Microbiology slides part 2

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Microbiology slides part 2

  1. 1. MacConkey agar with pink colonies <ul><li>Escherichia coli </li></ul><ul><li>2. Klebsiella pneumoniae </li></ul><ul><li>Striking mucoid appearance (large capsule) </li></ul><ul><li>IMViC --++, urease +, H2S + </li></ul>
  2. 2. A lady underwent a major operation, septicemia. <ul><li>Describe specimen and state most probable organism. </li></ul><ul><ul><li>Specimen- blood </li></ul></ul><ul><ul><li>Escherichia coli </li></ul></ul><ul><li>Test to confirm </li></ul><ul><ul><li>Urease -, H2S -, IMViC ++-- </li></ul></ul><ul><ul><li>Produce indole from tryptophan </li></ul></ul><ul><li>2 drugs </li></ul><ul><ul><li>Cephalosporin (cefotaxime) + aminoglycoside (gentamicin) </li></ul></ul><ul><li>2 sources of organism </li></ul><ul><ul><li>Water </li></ul></ul><ul><ul><li>Normal flora (GIT) </li></ul></ul><ul><ul><li>Urinary catheter </li></ul></ul>
  3. 3. Serology test <ul><li>VDRL + </li></ul><ul><li>TPHA – </li></ul><ul><li>HSV Ag + </li></ul><ul><li>LGV Ag - </li></ul>
  4. 4. 35 y.o. man active sexual history, painful ulcers on penile glans area. <ul><li>Comment on results </li></ul><ul><ul><li>VDRL false + (non-specific treponemal test) </li></ul></ul><ul><li>Most likely infection </li></ul><ul><ul><li>Herpes genitalis by Herpes simplex virus </li></ul></ul><ul><li>Describe briefly immunofluorescent test </li></ul><ul><ul><li>Ag detection by staining with specific Ab with fluorescent dye </li></ul></ul><ul><li>2 conditions produce false – for VDRL </li></ul><ul><ul><li>Recent infection </li></ul></ul><ul><ul><li>Measles, mumps, viral pneumonia </li></ul></ul>
  5. 5. Picture of HIV virus <ul><li>2 parts involved in pathogenesis </li></ul><ul><ul><li>gp 120 </li></ul></ul><ul><ul><li>Reverse transcriptase </li></ul></ul><ul><li>2 parts involved in diagnosis </li></ul><ul><ul><li>HIV p24 core antigen </li></ul></ul><ul><ul><li>HIV ssRNA </li></ul></ul>
  6. 6. Nagler’s reaction
  7. 7. Nagler’s reaction <ul><li>Describe principal </li></ul><ul><ul><li>Neutralization of alpha toxin by specific antitoxin. </li></ul></ul><ul><ul><li>Alpha toxin (lecithinase) produce opacity on antitoxin free half. Antitoxin half inhibit growth of organism (no opacity). </li></ul></ul><ul><li>What organism can be identified </li></ul><ul><ul><li>Clostridium perfringens </li></ul></ul><ul><li>Pathogenesis of the organism </li></ul><ul><ul><li>Spores contaminate wounds </li></ul></ul><ul><ul><li>Germinate in low O2 </li></ul></ul><ul><ul><li>Exotoxin alpha- hydrolyse lecithin in cell membrane, cell lysis </li></ul></ul><ul><ul><li>Exotoxin theta- rapid tissue destruction, direct vascular injury </li></ul></ul><ul><ul><li>Necrosis, gas formed further restrict blood supply, more necrosis </li></ul></ul>
  8. 8. Urethral discharge smear- PMN Thayer-Martin agar
  9. 9. Slide- Neisseria gonorrhoeae <ul><li>Describe (4m) </li></ul><ul><ul><li>Small, translucent grey, glistening colonies </li></ul></ul><ul><ul><li>Thayer-Martin agar </li></ul></ul><ul><ul><li>Intracellular gram – diplococci (PMN) kidney shaped </li></ul></ul><ul><ul><li>>= 4 PMN / hpf </li></ul></ul><ul><li>State identification test (2m) </li></ul><ul><ul><li>Oxidase + </li></ul></ul><ul><ul><li>Glucose utilization test- ferment glucose X maltose </li></ul></ul><ul><ul><li>Direct fluorescent Ab test </li></ul></ul><ul><ul><li>DNA probe assay </li></ul></ul><ul><li>Treatment & its rational (3m) </li></ul><ul><ul><li>Ceftriaxone (intramuscular) </li></ul></ul><ul><ul><li>X penicillin, resistance (beta-lactamase) </li></ul></ul><ul><ul><li>+ tetracycline (with Chlamydia trachomatis infection) </li></ul></ul><ul><li>Complication </li></ul><ul><ul><li>Septicemia </li></ul></ul><ul><ul><li>Spread to lymph nodes- lymphadenitis </li></ul></ul><ul><ul><li>Septic arthritis </li></ul></ul><ul><ul><li>Prostatitis </li></ul></ul>
