Question

The wound is known as infected if the bacterial count exceeds

• A. 10^5 number of bacteria per gram of tissue
• B. 10^6 number of bacteria per gram of tissue
• C. 10^2 number of bacteria per gram of tissue
• D. 10^8 number of bacteria per gram of tissue

Hint:

Wound Infection Threshold: Critical threshold for clinical wound infection and skin graft failure is $> 10^5$ bacteria per gram of tissue ($10^5\;\text{CFU/g}$).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Surgical wound microbiology threshold: the quantitative bacteriological definition of invasive clinical wound infection (Elek-Miles criterion) is $> 10^5$ CFU per gram of tissue.
Key Formula or Approach:
\[ \text{Critical Colonization / Clinical Infection Threshold} \ge 10^5\text{ CFU / gram of viable tissue} \]

Step 2: Detailed Explanation:
In surgical wound healing and wound infection microbiology:
- Normal skin colonizing bacteria inhabit open granulating wounds as harmless commensals (colonization).
- According to the classic Elek-Miles quantitative threshold validated in surgical pathology:
When the viable bacterial density exceeds $10^5$ organisms ($10^5\text{ CFU}$) per gram of tissue (or per mL of wound exudate), the host local immune defenses are overwhelmed, microbial invasion of viable tissue occurs, collagen synthesis is impaired, and true clinical wound infection supervenes.

Step 3: Final Answer:
Hence, the wound is known as infected if count exceeds 10^5 number of bacteria per gram of tissue, corresponding to option (A).