132. Given below are two statements: one is labelled as Assertion A and another one islabelled as
Reason R
Assertion A: It is essential that the animal cell cultures be maintained in antibiotic
free conditions otherwise cryptic contaminations will persist
Reason R: The constant use of antibiotics favours development of chroniccontamination. Many
organisms are inhibited but not killed by antibiotics, which mayresurface when conditions are
favourable.
In light of the above statements, choose the correct answer from the options below:
(a) A is false but R is true,
(b) A is true but R is false ,
(c) Both A and R is true and R is NOT the correct explanation of A,
(d) Both A and R is true and R is the correct explanation of A

Understanding the Impact of Antibiotics on Animal Cell Cultures

Introduction

In cell culture environments, maintaining a clean, uncontaminated culture is essential for accurate and reproducible experimental results. However, one of the critical aspects of maintaining cell cultures is the use of antibiotics to prevent microbial contamination. Despite their widespread use, there is an ongoing debate about whether antibiotics are beneficial or potentially harmful to long-term culture integrity. This article explores the importance of antibiotic use in animal cell cultures, the potential risks of constant antibiotic usage, and how it can affect the development of contamination.

Assertion and Reason

Given below are two statements regarding the use of antibiotics in animal cell cultures:

• Assertion A: It is essential that animal cell cultures be maintained in antibiotic-free conditions; otherwise, cryptic contaminations will persist.

• Reason R: The constant use of antibiotics favors the development of chronic contamination. Many organisms are inhibited but not killed by antibiotics, which may resurface when conditions are favorable.

Analyzing the Assertion

Assertion A suggests that for successful cell culture management, it’s essential to avoid using antibiotics continuously. While antibiotics can help prevent contaminants from overtaking cultures, the use of antibiotics in long-term culture conditions can allow cryptic contaminants (organisms that are not killed by antibiotics) to persist, even though they are not actively proliferating. These contaminants can resurface once the conditions are favorable, leading to problems later on.

Reason R provides an explanation for why the constant use of antibiotics can lead to chronic contamination. Antibiotics are designed to inhibit the growth of unwanted microorganisms. However, many antibiotics do not kill organisms outright; they only inhibit their growth. This means that microbes may survive in a dormant state and become active once the antibiotic pressure is removed. In such cases, the organisms can cause problems later, especially if conditions change.

Correct Answer and Explanation

The correct answer is:

(d) Both A and R are true and R is the correct explanation of A.

• Assertion A is true because constant antibiotic usage in cultures can lead to the persistence of cryptic contaminants.

• Reason R is true because the use of antibiotics inhibits but doesn’t necessarily kill microbes, allowing them to resurface when conditions change, leading to chronic contamination.

The explanation provided in Reason R directly supports the statement made in Assertion A, providing a valid rationale for why antibiotic-free conditions are critical for preventing long-term contamination issues.

Why Are Antibiotic-Free Conditions Important?

Antibiotics in Cell Culture: Benefits and Risks

Antibiotics are often added to cell culture media to protect cultures from bacterial contamination. However, their prolonged use can have unintended consequences:

1. Cryptic Contamination: Some microorganisms may survive in a dormant state due to the antibiotic’s inhibitory action, leading to chronic contamination.

2. Resistance Development: Over time, organisms exposed to antibiotics may develop resistance, making them harder to eliminate in the future.

3. Impairment of Cell Behavior: The use of antibiotics can sometimes interfere with the behavior and growth of the cells themselves, leading to unreliable results in experiments.

Key Takeaways

• Antibiotics are effective at preventing contamination but can lead to cryptic contamination when used in animal cell cultures for extended periods.

• Chronic contamination can occur when organisms are inhibited but not killed, resuming growth when conditions change.

• Maintaining antibiotic-free conditions is essential to ensuring the long-term health and accuracy of animal cell cultures.

Conclusion

While antibiotics can provide temporary protection against contamination, relying on them long-term can introduce risks, including the development of cryptic contamination and chronic contamination. Understanding the dynamics of antibiotic use and its potential consequences in animal cell cultures is vital for researchers to create stable and uncontaminated cell environments, ensuring more reliable experimental outcomes.