Which phase is maximum multiplication resulting in increased population of bacteria with reduced generation t… - RRB Nsg. Superintendent-20 July 2019 (Shift-2)

RRB Nsg. Superintendent-20 July 2019 (Shift-2)

Applied Microbiology & Infection control

Easy

Appeared in: RRB Nsg. Superintendent-20 July 2019 (Shift-2)

Explanation

The Log (or exponential) phase is characterized by rapid cell division where the bacterial population doubles at a constant, maximum rate.
During this phase, conditions are optimal with abundant nutrients and low waste, leading to the shortest possible generation time (the time it takes for the population to double).
This results in a steep, exponential increase in the number of viable bacterial cells, which is when the population grows the fastest.

Option A: In the stationary phase, the growth rate equals the death rate due to nutrient limitation and waste accumulation, resulting in a plateau, not maximum multiplication.
Option B: The lag phase is an initial adaptation period with high metabolic activity but minimal to no cell division; therefore, the population does not increase.
Option C: The decline or death phase is when the death rate exceeds the growth rate, causing the viable population to decrease, which is the opposite of maximum multiplication.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Phases of the bacterial growth curve as background academic context rather than a clinical decision trigger.
Understanding the log phase is crucial because bacteria are most susceptible to antibiotics and disinfectants during this period of active metabolism and division.
In clinical infections, a rapid progression to the log phase can lead to a quick onset of severe symptoms as the bacterial load increases exponentially, overwhelming the host's immune system.
What if? If a patient is given a bacteriostatic antibiotic (which inhibits growth) instead of a bactericidal one (which kills bacteria), the infection might only be held in the stationary phase, and could resume growth once the antibiotic is stopped, especially in an immunocompromised patient.

How to Approach the Question

First, identify the key concepts in the question: 'maximum multiplication', 'increased population', and 'reduced generation time'.
Recall the four phases of the bacterial growth curve: Lag, Log, Stationary, and Decline.
Analyze the meaning of each keyword. 'Maximum multiplication' points to the fastest growth rate. 'Reduced generation time' means the time to double the population is the shortest.
Match these characteristics to the correct phase. The Log (or exponential) phase is defined by these exact conditions of rapid, exponential growth.
Systematically eliminate the other options based on their definitions: Lag (adaptation, no growth), Stationary (growth equals death), and Decline (death exceeds growth).

Concept Tested & Keywords

Concept Tested: Phases of the bacterial growth curve
Stem keywords: bacterial growth, maximum multiplication, increased population, reduced generation time
Lead-in keywords: Which phase
Negative lead-in flag: false

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