Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages:

• A. prevent bacteria from acquiring antibiotic resistance
• B. inhibit bacterial growth by blocking protein synthesis
• C. can integrate their DNA into the bacterial genome, introducing new virulence genes
• D. directly kill bacteria by causing cell lysis

Answer: (C)

Verified step by step guidance

1. Understand the role of lysogenic bacteriophages in bacterial genetics: Lysogenic phages can integrate their DNA into the bacterial chromosome, forming a prophage.
2. Recognize that this integration can introduce new genes into the bacterial genome, including genes that may enhance bacterial virulence, such as toxin genes or other factors that increase pathogenicity.
3. Contrast lysogenic phages with lytic phages: lytic phages cause immediate bacterial cell lysis, while lysogenic phages establish a dormant state within the host genome.
4. Note that lysogenic phages do not prevent antibiotic resistance or inhibit bacterial growth by blocking protein synthesis; instead, their main contribution to virulence is through gene transfer.
5. Conclude that the key reason lysogenic bacteriophages contribute to bacterial virulence is their ability to integrate DNA into the bacterial genome, thereby introducing new virulence genes.