Category Archives: Bacillus cereus

Hong Kong – Packed milk drink sample found to contain excessive Bacillus cereus


Issue Date 8.6.2018
Source of Information Centre for Food Safety
Food Product Skimmed Hi-Calcium Milk Drink
Product Name and Description Product name: Skimmed Hi-Calcium Milk Drink

Manufacturer: Nestlé Hong Kong Limited

Volume: 236 millilitre per pack

Use-by date: June 2, 2018

Reason For Issuing Alert
  • The Centre for Food Safety (CFS) collected the concerned sample from a supermarket in Kwun Tong for testing under its routine Food Surveillance Programme. The test result showed that the sample contained Bacillus cereus at a level of 4 600 000 per gram. Under the Microbiological Guidelines for Food, if ready-to-eat food contains Bacillus cereus at a level of more than 100 000 per gram, it is considered unsatisfactory.
Action Taken by the Centre for Food Safety
  • The CFS had informed the manufacturer and the vendor concerned of the test result. Investigation was conducted at the production plant and the supermarket concerned and follow-up samples were collected for further testing. Investigation is ongoing.
  • The CFS had also provided health education on food safety and hygiene for the staff of the production plant and the supermarket and requested them to carry out thorough cleaning and disinfection.
  • The CFS will alert the trade, continue to follow up on the incident and take appropriate action in order to safeguard public health and food safety.
Advice to the Trade
  • According to Section 54 of the Public Health and Municipal Services Ordinance (Cap 132), all food available for sale in Hong Kong, locally produced or imported, should be fit for human consumption. An offender is subject to a maximum fine of $50,000 and imprisonment for six months upon conviction.
Advice to Consumers
  • Bacillus cereus is commonly found in the environment. Unhygienic conditions in food processing and storage may give rise to its growth. Consuming food contaminated with excessive Bacillus cereus may cause gastrointestinal upset such as vomiting and diarrhoea.
Further Information The CFS press release


Research – Effect of Electrolyzed Water on the Disinfection of Bacillus cereus Biofilms: The Mechanism of Enhanced Resistance of Sessile Cells in the Biofilm Matrix

Journal of Food Protection

This study examined the disinfection efficacy and mechanism of electrolyzed water (EW) on Bacillus cereus biofilms. B. cereus strains, ATCC 14579 and Korean Collection for Type Cultures (KCTC) 13153 biofilms, were formed on stainless steel (SS) and plastic slide (PS) coupons. Mature biofilms were treated with slightly acidic EW (SAEW), acidic EW (AEW), and basic EW (BEW). SAEW (available chlorine concentration, 25 ± 1.31 mg L−1; pH 5.71 ± 0.16; and oxidation reduction potential, 818 to 855 mV) reduced ATCC 14579 biofilms on plastic slides to below the detection limit within 30 s. However, biofilms on SS coupons showed a higher resistance to the SAEW treatment. When the disinfection activities of three types of EW on biofilms were compared, AEW showed a higher bactericidal activity, followed by SAEW and BEW. In contrast, BEW showed a significantly (P < 0.05) higher biofilm dispersal activity than AEW and SAEW. SAEW disinfection of the B. cereus biofilms was due to the disruption of the B. cereus plasma membrane. The higher resistance of biofilms formed on the SS coupon might be due to the higher number of attached cells and extracellular polymeric substances formation that reacts with the active chlorine ions, such as hypochlorous acid and hypochlorite ion of SAEW, which decreased the disinfection efficacy of SAEW. This study showed that the EW treatment effectively disinfected B. cereus biofilms, providing insight into the potential use of EW in the food processing industry to control the biofilm formation of B. cereus.


