Micro Final

Pneumonia + Hepatitis Q Fever Sulphur Granules Actinomyces israelii Chlamydia pneumoniae Atypical pneumonia. Upper and Lower respiratory infection. Trachoma Clamydia trachomatis - conjunctivities. Primarily in Africa. Immunotype A, B, C. Reiter's Syndrome Autoimmune. Antibodies against C. trachomatis attack urethra, joints, uveal tract. Rickettsia prowazekii Endemic typhoid. Flu-like --> maculopapular rash --> miningoencephalitis. Death from peripheral vascular collapse or bacteria pneumonia. Lice! Rickettsia tutsugamushi Scrub typhus. Vasculitis at site of lesion, rash, edema, hemorrhage, bacteremia. Mites or chiggers. Ehrlicosis Fever, headache, myalgia, thrombocytopenia, leukopenia, liver dysfunction. E. chaffensis (Lone Star tick, monocytes). What does the attached picture indicate? Leptospirosis What does the attached picture indicate? Leishmaniasis What does the attached picture indicate? Entamoeba hystolytica, ingests RBCs. Picture here is of cyst with 4 nuclei. Life cycle of Entamoeba hystolytica No animal reservoir. Cyst is ingested, trophozoite burrows into colon, ascending intestine. What is Metronidazole used to treat? Entamoeba hystolytica, Giardia lamblia Jerky motion of trophozoites on wet-mount. Trichomonas vaginalis Life cycle of Toxoplama gondi Humans and other mammals are intermediate hosts. Cysts ingested in undercooked meat or cat feces. Cysts rupture in small intestine, invade intestinal wall, enter macs and differentiate into trophozoites. Bradyzoites are slow-growing cysts that persist in muscle, CNS, other tissues. What does the attached picture indicate? "Sticky knobs" on RBCs infected with Tremponema. Hemaglobinurea "Black urine," sign of acute renal failure Duffy Antigen FyFy - lack prevents infection with P. vivax. P. ovale generally takes over. What is the treatment for P. falciporum? Doxycycline/quinine or oauone/proquanil. Malarial Life Cycle Sporozite infects human blood (Anopheles) --> burrows into liver cell --> nuclear division produces large, multinucleated schizont --> Membranes develop and merozoites burst from cell --> leave liver and infect RBC -->Cycle repeats. Sexual cycle occurs in Anopheles. Primaquine Follows chloraquinone to kill malarial sporozoites that remain in the liver. Facial edema, nodule at bite, lymphadenopathy, hepatosplenomegaly. Early signs of Chagas Disease, Trypanosoma cruzi. Myocarditis, megacolon, cardiac arrythmia, megaesophagus Chronic Chagas. Trypanosoma cruzi. Life cycle of Trypanosoma cruzi. Trypomastigote ingested or scratched in from Reduviid feces --> epimastigotes --> trypomastigotes in gut --> blood --> amastigotes form in tissues. How to diagnose Chagas. Find trypomastigotes in blood. African Sleeping Sickness Trypanosoma brucei gambiense, Trypanosoma brucei rhodesiense (acute) Tsetse Fly African Sleeping Sickness - T. gambiense or T. rhodesiense. Cutaneous (diffuse or localized) Leishmaniasis Leishmania tropica or Leishmania mexicana Mucocutaneous Leishmania Leishmania braziliensis Visceral Leishmania Leishmania donovani (sandfly) Tx for Leishmania (all types) Sodium stibogluconate Taenia sollium Taeniasis (larvae) or cysticercosis (eggs) Taenia saginata "Beef tapeworm" mild malaise and cramps. Endemic in Africa, South America, Eastern Europe. Trematodes of GI tract Schistosoma mansoni, Shistosoma japonicum. Usually self-limiting but chronic infection can include GI bleeding, hepatosplenomegaly, hematuria, secondary bacterial UTI. Granulomas around eggs may cause portal HTN, fibrosis. Coat allows for invasion. Schistosoma haematobium Urinary tract trematode Pinworm Enterobius vermicularis - treat with mebendazole Trichuriasis (Whipworm) Trichuris trichura Rhabditiform to infectious Filaform Trichuris trichura Ascaris lumbricoides Ascariasis - pneumonia, eosinophilia, abdominal pain. Oval egg with irregular surface. Hookworm Ancyclostoma canium or Ancyclostoma braziliense Necator americanus Hookworm with anemia b/c burrows into intestinal villi and releases anticoagulants. Rhabdiform and filiform. Periorbial edema, fever, muscle pain Trichanosis - Trichinella spiralis. In US most often from wild game. Vancomycin Glycopeptide used to treat gram-positive infections in penicillin allergic patients, or beta-lactam resistant gram-pos (MRSA). Vanc cannot cross gram-neg outer membrane b/c too large. Aminoglycoside Mech Binds irreversibly to 30S ribosomal subunit Aminoglycoside Application Aerobic gram-neg rod infections, M. tuberculosis, or in combination against resistant gram-pos bacteria Tetracyclines Bacteriostatic - reversibly bind 30S ribosomal subunit of some gram-neg and gram-pos bacteria Tetracycline Resistance Active efflux - energy-dependent pump removes drug before it can bind to 30S ribosomal subunit Macrolides Bacteriostatic - reversible binding to 50S subunit. Usually used against gram-pos bacteria, chlamydia, mycoplasma, treponemes, rickettsia. E.g. erythromycin, azithromycin, clarithromycin. Macrolide resistance Methylation of 50S subunit, blocking macrolide binding Rifampin Bactericidal - forms stable complex