus Cereus Group ◽  
Close Relatives

ABSTRACT Bacteria of the Bacillus cereus group are known to cause food poisoning. A rare phylogenetically remote strain, NVH391-98, was recently characterized to encode a particularly efficient cytotoxin K presumably responsible for food poisoning. This pathogenic strain and its close relatives can be phenotypically distinguished from other strains of the B. cereus group by the inability to grow at temperatures below 17°C and by the ability to grow at temperatures from 48 to 53°C. A temperate phage, phBC391A2, residing in the genome of NVH391-98 allows us to distinguish the three known members of this thermophilic strain cluster.

scholarly journals Characterization of Bacillus cereus in Dairy Products in China

Toxins ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 454 ◽  
Author(s):  
Xiao-Ye Liu ◽  
Qiao Hu ◽  
Fei Xu ◽  
Shuang-Yang Ding ◽  
Kui Zhu
Keyword(s):  
Bacillus Cereus ◽  
Virulence Factors ◽  
Prevalence Rate ◽  
Dairy Products ◽  
Foodborne Pathogen ◽  
Food Poisoning ◽  
Intervention Strategies ◽  
Epidemiological Characteristics ◽  
Shed Light

Bacillus cereus is a common and ubiquitous foodborne pathogen with an increasing prevalence rate in dairy products in China. High and unmet demands for such products, particularly milk, raise the risk of B. cereus associated contamination. The presence of B. cereus and its virulence factors in dairy products may cause food poisoning and other illnesses. Thus, this review first summarizes the epidemiological characteristics and analytical assays of B. cereus from dairy products in China, providing insights into the implementation of intervention strategies. In addition, the recent achievements on the cytotoxicity and mechanisms of B. cereus are also presented to shed light on the therapeutic options for B. cereus associated infections.

scholarly journals Identification of Bacillus cereus Group Species Associated with Food Poisoning Outbreaks in British Columbia, Canada

2008 ◽  
Vol 74 (23) ◽  
pp. 7451-7453 ◽  
Author(s):  
Lorraine McIntyre ◽  
Kathryn Bernard ◽  
Daniel Beniac ◽  
Judith L. Isaac-Renton ◽  
David Craig Naseby
Keyword(s):  
British Columbia ◽  
Bacillus Cereus ◽  
Food Poisoning ◽  
Bacillus Cereus Group ◽  
Group Species

ABSTRACT Food poisoning laboratories identify Bacillus cereus using routine methods that may not differentiate all Bacillus cereus group species. We recharacterized Bacillus food-poisoning strains from 39 outbreaks and identified B. cereus in 23 outbreaks, B. thuringiensis in 4, B. mycoides in 1, and mixed strains of Bacillus in 11 outbreaks.

scholarly journals PCR Assay of the groEL Gene for Detection and Differentiation of Bacillus cereus Group Cells

2003 ◽  
Vol 69 (8) ◽  
pp. 4502-4510 ◽  
Author(s):  
Yu-Hsiu Chang ◽  
Yung-Hui Shangkuan ◽  
Hung-Chi Lin ◽  
Hwan-Wun Liu
Keyword(s):  
Bacillus Cereus ◽  
Fragment Length Polymorphism ◽  
Restriction Analysis ◽  
Rflp Analysis ◽  
Pcr Assay ◽  
Bacillus Cereus Group ◽  
Phylogenetic Marker ◽  
16S Ribosomal Dna ◽  
Detection And Identification ◽  
Ribosomal Dna Sequence

ABSTRACT Strains of species in the Bacillus cereus group are potentially enterotoxic. Thus, the detection of all B. cereus group strains is important. As 16S ribosomal DNA sequence analysis cannot adequately differentiate species of the B. cereus group, we explored the potential of the groEL gene as a phylogenetic marker. A phylogenetic analysis of the groEL sequences of 78 B. cereus group strains revealed that the B. cereus group strains were split into two major clusters, one including six B. mycoides and one B. pseudomycoides (cluster II) and the other including two B. mycoides and the rest of the B. cereus group strains (cluster I). Cluster I was further differentiated into two subclusters, Ia and Ib. The sodA gene sequences of representative strains from different clusters were also compared. The phylogenetic tree constructed from the sodA sequences showed substantial similarity to the tree constructed from the groEL sequences. Based on the groEL sequences, a PCR assay for detection and identification of B. cereus group strains was developed. Subsequent restriction fragment length polymorphism (RFLP) analysis verified the PCR amplicons and the differentiation of the B. cereus group strains. RFLP with MboI was identical for all the B. cereus group strains analyzed, while RFLP with MfeI or PstI classified all B. cereus and B. thuringiensis strains into two groups. All cluster II B. mycoides and B. pseudomycoides strains could be discriminated from other B. cereus group bacteria by restriction analysis with TspRI.

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