Recent findings of molecules with anti-infective activity: screening of non-conventional sources

In recent years, the number of pathogenic microorganisms resistant to antibiotics has increased alarmingly. For the next 10-20 years, health organizations forecast high human mortality caused by these microorganisms. Therefore, the search for new anti-infectives is quite necessary and urgent. Traditionally, antibiotic-producing microorganisms have been isolated from common soil samples. However, this source seems to be exhausted considering the very few examples of antibiotic-producing microorganisms reported recently. In this review, non-conventional sources of anti-infective producing microorganisms are presented as a possible way to look for new and more effective compounds. These sources included arid soils, caves, areas with high temperatures (hot springs), high salinity or oceans and seas. Finally, other non-conventional sources of antibiotics reviewed are animal and invertebrate venoms, among others.