Effect of <i>Coptis chinensis</i> on Biofilm Formation and Antibiotic Susceptibility in <i>Mycobacterium abscessus</i>

Abstract

<i>Mycobacterium abscessus</i> infections are notoriously difficult to be treated and newer treatment options are required. <i>Coptis chinensis</i> (<i>C. chinensis</i>) and its main compound berberine are frequently used to treat bacterial and viral infections. In this study, the susceptibility of <i>M. abscessus</i> to <i>C. chinensis</i> extract and berberine was assessed by minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) evaluation. The effects of <i>C. chinensis</i> and berberine on biofilm formation and antibiotic susceptibility in <i>M. abscessus</i> were observed. <i>C. chinensis</i> at concentrations of MIC (1.5 mg/mL) and 2 × MIC (3.0 mg/mL) and berberine at ½ × MIC (0.125 mg/mL) demonstrated a strong inhibition of biofilm formation. Concentration of <i>C. chinensis</i> at ½ × MIC resulted in a significant reduction in MICs of trimethoprim/sulfamethoxazole (TMP/SXT), clarithromycin (CLA), and linezolid (LZD). Similarly, ½ × MIC berberine had a significant effect on the MIC reductions of nine antibiotics including TMP/SXT, CLA, and LZD. Notably, the resistance level MIC of LZD against <i>M. abscessus</i> was reversed to a susceptible level by treatment with either <i>C. chinensis</i> or berberine. Therefore, <i>C. chinensis</i> and berberine have the potential to produce a synergistic antimycobacterial effect, reduce biofilm formation, and decrease antibacterial resistance to LZD in <i>M. abscessus</i>.