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BACILLUS CEREUS

PATHOGEN SAFETY DATA SHEET - INFECTIOUS SUBSTANCES

SECTION I - INFECTIOUS AGENT

NAME: Bacillus cereus

SYNONYM OR CROSS REFERENCE: Bacillus cereus food-poisoning.

CHARACTERISTICS: 1.4 µm gram-positive rods, usually appear as pairs and short chains Footnote 1, Footnote 2. B. cereus are facultative anaerobes that are motile and able to form endospores, have colonial morphology of about 2-7 mm in diameter, and have a white granular texture Footnote 3. B. cereus grows above 10-20°C and below 35-45°C with an optimum temperature of about 37°C Footnote 1, Footnote 2. The bacteria are able to produce six types of toxins: five enterotoxins and an emetic toxin, which can be heat-stable or heat-labile depending on the strain Footnote 2, Footnote 4.

SECTION II - HAZARD IDENTIFICATION

PATHOGENICITY/TOXICITY: B. cereus causes self-limiting (24-48 hours) food-poisoning syndromes (a diarrheal type and an emetic type), opportunistic infections and is associated with clinical infections such as endophthalmitis and other ocular infections Footnote 2, Footnote 5-Footnote 7. The diarrheal form of B. cereus food poisoning is characterized by abdominal cramps, profuse watery diarrhea, and rectal tenesmus, and, occasionally, fever and vomiting. The emetic form of B. cereus food poisoning is characterized by nausea, vomiting, and malaise, occasionally with diarrhea Footnote 2. B. cereus can cause wound infections, bacteremia, septicaemia, meningitis, pneumonia, central nervous system infections, endocarditis, pericarditis, respiratory infections, and peripheral infections Footnote 2, Footnote 7, Footnote 8. Infection in immunocompromised individuals can be life-threatening Footnote 5. B. cereus strains which harbour a plasmid bearing B. anthracis-like virulence factors can cause severe pneumonia in immunocompetant people Footnote 9.

EPIDEMIOLOGY: Worldwide Footnote 2. Diseases cased by B. cereus are commonly found in places where there is improper food handling. Between 1973–1985, B. cereus caused 17.8% of the total bacterial food poisonings in Finland, 11.5% in the Netherlands, 0.8% in Scotland, 0.7% in England and Wales, 2.2% in Canada, 0.7% in Japan, and 15.0% (between 1960–1968) in Hungary Footnote 10. As of 2008, 103 confirmed outbreak cases have been reported in the US Footnote 11. In Norway, B. cereus was the most common microbe isolated from foodborne illnesses in 1990 Footnote 10.

HOST RANGE: Animals and humans, specifically those who are immunocompromised, intravenous drug users, or neonates Footnote 1, Footnote 2, Footnote 7.

INFECTIOUS DOSE: In diarrheal illness, the toxin responsible is produced by organisms in the small intestine and infective dose is 104-109 cells per gram of food. The emetic toxin is preformed and indigested in food (about 105-108 cells per gram in order to produce sufficient toxin) Footnote 2.

MODE OF TRANSMISSION: The primary mode of transmission is via the ingestion of B. cereus contaminated food Footnote 1, Footnote 2: emetic type of food poisoning has been largely associated with the consumption of rice and pasta, while the diarrheal type is transmitted mostly by milk products, vegetables and meat. It forms spores and spreads easily Footnote 10. In hospitals, B. cereus can be transmitted via contaminated linen Footnote 12.

INCUBATION PERIOD: The diarrheal form of B cereus has an onset period of 8-16 h while the emetic form has an onset period of 1-6 h. Recovery is usually complete in 24 h Footnote 1, Footnote 2.

COMMUNICABILITY: Not transmitted from person-to-person.

SECTION III - DISSEMINATION

RESERVOIR: Animals, humans, stool, organisms in soil Footnote 10, straw, and foods associated with foodborne disease (rice, pasta, milk products, spices, vegetables and meat) Footnote 13.

ZOONOSIS: None.

VECTORS: None.

SECTION IV - STABILITY AND VIABILITY

DRUG SUSCEPTIBILITY/RESISTANCE: B. cereus is susceptible to imipenem and vancomycin, and most strains are sensitive to chloramphenicol, aminoglycosides, ciprofloxacin, erythromycin, and gentamicin Footnote 1, Footnote 2, Footnote 7, Footnote 14. Some strains were moderately sensitive to clindamycin and tetracycline Footnote 1. Clindamycin with gentamicin, given early, is the best treatment for ophthalmic infections from B. cereus.

DRUG RESISTANCE: B. cereus produce large amounts of β lactamase and are resistant to penicillin, ampicillin, cephalosporins, trimethoprim Footnote 1, Footnote 2, Footnote 7.