  10. 10. HI = hemagglutination inhibition
  11. 11. Result of HI <ul><li>Describe result </li></ul><ul><ul><li>4-fold rise in paired sera, measles infection </li></ul></ul><ul><li>Other test </li></ul><ul><ul><li>Immunofluorescence test on nasopharyngeal swab to detest Ag </li></ul></ul><ul><li>2 clinical signs </li></ul><ul><ul><li>Maculopapular rashes </li></ul></ul><ul><ul><li>Fever, cough, coryza </li></ul></ul><ul><ul><li>Koplik’s spot at buccal mucosa </li></ul></ul><ul><li>Complication </li></ul><ul><ul><li>LRTI – Pneumonia, reactivation of TB </li></ul></ul><ul><ul><li>CNS - Encephalitis </li></ul></ul><ul><ul><li>URTI – Laryngitis, sinusitis, mastoiditis </li></ul></ul><ul><li>Treatment </li></ul><ul><ul><li>Symptomatic, isolation of patient, treat complication </li></ul></ul><ul><li>Prevention </li></ul><ul><ul><li>Live attenuated vaccine MMR (12 m, 6 y) </li></ul></ul><ul><ul><li>Passive immunization (Ig) to exposed </li></ul></ul>
  12. 13. Slide & nutrient agar <ul><li>Describe & name pathogen </li></ul><ul><ul><li>Golden yellow/grey-white colonies on ordinary agar </li></ul></ul><ul><ul><li>Gram + coccus, grape-like cluster </li></ul></ul><ul><ul><li>Staphylococcus aureus </li></ul></ul><ul><li>Identification tests </li></ul><ul><ul><li>Coagulase catalase + </li></ul></ul><ul><ul><li>Ferments mannitol </li></ul></ul><ul><ul><li>Beta-hemolysis on BA </li></ul></ul><ul><li>How it cause septicemia </li></ul><ul><ul><li>Skin, soft tissue infection </li></ul></ul><ul><ul><li>Device-associated </li></ul></ul><ul><ul><li>Impaired host defense/unhealed wound </li></ul></ul><ul><li>Treatment </li></ul><ul><ul><li>Cloxacillin </li></ul></ul><ul><ul><li>Vancomycin </li></ul></ul>
  13. 14. Molds: Aspergillus fumigatus A B C
  14. 15. Picture <ul><li>Label a-c </li></ul><ul><ul><li>A= hyphae </li></ul></ul><ul><ul><li>B= conidiospores </li></ul></ul><ul><ul><li>C= conidia </li></ul></ul><ul><li>Name the fungi </li></ul><ul><ul><li>Aspergillus fumigatus </li></ul></ul><ul><li>What disease </li></ul><ul><ul><li>Allergic bronchopulmonary aspergillosis </li></ul></ul><ul><ul><li>Fungal sinusitis </li></ul></ul><ul><li>Culture </li></ul><ul><ul><li>Sabouraud’s dextrose agar </li></ul></ul><ul><li>Treatment </li></ul><ul><ul><li>Amphotericin B </li></ul></ul>
  15. 16. Dark field- Leptospira <ul><li>Name the pathogen </li></ul><ul><ul><li>Leptospira interrogans </li></ul></ul><ul><li>Natural habitat </li></ul><ul><ul><li>Redent, wild & domestic animals </li></ul></ul><ul><li>Transmission </li></ul><ul><ul><li>Contact with water/wet soil contaminated with urine </li></ul></ul><ul><li>2 other organisms with almost same morphology, their mode of transmission and infection caused. </li></ul><ul><ul><li>Treponema pallidum, sexual contact, syphilis </li></ul></ul><ul><ul><li>Borrelia burgdorferi, tick bite, Lyme disease </li></ul></ul><ul><li>Treatment </li></ul><ul><ul><li>Penicillin </li></ul></ul><ul><ul><li>Tetracycline </li></ul></ul>
  16. 17. HIV blood test- HIV Ab detected in pregnant mother <ul><li>Interpret report (4m) </li></ul><ul><ul><li>Ab detected, she might be infected. </li></ul></ul><ul><ul><li>Result might be false + </li></ul></ul><ul><ul><li>2nd test should be repeated </li></ul></ul><ul><li>Other test to comfirm </li></ul><ul><ul><li>Particle agglutination, western blot </li></ul></ul><ul><li>Factors ass. with vertical transmission of infection </li></ul><ul><ul><li>High plasma viral load </li></ul></ul><ul><ul><li>Preterm delivery </li></ul></ul><ul><ul><li>Delivery >4 hours aft rupture of membrane </li></ul></ul><ul><ul><li>HIV subtype </li></ul></ul><ul><ul><li>No antiretroviral therapy </li></ul></ul><ul><ul><li>Coinfection: HSV 2 </li></ul></ul><ul><ul><li>Chorioamniotis </li></ul></ul>
