复旦大学微生物学（MBBS）.pdf

Cheng Ling How, Tai Lily, Peach Subannaphong, Priyanka Hingorani & Stella Muloongo Contents — Bacteria that cause: Gastroenteritis and Respiratory Infection — Viruses that cause: Gastroenteritis and Respiratory Infection — Fungi that cause: Respiratory Infection Bacteria That Cause Gastroenteritis DIAGNOSTICS : 1) Staphylococcus aureus : Gram stain – (+), in clusters ; Culture- beta-hemolytic, golden yellow pigment 2) Bacillus cereus : Culture specimen from suspected food source 3) Clostridium perfringens : Culture ( anaerobic ) , Gram stain – (+) 4) Clostridium botulinum : Culture (anaerobic ) , Gram stain – (+) Diagnostics : 1) E. coli : Gram stain - (-) ; Pink colonies on MacConkey agar ; Dark purple to black on EMB agar. 2) Vibrio parahaemolyticus : Blue colonies on TCBS agar. ( non sucrose fermenting ) Lab Diagnosis Shigella Dysenteriae Stool culture Salmonella Typhi Culture: blood, stool or urine Non-typhi groups of Salmonella Culture: blood, stool or urine Yersinia enterocolitica •Stool or blood cultures •colonscopy Vibrio cholarae •Dark field microscopy •Grows as fiat yellow colonies on selective media: thiosulfate-citrate-bile-saltssucrose agar Campylobacter jejuni •Microscopic exam of stool •Selective media with antibiotics at 42Gc Viruses That Cause Gastroenteritis Diagnosis: Rotavirus: Enzyme immunoassay ( EIAs) and PCR from stool Norovirus: RT- PCR from stool The experiment used to isolate and identify bacteria from feces sample is The experiment used to isolate and identify bacteria from feces sample is — Firstly, stool specimen is collected and stored. — Then streak plate is carried out on MacConkey agar and incubated — Morphology of colony on MacConkey agar is observed and recorded. — Gram staining and culturing are carried out with the predominant colony on MacConkey agar in streak plate. — Then, the cultured pure colony is inoculated on biochemical slip. The pure culture colony is also use to carry out antibiotic susceptibility test. — All the results are recorded. Bacteria that cause Respiratory Infection Streptococcus pneumoniae Staphylococous aureus Bacillus anthracis Clostridium botulinum , Clostridium tetani Ecoli Haemophilus influenza Bordetella pertusis,Legionella pneumophilia Yersinis pestis Mycobacterium TB Corynebacterium diphtheria Viruses That Cause Respiratory Infection — The Orthomyxovirus — Influenza Virus — The Paramyxovirus — Parainfluenza — Respiratory syncytial Virus — Measles ( Rubella) Viruses That Cause Respiratory Infection Diagnosis Influenza : 1. Isolation and identification : throat swab, nasal aspirates, sputum 2.RT- PCR 3.HI and ELISA Diagnosis: Parainfluenza: Rubella ( Geman measles) 1. Direct and indirect immunofluorescence test 2. Isolation and identification of virus in nasal wash 3. PCR, RT-PCR 4. Serology test: ELISA 1.Isolation ans identification of virus in nasopharyngeal or throat swabs 2.RT-PCR 3.HI test , ELISA test Respiratory Syncytial Virus inflection 1. Immunofluorescence on exfoliated cell or ELISA on nasalpharynal secretion, nasal secretion. 2. Isolation identification of virus in nasal wash 3. PCR, RT-PCR 4. Serology test ELISA Fungi that cause Respiratory Infection NAME RESEVOIR MORPHOLOGY CLINICAL TREATMENT DIAGNOSIS Coccidioides Immitis -Desert areas(SW. USA, N. Mexico) -Respiratory transmission Dimorphic -Mycelial forms with spores(25°C) -Yeast forms (37°C) Coccidioidomycosis -Asympyomatic (Mostly) -Pneumonia(lesions calcify) -Desseminated: Lung involvement -Amphotericin B -Itraconazole -Fluconazole -Biopsy of affected tissue? silver stain/ Sabourauds agar culture -Serology -Skin test Histoplasma Capsulatum -Mississipi river valley -Bird & bat droppings -Respiratory transmission Dimorphic -Mycelial forms with spores(25°C) -Yeast forms (37°C) Histoplasmosis -Asympyomatic -Pneumonia(lesions calcify) -Desseminated: Lung involvement (Usually) -Itraconazole -Amphotericin B (Immunosuppresed patients) -Biopsy of lung tissue? silver stain/ Sabourauds agar culture -Serology -Skin test NAME RESEVOIR MORPHOLOGY CLINICAL TREATMENT DIAGNOSIS Blactomyces Dermatitidis -Mississipi river valley -Soil & rotten food -Respiratory transmission Dimorphic -Mycelial forms with spores(25GC) -Yeast forms (37GC) Blastomycosis -Asymptomatic -Pneumonia(lesions rarely calcify) -Desseminated: Lung involvement -Itraconazole -Ketoconazole -Amphotericin B -Biopsy of affected tissue→silver stain/ Sabourauds agar culture -Serology -Skin test Cryptococcus Neoformans -Pigeon droppings -Respiratory transmission -Polysaccharide capsule -Yeast form (37GC) Cryptococcosis Pneumonia -Amphotericin B & Flucutosine -Fluconazole -India link stain of CSF showing encapsulated yeast -Cryptococcal antigen -CSF test Fungal culture NAME RESEVOIR MORPHOLOGY CLINICAL TREATMENT DIAGNOSIS Aspergillus 1.Aspergillus Fumugatus 2.Aspergillus Flavus 3.Aspergillus Niger - Everywhere (frequent lab contaminant) - Aspiration of Aspergillus fungi? Asthma Branching septated hyphae Aspergillosis 1-Allergic bronchopulmonary aspergilliosis: asthma type reaction with shortness of breath abd high fever 2-Aspergillioma: (fungal ball) hemoptysis? bloody cough 3-Invasive Aspergiolliosis: necroizing pneumonia 1-Corticosteroids 2-Surgical removal 3-Amphotericin B (Poor outcome) 1-High Ige& IgG, sputum culture, wheezing patient & x ray with fleeting infiltrates, Increased eosinophils, hypersensitivity skin test 2-Chest X-ray &Ct scan Mucormycosis 1.Rhizopus 2.Rhizomucor 3.Mucor Saprophytic molds Broad, non-septated, branching hyphae Mucomycosis 1-Rhinocerebral (starts in mucosa? sinus &orbit; Assoc. Diabetes) 2-Pulmonary mucomycosis Amphotericin B & surgery 1-Biopsy 2-Black nasal discharge