engleski

Long-term survival of Acinetobacter baumannii in water

Acinetobacter baumannii is a notorious hospital opportunistic pathogen that causes life- threatening infections worldwide [1]. It quickly acquires antibiotic resistance and survives adverse environmental conditions such as starvation [2], desiccation [2, 3] and a wide array of temperature and pH regimes [4]. The survival of one environmental (pan drug- resistant) and one clinical isolate (extensively-drug resistant) was monitored for the period of one year in commercially available spring water (SW) and diluted (1:100) nutrient broth (DNB). Isolates were incubated at 22 and 4°C at moderate oxygen saturation of 56%. Initial bacterial abundance determined on Muller-Hinton agar at 42°C/24h was 6.8 ± 0.1 log CFU/mL. Both A. baumannii isolates performed similar and survived for one year in tested conditions. Survival was slightly better in DNB than in SW, but without statistical significance. After one-year exposure to 22°C the average final abundance was 5.0 ± 0.2 log CFU/mL, while at 4°C the final abundance was 1.2 ± 0.3 log CFU/mL. Small translucent colony variants together with normal opaque colonies were recorded as the response to unfavourable temperature of 4°C. A. baumannii can survive in refrigerators as well as in suspensions kept at room temperature for a long time, which is important for its persistence and possible transmission in the hospital environment.

Acinetobacter baumannii, environment, water

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