Influence of environmental conditions on biofilm formation by Hafnia alvei strains.

Hafnia alvei is considered an opportunistic pathogen of animal and humans, affecting a wide range of homeothermic and poikilothermic hosts with different body temperatures. In this work, H. alvei strains isolated from different sources were studied with regard to their capacity to form biofilms under different environmental conditions. Strain, growth phase, temperature and culture media dependent changes of biofilm formation were semiquantitatively monitored using a microtiter plate method. Our study shows that all strains used could form biofilms in vitro, and that biofilm formation increases dramatically during growth at 25 degrees C but not at 37 degrees C, and decreases at both temperatures in presence of glucose. At 16 degrees C only one strain isolated from a lizard was able to form a dense biofilm showing that the ability to form biofilms in this species is regulated by environmental factors and is also strain specific.