In a healthy woman the only organism found in upper two-third of the vagina is:
A. Moniliasis
B. Doderlein’s bacillus
C. Gonorrhoea
D. Trichomoniasis
Correct Answer: B. Doderlein’s bacillus
Explanation: In a healthy, reproductive-age woman, the upper two-thirds of the vagina (like the lower third) is predominantly colonized by Lactobacillus species (most commonly Lactobacillus crispatus L. iners,L. gasseri, and L. jensenii).
These lactobacilli are not the “only” organism present in an absolute sense (small numbers of other bacteria can occasionally be detected), but they are by far the dominant organisms (often >90–95% of the microbiota) in a healthy state. They maintain the low vaginal pH (typically 3.8–4.5) through lactic acid production, which prevents overgrowth of pathogens.
So the correct answer in medical and microbiological contexts (e.g., in exams) is:
Lactobacillus (or specifically Döderlein’s bacilli, an older term for vaginal lactobacilli).
No other organism is normally the sole or predominant one in the upper two-thirds of a healthy vagina.
Other Options Details
A. Moniliasis
• Also known as Candidiasis or Vaginal thrush.
• Caused by Candida albicans (most commonly) or other Candida species (yeast/fungus).
• Symptoms: Thick, white, curd-like vaginal discharge, intense itching, redness, dyspareunia.
• Predisposing factors: Diabetes, pregnancy, antibiotics, immunosuppression, oral contraceptives.
• Diagnosis: Microscopy shows pseudohyphae and budding yeast cells; culture on Sabouraud’s agar.
Treatment: Topical or oral azoles (e.g., clotrimazole, fluconazole).
B. Doderlein’s bacillus
• This is NOT a pathogen; it is the normal vaginal flora.
• Scientific name: Lactobacillus species (formerly called Doderlein’s bacilli).
• Dominant in healthy reproductive-age women.
• Maintains acidic vaginal pH (3.8–4.5) by producing lactic acid from glycogen → protects against pathogenic organisms.
• Decreased in bacterial vaginosis, postmenopausal state, or after antibiotics.
• C. Gonorrhoea
• Caused by Neisseria gonorrhoeae (Gram-negative intracellular diplococci).
• Sexually transmitted infection.
• Symptoms in females: Often asymptomatic; when present → purulent vaginal discharge, cervicitis, dysuria, intermenstrual bleeding; can cause pelvic inflammatory disease (PID), infertility, disseminated infection.
• Complications: PID, Bartholin’s abscess, Fitz-Hugh-Curtis syndrome, neonatal conjunctivitis.
• Diagnosis: NAAT (nucleic acid amplification test) is gold standard; culture on Thayer-Martin medium.
• Treatment: Ceftriaxone + azithromycin (dual therapy due to resistance).
• D. Trichomoniasis
• Caused by Trichomonas vaginalis (flagellated protozoan).
• Sexually transmitted.
• Symptoms: Frothy, yellow-green, foul-smelling vaginal discharge (“strawberry cervix” on speculum — punctate hemorrhages), itching, dyspareunia, dysuria.
• Many women are asymptomatic; men usually asymptomatic carriers.
• Diagnosis: Wet mount microscopy shows motile trichomonads (gold standard for rapid diagnosis); NAAT is most sensitive.
• Treatment: Metronidazole or tinidazole (treat partner simultaneously).
Summary Table for Quick Revision
Option Causative Agent Type Discharge Key Feature
A. Moniliasis Candida albicans (fungus) Fungal Thick, white, curd-like Itching, pseudohyphae on microscopy
B. Doderlein’s bacillus Lactobacillus spp. Normal flora None (physiological) Maintains acidic pH, protective
C. Gonorrhoea Neisseria gonorrhoeae Bacterial (STI Purulent, yellowish Intracellular diplococci, often PID risk
D. Trichomoniasis Trichomonas vaginalis Protozoal (STI)| Frothy, green-yellow, fishy Motile flagellates, strawberry cervix
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Writer: Vandita Singh, Lucknow (GS India Nursing Group)