Unravelling the microbial fitness and the acquired co-resistances towards environmental extremes of vancomycin resistant enterococci

Abstract

The World Health Organization listed vancomycin-resistant enterococci (VRE) within high priority on the global list of antibiotic resistant bacteria, which prioritizes the development and research of novel antibiotics. As a cause of endemic hospital outbreaks worldwide, VRE emerged as nosocomial pathogens, which can cause severe infections like bacteremia. One representative is vancomycinresistant Enterococcus faecium, an opportunistic pathogen that is part of the human intestinal microbiota but can be life threatening for immunosuppressed patients. Weakened immune functions are also a health issue for astronauts exposed to various stressors on long-term space missions. Therefore, VRE can become a threat whether on earth or in space. To prevent VRE infections and guarantee the health of the crew members it is important to understand the influence of microgravity on the development of antibiotic resistances. To investigate changes in the antibiotic resistance behavior due to microgravity, clinical VRE isolates were tested in their antibiotic resistances under simulated microgravity. As a result, the majority of the VRE isolates showed no change in their susceptibility to 22 different antibiotics or growth-inhibiting compounds after simulated microgravity. The unchanged resistance behavior stresses importance under both conditions and allows for similar containment and therapy strategies in the healthcare environment and in spaceflight. To estimate the risk of VRE and their role in an already existing pandemic of drug resistant infections it is essential to investigate VRE fitness and narrow down methods against the arising challenge of antibiotic resistant bacteria. Therefore, analysis of multi-stress factors of VRE and research of coresistance towards environmental extremes and space conditions will be implemented to improve the understanding how to fight drug resistant bacteria and, therefore, minimize healthcare-associated infections worldwide.