Loss of thermotolerance in antibiotic-resistant .

Bacterium is a leading cause of nosocomial infections. The occurrence of antibiotic-resistant isolates outside hospitals suggests that monitoring of this pathogen in environmental samples is needed. Survival of pandrug-resistant was followed on selective plates with and without carbapenems in water and soil. After a few days of starvation, lost the ability to be cultivated at 44°C on plates supplemented with carbapenems. Once cultivated on plates without carbapenems and/or at 36°C, could grow again at 44°C in the presence of carbapenems. Comparative proteomic analysis revealed that impaired membrane integrity and reduced function of efflux pumps due to elevated temperature combined with antibiotic exposure were the main reasons for this phenomenon. Loss of thermotolerance in the presence of antibiotics points to the need for temperature adjustment in long-term monitoring of in environmental samples, to avoid the underestimation of viable bacteria.