Exploring actinobacteria isolated from coral originated from Tulamben Bali in inhibiting multidrug resistance bacteria

Abstract

Increasing bacterial resistance has reduced the effectiveness of most clinical antibiotics. The limited option of antibiotics to treat Multi-Drug Resistance pathogen infections indicates that there is an urgency to explore new antibiotic candidates. Coral is recognized to produce bioactive compounds that have the potential to develop new medicinal materials with antibacterial properties. The use of marine invertebrates for compound production will reduce populations in nature, therefore associated microbes are preferred due to their environmental friendliness. Actinobacteria is one of the coral-associated microbes capable of producing active compounds of secondary metabolites as antibacterials. This study aimed to identify coral and obtain isolates of Actinobacteria associated with coral potential as an antibacterial against MDR bacteria. This research uses an explorative method. The method used is coral identification based on the morphology and shape of the sclerite. Screening of antibacterial activity was carried out using the agar plug method, microscopic observation using Gram staining and molecular identification of potential isolates by PCR. The results showed that the coral genera obtained were Siphonogorgia sp., Menella sp., Echinomuricea sp., Dendronephthya sp., and Epizoanthus sp. The results of antibacterial activity indicated that 19 isolates inhibited the growth of MDR pathogen bacteria. However, only the potential isolates were identified. The microscopic observations showed isolate III.ISP2.10-2.3 and III.ISP2.10-2.6 have Gram-positive coccus and bacillus-shaped, respectively. Potential isolates III.ISP2.10-2.3 (Micrococcus yunnanensis) were found to have antibacterial activity against Acinetobacter baumanii, Pseudomonas aeruginosa, and Bacillus subtilis, while isolate III.ISP2.10-2.6 (Brevibacterium pigmentatum) had the greatest activity against B. subtilis.