  17. 19. Blood culture 25y.o. female with burns. Admitted 10 days ago <ul><li>Describe & name pathogen (4m) </li></ul><ul><ul><li>Blue green on ordinary agar </li></ul></ul><ul><ul><li>Large mucoid colonies with irregular edge </li></ul></ul><ul><ul><li>Fruity aroma </li></ul></ul><ul><ul><li>Pseudomonas aeruginosa </li></ul></ul><ul><li>Microscopic features with gram stain (2m) </li></ul><ul><ul><li>Gram – bacilli, polar flagellum, X spore X capsule </li></ul></ul><ul><li>What are the likely source of organism (3m) </li></ul><ul><ul><li>Soil, water </li></ul></ul><ul><ul><li>Simple aqueous solution </li></ul></ul><ul><ul><li>Normal flora of colon and URT </li></ul></ul><ul><li>Other organism that can cause wound infection from burn </li></ul><ul><ul><li>Staphylococcus aureus </li></ul></ul><ul><ul><li>Streptococcus pyogenes </li></ul></ul><ul><li>2 antimicrobials </li></ul><ul><ul><li>Gentamicin </li></ul></ul><ul><ul><li>Polymyxin B & E </li></ul></ul>
  18. 21. Isolated from skin infection, stained with lactophenol cotton blue <ul><li>Describe & name pathogen </li></ul><ul><ul><li>Macroconidia - rare, thin, smooth walled, cigar shaped </li></ul></ul><ul><ul><li>Microconidia - numerous, tear-shaped on lateral septated hyphae </li></ul></ul><ul><ul><li>Trichophyton </li></ul></ul><ul><li>Natural habitat </li></ul><ul><ul><li>Soil, animal, human </li></ul></ul><ul><li>Best medium for isolation </li></ul><ul><ul><li>Sabouraud’s dextrose medium </li></ul></ul><ul><li>Other side of body affected </li></ul><ul><ul><li>Scalp, nails, hair, groin </li></ul></ul><ul><li>2 antimicrobials </li></ul><ul><ul><li>Miconazole </li></ul></ul><ul><ul><li>Itraconazole </li></ul></ul>
  19. 23. Slide- leaf like macroconidia <ul><li>Describe (4m) </li></ul><ul><ul><li>Macroconidia: thick walled, spindle shaped, spiny surface, knoblike ends </li></ul></ul><ul><ul><li>Microconidia: present but few </li></ul></ul><ul><ul><li>Microsporum </li></ul></ul><ul><li>Name 2 possible organism with the disease they cause (4m) </li></ul><ul><ul><li>Tinea capitis </li></ul></ul><ul><ul><li>Tinea corporis </li></ul></ul><ul><li>2 drugs (2m) </li></ul><ul><ul><li>Itraconazle </li></ul></ul><ul><ul><li>Miconazole </li></ul></ul>
  20. 25. Photo- Neisseria meningitidis <ul><li>Describe and name </li></ul><ul><ul><li>Gram – diplococci in paired (kidney shaped) seen in CSF </li></ul></ul><ul><ul><li>Large colonies on Thayer-Martin agar </li></ul></ul><ul><li>Prevention </li></ul><ul><ul><li>Active immunization in high risk settings </li></ul></ul><ul><ul><li>Prophylaxis (rifampicin, ceftriaxone) </li></ul></ul>
  21. 26. Germ-tube
  22. 27. Microscope- Candida albicans <ul><li>Describe (4m) </li></ul><ul><ul><li>Yeast like colonies, pearl like, cream colored, waxy, soft </li></ul></ul><ul><ul><li>Pseuudomycelium, gram – budding cells </li></ul></ul><ul><ul><li>Germ tube (37 C), chlamydospore (25 C) </li></ul></ul><ul><li>Disease & etiology (2m) </li></ul><ul><ul><li>Candidiasis, candida albicans </li></ul></ul><ul><li>2 tests (2m) </li></ul><ul><ul><li>Culture on SDA </li></ul></ul><ul><ul><li>Germ tube test </li></ul></ul><ul><ul><li>Urease – </li></ul></ul><ul><li>Drugs (2m) </li></ul><ul><ul><li>Amphotericin B </li></ul></ul><ul><ul><li>fluconazole </li></ul></ul>

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