Vaginal acidity is maintained by ?

RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Applied Microbiology & Infection control

Medium

Appeared in: RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Explanation

Doderlein bacilli are various species of the genus Lactobacillus that constitute the predominant normal flora in a healthy vagina.
These bacteria metabolize glycogen, which is present in the vaginal epithelial cells due to estrogen stimulation.
The metabolism of glycogen by Doderlein bacilli produces lactic acid.
This continuous production of lactic acid is what maintains the acidic pH of the vagina, typically between 3.8 and 4.5.
This acidic environment is protective as it inhibits the growth of many pathogenic microorganisms.

Option A: While some Streptococcus species can be found in the vagina, they are not the primary organisms responsible for producing the lactic acid that maintains its acidic pH.
Option C: This is not a standard or recognized medical term for the bacteria involved in maintaining vaginal acidity.
Option D: While the name suggests acid production, 'Acidobacillus' is not the specific, medically accepted term for the lactobacilli that dominate the vaginal flora. Doderlein bacilli is the correct eponym.

Visual 1: Diagram: Illustrating the hormonal and microbial mechanism of vaginal pH regulation. Shows estrogen acting on vaginal epithelium, glycogen storage, metabolism by Doderlein bacilli, and lactic acid production leading to acidic pH.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Regulation of vaginal pH by normal flora as background academic context rather than a clinical decision trigger.
Nurses educate patients that a healthy, acidic vaginal pH is a natural defense against infections like bacterial vaginosis (BV) and vulvovaginal candidiasis.
Understanding this mechanism is crucial for counseling patients on factors that can disrupt the vaginal ecosystem, such as broad-spectrum antibiotic use, douching, and hormonal shifts (e.g., menopause, pregnancy).
What if? A postmenopausal woman not on hormone therapy presents with recurrent vaginal infections. The nurse should recognize that her lower estrogen levels lead to reduced glycogen, fewer lactobacilli, a higher vaginal pH, and thus a greater susceptibility to infections.

How to Approach the Question

This is a factual recall question based on microbiology and gynecological physiology.
Identify the core of the question: What is responsible for the acidic nature of the vagina?
Recall the concept of normal body flora and its function in different parts of the body.
Evaluate the options. Doderlein bacilli is the specific eponym for the Lactobacillus species that perform this function.
Eliminate the other options. Streptococcus is a known bacterium but not for this primary role. Mucobacilli and Acidobacillus are incorrect or non-standard terms in this context.

Concept Tested & Keywords

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