Conventional Method for coliforms, fecal coliforms and E. coli
I.
Equipment and Materials
A.
Covered water bath, with circulating system to maintain temperature of 44.5 ±
0.2°C. The temperature for water baths for the shellfish program is 44.5°C ±
0.2°C. Water level should be above the medium in immersed tubes.
Immersion-type thermometer, 1-55°C, about 55 cm long, with 0.1°C subdivisions,
certified by National Institute of Standards and Technology (NIST), or equivalent
Incubator, 35 ± 0.5°C.
Balance with capacity of >2 kg and sensitivity of 0.1 g
Blender and blender jar (see Chapter 1)
Sterile graduated pipets, 1.0 and 10.0 mL
Sterile utensils for sample handling (see Chapter 1)
Dilution bottles made of borosilicate glass, with polyethylene screw caps
equipped with Teflon liners. Commercially prepared dilution bottles containing
sterile Butterfield's phosphate buffer can also be used.
Quebec colony counter, or equivalent, with magnifying lens
Longwave UV light [~365 nm], not to exceed 6 W.
pH meter
Media and Reagents
B.
Brilliant green lactose bile (BGLB) broth, 2% (M25)
Lauryl tryptose (LST) broth (M76)
Lactose Broth (M74)
EC broth (M49)
Levine's eosin-methylene blue (L-EMB) agar (M80)
Tryptone (tryptophane) broth (M164)
MR-VP broth (M104)
Koser's citrate broth (M72)
Plate count agar (PCA) (standard methods) (M124)
Butterfield's phosphate-buffered water (R11) or equivalent diluent
(Note: This same formulation is referred to as Buffered Dilution Water in American Public Health
Association. 1970. Recommended Procedures for the Examination of Seawater and Shellfish,
4th ed. APHA, Washington, DC., p14-15)