Specific detection of Aspergillus parasiticus in wheat flour using a highly sensitive PCR assay.
Aspergillus parasiticus is one of the most important aflatoxin-producing species that contaminates foodstuffs and beverages for human consumption. In this work, a specific and highly sensitive PCR protocol was developed to detect A. parasiticus using primers designed on the multicopy internal transcribed region of the rDNA unit (ITS1-5.8S-ITS2 rDNA). The assay proved to be highly specific for A. parasiticus when tested on a wide range of related and other fungal species commonly found in commodities, and allowing discrimination from the closely related A. flavus. Accuracy of detection and quantification by conventional PCR were tested with genomic DNA obtained from wheat flour artificially contaminated with spore suspensions of known concentrations. Spore concentrations equal or higher than 10(6) spore/g could be detected by the assay directly without prior incubation of the samples. The assay described is suitable for incorporation in routine analyses at critical points of the food chain within HACCP strategies.
Sardiñas
Noelia
N
Departamento de Microbiologia III, Facultad de Biologia, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Vázquez
Covadonga
C
Gil-Serna
Jessica
J
González-Jaen
M Teresa
MT
Patiño
Belén
B
D000348:Aflatoxins / Q000032:analysis / Q000235:genetics; D001230:Aspergillus / Q000235:genetics* / Q000302:isolation & purification*; D001939:Bread / Q000382:microbiology; D005433:Flour / Q000382:microbiology*; D005502:Food / Q000592:standards*; D020387:Food Chain; D005506:Food Contamination / Q000517:prevention & control; D001467:Hordeum / Q000382:microbiology; D006801:Humans; D009754:Nuts / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D012988:Soil Microbiology; D014908:Triticum / Q000382:microbiology*; D027843:Vitis / Q000382:microbiology
D000348:Aflatoxins