Chapter 18, Problem 1Q

Which of the following microbes have evolved an intracellular life style?

1. a. Bacillus anthracis
2. b. Coxiella burnetii
3. c. MRSA
4. d. two of these

Summary Introduction

Introduction:

Bacteria are defined as small, microscopic, prokaryotic and unicellular organisms that are not seen by naked eyes. They are found everywhere in nature and hence, are called ubiquities.

Answer to Problem 1Q

Correct answer:

The microbes such as Coxiella burnetii have evolved an intracellular life style. Therefore, option (b) is correct.

Option (b) is given as “Coxiella burnetii”.

Explanation of Solution

Justify reason for the correct statement:

The bacteria Coxiella burnetii is an obligate intracellular pathogen which has evolved and able to survive in harsh conditions inside the intracellular compartments of cells called as phagolysosome. Inside it, the Coxiella phagosome is further developed into large and spacious parasitophorous vacuole. This parasitophorous vacuole has all characteristics of lysosome such as acidic pH, acid hydrolase enzyme and cationic peptides. It provides a defense against host invaders.

Hence, option (b) is correct.

Justify reasons for the incorrect statements:

Option (a) is given as “Bacillus anthracis”.

The life cycle of Bacillus anthracis involves two alternate phages such as vegetative and endospores on the basis of availability of nutrients. Hence, it is a wrong answer.

Option (c) is given as “MRSA”.

It is denoted as methicilin-resistant Staphylococcus aureus and forms colonies for division. Hence, it is a wrong answer.

Option (d) is given as “two of these”.

Coxiella burnetii have evolved to follow intracellular life style. Hence, it is a wrong answer.

Hence, options (a), (c), and (d) are incorrect.

Conclusion

The bacterium Coxiella burnetii is an obligate intracellular pathogen which has evolved and able to survive in harsh conditions inside the intracellular compartments of cells called as phagolysosome.