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Class

Name

Toxin/virulence factor

Properties

Staph aureus

protein A

septic arthritis, abscesses, septic abx, endocarditis, Catalase (+) Coagulase (+) Beta hemolytic Pneumonia, osteomyelitis* (especially following bacteremia d/t intravascular Penicillin, Nafcillin or Mannitol fermenting, MRSA exists in devices - catheters), toxic shock, scalded skin, food poisoning, Vancomycin for MRSA nasopharynx of asx carriers impetigo; heart issues in IV drug users

Staph epidermidis

biofilm aka synth of polysac extracellular matrix

Catalase (+) Coagulase (-) Urease (+) Novobiocin sensitive

Endocarditis of artificial valves*, orthopedic joint infections, contamination of blood cultures

Catalase (+) Coagulase(-) Urease (+) Novobiocin resistant

UTIs in sexually active females

Staph saprophyticus

Strep pyogenes (GAS)

streptolysin O (ASO Abs) streptokinase SpeA,C, and B (exotoxin), M protein = homologous to myosin and tropomyosin - evades phagocytosis (RF) DNAses

Treatment

Vancomycin

impetigo, pharyngitis, cellulitis, erysipelas, necrotizing fasciitis*, Catalase (-) Coagulase (-) Beta hemolytic toxic shock, rheumatic fever (type II hypersensitivity, mimicry of Bacitracin sensitive, non-immunogenic myosin in tumbling motility extracellular, catalase meningitis of newborn or termination of pregnancy, elderly can ampicillin (+), "Acting rocket" movement, multiplies get meningitis; granulomatosis infantisepticum in near freezing temp

Actinomyces israaelii

with jaw trauma (i.e. dental work) --> abscess, draining obligate anaerobe, branching filamentous assoc sinus tracts, yello sulfurous secretions; cervical facies rods actinomyces infection

Nocardia spp.

catalase (+), branching filamentous rod, immunocompromised at risk (esp CGD*), M > F, brain abscesses, obligate aerobe (vs actinomyces), in soil, pneumonia-like sx -> cavitations in the lung, cutaneous sx -> sulfonamides mycolic acids - acid fast, urease (+) indurated lesions and inflammatory rxn

Neisseria spp.

N. meningitides

penicillin

pilus(attachment and has antigenic variation), IgA protease promotes survival along mucosal surfaces

oxidase (+), grows on chocolate agar specifically VPN/Thayer-Martin (vancomycin, polymixin, nyastatin) selective for Neisseria spp

patients without C5-C9 MAC intact are particularly susceptible

"

" and also ferments glucose AND maltose, polysaccharide capsule is virulence factor esp type B, LOS induces inflammatory response

lives in nasal cavities, resp droplet transmission, hematogenous spread (SCD more susceptible) --> inflammatory response --> inc ceftriaxone for patients, vascular permeability --> hypovolemia --> petechial rash --> DIC rifampin for close contacts and shock; Waterhouse-Freiderich syndrome (adrenal infarction d/t vasoconstriction response to hypovolemia)

N. gonorrhea

"

" and ONLY ferments glucose, NO CAPSULE, facultative intracellular within PMNs- does not gram stain well and difficult to grow

males = urethritis, prostatitis, orchitis; females = PID, Fitz Hugh Curtis syndrome, violin string-like adhesions in liver; assymmetric ceftriaxone + macrolide for polyarthritis in both sexes, neonatal conjunctivitis within 5 days chlamydia (co-infection) after birth - purulent white discharge

Klebsiella

polysaccharide capsule

lactose-fermenting (MacConkey agar), immotile, urease positive

nosocomial infection, UTI and pneumonia, cavitary lesions in lungs resembling TB; 3 As = Alcoholics, Abscesses, Aspiration; currant jelly sputum

clindamycin, carbopenam

Enterobacter

lactose-fermenting (MacConkey agar), motile

nosocomial infection, UTI and pneumonia

clindamycin, carbopenam

Serratia

lactose-fermenting (MacConkey agar), motile, catalse positive

nosocomial infection, UTI and pneumonia

clindamycin, carbopenam

Salmonella enterica

non-lactose fermenter (white on MacConkey), motile, H2S positive (black capsule - invasion of colon via on hektoen agar), capsulated, acid labile MO's (destroyed in stomach acid usually), facultative intracellular, positive for citrate utilization (blue)

ingestion of uncooked chicken, patients on PPI's more susceptible salmonella septicemia = (inc pH, inc ability to grow), inflammatory diarrhea, chloramphenicol, Amp, Amox, gastroenteritis, contains type 3 secretion system - detects or TMP/SMX for 10 days eukaryotic cells that inc infectivity

