engleski

Survival of ESKAPE pathogen Acinetobacter baumannii in water media of different temperature and pH

Acinetobacter baumannii is an emerging human opportunistic pathogen that causes nosocomial as well as community-acquired infections. A. baumannii is assigned to ESKAPE group of pathogens due to its ability to „escape“ the biocidal activity of antibiotics. The aim of this study was to test the behaviour of A. baumannii isolates in water media under different temperature and pH conditions in order to predict its behaviour in the environment. Survival of 5 A. baumannii isolates was monitored during 7 weeks in commercially available spring water and diluted Nutrient broth. Tested temperatures at neutral pH were: -20, 4, 22, 35, 44, 50 and 63 °C. Tested pH values were 2, 7 and 12 at 22 °C. Bacterial numbers were determined on Nutrient agar and expressed as log CFU mL-1 from which survival rates were calculated. A. baumannii successfully survived at temperatures ranging from -20 to 44 °C during 7 weeks. It was able to survive classic pasteurization procedure (63 °C/30 min) and was destroyed after 2h of contact. Prolonged survival of A. baumannii at extreme temperatures and pH values indicates that this pathogen is resilient and persistent under different conditions that are unfavourable for the majority of other mesophilic non-sporogenic bacteria. Optimal conditions for the growth and survival of this pathogen are room temperature and neutral pH, which is a prerequisite for the existence of isolates in hospital environment. Multidrug-resistant isolates survive better in harsh environmental conditions than sensitive isolates, which represents a major healthcare concern.

Acinetobacter baumannii, temperature, pH

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