The bacteria that grow between 20 to 50 degrees Celsius temperature are called?

AIIMS CRE SNO - 2023

Microbiology

Easy

Appeared in: AIIMS CRE SNO - 2023

Explanation

Mesophiles are bacteria that thrive in moderate temperatures, with a typical growth range of 20°C to 45°C.
The temperature range provided in the question, 20°C to 50°C, best fits the description of mesophilic bacteria.
This group includes most human pathogens because their optimal growth temperature is around 37°C, which is the normal human body temperature.
Examples of mesophilic bacteria include common organisms like Escherichia coli and Staphylococcus aureus.

Option A: Hyperthermophilic bacteria grow in extremely hot environments, with optimal temperatures above 80°C. This is far outside the 20-50°C range.
Option B: Thermophilic bacteria are 'heat-loving' and grow best at temperatures between 45°C and 80°C. While the upper end of the question's range (50°C) touches this, the lower end (20°C) is too cold for thermophiles.
Option D: Psychrophilic bacteria are 'cold-loving' and thrive at low temperatures, typically below 20°C. The range of 20-50°C is too warm for them.

Visual 1: Diagram: A graph showing the growth rates of psychrophiles, mesophiles, thermophiles, and hyperthermophiles plotted against temperature. This would visually demonstrate the optimal temperature range for each bacterial type.
Visual 2: Infographic: A chart illustrating the different classifications of bacteria based on environmental requirements (temperature, oxygen, pH) with examples for each category.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of bacteria based on temperature requirements as background academic context rather than a clinical decision trigger.
Understanding bacterial temperature preferences is crucial for infection control. Most pathogenic bacteria are mesophiles, which is why maintaining proper body temperature and controlling fever is important in patient care.
This knowledge is fundamental to microbiology lab practices, such as incubating cultures at 37°C to grow most clinically relevant bacteria, and using refrigeration (around 4°C) to slow down or stop the growth of mesophilic bacteria in samples.
What if? If a clinical sample needs to be stored for a few hours before processing, it should be refrigerated. This is because refrigeration temperatures are below the optimal growth range for mesophiles, preventing the bacteria from multiplying and altering the test results.

How to Approach the Question

First, identify the key information in the question: the temperature range is '20 to 50 degrees Celsius'.
Next, recall or look up the definitions for the terms in the options: Hyperthermophilic, Thermophilic, Mesophilic, and Psychrophilic.
Compare the given temperature range with the known growth ranges for each type of bacteria.
Psychrophilic means 'cold-loving' (below 20°C), so this is incorrect.
Thermophilic and Hyperthermophilic mean 'heat-loving' and 'extreme-heat-loving' respectively (above 45°C and above 80°C), so these are also incorrect for the lower end of the range.
Mesophilic means 'middle-loving', with a typical range of 20-45°C. This is the best match for the 20-50°C range provided.

Concept Tested & Keywords

QtgePgg8UJ3oqoOrCgsTNh