with bacterial DNA-dep-RNApol, preventing initiation of DNA transcription. Fluoroquinolones Inhibit DNA gyrase. E.g. ciprofloxacin, levofloxacin, moxifloxacin. Cipro Binds DNA gyrase. Fluoroquinaline Fluoroquinalone Mutation in DNA gyrase or efflux pump Metronidazole Bactericidal against anaerobic bacteria - reduces nitro group to produce highly cytotoxic intermediates that disrupt DNA. Also used against intestinal protozoa (giardia, entamoeba) Trimethoprim Inhibits bacterial folate metabolism. Works against gram-neg and gram-pos. Enterococcus is intrinsically resistant. Tuberculosis Drugs RIPE Isoniazid - inhibits cell wall mycolic acid synthesis Rifampin - inhibits DNA-dep-RNApol Ethambutol - inhibits cell wall cynthesis Pyrizinamide Amphotericin B Broad-spectrum anti-fungal. Binds ergosterol in fungal cell membrane, loss of membrane integrity. Parenteral, very serious. Azoles (fluconazole, itraconazole, etc.) Interfere with fungal cell wall ergosterol synthesis. Non-toxic, easier to administer than amphotericin B. Echinocandins "Penicillin for fungi" inhibit glucan synthesis in cell wall of yeasts and some mold fungi Flucytosine Inhibits DNA and RNA synthesis of some fungi. Toxic to bone marrow. Caspofungin Acts on B-glucan, fungiside Sonoran Fever, more common in African Americans and Filipinos Coccidiodes immitis Cultures show arthrospores and hyphae Coccidiodes immitis Yeasts within macrophages Histoplasma capsulatum Granulomas of skin, bone or other. Tissue shows broad-based bud Blastomyces dermatitidis Most common cause of fibrosing medistinitis Histoplasma capsulatum Characteristics of Histoplasma capsulatum - Yeast survives inside phagosome, produces alkaline substances. - Birds, boats, bats - Tuberculate macroconida and microconida Itraconazole Azole antifungal, inhibits synthesis of ergosterol, oral or IV, Dimorphic, thick-walled, "Ships Wheel" Paracoccidiodes brasiliensis Right-sided endocarditis in IV drug user, oval yeast with single bud or pseudohyphae Candida albicans Most common life-threatening fungal infection in AIDS patients Cryptococcus neoformans Cryptococcus neoformans Cryptococcal meningitis, lung infection (although may often be asymptomatic) Most common cause of fungal sinusitis Aspergillis fumigalis High IgE titer and expectorate brownish bronchial plugs containing hyphae Aspergillis fumigalis Anaphalatoxins from nuts Aspergillis flavus Weight loss, fever, night sweats, headache, joint pain, dry cough, severe fatigue Coccidiodes immitis Ulcerations in the oral cavity, lesions at the angles of lips, recent trip to Venezuala, Cough and purulent sputum. Paracoccidiodes brsiliensis Fever, nonproductive cough, progressive dyspnea, tachypnea, fatigue for two weeks. Had recently stopped taking his AIDS medication. Bilateral rales and ronchi, oral candidiasis, bilateral infiltrates with "ground-glass" appearance. Plasma infiltrates in lungs (picture) Pneumocystis carinii Diabetic patient with ketoacidosis, sudden onset fever, chills, pleuritic chest pain, black necrotic lesion, periorbital swelling, ptosis, bloody sputum. Chest X-ray shows patchy infiltrates with cavitation. Fungus with branching nonseptate hyphae at right angles. Mucormycosis Leukemia patient, fever, chills, bloody cough, pleuritic chest pain. "Fungus ball," cultures show septate hyphae with two-way branches at 45 degrees. Aspergillis fumigalis HiV patient, not on therapy, disoriented, nuchal rigidity, CSF showed budding yeast cells surrounded by huge capsule Cryptococcus neoformans Beta lactam Inhibits cell wall cynthesis. Cefttriaxone, Cef- drugs Third generation cephalosporins. Cell wall inhibitors. Glycopeptides Interfere with peptidoglycan precursor. Used with gram-positive bacteria. E.g. vancomycin Vancomycin resistance Enterococcus, plasmic conferring vanc. reistance. Aminoglycosides Inhibit bacterial protein synthesis by binding irreversibly to 30S ribosomal subunit. Used against gram-negative rods, M. tuberculosis, and some gram-pos bacteria. E.g. neomycin. Tetracycline Bacteriostatic - inhibit protein synth by binding reversibly to 30S ribosomal subunit Tetracycline resistance Active efflux Macrolides Inhibit protein synth by binding reversibly to 50S ribosomal subunit. Used against gram-positive (chlamydia, mycoplasma, treponemes, rickettsia). E.g. erythromycin, azithromycin, clarithromycin. Rifampin forms a stale complex with bacterial DNA-dep-RNApol, used with M. tuberculosis. Fluoroquinolones inhibit DNA gyrase, used with gram-neg and gram-pos. Metronidaole Bacteriocidal against anaerobic bacteria and some intestinal protazoa Bactrim Trimethoprim/Sulfamethoxazole - inhibit bacterial folate metabolism. Plasmid-mediated resistance does occur. RIPE Treatment for TB - rifampin, isoniazoid, pyrizinamide, ethambutol Amphotericin B Binds to ergosteral in fungal membranes, destabilizing membrane. Highly toxic, parenteral. Azoles Interfere with ergosterol synthesis. E.g. fluconazole, itraconazole. Flucytosine Inhibitis DNA and RNA synth in some fungi. Toxic to bone marrow. Fungi with septate hyphae Trichophyton