Granuloma inguinale is caused by
**Core Concept**
Granuloma inguinale, also known as Donovanosis, is a sexually transmitted infection (STI) characterized by the formation of granulomatous lesions in the genital area. It is caused by a bacterium that belongs to the Klebsiella-Enterobacter group.
**Why the Correct Answer is Right**
Granuloma inguinale is caused by Klebsiella granulomatis, a gram-negative bacterium. The bacterium enters the body through microabrasions or mucous membranes during sexual contact. Once inside, it causes an intense inflammatory response leading to the formation of granulomas. The bacteria are typically found in large numbers within the granulomas, which can eventually lead to tissue destruction and ulceration.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the correct causative agent of Granuloma inguinale is Klebsiella granulomatis, not Haemophilus ducreyi, which causes chancroid.
**Option B:** This option is incorrect because Treponema pallidum causes syphilis, a different STI with distinct clinical manifestations.
**Option C:** This option is incorrect because Chlamydia trachomatis causes chlamydia, a common STI characterized by urethritis and cervicitis.
**Clinical Pearl / High-Yield Fact**
Granuloma inguinale can be treated with antibiotics, such as azithromycin or doxycycline, and is typically curable within a few weeks of treatment. However, it can cause significant morbidity if left untreated, particularly in immunocompromised individuals.
**Correct Answer: D. Klebsiella granulomatis**