Investigating the anti-growth, anti-resistance, and anti-virulence activities of Schoepfia schreberi J.F.Gmel. against the superbug Acinetobacter baumannii.

Schoepfia schreberi has been used in Mayan folk medicine to treat diarrhea and cough. This study aimed to determine the anti-growth, anti-resistance, and/or anti-virulence activities of S. schreberi extracts against Acinetobacter baumannii, a pathogen leader that causes healthcare-associated infections with high rates of drug-resistant including carbapenems, the last line of antibiotics known as superbugs, and analyze their composition using HPLC-DAD. Ethyl acetate (SSB-3) and methanol (SSB-4) bark extracts exhibit antimicrobial and biocidal effects against drug-susceptible and drug-resistant A. baumannii. Chemical analysis revealed that SSB-3 and SSB-4 contained of gallic and ellagic acids derivatives. The anti-resistance activity of the extracts revealed that SSB-3 or SSB-4, combined with imipenem, exhibited potent antibiotic reversal activity against A. baumannii by acting as pump efflux modulators. The extracts also displayed activity against surface motility of A. baumannii and its capacity to survive reactive oxygen species. This study suggests that S. schreberi can be considered a source of antibiotics, even adjuvanted compounds, as anti-resistant or anti-virulence agents against A. baumannii, contributing to ethnopharmacological knowledge and reappraisal of Mayan medicinal flora, and supporting the traditional use of the bark of the medicinal plant S. schreberi for the treatment of infectious diseases.