Disinfectants such as povidone iodine prep pads have been recalled due to contamination. Which organism is most likely to be isolated in such cases?

• A. Bordetella bronchiseptica
• B. Klebsiella pneumoniae
• C. Pseudomonas aeruginosa
• D. Serratia marcescens

Answer: (C)

Disinfectant products contaminated during production or storage are most commonly associated with organisms that thrive in moist, nutrient-poor environments and resist many disinfectants. Pseudomonas aeruginosa fits this pattern perfectly. It is a water-loving, Gram-negative bacterium that can grow in trace amounts of residual disinfectants and readily forms biofilms on surfaces. Its inherent resistance mechanisms—such as efflux pumps and biofilm formation—allow it to persist in moist settings like manufacturing lines, storage containers, and reusable pads. Because of these traits, Pseudomonas aeruginosa is a frequent culprit in outbreaks linked to contaminated antiseptics and disinfectants, including povidone-iodine prep pads.

Bordetella bronchiseptica is more often associated with animal pathogens and occasional human infections, not a common contaminant of disinfectant products. Klebsiella pneumoniae is a hospital-acquired pathogen typically linked to contaminated sterile solutions or devices rather than consumer prep pads. Serratia marcescens can be found in moist environments and has caused some product recalls, but it does not match the widespread association of Pseudomonas aeruginosa with disinfectant contamination.