The microbiological analysis includes:
1. Determination of the total microbal number. It assumes determination of the total number of colonies of various bacteria types, but its results can’t be the basis for precise estimation of pathogenic microbes presence in the sample. However, the high microbal number points to the overall bacterial contamination of the sample and high probability of pathogenic organisms.
2. Determination of bacteria of the Enterobacteriaceae group (enterobacteria). It assumes determination of bacteria groups which may entail infections of the gastrointestinal tract or other organs. The group of enterobacteria includes salmonellas, shigellas, echerichiae (coli bacilli), clebsiellae, enterobacteries, cerratia, protea, morganellae, providentiae and ierciniae.
The microbiological analysis is carried out in three stages:
1. Seeding—1 ml of the sample is applied on the plate and covered with a film.
2. Incubation means holding under a temperature set for each type of analysis (to determine the total microbal count—48 hours, to determine enterobacteria—24 hours). During the incubation period, bacteria are given the conditions for reproduction and for generation of distinct colonies which are easy to count.3. Counting is performed at the standard colonometer, or manually using the marking applied on the plate.