Candida Albicans • Ringworm Fungi – Trichophyton Spp

Welcome to Pathogen Group 2

• Candida albicans • Ringworm fungi – Trichophyton spp. – Microsporum spp. – Epidermophyton spp. • Cryptococcus neoformans • Mycobacterium tuberculosis • Mycobacterium leprae Candida albicans • gram +, non-motile • dimorphic fungus: pseudohyphae, yeast cells • chlamydospores • normal ﬂora (normal microbiota) • opportunistic pathogen • About 20% of women carry in vagina; higher in pregnancy • candidiasis, thrush, yeast infection • 40-75% of women will have vaginal yeast infection at some time: thick white discharge, itching, burning, dyspareunia (see diseases in focus 26.2 in your textbook) • Now a common cause of healthcare-associated bloodstream infections & some are resistant to many antifungal medications! Candida: thrush; neonatal thrush Candida diaper rash Candida albicans in sputum Candida albicans chlamydospores Candida albicans germ tubes (diagnostic) in culture Ringworm fungi

• any fungus attacking skin, scalp, or nails • tinea = ringworm – Tinea corporis – Tinea pedis – Tinea capitis – Tinea unguium • Genera: Trichophyton, Microsporum, Dermatophyton, etc • multicellular arthrospores Tinea corporis ringworm Tinea capitis Tinea unguium Tinea pedis Cryptococcus neoformans

• cryptococcosis: lungs, systemic, meningitis • yeast-like fungus with capsule • reservoir: pigeon or other bird feces • airborne • HIV patients; others with poor body defenses Cryptococcus neoformans cycle Disseminated Cryptococcus

• fatal case • slimy because of capsule Mycobacterium tuberculosis

• Tuberculosis infects over 1/3 of worldʼs population • 3.5 million annual deaths • acid-fast, gram + bacillus • non-motile, non-spore forming • can infect any part of body, usually lungs • The pathogenesis of TB – (see ﬁgure 24.9) • BCG vaccine-why not in U.S.? Multiple Drug Resistant TB

• TB re-emerged in the mid 90ʼs with increased drug resistance • Public health infrastructure had been weakened as the disease was thought to be under control • Patients with MDR-TB require treatment for 18-24 months compared to 6-months for drug sensitive organism • Susceptibility testing on initial MTB isolates are essential. It is also important to have cultures in addition to the acid-fast smear. • In 2006, a new strain was identiﬁed and named XDRTB (extensively drug-resistant TB) tb skin testing

48 hours

injection of tuberculin

induration = positive test Mycobacterium leprae • leprosy • acid-fast, gram + bacillus • non-motile, non-spore forming • difﬁcult transmission, long incubation period • wonʼt grow on media; culture on armadillo • anesthesia, pigment changes • trophic changes: atrophy and hypertrophy leprosy: trophic changes leprosy Leprosy Leprosy: 2 years of development (1930s) Leprosy treated (now)