Which mycobacteria has an optimal growth temperature of 30-32°C?

Which mycobacteria has an optimal growth temperature of 30-32°C?

• A. M. ulcerans
• B. M. avium complex
• C. M. bovis
• D. M. xenopi

Answer: (A)

Some mycobacteria have distinct optimal growth temperatures that reflect their ecological niches. M. ulcerans grows best at about 30–32°C, which is cooler than the human body’s core temperature and explains why it is typically cultured around 30°C. This cooler preference matches its environmental habit and the slower, temperature-tolerant growth observed in laboratories. In contrast, the other species listed generally prefer body temperature around 37°C to grow well, so they do not thrive at 30–32°C. M. xenopi tends to grow best at higher temperatures (around 42°C), while M. avium complex and M. bovis favor near 37°C. Thus, the organism with an optimal growth temperature of 30–32°C is M. ulcerans.

Some mycobacteria have distinct optimal growth temperatures that reflect their ecological niches. M. ulcerans grows best at about 30–32°C, which is cooler than the human body’s core temperature and explains why it is typically cultured around 30°C. This cooler preference matches its environmental habit and the slower, temperature-tolerant growth observed in laboratories.

In contrast, the other species listed generally prefer body temperature around 37°C to grow well, so they do not thrive at 30–32°C. M. xenopi tends to grow best at higher temperatures (around 42°C), while M. avium complex and M. bovis favor near 37°C.

Thus, the organism with an optimal growth temperature of 30–32°C is M. ulcerans.