Influence of biocide treatment regimen on resistance development to methylchloro-/methylisothiazolone in Pseudomonas aeruginosa

• Published in: International biodeterioration & biodegradation Vol. 43; no. 3; pp. 85 - 92
• Main Authors: Sondossi, M, Rossmoore, H.W, Lashen, E.S
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.01.1999; Elsevier
• Subjects: 5-chloro-2-methyl-4-isothiazolin-3-one; Action of physical and chemical agents on bacteria; Bacteria; Bacteriology; Biological and medical sciences; Cell culture; Chlorine compounds; Fundamental and applied biological sciences. Psychology; Industrial biocides; isothiazolone; Metal working; Metalworking fluid; Microbiology; Pseudomonas aeruginosa; Resistance; Sulfur compounds; Resistance; 5-chloro-2-methyl-4-isothiazolin-3-one; Industrial biocides; Metalworking fluid; Pseudomonadales; Laboratory study; Concentration effect; Metalworking oil; Bacteria; Pseudomonadaceae; Isolation; Pseudomonas aeruginosa; Biocide; Adaptation; Dose activity relation
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/S0964-8305(99)00034-7

Resistance development among microbial populations exposed to industrial biocides intending to control microbial levels has received increasing attention in the last few years. Usually studies dealing with resistance development are done after the process has taken place. Characterization of resistant organisms by isolation of dominant populations reveals some details, but the steps leading to resistance usually remain unclear. In this study, development of resistance to methylchloro-/methylisothiazolone (IT) biocide under laboratory conditions is described. Results with experimental setups relevant to field dosing conditions demonstrated how the pattern of biocide treatment influenced the degree of resistance development. The induction of higher resistance in the laboratory populations exposed to different dosing patterns varied. Sequential treatment of culture with a constant increase in concentrations of isothiazolone (5–10 μl l −1 of commercial product) resulted in increasing resistance, exceeding ten-fold. However, additional increases of 25–50 μl l −1 in each step were lethal, suggesting threshold levels of resistance in populations tested. Extrapolation of laboratory data to field conditions appeared more relevant after Pseudomonas species, highly resistant to IT, were isolated from metalworking fluids. In these fluids the biocide treatment regimen in the field was similar to the one used in the laboratory. An understanding of the factors contributing to resistance development and selection in the field is emphasized.