CRCST Practice Exam

Bacteria that are often pathogenic to humans because they grow well at body temperature are

1. Halophiles

2. Mesophiles

3. Psychrophiles

4. Thermophiles

The correct answer is: Mesophiles

Mesophiles are bacteria that thrive and grow well at moderate temperatures, typically around human body temperature (37 degrees Celsius). This makes them more likely to be pathogenic to humans compared to bacteria that prefer extreme temperatures. The other options, halophiles, psychrophiles, and thermophiles, thrive in high salt concentrations, cold temperatures, and high temperatures, respectively. These types of bacteria are not as commonly pathogenic to humans as mesophiles due to their preference for extreme environmental conditions that are not typically found in the human body.