Salmonella typhi

"

#1 cause of osteomyelitis in adults with SCD, pea soup diarrhea, three phases: 1) lethargy, dull frontal HA, constipation, rise in " and also harbored in gallbladder, always body temp 2) bacteremia, fever, severely ill, dull expresionless from HUMAN source look, rose spots develop on trunk 3) second bacteremia d/t reinfection of biliary tract, pus in stools and bleeding in peyes patches (Ileum necrosis)

Shigella (sonnei and dysenteria)

Shiga toxin - binds 60S ribosomal subunit; LPS endotoxin leads to inflammation

type 3 secretion system to release micro enzymes, green colonies on hektoin agar, indole positive (vs salmonella), acid stable, immotile, non-lactose fermenter, non H2S, facultative intracellular

E. coli

capsular K antigen

ferments lactose (pink on MacConkey), #1 cause UTI, leading cause of gram neg sepsis by LPS endotoxin facultative anaerobic, oxidase neg, green in outer cell membrane, causes neonatal meningitis only if K Ag sheen on EMB present

EHEC

Shiga-like toxin - binds 60S ribosomal subunit

O157:H7 assoc with outbreaks; only E. coli that does NOT ferment sorbitol

gastroenterits, watery diarrhea --> bloody diarrhea, fewer organisms cause sx, induces M cells in Peyers patches to phagocytose them -> escape from phagolysosome -> has a tail and propels from one cell to another; HUS > 10 years old child most common: diarrhea followed by acute renal failure

undercooked meat, bloody (hemorrhagic) diarrhea, HUS --> damaged endothelium --> adherence of platelets --> dec platelet count --> thrombocytopenia --> hemolysis of RBCs; little to no fever with mucosal inflammation/invasion

fluoroquinolone (cipro/levo) or cephalosporin (ceftriaxone); live attenuated vaccine; DO NOT USE ANTIDIARRHEAL

macrolides and fluoroquinolones

Gram negative

ETEC

LT enterotoxin; heat labile toxin - inc cAMP (cholera-like toxin), stabile toxin - inc cGMP

"Traveler's diarrhea" - esp after Mexico trip, transmitted in contaminated water; watery diarrhea

TMP/SMX or fluoroquinolones

Yersinia enterocolitica

capsule

transmitted through puppy feces and contaminated milk - children most commonly affected; bloody diarrhea, resistant to cold temp, stain on both ends products fever, intestinal issues, leukocytosis, abscesses, major bowel (safety pin staining) issues, can mimic appendicitis in children (RLQ pain, fever, etc), reactive polyarthritis in HLA B27 indv

Yersinia pestis

YOP (yersinia outer proteins) inh MO via tyoe 3 secretion inh phagocytosis; endotoxin, neurotoxin

fleas are vector - prarie dogs reservoir, humans incidental host

form buboes with swollen tender lymph nodes, abscesses in organs, DIC from endotoxin and neurotoxin

Campylobacter jejuni

colonization of intestinal mucosa --> attach to epithelial cells and replicate intracellularly via acute PMN response

curved rod (comma), grows on campy medium or skirrow agar, prefers warm (42 C) environment, reservoir is poultry GI tract, fecal-oral transmission, contaminated water, ingestion of raw milk, oxidase positive

acute enteritis, bloody diarrhea, bacteremia --> invasive, reactive supportive care arthritis (Reiter's syndrome), Guillan Barre syndrome

Vibrio cholera

curved rod, enteric tract bacilli, grows in cholera toxin - inc cAMP, AB alkaline media ("Base cAMP"), acid labile, toxin, activates GS pathway --> attaches to mucosal wall via fimbriae --> watery "rice water" diarrhea, transmitted fecal-ral efflux of Cl- and H2O attaches to ganglioside receptors in intestinal wall

