The isolation of Gram-negative bacteria from some of the products is of serious concern. P. aeruginosa is an opportunistic pathogen with spoilage potential and E. coli is an indicator of fecal pollution. The mere presence of any of these two organisms renders the product unsafe for use. E. coli was isolated from one shampoo preparation whereas P. aeruginosa was isolated from all contaminated products except the hair conditioners. Most legislative authorities require the product to be free from specified microorganisms such as E. coli, S. aureus, and P. aeruginosa. This specification does not exempt manufacturers from protecting their products against other objectionable microorganisms with possible health risks and deterioration potentials (Sutton, 2006b). It is clear from Table 2 that many brands studied were out of specifications as certain named microorganisms were detected. According to the ISO standards these organisms should be absent. Objectionable microorganisms are product-related and it is the responsibility of
the manufacturing companies to establish what constitutes such a flora in a given product.