COCCIDOIDES PASADASII.pptx. .

Microbiology

1. COCCIDOIDES PASADASII

2. OVERVIEW Coccidioides are a dimorphic fungus that exists in the soil as a mold. Spores are released into the air due to wind and farming. The spores are inhaled and form spherules in the lungs. Causes a disease known as coccidioidomycosis . Coccidioidomycosis , also known as Valley Fever, gets its name from the San Joaquin Valley in C alifornia which sees a large number of cases. The causative agent is either Coccidioides immitis or Coccidioides posadasii

3. MORPHOLOGY It has two forms: White fluffy mold on most cultural media ( Sabouraund dextrose agar) and non-budding spherical form- spherule, in host tissue. R eproduces within mature spherules in the host tissue by forming small endospores. Through the formation of thick-walled barrel-shaped spores, called arthrospores , the fungus is identified by its appearance. The fungus is identified by its appearance by the formation of thick-walled barrel-shaped spores, called arthrospores .

4. EPIDEMIOLOGY Naturally, it exists in the soil and animals . C. posadasii is found in the Southwest US, Mexico, and South America. Endemic areas affected are the arid areas of the United States in Arizona, California, Nevada, New Mexico, Texas, Utah, and Northern Mexico

5. Incubation Period Primary pulmonary form -Usually 1-3 weeks Disseminated disease, chronic pulmonary form -Can occur months to years after initial infection

6. PATHOGENESIS

7. Primary Pulmonary Coccidioidomycosis Acute disease form -Most asymptomatic or mild Symptomatic disease -Often flu-like -May resemble pneumonia -Skin lesions 10-50% of patients with pulmonary disease

8. Progressive Pulmonary Coccidioidomycosis Clinical signs do not resolve -Chronic and progressive disease Lesions -Nodular or cavitary in lungs -Cavitary lung disease with fibrosis - Miliary pulmonary dissemination Disease usually limited to respiratory tract

9. Causative agents of Coccidioidomycosis Dimorphic Fungi, Coccidioides is the causative agent of Coccidioidomycosis. Coccidioides are a genus of dimorphic fungi that exist as mycelia or as spherules of asexual forms and lack the reproduction and structures of the sexual form The two species of Coccidioides are Coccidioides immitis and Coccidioides posadasii. Infective spores known as arthroconidia are produced by Coccidioides. During inhalation, the arthroconidia get deposited into the lungs. They then germinate and grow into spherules within the lungs and tissues.

10. Clinical manifestations of Coccidioidomycosis Most of the infections are asymptomatic pulmonary nodules. Acute pneumonia Chronic fibrocavitatory pneumonia Chronic dissemination: Bone Meninges Skin Joints Subcutaneous tissue

11. Transmission

12. Transmission Routes of transmission -Inhalation of dust containing arthrospores -Dust-covered fomites or dust storms containing fungal spores Communicability -Direct transmission between people very rare but immunocompromised are at greater risks e.g HIV, organ transplant, diabetic patient and pregnant women

13. Diagnosis of Coccidioidomycosis Physical examination and history of patients for extrathoracic by chest X-rays that indicate unilateral infiltration Laboratory Diagnosis of Coccidioidomycosis : It depends on the site of infections and the most common specimens are sputum, pleural fluid, lesion exudates, cerebrospinal fluid, and biopsy . Serological Testing

14. TREATMENT Some infections don’t require treatment in the case of uncomplicated coccidioidomycois . Treatment for primary pulmonary coccidioidomycosis is suggested for patients with the following conditions 1. Are immunosuppressed , have severe or significantly debilitating illness 2. have diabetes or are frail due to age or comorbidities 3. Are pregnant .

15. Disseminated ,complicated coccidioidomycosis requires treatment. Fluconazole 400-800 mg/day oral or IV Amphotericin B 0.5-0.7 mg/kg/day IV Ketoconazole 400 mg/d oral The drug of choice is fluconazole for 3-6 months A rapidly progressive coccidioidomycosis requires Amphotericin B

16. References https ://www.msdmanuals.com/professional/infectious-diseases/fungi/coccidioidomycosis Mitchell N.M., Sherrard A., Dasari S., Magee D.M., Grys T., Lake D.F. Proteogenomic Re-Annotation of Coccidioides posadasii Strain Silveira . Proteomics. 2018;18:1700173. doi : 10.1002/pmic.201700173. [PubMed] [ CrossRef ] [Google Schola ) Stockamp N.W., Thompson G.R., III Coccidioidomycosis . Infect. Dis. Clin . N. Am. 2016;30:229–246. doi  10.1016/j.idc.2015.10.008. [PubMed] [ CrossRef ] [Google Scholar]