Vibrio vulnificus and paraliticus

"

"

found in seafood, esp oysters, vulnificus causes acute gastroenteritis, paraliticus causes fulminating septicemia leading to marked edema, necrosis, and death

Pseudomonas

exotoxin A - identical to diphteria toxin -> ribosylation of EF2 -> inh protein synth and cell death

oxidase (+), catalase (+), obligate aerobe, produces green pigment via Pyocyanin and pyoverdin, grape-like odor, encapsulated, thrives in aquatic environments

CGD inc risk, nosocomial UTIs, hot tub folliculitis, CF patients inc piperacillin (penicillin), risk pneumonia and resp failure, nosocomial pneumonia, aminoglycosides, osteomyelitis in IV drug users and diabetics, burn patients inc risk fluoroquinolones infection, ecthyma gangrenosum, otitis externa (swimmer's ear)

Proteus mirabilis

creates alkaline environment

urease (+), swarming motility, fishy odor, struvite stones --> staghorn calculi, formed of ammonia, Mg2+, H2S positive, facultative anaerobe and phosphate, causes UTIs

killed vaccine (not commonly used), treat with aminoglycosides + tetracyclin

oral rehydration therapy

Bordatella pertussis

pertussis toxin - ribosylates Gi --> disables and causes inc cAMP; EF = adenylate cyclase toxin similar to anthracis toxin edema factor, also inc cAMP; tracheal toxin damages ciliated cells; aerobic, non motile

ADP diables chemokine rec for lymphocytes --> lymphocytosis in blood; transmitted via resp droplets --> pili, filamentous hemagglutinin

whooping cough - 1) catarrhal phase = most infectious stage, nonspecific sx, 1-2 weeks 2) paroxysmal stage = cough 3) macrolides, DTaP acellular convalesence stage lasts 3 months with a cough, 100 day cough - vaccine using purified Ag most susceptible to secondary infections

Haemophilus influenza

type B capsular Ag important in meningitis

grows on chocolate agar, needs Factor 10 (hemodin) and Factor 5 (NAD) "hemoTEN", infection via aerosol transmission, cocobacillary shape

epiglottitis in hildren: drooling, inflamed epiglottis, stridor; otitis media in children, meningitis (only if type B capsular form), sepsis and septic arthritis in asplenic pts and those with SCD, pneumonia

Legionella

Zinc metalloprotease cytotoxic and inh PMN production, inh superoxide reduction, and deactivates IL1, CD4, TNF

CYE (charcoal) with iron and cystein to grow, silver stain to visualize, oxidase positive, rapid urine Ag test to confirm

1) atypical/walking pneumonia, esp in elderly men who smoke, presents with high fever 104 F, watery diarrhea, hyponatremia, fluoroquinolones first line, can and neuro sx; patchy unilobed infiltrate on CXR 2) Pontiac fever - also use macrolides fever and malaise self limiting

Wartharin starry stain (silver stain) to visualize

1) cat scratch fever: fever + painful lymphadenopathy in axilla immunocompetent indv 2) bacillary angiomatosis: red vascular lesions all over body - immunocompromised indv; also culturenegative endocarditis

Bartonella henselae

ceftriaxone, rifampin for close contacts, conjugated with diptheria toxoid for vaccination of 2-18 mo old babies

Doxycycline for bacillary angiomatosis and macrolides (azithromycin) to tx both

Brucella

farm animal is reservoir, indirect contact with unpasteurized milk or cheese travels in MO, catalase and products, facultative intracellular in MO's fever, chills, anorexia, undulant fever --> enlargement of spleen, SOD prevents respiratory burst - jumps from organ to organ in liver, and LNs; can cause osteomyelitis (chronic infection) endothelial reticular organs; urease and H2S positive, req CO2 to grow

Francisella Tularensis

facultative intracellular, does not induce ocidative burst

tick vector (dermacentor, M/C) or rabbit vector, coccobacilli, facultative intracellular in MO; can be aerosolized used in bioterrorism and must be reported

