Natural products from Eastern Australian marine invertebrates; A source of drug-like molecules with Staphylococcus aureus inhibitory

Abstract

Bacteria that cause diseases in humans can rapidly acquire resistance to the antibiotics that are used to eradicate them. As a result of the use and misuse of antibiotics, the number of multidrug resistant (MDR) bacterial strains is on the rise. Over the last thirty years the number of new antibiotics introduced to treat human infections has declined, this observation in combination with rising incidence of MDR bacterial strains have resulted in an urgent need to discover new antibiotics. Of the antibiotics that we currently use, the majority were originally isolated from, or derived from natural sources. The primary focus of this study is the identification of novel natural products, which are bioactive against Staphylococcus aureus. To achieve this, a collection of 500 marine invertebrates, consisting predominantly of sponges, ascidians and bryozoans, were screened against S. aureus. The marine invertebrates were collected from the northern New South Wales region of Australia. The marine invertebrate biodiversity of this region is poorly understood, and thus knowledge relating to their chemistry is virtually non-existent. As a result of this lack of knowledge it was expected the majority of isolated bioactive compounds would be novel. Purified compounds were screened against a suite of S. aureus strains to assess inter-strain resistance/inhibition variations. This presentation will report on the bioactivity, chemistry and selectivity of marine natural products isolated as part of this study.