Prevalence and characterisation of Bacillus cereus in cooked rice retailed in Ilara-mokin, Nigeria (original) (raw)
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International Journal of PharmTech Research, 2015
The aim of this study has been an investigation of the presence of Bacillus cereus and detection of enterotoxigenic genes in cooked rice samples through utilizing a PCR technique. In this study the providence of B.cereus was carried out to cooked rice samples and the B.cereus isolates were investigated for enterotoxigenic gene. The cooked rice samples were purchased from several restaurants in the area of (Bangi, Kajang and UKM) Selangor, Malaysia. A total of 70 samples have been analyzed. B. cereus contamination has been formed between 1.2 × 10 4 to 1.6 × 10 6 cfu/g cooked of 110 colonies of tentative B. cereus have been tested onto mannitol egg yolk polymyxin agar and Chromogenic Bacillus cereus Agar, and 35 colonies have been detected as B. cereus using biochemical test and partial sequence of 16s r DNA sequences analysis. The B. cereus isolates that are BC1 to BC35 have been distinguished for hemolytic enterotoxin (HBL complex encoding gene (hblD), and ematic (ces) gene toxin. 12 isolates have been reported to be positive towards hblD, None of the B. cereus isolates have been found positive towards ematic(ces) gene. Therefore, the presence of B. cereus and their enterotoxigenic genes in cooked rice samples can be regarded as a potential risk for public health.
2012
Sixty-four food samples of "cooked rice", "masa", "agidi" and "epiti" purchased from local markets in Obio-Akpor Local Government Area of Port Harcourt, Nigeria were examined microbiologically. Plate count analysis on mannitol egg-yolk bromothymol blue polymyxin B (MYP) agar revealed that "cooked rice" had the highest frequency of occurrence of Bacillus cereus isolates (29.51%), "masa" (26.23%), "agidi" (22.95%) and "epiti" had the least frequency of 21.31%. All Bacillus cereus isolates tested were found to be susceptible to rifampin (30µg), chloramphenicol (20µg), erythromycin (30µg), ciprofloxacin (10µg), streptomycin (30µg), gentamycin (10µg) and lincocin (30µg) and 100% resistance against norfloxapin (30ug), floxapen (30µg) and ampiclox (30µg). The study unveils the presence of Bacillus cereus in food samples sold in Port Harcourt especially in 'cooked rice" and "masa" which may po...
Journal of microbiology, biotechnology and food sciences, 2019
Food borne disease caused by Bacillus cereus has been a major health issue because of its ability to cause two syndromes: diarrhoeal and emetic which sometimes lead to death. Six hundred (600) samples of some retailed foods: cooked rice, jollof rice, fried rice, meat pie, smoked fish: African chad, Titus, blue whiting, fried meat, smoked hide, carrot, runner beans, cabbage and raw green pea were collected from the eight main markets in Ogun State. Serial dilutions of the samples were carried out and cultured on Mannitol Egg Yolk Polymyxin Agar (MYP) using the spread plate technique. B. cereus was confirmed with standard biochemical methods. Antibiotic susceptibility was performed by the Kirby – Bauer disc diffusion method with nine antibiotics. The mean microbial load in the retailed food was in the range of 1.00 x 104 – 8.92 x 104cfu/g. All the isolates were gram positive rods, catalase and citrate positive. Most of the isolates were motile (97.7%). Two hundred and twenty one (221)...
Enumeration, isolation and characterization of Bacillus cereus strains from Spanish raw rice
Food Microbiology, 2002
Bacillus cereus was present in 61 samples of raw rice analysed representing unhusked, husked and commercial origins. B. cereus in husked and white rice samples did not reach 10 2 cfu g À1 , while in the unhusked rice B. cereus densities exceeded 10 3 cfu g À1 . Processing steps such as drying, husking and polishing reduced the number of B. cereus in the ¢nal product. Eight strains with typical morphology of B. cereus on Polymyxin^Mannitol^EggYolk^Phenol Red Agar (PMYPA) were isolated. According to ISO con¢rmatory tests, the API System tests and supplementary tests of motility, oxidase activity and enterotoxin production, these isolates were characterized and identi¢ed as B. cereus. All strains were motile, oxidase-negative and produced diarrheal enterotoxin inTSB. D and z-values were used to characterize heat resistance of spores obtained from the eight strains of B. cereus characterized. A large diversity in heat resistance was observed among the isolates. At 901C, D-values ranged from 2?23 to 23?26 min, with ¢ve groups of D-value means signi¢cantly di¡erent at the 95% con¢dence level. D 95and D 100 values calculated for the eight strains ranged from 0?69 to 5?17 min and from 0?43 to 1?09 min, respectively. Statistical analysis revealed that there was signi¢cant di¡erence between the D-value means obtained for the strains at each temperature.The z-values for the eight strains of B. cereus tested in this study ranged from 7?421C to 8?201C with an average of 7?71C.
