Immunoassay and polymerase chain reaction techniques for detection of enterotoxigenic Bacillus cereus.
OBJECTIVE
To compare the Reverse Passive Latex Agglutination (RPLA) and Enzyme Linked Immunosorbent Assay (ELISA) techniques with a Polymerase Chain Reaction (PCR) for detection of enterotoxigenic Bacillus cereus.


METHODS
A cross-sectional study.


METHODS
The Department of Public Health, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi.


METHODS
Forty seven Bacillus cereus strains previously isolated from foods.


METHODS
Detection of hemolysin BL, non-hemolytic enterotoxin, binding protein gene (hblA) of the hemolysin BL, and binding protein gene (nheA) of nonhemolytic enterotoxin.


RESULTS
Twenty five (53.2%) of the isolates produced hemolysin BL, while 81% of them produced non-hemolytic enterotoxin. Thirty eight (38.3%) produced both hemolysin BL and non-hemolytic enterotoxin. A polymerase chain reaction amplification assay detected the presence of hblA gene in all hemolysin BL positive isolates and nheA gene in 91.5% of non-hemolytic enterotoxin positive isolates. There was a strong association between PCR test and RPLA test (Pearson's X2 = 12.65; p < 0.001) as well as between PCR test and visual immunoassay test (Pearson's chi-square X2 = 18.46: p < 0.01).


CONCLUSIONS
Polymerase chain reaction amplification assay technique for detection of enterotoxigenicity of B. cereus compare well with the immunoassay tests. The technique is sensitive detecting even strains with silentgenes, and is rapid with the test complete within 24 hours.
Ombui
J N
JN
Department of Public Health, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, P.O. Box 29053, Nairobi, Kenya.
Nduhiu
J G
JG
Macharia
J K
JK
D001409:Bacillus cereus / Q000302:isolation & purification*; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005516:Food Microbiology; D006801:Humans; D007841:Latex Fixation Tests / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*