Streptomyces Isolates from the Soil of an Ancient Irish Cure Site, Capable of Inhibiting Multi-Resistant Bacteria and Yeasts

Traditional Irish medicines are often intertwined with ritual and spirituality, making it difficult to substantiate the validity of their claims. In this manuscript, we use molecular and microscopic techniques to investigate some microorganisms that might be responsible for the reputed healing properties of an ancient Irish soil cure known as the Blessed clay from a site in Boho in the West Fermanagh Scarplands. We previously reported the isolation of an antibiotic producing bacteria from this soil. In this report, we characterize the antibiotic activity of a further six isolates of Streptomyces from this source. Two of these isolates inhibit the growth of multi-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, two inhibit the growth of the yeast Starmerella bombicola, and two have as yet undetermined activity. Genetic analysis of these Streptomyces reveals the potential to synthesize varieties of antibiotics similar to cypemycin, griseochelin, macrolactams, and candicidin. From these observations, we suggest that part of the medicinal reputation of the Blessed clay may lie in the diversity of antimicrobial producing Streptomyces isolated from this soil. These findings highlight the potential for antibiotic discovery in this area.