Isolating Some Pathogenic Bacteria from Packed Milk and Detecting of Formalin in its Components

Aims: The main aims of thisstudyis to isolate pathogenic bacteria from packed milk in Basrah city, and to detect the presence of formalin in milk samples. Methodology:A total of 9types of packed milk were collected from the market in different period. The samples were transported to the laboratory in cooling conditions. They were stored in a refrigerator and analyzed within 24 hours. One ml from each sample was diluted in 9ml sterile distilled water, the diluted sample was a streak inoculated on chromogenic media. Three ml of milk sample was taken in a test tube and diluted with equal size of water. 5ml of sulfuric acid (90%) were added to the diluted milk slowly to the side of test tube which must handle with slant position in order to form separation layer. In case of formaldehyde presence a violet layer will form. This method detect of 1 part of formaldehyde in 200000 parts of milk Result: The result showed only Staphylococcus saprophyticus and Staphylococcus aureus have been isolated from milk samples (23.4 %) and (10.6 %) respectively. The result showed that high temperature not very effective since two pathogenic bacterial species have been isolated and formalin have been detected in milk samples. The result showed no effect of addition of formalin in some sample and did not inhibit the growth of bacteria. Conclusions: This study concludes that most of the packed milk under study contaminated with some pathogenic bacterial species, most of milk samples contained formalin.