Question

Bacillus cereus

1. What was the transmission pattern? How was this disease possibly transmitted to the patients?
2. What risk factor/s did the patients possess?
3. How could this disease be treated? Is there evidence of resistance?
4. How could this disease be prevented?

Answer 1

BACILLUS CEREUS

Bacillus cereus is a Gram-positive, rod-shaped, facultatively anaerobic, motile, beta-hemolytic, spore forming bacterium commonly found in soil and food. The specific name, cereus, meaning "waxy" in Latin, refers to the appearance of colonies grown on blood agar

MODE OF TRANSMISSION: The primary mode oftransmission is via the ingestion of B. cereuscontaminated food 1, 2: emetic type of food poisoning has been largely associated with the consumption of rice and pasta, while the diarrheal type is transmittedmostly by milk products, vegetables and meat.

cereus can be isolated from stools of asymptomatic people, but person-to-persontransmission does not occur. Confirmation of food poisoning requires isolation of B. cereusfrom stool or emesis in addition to isolation of B. cereus (105 colony-forming units/g) in contaminated food.

RISK FACTORS

In addition to food poisoning, B. cereuscauses a number of systemic and local infections in both immunologically compromised and immunocompetent individuals. Among those most commonly infected are neonates, intravenous drug abusers, patients sustaining traumatic or surgical wounds, and those with indwelling catheters.

TREATMENT

B. cereus produces beta-lactamases, unlike Bacillus anthracis, and so is resistant to beta-lactam antibiotics; it is usually susceptible to treatment with clindamycin, vancomycin, gentamicin, chloramphenicol, and erythromycin. Simultaneous therapy via multiple routes may be required.

EVIDENCE OF RESISTANCE

Isolate UFV-101 of Bacillus cereus was selected in previous studies for promoting growth inducing resistance in plants. In a previous study, supernatant from cultures of the microorganism in a liquid medium was found to induce resistance in tomato foliage against the pathogens Pseudomonas syringae pv. tomato, Xanthomonas vesicatoria, Alternaria solani and Corynespora cassiicola. In the present work the microorganism was grown in a minimal medium for 48 h and the cells precipitated for centrifugation. The supernatant was concentrated by lyophilization, dialyzed in a 12 kDa cut-off point membrane and fractioned in column containing Sephadex G25 balanced in PBS buffer. The fractions corresponding to a protein peak were applied to tomato seedlings. After four days leaflets were collected and inoculated with the pathogen. C. cassiicola. The numbers of lesions produced by the pathogen on leaflets exposed to the bacterial supernatant were similar to those exposed to acibenzolar-S-methyl but fewer than in those treated with water. It is concluded that the supernatant contained protein which induced resistance in the tomato leaves against C. cassiicola.

Bacillus cereus s.s. is typically resistant to penicillin and other β-lactam antibiotics [22] and can furthermore acquire resistance to commonly used antibiotics such as ciprofloxacin, cloxacillin, erythromycin, tetracycline and streptomycin [22, 23]. Foodborne illness associated with B

PREVENTION

Keep hot foods above 60°C and cold foods below 4°C to prevent the formation of spores. Wash hands, utensils, FCSs with hot soapy water after they touch raw meat or poultry, or before food preparation, and after using the bathroom.