Prevalence of Bacillus cereus and Associated Risk Factors in Chinese-Style Fried Rice Available in the City of Colombo, Sri Lanka, 2012
The present study aimed to assess the prevalence of Bacillus cereus and its associated risk factors in Chinese-style fried rice available in Colombo city. In 200 samples of fried rice the prevalence of B. cereus was 56%. The prevalence by variety of fried rice was chicken (20.0%), vegetable (18.0%), seafood (10.0%), egg (5.0%), mixed (2.0%), and beef (1.0%). Of analyzed samples, 28 (14%) had colony counts > 10 6 colony forming units per gram (cfu/g), the infectious dose for B. cereus food borne outbreaks. Occurrence of > 10 6 cfu/g of B. cereus were associated with storage of boiled rice at room temperature (p = 0.030), > 4 hours of storage at room temperature (p = 0.042) and cooking frequency of more than once per dining session (p = 0.017). The type of rice and the quantity boiled per day were not independent risk factors for high B. cereus counts. Majority of B. cereus isolates (53.7%) in this study were not typable. The serotypes observed included H15 (14.3%), H19 (14.3%), and H20 (10.7%). These serotypes are known to be associated with both emetic and diarrheal syndromes. All isolates were sensitive to ciprofloxacin (100%), erythromycin (100%), gentamicin (100%), chloramphenicol (100%), and ami-kacin (100%) whereas 100% resistance was observed for penicillin with minimal inhibitory concentration range of 32-256 lg/mL.
Risk of Bacillus cereus in Relation to Rice and Derivatives
Foods, 2021
Rice is a very popular food throughout the world and the basis of the diet of the citizens of many countries. It is used as a raw material for the preparation of many complex dishes in which different ingredients are involved. Rice, as a consequence of their cultivation, harvesting, and handling, is often contaminated with spores of Bacillus cereus, a ubiquitous microorganism found mainly in the soil. B. cereus can multiply under temperature conditions as low as 4 °C in foods that contain rice and have been cooked or subjected to treatments that do not produce commercial sterility. B. cereus produces diarrhoeal or emetic foodborne toxin when the consumer eats food in which a sufficient number of cells have grown. These circumstances mean that every year many outbreaks of intoxication or intestinal problems related to this microorganism are reported. This work is a review from the perspective of risk assessment of the risk posed by B. cereus to the health of consumers and of some con...
Inactivation of Bacillus cereus Spores during Rice Cooking
Food Science and Technology Research, 2004
The D-values at 80, 90 and 100'C of Bacillus cereus spores (Philippine strain 1061) in 2% broth of Philippine rice cultivar PSB Rc72H were 38, 12 and 5 min, respectively. The Z-value of the test spore was 20'C. The mathematically calculated lethality for the Bacillus spores in rice cooked at 100'C was established to be 25 min, which could be adequately attained during normal rice cooking times of ~25 min by boiling.
Antibiograms of Bacillus cereus isolates from some Nigerian Foods
Nigerian Food Journal, 2007
Short Communication A total of 300 isolates of B cereus from nine of some Nigeria food were tested for their sensitivity to ten commonly used antibiotics. An average of 25 isolates were obtained per food sample. All B. cereus isolates tested were found to be susceptible to ciprofloxacin (5 mg), chloramphenicol (30 mg), ofloxacin (10 mg) and less than 10% were resistance to gentamicin (10 mg) and nalidixic acid (10 mg). Overall resistance to penicillin G (82%), cefotaxime (56.7%), ceftriaxone (53.3%) and ampicillin (44%) were most frequent, whereas isolates were least resistance to tetracycline (6.7%) nalidixic acid (3%) and gentamicin (1%). The predominant antimicrobial resistance patterns irrespective of food source were cefotaxime, penicillin, ampicillin and ceftriaxone (23%), penicillin (16.3) and cefotaxime, penicillin and ceftriaxone (10.3%).