246173104 Microbiology Step 1 Weird Exceptions and Detail

Microbiology Step 1 weird exceptions and forgotten detail Introduction  

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Prokaryotes: have a nucleoid instead of a nucleus Mycoplasma has cholesterol in membrane and no peptidoglycan o Cant gram stain it and beta-lactams don’t work (so use macrolides) o Cholesterol needed to grow it Fungi have ergosterol except PCP ( therefore need to use TMP/SMX trimethoprim/ sulfamethoxazole ) o PCP visualized by SILVER STAIN Polycistronic DNA only bacteria and viruses o One mRNA carry many proteins (have multiple SHINE DELGARNO sequences) Sterile organs (detection any organism= pathological) o Blood o CSF o Stomach Candida is normally present in the mouth, when decreased immune it over grows and causes oral thrush Breast fed only= bifidobacterium ( BB= breastfed baby)

Pathogenicity  Antigenic Variation o N.gonorrhea pili o Trypanosome brucie (African sleeping sickness) o Enterobacteriaceae: capsular and flagellar antigen o HIV : antigenic drift of gp120  IgA protease : SHiN  Strep pyogenes M protein = degrade C3b  Survive intracellular o TB : sulfatides prevent fusion phago and lysosome o Listeria: listerolysin O escape phagosome  Physical damage o Entamoeba histolytica: ulceration intestine and liver abscess o Cysticerosis causes brain lesions seizure Endotoxins  LPS = Gram negative (LIPID A toxic potion)

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T cell independent antigen Causes release of cytokines IL-1 IL-6 TNF-alpha Leads to SEPSIS (septic shock) * works the same mechanism as superantigen from Straph aureus and strep pyogenes = high cytokines  they activate many CD4 T cells = polyclonal activation T cells  sunburn rash and involves palms and soles

Exotoxins  Protein synthesis o EF2 ADP ribosylation(stops translation): C.dipthernia, Pseudomonas aueriginosa o 28S of the 60S ribosome : Shigella, EHEC  Neurotoxin: by inhibit release NT o C.tetani: prevent release glycine and GABA o C.botulinum: prevent release Ach  Superantigen: staph aureus and strep pyogenes  CAΣP : cholera, anthrax, Ecoli ETEC, Pertusis o CAΣ: work via Gs o P works via Gi  Cytolysins: ALPHA TOXIN o Clostridium perfringens: lecithinase = GAS gangrene o Straph aureus: cell membrane leaky

Bacteria Structure  Cell wall protect from osmotic damage (peptidoglycan) o Therefore penicillin will break this down  Capsule protects (only removed by OPSINIZATION) o Bacillus anthracis made from polyglutamate can activate T cell  Spores: bacillus and clostridium o Diplicolinic acid, calcium dipicolinate , keratin o Spores are made in the stationary phase when birth=death Growth on medias  Thioglycolate : anerobes “ cant breath air” : clostridium, bacterioides, actinomyces  Chocolate agar o Neisseria ( Thayer-Martin, VNP : vancomycin, colistin, nystatin)

o Haemophilus influenza. * also grows SATELLITE colony with Staph aureus  Need vactors X and V ( protoporphyrin and NAD)  Atypical pneumonia ( all don’t stain with gram) o Mycoplasma pneumonia = grows MALBURY colony on sterol agar o Legionella: grows on cysteine and iron o Chlamydia : intracellular Oxygen special  Anerobes: “cant breath air” = clostridium. Bacteroides, actinomycin  Obligate aerobes: mycobacterium, Nocardia, and pseudomonas aeruginosa, bacillus  Microaerophil: campylobacter and Helicobacter o They will say “SPECIAL INCUBATOR” Stains  Acid fast : cryptosporidium  Gomori’s methamine silver stain = PCP  Auramine rhodamine fluorescent dye: TB Don’t stain with GRAM 1. Mycobacteria due to waxy cell wall 2. Spirochetes thin 3. Chlamydia and rickettsia intracell 4. Legionella (use silver) Top nosocomial infections 1. Staph aureus : IV, skin, 2. Pseudomonas * ventilator DTP : all TOXOID VACCINE (toxin inactivated by formaldehyde) SHiN: strep pneumonia, Haemophilus influenza, Neisseria meningitides  All have capsule, and VACCINE that is conjugated to protein (diphtheria toxoid)  IgA proteinase  Transformation takes up material from outside  Latex agglutination Latex agglutination  Strep pneumonia  Neisseria meningitides  Hemophilus infuelnzae  Cryptococcus Granulomas  Listeria ( also only Gram + with LPS)