SUSCEPTIBILITY TO DISINFECTANTS: Gluteraldehyde is a chemical agent used to sterilize bacillus-contaminated material. Spores can be killed by 1% sodium hypochlorite, paracetic acid, activated hydrogen peroxide, chlorine dioxide Footnote 15, formaldehyde, iodine, acids, alkali Footnote 7, Footnote 16. These chemical agents should be highly concentrated and required greater time of contact to kill spores. Oazolidinones are also effective antibacterial agents for B. cereus Footnote 1.

PHYSICAL INACTIVATION: B. cereus can be inactivated by pulse electric field in 0.15 % NaCl solution Footnote 17. B. cereus spores can be resistant to heat and radiation, but heating at 100°C for 5 minutes results in cellular damage to the membranes and ribosomes Footnote 2, Footnote 18. Gamma irradiation at 2-5 kGy is required to inactivate B. cereus cells Footnote 19.

SURVIVAL OUTSIDE HOST: B. cereus survives in soil and on vegetation, and is generally heat-resistant and thus may survive thermal food processing with or without injury to cells Footnote 11, Footnote 20.

SECTION V – FIRST AID / MEDICAL

SURVEILLANCE: Monitor for symptoms. B. cereus strains can be isolated and grown in laboratory media at 37°C. Specimen isolated from contaminated human stool can be grown with tryptic soy broth with polymyxin Footnote 2. The organism can be isolated in B. cereus medium, i.e. in mannitol, egg yolk, polymyxin B agar (MEYP) or polymyxin B, egg yolk, mannitol, bromthymol blue agar (PEMBA). Immunological assays, polymerase chain reaction and biological tests, have been used to detect the enterotoxin activity of B. cereus Footnote 10. Isolation of greater than 105 organisms/g from contaminated food can confirm B. cereus contamination Footnote 1.

Note: All diagnostic methods are not necessarily available in all countries.

FIRST AID/TREATMENT: Administer appropriate drug therapy with supportive treatment Footnote 6. Oral rehydration therapy is the treatment for acute food poisoning syndromes, and antibiotics are seldom required Footnote 21. Patients are given corticosteroids and antibiotics as a first line treatment for eye infections from B. cereus Footnote 22. Whenever gram-positive rods are discovered in the blood or the cerebrospinal fluid of an immunocompromised patient with clinical signs of infection, the empiric antibiotic treatment should cover B. cereus (B. cereus is usually sensitive to clindamycin, aminoglycosides, vancomycin, chloramphenicol, and erythromycin) Footnote 1, Footnote 23.

IMMUNIZATION: None.

PROPHYLAXIS: In cases of an acute non-inflammatory infectious diarrhea, a pharmacologic prophylaxis with bismuth subsalicylate in a dose of two tablets four times daily with meals and at bedtime may be useful. Duration of use should not exceed 3 weeks Footnote 21.

SECTION VI - LABORATORY HAZARDS

LABORATORY ACQUIRED INFECTIONS: No reported cases.

SOURCES / SPECIMENS: Human stool Footnote 1, food specimens Footnote 10, soil Footnote 7, Footnote 10.

PRIMARY HAZARD: Ingestion of contaminated material. B. cereus produces toxins that can be present in food and soil Footnote 10.

SPECIAL HAZARD: None.

SECTION VII – EXPOSURE CONTROLS / PERSONAL PROTECTION

RISK GROUP CLASSIFICATION: Risk Group 2.

CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures Footnote 24.

PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes Footnote 24.

OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities Footnote 24.

SECTION VIII – HANDLING AND STORAGE

SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant (1% sodium hypochlorite), starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up.

DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration Footnote 24.

STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labelled.

SECTION IX - REGULATORY AND OTHER INFORMATION

REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.

UPDATED: December 2011

PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada

Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright ©
Public Health Agency of Canada, 2011
Canada

REFERENCES:

Footnote 1
Murray, P. R., Baron, E. J., Jorgensen, J. H., Landry, M. L., & Pfaller, M. A. (Eds.). (2007). Manual of Clinical Microbiology (9th ed.) American Society of Microbiology Press.

Footnote 2
Logan, N. A., & Rodrigez-Diaz, M. (2006). Bacillus spp. and Related Genera. In S. H. Gillespie, & P. M. Hawkey (Eds.), Principles and Practice of Clinical Bacteriology (2nd ed., pp. 139-158). West Sussex, England, UK: John Wiley and Sons Ltd.

Footnote 3
Ray, C. G. (2004). Enteric Infections and Food Poisoning. In K. J. Ryan, & C. G. Ray (Eds.), Sherris Medical Microbiology (4th ed., pp. 857-865). USA: Mcgraw Hill.

Footnote 4
From, C., Pukall, R., Schumann, P., Hormazabal, V., & Granum, P. E. (2005). Toxin-producing ability among Bacillus spp. outside the Bacillus cereus group. Applied and Environmental Microbiology, 71(3), 1178-1183. doi:10.1128/AEM.71.3.1178-1183.2005

Footnote 5
Le Scanff, J., Mohammedi, I., Thiebaut, A., Martin, O., Argaud, L., & Robert, D. (2006). Necrotizing gastritis due to Bacillus cereus in an immunocompromised patient. Infection, 34(2), 98-99. doi:10.1007/s15010-006-5019-6

Footnote 6
Bayless, & Diehl (Eds.). (2005). Advanced Therapy in Gastroenterology and Liver Disease (5th ed.) BC Decker Inc.

