Antimicrobial Potential and Phytochemical Screening of sp. 1 and () Sponge Crude Extracts Obtained from the South East Coast of South Africa.

Scientists have continuously searched for novel bioactive compounds to overcome the inherent problems associated with drug resistance, the evolution of unknown diseases, and the toxicity of currently used compounds. The ocean has been considered a rich source of compounds that possess unique chemical structures and novel biological capabilities. Biologically active molecules isolated from marine flora and fauna have shown significant advancement over the past century in the pharmaceutical industry. Marine natural products (MNPs) have been used as nanomedicine, cosmetics, wound healing, antimicrobial agents, anticancer agents, and anti-inflammatory agents. The physicochemical parameters of the collection site were also recorded. This study's marine sponge species were collected from Phillip's Reef, South Africa, at 12 m during the spring season. Ethyl acetate (EA) and dichloromethane : methanol (DCM : ME, 1 : 1) were used as extraction solvents. Crude extracts of the marine sponges were tested against MRSA, , , , and . Phytochemical screening was conducted to identify seven critical phytochemical groups. A pH reading of 8.01 and a temperature of 15.45°C were recorded at the sampling site. sp. 1 and () EA crude extracts showed bioactivity against all five test pathogens. The DCM : ME crude extract of sp. 1 was the only bioactive crude extract from DCM : ME extracts. This crude extract was only bioactive against as no activity was observed against the other four pathogens. EA crude extracts of sp. 1 yielded more significant inhibition zones against both fungal pathogens. These EA crude extracts performed better than fluconazole as inhibition zones of 35 ± 0 mm at 24 mg/ml, 31 ± 0 mm at 19 mg/ml, 31 ± 0 mm at 14.4 mg/ml, 30 ± 0 mm at 9.6 mg/ml, and 25 ± 0 mm at 7.2 mg/ml were recorded. sp. 1 crude extracts exhibited higher inhibition zones compared to () . The antibiotic imipenem (26 ± 0.7 mm at 10 g) and ciprofloxacin (30 ± 0.3 mm at 5 g) exhibited higher zones of inhibition than EA crude extracts of () at all test concentrations. In this study, sp. 1 was observed to have broad-spectrum bioactivity as EA crude extracts were bioactive against MRSA, , , , and . In addition to this, the EA crude extract of sp. 1 was bacteriostatic (9.6 mg/ml). sp. 1 DCM : ME crude extract only tested positive for the presence of terpenoids. In contrast, EA crude extracts did not test positive for the existence of any of the seven phytochemicals. Our study has revealed that () and sp. 1 sponge species collected from Phillip's Reef in South Africa can produce bioactive compounds useful against bacterial and fungal species.