A Screen of Traditional Chinese Medicinal Plant Extracts Reveals 17 Species with Antimicrobial Properties

Antimicrobial resistance (AMR) is a growing threat that undermines the effectiveness of global healthcare. The Centers for Disease Control and Prevention and the World Health Organization have identified numerous microbial organisms, particularly members of the ESKAPEE pathogens, as critical threats to global health and economic security. Many clinical isolates of these pathogens have become completely resistant to current antibiotics, making treatment nearly impossible. Herbal remedies, such as those found in Traditional Chinese Medicine (TCM), have been practiced for thousands of years and successfully used to treat a wide range of ailments, including infectious diseases. Surprisingly, despite this extensive knowledge of folk medicine, no plant-derived antibacterial drugs are currently approved for clinical use. This study explores a comprehensive library comprising 664 extracts from 132 distinct TCM plant species for antimicrobial properties against gram-negative (Escherichia coli) and gram-positive (Micrococcus luteus) bacteria using liquid and solid in vitro assays. Intriguingly, our results reveal 17 plant species with potent antimicrobial properties effective primarily against gram-positive organisms, including Streptococcus aureus and epidermidis. Our results indicate that phytobiotics from the identified plants may be potential candidates for novel antimicrobials.