Marine Sediment Recovered Salinispora sp. Inhibits the Growth of Emerging Bacterial Pathogens and other Multi-Drug-Resistant Bacteria

Abstract

Marine obligate actinobacteria produce a wide variety of secondary metabolites with biological activity, notably those with antibiotic activity urgently needed against multi-drug-resistant bacteria. Seventy-five marine actinobacteria were isolated from a marine sediment sample collected in Punta Arena de La Ventana, Baja California Sur, Mexico. The 16S rRNA gene identification, Multi Locus Sequence Analysis, and the marine salt requirement for growth assigned seventy-one isolates as members of the genus Salinispora, grouped apart but related to the main Salinispora arenicola species clade. The ability of salinisporae to inhibit bacterial growth of Staphylococcus epidermidis, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacer baumannii, Pseudomonas aeruginosa, and Enterobacter spp. was evaluated by cross-streaking plate and supernatant inhibition tests. Ten supernatants inhibited the growth of eight strains of S. epidermidis from patients suffering from ocular infections, two out of the eight showed growth inhibition on ten S. epidermidis strains from prosthetic joint infections. Also, it inhibited the growth of the remaining six multi-drug-resistant bacteria tested. These results showed that some Salinispora strains could produce antibacterial compounds to combat bacteria of clinical importance and prove that studying different geographical sites uncovers untapped microorganisms with metabolic potential.

Marine Actinobacteria a New Source of Antibacterial Metabolites to Treat Acne Vulgaris Disease—A Systematic Literature Review

“…Regarding the nitrogen source, the most common were yeast extract–peptone [ 81 , 94 , 102 ], yeast–malt extract [ 20 , 38 , 145 ], potassium nitrate [ 10 , 40 , 146 ], ammonium compounds as ammonium sulfate [ 147 ], ammonium chloride [ 79 ], ammonium nitrate [ 114 ], and casein [ 22 , 43 , 148 ] as shown in Figure 6 B. The quenching potential also has been subjected to optimization processes to maximize its performance, finding that soybean meal and sodium chloride were two crucial factors in the culture medium that significantly increased both the bioactivity and metabolite production (302 and 241%, respectively) when compared to the original condition [ 29 ].…”

Marine Bacterial Secondary Metabolites: A Treasure House for Structurally Unique and Effective Antimicrobial Compounds

“…A total of seventy-one isolates were confirmed belonging to the genus Salinispora by 16S rRNA gene identification and multilocus sequence analysis. They subsequently evaluated the antibacterial potential of supernatants from several Salinispora strains, revealing that supernatants from ten Salinispora strains had excellent growth inhibition activity against ESKAPE pathogens [86]. Similarly, in another study, a total of 148 Actinobacteria were isolated from Diu Island's intertidal sediments in the Arabian Sea [79].…”

On the Selective Isolation of Actinobacteria from Different Mexican Ecosystems

“…Molecular identification of strain C6-CCA-May-1 was carried out following protocols previously published [8,24]. First, the DNA of strain C6-CCA-May-1 was extracted and used as a template for PCR amplification using the 16S rRNA gene (Appendix B).…”

“…In the present project, a total collection of 34 marine sediments or sponges were collected at RANP during two expeditions (December 2017 and January 2018). A selective isolation strategy using 11 of the marine sediments and two different media was developed following a previously reported study [24]. In order to isolate marine obligate and nonobligate actinobacteria, 1 g of wet sediments was transferred to tubes containing 9 mL of saline solution (0.9%; NaCl; Sigma-Aldrich, Mexico), four dilutions were prepared (10 À1 to 10 À4 ) and 100 μL (Gilson, France) of each dilution were spread onto marine GYM medium and 1:10 marine GYM medium (Appendix A); both media supplemented with Rifampicin [15, 25 and 50 μg/mL] and Nystatin (100 μg/mL).…”

“…To isolate obligate and nonobligate marine actinobacteria from the sponge samples, five different species of Aplysina (A. airapii, A. clathrata, A. encarnacionae, A. gerardogrenii, and A. sinuscaliforniensis) were selected. The selective isolation strategy was based on that previously reported by [3,24]. Ten grams of each sponge were transferred into 90 mL of saline solution that was previously added to a plastic bottle with a wide mouth (Figure 7).…”