Abstract

The effect of oxidative stress exerted by 0.03% crystal violet, 0.3% bile salt, 4.0% NaCl and 8% ethanol on the survival and production of virulence factors amongAcinetobacter haemolyticus isolates obtained from wastewater and river water samples was investigated. Though generally there was insignificant lethal effect against all the isolates, crystal violet exerted the highest lethal effect followed by ethanol and bile salt, NaCl exerted the least effects as compared to crystal violet and ethanol. Isolates from wastewater demonstrated the highest rate of resistance compared to isolates from river water. Presence of resistant verotoxic A. haemolyticus in the environments investigated is a cause for concern. Resistance exhibited by the bacteria means that the efficacy of these salts, chemicals and temperature conditions frequently employed as control/preservation agents in hospitals and food industries may be undermined.

Key words: Cell viability, hydrophobicity, contamination, food-borne pathogens, oxidative stress, virulence.