Evaluation of bacterial resistance to Chloramine T Biocide and effects on Rifampicin Antibiotic Susceptibility as a consequence of biocide usage in Cooling System Biofilm including Legionella pneumophila

Cooling towers provide an ideal environment for microbial growth and have been attributed as a source for accumulation and dissemination of pathogenic organisms, especially Legionella pneumophila [1,2]. Since Legionella infections have frequently been traced to contaminated aerosols generated at distances over 6 km, cooling systems have a potential risk for public health. Inhalation of Legionella-contaminated aerosols may cause Legionnaires' Disease or Pontiac fever in humans [3]. The most common approach to eliminate or reduce the biofouling problem in contaminated systems is chemical treatment primarily by using biocides [4]. Owing to the fact that biofilm bacteria are more resistant than their planktonic counterparts to the biocides, biocide concentrations can lead to microbial resistance build-up first to the biocide and then consequently to the antibiotics.