[Biofilm formation and response to oxidative stress in Pseudomonas aeruginosa and Vibrio cholerae non-O1 depending on culture media].
OBJECTIVE
To evaluate the effect of six culture media (five complex and one mineral) on biofilm formation and response to oxidative stress in Pseudomonas aeruginosa (3 strains) and Vibrio cholerae non-O1 (3 strains).


METHODS
Biofilm formation was quantitatively determined by a crystal violet absorption assay. The bacterial response to oxidative stress evoked by hydrogen peroxide was visualized as a zone of clearing around the disc after 24 h incubation at 37 degrees C.


RESULTS
For both of the bacterial species studied, biofilm formation was the highest after cultivation in tryptone soya broth (TSM) or in TSM supplemented with 8% glucose (TSM+GL), being the lowest in mineral medium (MM). V. cholerae non O1 strains were 1.4 to 4.3 times more responsive on average to oxidative stress depending on culture medium as compared with P. aeruginosa strains. The culture medium had no significant effect on H2O2 evoked by response to oxidative stress in vibrios in contrast to P. aeruginosa. In P. aeruginosa, the highest mean resistance to H2O2 was observed after cultivation in peptone water while the most sensitive cells were found after incubation in TSM+GL and MM.


CONCLUSIONS
The culture medium composition influnced biofilm formation in both of the bacterial species tested and had a considerable effect on response to oxidative stress in P. aeruginosa.
Slovenská zdravotnícka univerzita, Bratislava, Slovenská republika. anna.hostacka@szu.sk
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Ciznár
D018441:Biofilms / Q000254:growth & development*; D003470:Culture Media; D006861:Hydrogen Peroxide / Q000494:pharmacology; D018384:Oxidative Stress; D011550:Pseudomonas aeruginosa / Q000378:metabolism / Q000502:physiology*; D044163:Vibrio cholerae non-O1 / Q000378:metabolism / Q000502:physiology*
D003470:Culture Media; D006861:Hydrogen Peroxide