Footnote 7
Rosovitz, M. J., Voskuil, M. I., & Chambliss, G. H. (1998). Bacillus. In L. Collier, A. Balows, M. Sussman, A. Balows & B. I. Duerden (Eds.), Topley & Wilson's Microbiology and Microbial Infection: Systematic Bacteriology (9th ed., pp. 709-729). USA: Arnold.

Footnote 8
Drobniewski, F. A. (1993). Bacillus cereus and related species. Clinical Microbiology Reviews, 6(4), 324-338.

Footnote 9
Avashia, S. B., Riggins, W. S., Lindley, C., Hoffmaster, A., Drumgoole, R., Nekomoto, T., Jackson, P. J., Hill, K. K., Williams, K., Lehman, L., Libal, M. C., Wilkins, P. P., Alexander, J., Tvaryanas, A., & Betz, T. (2007). Fatal pneumonia among metalworkers due to inhalation exposure to Bacillus cereus Containing Bacillus anthracis toxin genes. Clinical Infectious Diseases : An Official Publication of the Infectious Diseases Society of America, 44(3), 414-416. doi:10.1086/510429

Footnote 10
Kotiranta, A., Lounatmaa, K., & Haapasalo, M. (2000). Epidemiology and pathogenesis of Bacillus cereus infections. Microbes and Infection, 2(2), 189-198.

Footnote 11
Venkitanarayanan, K. S., & Doyle, M. P. (2008). Microbiological Safety of Foods. In C. D. Berdanier, J. Dwyer & E. B. Feldman (Eds.), Handbook of Nutrition and Food (2nd ed., pp. 37-67). USA: CRC Press.

Footnote 12
Barrie D, Wilson JA, Hoffman PN, Kramer JM. (1992). Bacillus cereus meningitis in two neurosurgical patients: an investigation into the source of the organism. J Infect., 25(3), 291-297.

Footnote 13
Jackson SG, Goodbrand RB, Ahmed R, Kasatiya S. (1995). Bacillus cereus and Bacillus thuringiensis isolated in a gastroenteritis outbreak investigation. Lett Appl Microbiol., 21(2), 103-105.

Footnote 14
David, D. B., Kirkby, G. R., & Noble, B. A. (1994). Bacillus cereus endophthalmitis. The British Journal of Ophthalmology, 78(7), 577-580.

Footnote 15
Majcher, M. R., Bernard, K. A., & Sattar, S. A. (2008). Identification by quantitative carrier test of surrogate spore-forming bacteria to assess sporicidal chemicals for use against Bacillus anthracis. Applied and Environmental Microbiology, 74(3), 676-681. doi:10.1128/AEM.01715-07

Footnote 16
Laboratory Safety Manual (1993). (2nd ed.). Geneva: World Health Organization.

Footnote 17
Cserhalmi, Z., Vidács, I., Beczner, J., & Czukor, B. (2002). Inactivation of Saccharomyces cerevisiae and Bacillus cereus by pulsed electric fields technology. Innovative Food Science and Emerging Technologies, 3(1), 41-45.

Footnote 18
Silva, M. T., & Sousa, J. C. (1972). Ultrastructural alterations induced by moist heat in Bacillus cereus. Applied Microbiology, 24(3), 463-476.

Footnote 19
Abostate, M. A. M., Zanran, D. A., & Hifnawi, H. N. (2006). Incidence of Bacillus cereus in Some Meat Products and the Effect of Gamma Radiation on Its Toxin(s). International Journal of Agriculture and Biology, 8(1)

Footnote 20
Faille, C., Lebret, V., Gavini, F., & Maingonnat, J. F. (1997). Injury and Lethality of Heat Treatment of Bacillus cereus Spores Suspended in Buffer and in Poultry Meat. Juornal of Food Protection, 60(5), 544-547.

Footnote 21
Bennett , B. B. (1998). Gastroenteritis. Medical Update for Psychiatrists, 3(4), 95-98.

Footnote 22
Liu SM, Way T, Rodrigues M, Steidl SM. (2000). Effects of intravitreal corticosteroids in the treatment of Bacillus cereus endophthalmitis. Arch Ophthalmol., 118(6), 803-806.

Footnote 23
Haase, R., Sauer, H., Dagwadordsch, U., Foell, J., & Lieser, U. (2005). Successful treatment of Bacillus cereus meningitis following allogenic stem cell transplantation. Pediatric Transplantation, 9(3), 338-341.

Footnote 24
Public Health Agency of Canada. (2004). In Best M., Graham M. L., Leitner R., Ouellette M. and Ugwu K. (Eds.), The Laboratory Biosafety Guidelines (3rd ed.). Canada: