An outbreak of waterborne pathogens in a healthcare facility is likely caused by which organism when the outbreak is linked to contaminated equipment?

• A. Escherichia coli
• B. Pseudomonas aeruginosa
• C. Neisseria meningitidis
• D. Staphylococcus aureus

Answer: (B)

The main idea is that outbreaks tied to contaminated equipment in healthcare settings are typically caused by organisms that love moisture and readily form biofilms, which helps them persist on sinks, humidifiers, and medical devices. Pseudomonas aeruginosa fits this pattern: it thrives in water, survives in damp environments, and easily colonizes equipment and water systems. It’s notorious for causing healthcare-associated infections in vulnerable patients when equipment or taps become contaminated, leading to waterborne transmission through reservoir water or device surfaces.

In contrast, Neisseria meningitidis is spread mainly person-to-person by respiratory droplets, not through water or equipment. Staphylococcus aureus is a common cause of skin and device-related infections but is not characteristically linked to waterborne outbreaks from contaminated equipment. Escherichia coli is strongly associated with fecal contamination and GI illness rather than outbreaks arising from moist equipment in a healthcare setting.