Abstract
The problem of multidrug-resistant pathogens as bacteria, fungi and yeast in addition to the restriction of using antibiotics as growth promoting substances in feed has attracted attention for looking for alternative sources instead of conventional antibiotics like natural products which have antimicrobial activity. Much interest and researches have been focused on using natural antimicrobial peptides and chemicals extracted from animal secretions and some insect’s venoms as they exhibit antimicrobial activity against pathogens with lower resistance and higher synergistic effects if they were given in combination with blends of them. In this paper, some antibacterial peptides extracted from honeybees venom and expression with yeast Saccharomyces cerevisiae will be discussed as well as antimicrobial chemicals extracted from giraffes in addition to their inhibitory effects on liver microsomal enzymes CYP450 will be discussed also with its activity against microorganisms which are Agrobacterium rhizogenes, Aspergillus niger, Candida albicans and E. coli using optical density analysis technique then their minimum inhibitory concentrations (MIC) will be determined as well as ICs 50 to measure the potency to inhibit a biological function using programmes like Gene5, graph pad prism and clone manager as well as testing antimicrobial activity of some chemicals which are provided in animal secretions.