Microbiology
Summary
Paracoccidioides brasiliensis is a dimorphic fungus that causes paracoccidioidomycosis. This fungus is found predominantly in Brazil and other parts of South America and is transmitted via inhalation of mold spores. A key identifier of Paracoccidioides brasiliensis is its appearance in yeast form, where multiple buds radiate out from a central cell, similar to a captain's wheel.
Important clinical symptoms of paracoccidioidomycosis include coughing and lymphadenopathy that can affect cervical, axillary, and even inguinal chains of lymph nodes. The disease also progresses to affect the upper respiratory system and the lungs, where granulomas are typically seen. Mucosal ulcers in the upper respiratory tract are also common. The treatment options include azoles for mild infections and amphotericin B for severe ones.
Lesson Outline
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FAQs
Paracoccidioides brasiliensis is a dimorphic fungus, native to South America, that causes a systemic mycosis known as paracoccidioidomycosis. This fungus exists in two forms: a yeast form in the human body and a mold form in the environment.
Paracoccidioides brasiliensis infection typically presents with lymphadenopathy and mucocutaneous lesions. Additionally, it can affect almost any organ system leading to a variety of symptoms depending on the organ affected. It is often characterized by the presence of multiple granulomas.
The term 'captain's wheel' is used to describe the unique morphology of the yeast form of Paracoccidioides brasiliensis under the microscope. The yeast cells tend to form multiple budding daughter cells around a central mother cell, creating an appearance reminiscent of a ship's wheel.
Paracoccidioides brasiliensis infections are most prevalent in South America, particularly in Brazil. However, cases have also been seen in Central America. The fungus is usually found in soil and vegetation, and infection often occurs from inhaling spores.
The antifungal medications itraconazole and amphotericin B are commonly used to treat paracoccidioidomycosis. Itraconazole is often the first choice, partly due to its better side-effect profile. However, in severe or disseminated disease, amphotericin B may be used instead.
