The emergence of antibiotic resistant strains along with the increasing public health concern regarding infectious diseases and hospital-acquired infections has led to the necessity of finding viable alternatives to antibiotics.
Nature has been a source of compounds with interesting medicinal properties for millennia. For many decades, natural products have been a wealthy source of antimicrobials and more recently academic drug discovery in this research area has been accentuated, though pharmaceutical industries devote fewer resources to antimicrobial drug discovery programs, in comparison with their investment several decades ago.
Though, initially, the developments in drug discovery were aimed towards synthetic chemical libraries, nowadays they are also greatly used in the research of bioactive natural products, in order to keep up with the developments in similar areas. Moreover,
these developments allowed to overcome several problems associated with natural products drug discovery by using molecular techniques (i.e. genome mining) when organisms are not cultivable on the laboratorial environment. In this chapter, various examples of natural products with antimicrobial properties from marine organisms and plants are referred, highlighting their important and promising results against pathogenic bacteria, fungi, viruses and protozoa.
Keywords: Antibacterial, Antibiotics, Antifungal, Antiprotozoal, Antiviral, Bacteria, Bioactive molecules, Drug discovery, Fungi, Infectious diseases, Marine organisms, Natural products, Pathogenic microorganisms, Plants, Secondary metabolite.