RASFF Alert – Bacillus cereus – Spice Mix

kswfoodworld food safety poisoning

RASFF-Bacillus cereus (15000 CFU/g) and unauthorised colour auramine O in spice mix from Bangladesh in Finland

RASFF Alert – Bacillus cereus – Spice Mix

kswfoodworld food safety poisoning

RASFF-Bacillus cereus (14000 CFU/g) and unauthorised colour auramine O in spice mix from Bangladesh in Finland

Research – Effect of Gum Arabic‐polyvinyl alcohol films containing seed cover extract of Zanthoxylum rhetsa on shelf life of refrigerated ground chicken meat

Wiley Online


The aim of this study was to improve shelf life of ground chicken meat in chilled storage by employing active packaging incorporating seed cover extract (SCE) of Zanthoxylum rhetsa. The total phenolic and flavonoid content in SCE was estimated to be 194 and 44.5 mg/g, respectively, in terms of catechin equivalents. SCE scavenged free radicals, exhibited good reducing power, and high antioxidant activity coefficient. SCE was effective against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Pseudomonas fluorescens. The major phenolics compounds identified in SCE were catechin, vanillin, gallic acid, and ferulic acid. SCE was incorporated to get active films of Gum Arabic, polyvinyl alcohol, and sorbitol. Films had good mechanical and barrier properties. Ground chicken meat packed in normal films spoiled in less than 6 days whereas active packaging led to reduction in lipid peroxidation and improvement in shelf life up to 12 days at chilled condition.

Practical applications

Globally, tonnes of food get wasted annually at retail and consumer level due to lack of proper packaging and storage facilities. Meat is a highly perishable commodity and various strategies are used to preserve it for long time. Packaging and freezing are two important techniques used for this purpose. Freezing is energy intensive and conventional packaging using petroleum‐based polymers leads to burden on environment. Active packaging with the use of biodegradable polymers and natural preservatives is an emerging area of research in food industry. Zanthoxylum rhetsa is low cost spice and is rich in bioactive compounds. This can be used as the active component in biodegradable films that can extend the shelf life of the meat packed in it at chilled temperatures. Thus the burden on energy as well as petroleum resources can be minimized.

RASFF Alert – Bacillus cereus – Ground Ginger

kswfoodworld food safety poisoning

RASFF-Bacillus cereus (>100000 CFU/g) in ground ginger from Spain in France

Research – Levels of microbial contamination of domestic refrigerators in Italy

Science Direct iStock_000012710183Small


According to the EFSA Report 2013, 32.7% of outbreaks of foodborne illness registered in Europe occurs within the home, due to inadequate hygienic behaviour of consumers when preparing foods in the kitchen. The efficacy of proper cleaning of cutting boards, dishes and cutlery in limiting microbial cross-contaminations in the kitchen has been documented many times, whereas few researches have been performed to determine the microbial load of the internal walls of domestic refrigerators, in Italy. The aim of this investigation is to ascertain the role played by internal surfaces of home refrigerators as possible sources of microbial contamination of foods.

Material and methods

We analyzed 293 domestic refrigerators of students or workers at the university campus of Agripolis (Legnaro, Italy). For each refrigerator, 2 internal surfaces were sampled using sponge-bags. The amounts of total viable count (TVC), Gram-negative spoiling bacteria, moulds and yeasts and the main pathogenic bacterial species were determined.


TVCs greater than 1 log CFU cm−2 are in a little over 50% of the samples analyzed and are found mainly on the bottom of the refrigerator (61%) compared to the walls (39%) (P < 0.001). Even for other microbial counts the risk ratio of finding them on the bottom of the refrigerator is significantly higher than on the walls; the possibility of there being a finding on the bottom with respect to the walls varies from 2.5 to 8.5 times respectively for moulds and Aeromonas spp. Salmonella spp. was found in 1.7% of the samples, Bacillus cereus in 5.6%, Coagulase-positive staphylococci (CPS) in 4%, the prevalence of which is always higher on the bottom of the refrigerator. Listeria monocytogenes and Yersinia enterocolitica were never found.


It is necessary to better educate consumers to clean their appliances more frequently.