TALAROMYCOSIS - Introduction, Morphology, Epidemiology, Clinical symptoms,pathophysiology, laboratory diagnosis, Treatment.

Talaromycosis also known as penicillosis. It is a fungal infection Caused by Talaromyces marneffi (formerly penicillium marneffi ).
Infections involved in mononulear phagocytic system and occurs primarily in HIV - infected individuals.
It's a Disseminated mycosis.Pigment producing fungus , this is the only pathogenic fungus in Talaromyces family.

1. INTRODUCTION Talaromycosis is a Dimorphic fungus and Endemic fungi . Caused by Talaromyces marneffi (formerly penicillium marneffi ). Infections involved in mononulear phagocytic system and occurs primarily in HIV - infected individuals. It's a Disseminated mycosis.

2. MORPHOLOGY Saprobic phase[ Mold in 25 ° C] Mold with conidiophores terminating in conspicuous , penicillus - bearing , ellispsodial,Smooth conidia . Formation od Red pigment that diffuses into agar . It exhibits sporulating structures that are typical of the genus.

3. Parasitic phase [yeast in 37 ° c] Pleomorphic elongated yeast (1-8 micrometer ) with transverssepta. Morphology in tissue Globose to elongated sausage - shaped yeast (3-5 micrometer ) that are intracellular ,divided by Fission .

4. EPIDEMIOLOGY T.marneffi as a prominent mycotic pathogen among HIV-infected individuals in South East Asia. Talaromycosis (penicillliosis) has become an early indicator of HIV-infection . It has been isolated from Bamboo rats and occasionally from soil. T.marneffi is only pathogenic fungi in genus Talaromyces.

5. CLINICAL SYMPTOMS The infection may mimic Chronic cervical lymphadinitis (resembling tuberculosis) Leishmaniasis Other opportunistic infection AIDS- related such as histoplasmosis ,Cryptococcosis. Patients may present with fever, cough , lymphadenopathy , organomegaly , anemia , leuko /Thrombocytopenia. Bronchopneumonia with or without alenopathy , cavitary lung lesion.

6. Pathogenesis Infection due to inhalation of conidia of T.marneffi which present in soil. Affects the pulmonary part of the body. Incubation period- 2 weeks to years . Asymptomatic in immunocomptent hosts and disseminated infection develops. Later ,Skinlesions reflects hematogenous dissemination and appear molluscum contagiosum - like lesions on face and trunk .

7. LABORATORY DIAGNOSIS Clinical specimens For microscopic demonstration , mucosal scraping ,sputum, blood, lung and liver biopsy, broncho alveolar lavage and tissue. Staining Staining of skin, lymph- H & E stain , PAS (periodic acishaff's stain, Wright 's and calcofluor white stain. Gomori methensmine silver stain - stained yeast forms of Talaromyces marneffi was used wide ,transverse septa , single forms .

8. Culture morphology In culture 25 ° c to 30 ° c , typically penicillium-like morphology and diffusible red pigmentation . Conversation to yeast phase at 37 ° c is Confirmatory phase. Microscopy - Elliptic fission yeast inside phagocytes in buffy coats of smears. Serogical tests Indirect IFAT, Immunoblot PCR and DNA sequencing for sp. Detection. But nconnmercial standardized test available.

9. TREATMENT A lipid Formation of Amphotericin B, Vorironazole & intaconazole. Administration of Amphotericin B for 2 weeks should followed itraconazole for another10 weeks . AIDS patients may require life-long treatment with intaconazole and Vorironazoke. Echinocandins as well posaconazole and terbinafine may be useful .

10. REFERENCE " MEDICAL MICROBIOLOGY" by Murray, Rosenthal, Pfaller , consultant JMI laboratories- 8thedition ,Elsevier publication canada,2016.