This standard specifies the methods to examine the Shigella in foods.
This standard is applicable to the examination of Shigella in foods.
2 Apparatus and Materials
In addition to the conventional sterilization and cultivation apparatus in the microbiological laboratory, other apparatus and materials needed for the examination are as follows:
a) Thermostatic incubator: 36℃±1℃;
b) Refrigerator: 2℃~5℃;
c) Membrane filter system;
d) Anaerobic cultivation device: 41.5℃±1℃;
e) Electronic balance: sensibility of 0.1g;
f) Microscope: 10×~100×;
g) Homogenizer;
h) Oscillator;
i) Sterile pipette: 1mL (with 0.01mL scale), 10mL (with 0.1mL scale) or micropipettor and sucker head;
j) Aseptic homogenizing cup or aseptic homogenizing bag: 500mL;
k) Sterile Petri dish: diameter of 90 mm.
l) PH meter or pH colorimetric tube or precise pH paper;
m) Full automatic biochemical identification system of microorganisms.
3 Culture Medium and Reagents
3.1 Enriched Shigella broth - novobiocin: see A.1 in Appendix A.
3.2 MAC agar: see A.2 in Appendix A.
3.3 XLD agar: see A.3 in Appendix A.
