Vancomycin Derivative Inactivates Carbapenem-Resistant Acinetobacter baumannii and Induces Autophagy

Vancomycin is a standard drug for the treatment of multidrug-resistant Gram-positive bacterial infections. Albeit, development of resistance (VRE, VRSA) and its inefficacy against persistent infections is a demerit. It is also intrinsically inactive against Gram-negative bacteria. Herein, we report a vancomycin derivative, VanQAmC(10), that addresses these challenges. VanQAmC(10), was rapidly bactericidal against carbapenem-resistant A. baumannii (6 log(10) CFU/mL reduction in 6 h), disrupted A. baumannii biofilms, and eradicated their stationary phase cells. In MRSA infected macrophages, the compound reduced the bacterial burden by 1.3 log(10) CFU/mL while vancomycin exhibited a static effect. Further investigation indicated that the compound, unlike vancomycin, promoted the intracellular degradative mechanism, autophagy, in mammalian cells, which may have contributed to its intracellular activity. The findings of the work provide new perspectives on the field of glycopeptide antibiotics.