Quality control of Aspergillus flavus and A. parasiticus agar and comparison with dichloran 18% glycerol agar: a collaborative study.
AFPA culture medium, which is used for recognition of Aspergillus flavus and A. parasiticus, has been validated in a collaborative study including nine laboratories located in Australia, Brazil, Denmark, The Netherlands, Sweden and United Kingdom. Three freeze-dried fungal mixtures, containing A. flavus/A. parasiticus and background fungi, were produced and checked for homogeneity. The coefficients of variance were low, ranging from 0.81% to 1.09% for total fungal counts and between 2.50% and 2.72% for counts of A. flavus/A. parasiticus. The laboratories analysed the contents of two vials of each mixture on commercial A. flavus and A. parasiticus agar (AFPA), in-house-made AFPA, and on a standard media, dichloran 18% glycerol agar (DG18). Reproducibility values for counts of A. flavus/A. parasiticus indicated no differences between the commercial AFPA and the in-house-made AFPA. Variation between laboratories was low, indicating that the medium was effective in use. Reproducibility values for DG18 were higher. There were no differences in counts of A. flavus/A. parasiticus on AFPA and DG18. However, DG18 gave slightly higher total fungal counts compared to AFPA.
Microbiology Division, National Food Administration, Box 622, SE-751 26 Uppsala, Sweden.
Emma
E
Frändberg
John
J
Pitt
Monica
M
Olsen
D000362:Agar; D000814:Aniline Compounds / Q000494:pharmacology*; D001230:Aspergillus / Q000254:growth & development* / Q000302:isolation & purification; D001231:Aspergillus flavus / Q000254:growth & development / Q000302:isolation & purification; D001431:Bacteriological Techniques; D015169:Colony Count, Microbial; D003470:Culture Media / Q000737:chemistry / Q000592:standards*; D005990:Glycerol / Q000378:metabolism; D007391:International Cooperation; D011786:Quality Control; D015203:Reproducibility of Results
D000814:Aniline Compounds; D003470:Culture Media; D000362:Agar; C004354:dicloran; D005990:Glycerol