PSI Barbering Practice Exam

What are bacterial spores resistant to in terms of disinfection?

1. Heat

2. Moisture

3. Common Disinfectants

4. Time

The correct answer is: Common Disinfectants

Bacterial spores are highly resilient structures formed by certain bacteria as a survival mechanism under adverse conditions. One of their key characteristics is their resistance to common disinfectants. While many disinfectants can effectively kill vegetative bacterial cells and viruses, they often struggle to penetrate and eradicate bacterial spores due to the spores' tough outer protective layer. This outer coat makes them less permeable to chemicals, allowing them to survive in environments that would eliminate other forms of bacteria. In contrast, spores have varying degrees of resistance to heat, moisture, and time, but it is their ability to withstand the effects of standard disinfectants that sets them apart. Heat can destroy spores at high temperatures, particularly through processes like autoclaving, which utilizes steam under pressure. Moisture is not a major factor since spores can remain dormant in dry conditions and activate when they come into contact with moisture. Time is a critical factor, as prolonged exposure to certain conditions may eventually lead to spore inactivation, but in general, the immediate effect of disinfection is where their resilience is most evident. Thus, the focus on common disinfectants highlights the unique challenges presented by bacterial spores in disinfection protocols.