Screening of antibiofilm activity and toxicity assay of methylotrophic bacteria compounds isolated from the human mouth

Abstract

Biofilm is a community consisting of one or more species of bacteria attached to a surface using a matrix. Biofilms can cause health problems in humans, such as dental plaque. Biofilm is one form of self-defense of bacteria against antibiotics, so biofilm often has implications for the rise in resistance of bacteria. Therefore, antibiofilm compounds can be used to increase the sensitivity of bacteria to the antimicrobial agent. The purpose of this study is to determine the antibiofilm activity and the potential toxicity of the methylotrophic bacteria compound isolated from the human mouth. Based on the results of the study, 21 out of 37 isolates of methylotrophic bacteria had antibiofilm activity using two different supernatant concentrations (5% and 10%). The isolate of M28L2 showed the highest anti-biofilm inhibition activity: 47.64% against EHEC and 50.97% against Pseudomonas aeruginosa ATCC 27583. Meanwhile, M30G1 isolate showed the highest anti-biofilm destruction activity: 44.062% against EHEC and 39.17% against ETEC. Toxicity test was performed on five isolates that had the highest antibiofilm activity using a lethal dose test. Based on these test results, five isolates had LC50 values greater than 1000μg/mL, indicating that the compound was not toxic. Subsequently, PCR amplification for the DNA sequencing stage was performed on one isolate, M28L2. Based on the sequencing results, M28L2 had a 99% similarity to Pseudomonas stutzeri.