X hits on this document

PDF document

Chapter 8*: SANITARY INSPECTION AND MICROBIOLOGICAL WATER QUALITY - page 22 / 52

222 views

0 shares

0 downloads

0 comments

22 / 52

4. BHIB Incubation conditions 48 h at 45 ± 0.5 °C Reaction Growth = (+) 5. BHIB containing 6.5% NaCl Incubation conditions 48 h at 35 ± 0.5 °C Reaction Turbidity = (+) Final reaction

A (+) BEA with a (+) BHIB 45 °C (test number 4) = faecal streptococci; a (+) BEA with (+) BHIB 45 °C (test number 4) and (+) BHIB 6.5% NCI (test number 5) = enterococci

MF KF

Membrane filtration KF streptococcus agar

BEAA Bile esculin azide agar

BHIB

Brain heart infusion broth

APHA American Public Health Association

TTC BHIA BEA

Triphenyl-tetrazolium chloride Brain heart infusion agar Bile esculin agar

ISO 7899-2 is currently under revision; the new proposed version under the same ISO reference is given in Table 8.7 1

MF methods for conforms and E. Coli ISO DIS 9308-1 (ISO, 1997)1

MF methods for intestinal enterococci ISO DIS 7899-2 (ISO, 1999b)2

MPN methods for intestinal enterococci ISO DIS 7899-1 (96 wells) (ISO, 1999a)3

Isolation media

Isolation media

Isolation media

Slanetz-Bartley has the same formulation as m-Enterococcus but the latter already includes TTC 2

Table 8.7 Recently proposed modifications to ISO standard methods

For a standard test use a lactose TTC agar with Tergitol-7, incubate for 21 ± 3 h at 36 ± 2°C4; typical colonies will turn the medium yellow

For a rapid test use tryptone soya agar and incubate for 4-5 h at 36 ± 2°C4

Use a m-Enterococcus agar (Slanetz-Bartley) with a 1% sterile solution of TTC added to the cooled basal medium, incubate for 44 ± 4 h at 36 ± 2°C4; typical colonies are light and dark red

Use a medium with tryptose, nalidixic acid, TTC thallium acetate and MUD (MUD/SF medium); incubate for 36-72 h at 44 ± 0.5°C; fluorescence indicates intestinal enterococci

Document info
Document views222
Page views222
Page last viewedTue Jan 24 09:55:14 UTC 2017
Pages52
Paragraphs971
Words20468

Comments