Sponge-Derived Kocuria and Micrococcus spp. as Sources of the New Thiazolyl Peptide Antibiotic Kocurin

Abstract

Forty four marine actinomycetes of the family Microccocaceae isolated from sponges collected primarily in Florida Keys (USA) were selected from our strain collection to be studied as new sources for the production of bioactive natural products. A 16S rRNA gene based phylogenetic analysis showed that the strains are members of the genera Kocuria and Micrococcus. To assess their biosynthetic potential, the strains were PCR screened for the presence of secondary metabolite genes encoding nonribosomal synthetase (NRPS) and polyketide synthases (PKS). A small extract collection of 528 crude extracts generated from nutritional microfermentation arrays was tested for the production of bioactive secondary metabolites against clinically relevant strains (Bacillus subtilis, methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumannii and Candida albicans). Three independent isolates were shown to produce a new anti-MRSA bioactive compound that was identified as kocurin, a new member of the thiazolyl peptide family of antibiotics emphasizing the role of this family as a prolific resource for novel drugs.

Diversity and Bioactivity of Marine Bacteria Associated with the Sponges Candidaspongia flabellata and Rhopaloeides odorabile from the Great Barrier Reef in Australia

“…The occurrence of specific genes involved in the reported production of secondary metabolites [45] was screened in all isolates. For all the heterotrophic bacteria (except the actinobacteria), degenerate primers MDPQQRf (5 -RTRGAYCCNCAGCAICG-3 ) and HGTGTr (5 -VGTNCCNGTGCCRTG-3 ) [45] were used to amplify the B-ketosynthase (KS) domain fragment within the Type I polyketide synthase genes (PKS-I).…”

“…For all the heterotrophic bacteria (except the actinobacteria), degenerate primers MDPQQRf (5 -RTRGAYCCNCAGCAICG-3 ) and HGTGTr (5 -VGTNCCNGTGCCRTG-3 ) [45] were used to amplify the B-ketosynthase (KS) domain fragment within the Type I polyketide synthase genes (PKS-I). Amplification of the non-ribosomal peptide synthetase (NRPS) gene was carried out using primers MTF (5 -CCNCGDATYTTNACYTG-3 ) and MTR (5 -GCNGGYGGYGCNTAYGTNCC-3 ) to amplify the conserved A domain [46].…”

Distribution of bacteria in the mineral waters of the Polish Lowlands

“…In ad dition, sev eral Staph y lo coc cus and Kocuria spe cies were also found in afore men tioned brines, but no Micrococcus rep re senta tives were ob served (Roohi et al, 2014). Halotolerant Actinobacteria, K. palustris and Micrococcus yunnanesis, found dur ing the pres ent study, were re ported to be iso lated from a ma rine sal tern of Goa (Ballav et al, 2015) and ma rine sponges Xestospongia muta of the Conch Reef, Florida (Palomo et al, 2013). Gammaproteobacteria were rare among the iso lates ob tained from stud ied brines and they were rep resented by rel a tives of two spe cies, Marinobacter lipolyticus and Pseudoalteromonas issachenkonii.…”

Scanning electron microscopy and antibiotic sensitivity of the actinobacterium, Kocuria sediminis DDK6

“…Furthermore, production of probiotics, bioactive and plantgrowth promoting compounds are examples of the beneficial roles of Kocuria spp. [10][11][12][13]. Nonetheless, certain members of the genus Kocuria are human pathogens such as K. kristinae [14], K. palustris [15], K. marina [16], K.rosea [17], indicating the spectrum of human infections is expanded.…”