The genetic exchange process in which donor DNA is introduced to the recipient by a virus is:

ESIC Nursing Officer -2019 (Shift -1)

Applied Microbiology & Infection control

Easy

Appeared in: ESIC Nursing Officer -2019 (Shift -1)

Explanation

Transduction is the process where bacterial DNA is transferred from a donor cell to a recipient cell via a bacteriophage, which is a virus that infects bacteria.
The bacteriophage acts as a vector, accidentally picking up a fragment of the donor bacterium's DNA and injecting it into the next bacterium it infects.
This process is a key mechanism of horizontal gene transfer and is explicitly defined as virus-mediated DNA exchange.
The provided image visually confirms this, showing a bacteriophage injecting DNA into a bacterial cell as the mechanism for transduction.

Option A: Transfection is the process of deliberately introducing nucleic acids into cells by non-viral methods, such as chemical or physical means. It does not involve a virus as a natural vector.
Option C: Conjugation involves the transfer of genetic material through direct physical contact between two bacterial cells, mediated by a structure called a sex pilus. It does not involve a virus.
Option D: Transformation is the uptake of naked, free-floating DNA from the surrounding environment by a competent bacterial cell. No virus is involved in this process.

Visual 1: Diagram - A comparative diagram showing the mechanisms of Transformation, Transduction, and Conjugation. This helps to visually differentiate the role of naked DNA, bacteriophages, and cell-to-cell contact in each process.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Mechanisms of horizontal gene transfer in bacteria as background academic context rather than a clinical decision trigger.
Understanding transduction is critical for nurses, as it is a primary way bacteria spread antibiotic resistance genes. A non-resistant bacterium can become resistant after being infected by a phage carrying a resistance gene.
Transduction can also transfer virulence factors, such as the genes for producing toxins (e.g., Diphtheria toxin, Cholera toxin), turning a harmless bacterium into a pathogen.
What if? If a patient has an infection with bacteria that are rapidly developing resistance to multiple drugs, it's possible that transduction (or conjugation) is occurring within the bacterial population, highlighting the need for strict infection control and appropriate antibiotic stewardship.

How to Approach the Question

First, identify the key terms in the question stem. The most critical word here is 'virus'.
Next, review the options provided. Each option represents a different mechanism of genetic exchange.
Recall the definition of each term. Your goal is to match the mechanism involving a 'virus' with the correct term.
Transformation involves naked DNA. Conjugation involves cell-to-cell contact. Transfection is an artificial, non-viral method. Transduction is the only process that uses a virus (bacteriophage) as a vector.
Therefore, select the option that corresponds to virus-mediated DNA transfer.

Concept Tested & Keywords

QsIaYSa9q43K6fcfZU8yfv