Gram Positive cocci  

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Strep agalactiae : CAMP test + HIppucrate Staph aureus o Coagulase forms abscess bc fibrinogen fibrin  Yersinia other who has coagulase o Scalded skin syndrome : epidermis peal (exfoliative toxin) Nikolski + o Draining sinus from osteomyelitis  predispose to squamous cell cancer o ACUTE ENDOCARDITIS (HIGH fever, fatigue, murmer)  Subacute: splinter hemorrhage, osler nodes, roth spots, weighloss, night sweats o Treatment 1. Nafcillin and oxacillin 2. MRSA: vancomycin 3. VISA and VRSA: quinupristin, linezolin, streptogramin, daptomycin Strep pneumonia o Serotype via capsule o Strep Pneumonia : #1 MOPS ( meningitis, otitis media, Pneumonia, sinusitis) o RUSTY sputum, with consolidation whole lobe, or whole lung Strep pyogenes o Serotype via M protein  M12 = glomerulonephritis o PYR + (pyrrolidonyl arylamidase) o ASO + ( streptolysin O) o DNAse B o Streptokinase ( break down clots) Enterococcus o Subacute endocarditis after GI or GU procedure (Transurethral resection, colonoscopy)

Gram Positive rods Bacillus anthracis “ boxcar large gram  Wool sorter disease ( animals) + postal worker (bioterrorism)  Skin: MALIGNANT pustules= central eschar(black) and red border  Pneumonia: mediastial widening, dyspnea and FACIAL EDEMA Clostridium tetani and botulinum  Both PREVENT THE RELEASE of NT (damage the SNARE protein)

Tetanus  Spores germinate in tissues  Treatment if symptomatic or no vaccine= Ig + metronidazole(anaerobe) + diazepam for spasm  Tetanus prone o If didn’t get primary vaccination or unknown: vaccine + Ig o If had vaccine : give vaccine if booster was 5 years ago Perfringens  Stormy fermentation for milk + double zone hemolysis  Crepitus  ALPHA toxin/ phospholipase C = lecithinase  Identify on EGG YOLK agar  Hyperbaric chamber after debridement and clindamycin bc its anerobic therefore die from high O2 Difficile  Autoclave things to kill spores  If rxn need 1. Stop antibiotic 2. Give metronidazole 3. Give vancomycin 4. Remove infected tissue Listeria  PREGNANT AND HIV DON’T EAT SOFT CHEESE OR DELI  Causes spontaneous abortion  Granulomatosis infantisepticum  Tumbling motility + facultative intracellular + cold grow Corynebacterium diphtheria  Club shaped, chinese letter  Phage carried toxin ( EF2 ADP ribosylation= stop elongation translation)  Myocarditis , ECG change, hoarsness of voice (recurrent laryngeal)  Tinsdale/ tellurite agar  Elek test= toxin  Loeffler serum Nocardia 1. Asteroides: causes pulomary like TB mimicks it 2. Brasiliensis = cutaneous only Mycobacteria TB  Produces B3= niacin  Pathogenesis o Sulfatides: prevent fusion phago and lysosome o Cord factor= serpentile growth , inhibit WBC migration  Correlates with virulence

o Tuberculin :surface protein + mycolic cause PPD  Zone of induration = MEANS EXPOSED (not diseased) o 5mm : HIV or recent exposure o 15 mm : normal people Mycobacteria leprae:  Tuberculoid = Lepromin + test, granuloma, Th1, little acid fast  Leptromatous: test -, Th2, many acid fast

Gram Negative Facultative intracell  Legionella  Francisella - granulomatous  Brucella- granulomatous Rifampin prophylactic exposure  N.meningitisis  Hemophilus Oxidase positive (all enterobacteriacea negative for oxidase)  Neisseria  Pseudomonas  Helicobacter  Campylobacter Urease + “PUNCH” -proteus -urea plasma - nocardia -cryptococcus -h.pylori Spontaneous peritonitis : CHEMOTHERAPY PATIENTS ( the epithelium damaged)  enter in cause peritonitis ( also nephrotic) -Bacteriodes fragillis -E.coli

Bacteria Neisseria meningitides  Usually associated with DIC bc only gram negative to RELEASE LPS since it over produces it  Vaccine only (YWCA) NOT B which is 50% of meningitis in US bc capsule nonimunogenic Gonorrhea  Gram negative diplococci INTRACELLULAR  SEPTIC arthritis in sexually active young KNEE  Causes ophthalmia like chlamydia o Chlamydia also has PNEUMONIA

Pseudomonas aeruginosa  In respirators, in flowers and water, and raw vegetables therefore not allowed in burn units  LIVER PRIMARY TARGET ( Diptheria was