Indicator paper systems for identification of microorganisms Sets No. 3, No. 4
for sanitary-bacteriological analysis of water
Form of issue
NIB-disks with lactose of 9-10 mm in diameter are released in vials, NIB-disks for determination of oxidase with a diameter of 35 mm are produced in bags of light-proof paper packed in a package of a film of metallized. SIB strips for the determination of oxidase width of 7-8 mm, length 70-80 mm are released in test tubes in opaque packaging.
Composition
Indicator paper systems (NIBs) for the identification of microorganisms are discs or strips of chromatographic paper containing certain amounts of a substrate in combination with an indicator stabilized by a film-forming coating - polyvinyl alcohol.
Sets are completed in cardboard packs. Kit number 3 includes: 1 bottle of SIB with lactose of 50 disks and 1 tube - NIB for determination of oxidase by 5 strips with instructions for use. Kit number 4 includes: 1 bottle of NIB with lactose of 50 disks and 1 packet - NIB for determination of oxidase by 50 disks with instructions for use.
Set No. 3 and Kit No. 4 provide 50 tests.
Indications for use
Identification of total and thermotolerant coliform bacteria in the control of water quality.
SET 3
NIB for determining the coliform index of water (from 2 tests).
Used for sanitary-bacteriological quality control of drinking water - determining the presence in water of bacteria of the Enterobacteriaceae family by a titration method. It allows to determine the following biochemical properties: glucose utilization and the presence of oxidase.
SET № 4
NIB for sanitary-bacteriological analysis of water (from 3 tests).
They are used for sanitary-bacteriological quality control of drinking water - determination in water of bacteria of the Enterobacteriaceae family and thermotolerant coliform bacteria by membrane filtration.
Allows to determine the following biochemical properties: the utilization of glucose and lactose, the presence of oxidase.
Dosage regimen and method of administration
The basic requirements for working with NIB:
- studies are conducted with colonies grown on a dense Endo culture medium or on a membrane filter placed after filtering on Endo's medium;
- immersion of discs in test tubes is made with burnt tweezers;
- to obtain clear results, it is necessary to comply with the temperature regime of the thermostat (37 ± 1) ° C and (44 ± 1) ° C, the pH of the nutrient medium used and the treatment of the dishes.
Determination of oxidase activity.
Streaked or on a membrane filter.
a) A stroke. A strip or disk of SIB for oxidase is placed in a Petri dish and
moistened with sterile distilled water. Part of the colony under investigation with a glass rod or platinum loop is applied to the NIB for the determination of oxidase.
A positive reaction occurs within 30-60 seconds. If a poorly defined result is obtained when examining the dark-red colony, the culture is transferred from the Endo medium to nutrient agar, incubated at a temperature of (37 ± 1) ° C for 3-6 hours, and the sample is repeated.
On one strip or disk, no more than 10-14 colonies can be examined.
b) On the membrane filter.
The membrane filter, after the end of filtration, is transferred to a dense Endo culture medium. Incubate at a temperature of (37 ± 1) ° C for 22-24 hours. The disk of SIB for oxidase is placed in a petri dish and moistened with sterile distilled water. On it, tweezers are placed, without turning, a membrane filter with the colonies growing on it. The rate of manifestation of the reaction is not the same when using membrane filters of different brands. No later than 5 minutes after the appearance of signs of a positive reaction, the membrane filter is transferred back to the Endo medium. The result is taken into account after a clear reaction.
Determination of the nature of lactose fermentation.
In sterile tubes with 1 ml of 0.5% peptone water or a nutrient broth pH 7.3 ± 0.2 loops, the remainder of the oxidase-negative colonies examined by the stroke or the selected oxidase-negative colonies are suspended. Subsequently, NIB disks with lactose are immersed. The medium in the test tubes becomes red as a result of the diffusion of the indicator into it. To account for the formation of gas in a test tube, place a small lump of sterile absorbent cotton. As a control, SIB disks with lactose are immersed in sterile tubes with 1 ml of 0.5% peptone water or a nutrient broth pH 7.3 ± 0.2.
a) In determining the total coliform bacteria, the cultures are incubated at a temperature of (37 ± 1) ° C. In the presence of a clear positive reaction, the result can be taken into account after 4-6 hours. If the reaction is negative, test tubes with crops are examined after 24 hours. The final record of the negative result is made after 48 hours.
b) In the determination of thermotolerant coliform bacteria, the crops are made into a medium with NIB-lactose preheated to a temperature of (44 ± 1) ° C. It is then incubated at a temperature of (44 ± 1) ° C. In the presence of a clear positive reaction, the result can be taken into account after 4-6 hours.
