Materials and Methods
Twenty-one sample of various food products (Table
1), including 7 samples of cheese, 3 raw meat and fish
products, 5 ready-to-eat meat and chicken products, one
spice and one dried fruit mixture, obtained from retail
outlets, as well as wholesalers, were tested. All products
had been properly stored or refrigerated and tested before
their respective ’sell-by’ dates. One evaluated meat
sample was artificially inoculated.
Five presumptive positive Listeria monocytogenes colonies
from previously tested products similar to products
in Table 1 were also evaluated. These colonies were
taken from RAPID’L. mono (Biorad, France) plates. When
performing these tests, the colony served as a sample
and no food product was added.
Confirmation of Listeria species, i.e. L. monocytogenes
and L. ivanovii, by means of API Listeria (bioMérieux) was
performed according to manufacturer’s instructions.
Inocula of the controls used in the PCR reaction, i.e.
L. monocytogenes UWC1 (positive control), L. ivanovii
UWC1 and Bacillus cereus UWC1 (negative controls), were
prepared by inoculation of a loopful of glycerol stock
culture into 5 mL of brain-heart infusion (BHI) broth (Oxoid
CM025) and incubated in a shaking incubator at 37
°C for 18–24 h.
Listeria monocytogenes presumptively positive colonies
on RAPID’L. mono agar, i.e. blue colonies, were
subcultured on nutrient agar (Oxoid CM1) and incubated
at 37 oC for 18–24 h. A loopful of this growth was
used to inoculate BHI broth.
- 山伯兄Lv 51 decade agoFavorite Answer
Api 李斯特菌己經確定的品系有李斯特單胞菌和L. ivanovi是根據API Listeria (bioMérieux)公司.
, L. ivanovii UWC1和Bacillus cereus UWC1(陰性對照),使用loop接種在5ml的brain-heart infusion (BHI) broth (OxoidCM025)並振盪18-24小時37度.
李斯特單胞菌 根據推定陽性菌種在RAPID’L. mono培養基,例如藍色的菌種,在營養培養基次培養(Oxoid CM1)在37度18-24小時.用loopfu接種在BHI broth.