Jepri Agung Priyanto, Muhammad Eka Prastya, Egiyanti Nur Widhia Hening, Erma Suryanti, Rhesi Kristiana
Methicillin-resistant Staphylococcus aureus (MRSA) is considered a priority pathogen causing high mortality that requires effective control measures. This study aimed to detect the presence of antibiotic-biosynthetic genes and to evaluate the anti-MRSA activity of two strains of endophytic Bacillus velezensis isolated from Archidendron pauciflorum. PCR-based screening showed that B. velezensis strains, such as DJ4 and DJ9 possessed six antibiotic-biosynthetic genes, namely MlnA, DhbE, BacD, DfnD, SrfA, and BaeR. According to the preliminary test conducted using disc-diffusion assay, metabolite extracts from these strains have anti-MRSA activity with clear zone diameters of 13.00 ± 0.82 mm, and 17.33 ± 0.47 mm, respectively. Extract from DJ9 strain was more active to MRSA, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 62.50 µg/mL and 250 µg/mL, respectively. Furthermore, a bactericidal effect was observed, as evidenced by MBC/MIC ratio of four. Both DJ9 and DJ4 extracts showed a dose-dependent inhibitory effect on MRSA biofilm formation. Furthermore, a maximum inhibition percentage of 60.12 ± 2.5% was shown by DJ9 extract in two-fold MIC. The corresponding extract disrupted MRSA mature biofilms most effectively at 55.74 ± 1.4%. In conclusion, crude extract, particularly the DJ9 strain had significant potential in inhibiting MRSA cell growth, MRSA biofilm formation, and disrupting MRSA mature biofilm in vitro. © Association of Microbiologists of India 2024.
Division of Microbiology, Department of Biology, Faculty of Mathematics and Natural Sciences, IPB University, Agatis Street, IPB Dramaga Campus, West Java, Bogor, 16680, Indonesia; Research Center for Pharmaceutical Ingredients and Traditional Medicine, National Research and Innovation Agency (BRIN), Kawasan Sains Dan Teknologi (KST) B.J Habibie (PUSPIPTEK), Serpong, Banten, South Tangerang, Indonesia; Department of Biology, Faculty of Sciences, Sumatera Institute of Technology, Lampung Selatan, Lampung, Indonesia; Indonesian Marine Education and Research Organisation (MERO) Foundation, Br. Dinas Muntig, Bali, Indonesia