Biotechnology and Bioinformatics (1+1)

6.4.4 Safety and evaluation of probiotics

The gene ral concept that the use of probiotics in aquaculture may produce various beneficial effects has been proven beyond doubt. The scientific application of this concept to hydrobionts health and disease, although still in its infancy, has already produced some positive results. However, safety considerations neglected for a long time are now taken into account for the development and marketing of probiotics. Safety is the state of being certain that adverse effects will not be caused by an agent under defined conditions.

New species and more specific strain s of probiotic bacteria are constantly identified. It cannot be assumed that these novel probiotic organisms share the historical safety of tested or traditional strains. Prior to incorporating them into products, new strains should be carefully assessed and evaluated for both safety and efficacy. In addition, Probiotic manufacturers should apply modern molecular techniques to ensure that the species of bacteria used in their products are correctly identified, for quality assurance as well as safety.
Lactic acid bacteria treated as probiotics are generally considered to be non-pathogenic. However, a growing number of diseases that appeared with the worldwide development of aquaculture may be assigned to distinct bacteria belonging to the genera Streptococcus, Lactococcus, Vagococcus and Cornybacterium.

Therefore, the safety profile of a potential probiotic strain is of critical importance in the selection process. This testing should include the determination of strain resistance to a wide variety of common classes of antibiotic s such as tetracyclines, quinolones and macrolides and subsequent confirmation of non-transmission of drug resistance genes or virulence plasmid s. Evaluation should also take the end-product formulation into consideration because this can induce adverse effects in some subjects or negate the positive effects altogether.