Coxiella burnet

spores

obligate intracellular, placental excretions Q fever, NO RASH, pneumonia and HA, hepatitis, hemorrhage on self-limiting, supportive care; of farm animals and droppings, aerosol fingers prevent by pasteurizing milk transmission

Tularemia: causes painful ulcer (ulceroglandular disease) -> enters through ulcer and into MO to reticuloendothelial system -> caseation necrosis/granulomas and regional lymphadenopathy; req cell-mediated immunity to clear

tetracycline and doxycycline + rifampin for primary treatment

aminoglycosides (streptomycin)

Gram indeterminate

Pasteurella Multocida

capsule

catalase positive, oxidase positive, grows cat and dog bites, causes cellulitis, necrotizing fasciitis, or on 5% sheep's blood agar, bipolar/safety osteomyelitis; can cause lymphadenopathy in liver dz or COPD pin staining like Yersinia

penicillin + beta lactamase inhibitor amoxillin and clavulanic acid

Reiter's syndrome = cross react of Abs against knee or SI joint "cant see, cant pee, cant climb a tree"; 3 trachomas 1) A-C types = blindness* leading cause blindness in world2) D-K types = STI, macrolides (azithromycin), watery discharge, PID, neonatal conjunctivitis and pneumonia - tetracyclines, if also gonorrhea staccato cough 3) L1-L3: Lymphogranuloma venereum - tender tx with ceftriaxone lymph + draining LN; Chlamydia pneumonia = walking pneumonia, C. psittaci = transmission by birds - pneumonia

Chlamydia trachomatis, psitacci

obligate intracellular, cannot make own ATP, elementary bodies = 1st stage life cycle outside cell - infectious form, reticulate body = 2nd stage and dividing form "reticulate replicates"; Giemsa stain - inclusion bodies, Dx with NAAT aka PCR

Gardnerella vaginalis

gram variable rod, overgrowth of normal anerobic flora causes problems, KOH white grey discharge from vulva, malodorous positive whiff test, pH > 4.5; blue clue cells show bacteria

metronidazole, clindamycin

Mycoplasma pneumonia

no cell wall, no gram stain, cholesterol in cell membrane (sterols), Xray (patchy infiltrates) looks worse than clinical pneumonia + cold intolerance presentation, IgM cold agglutinins, military recruits < 30 years, EATON agar

macrolides

Rickettsia rickettsi

Rickettsia Prowazekii

Rocky Mountain Spotted fever: transmitted by dermacenter tick via direct biting, incubation of 2-14 d - maculopapular rash starts on ankles and wrists and moves centrally; HA, severe fever, myalgia

obligate intracellular, pleomorphic, colonize endothelial cells --> endothelial Doxycycline, chloramphenicol hyperplasia and rash, coccobacillary if pregnant (rarely used shape, weakly gram (-), cant make NAD+ otherwise), supportive care and CoA on own, Weil Felix agglutination test, Giemsa stain endemic typhus: assoc with poor living conditions/poor hygeine, transmitted by lice via defecation and scratching of feces into skin, rash starts at trunk and moves to extremities, spares hands, feet and head, affects military recruits and POWs; myalgia and arthralgia, pneumonia, encephalitis, can cause COMA, HA

Mycobacterium Spirochetes

acid fast - mycolic acids stain with carbol fuchsin, grows on Lowenstein-Jensen medium, obligate aerobe, transmitted via respiratory droplets

primary infection = middle lobe + hilar lymphadenopathy, caseating granulomas --> Ghon complex, visual calcification, Langerhans giant cells; long fever and in children resolves by fibrosis; secondary (reactivation) infection = upper lobe involvement, cough + fever + night sweats + hemoptysis; miliary TB = multiorgan failure, downreg of TNFa triggers; Potts disease (TB in spine), CNS involvement - meningitis or tuberculoma

RIPE (rifampin, isoniazid, pyrazinamide, ethambutol), prophylaxis = rifampin or isoniazid for 9 mo; testing = PPD, BCG shows (+) skin test

armadillo reservoir

thrives in cool temps, armadillo is reservoir in US, acid fast, carbol fuchsin stain, aka Hansen's disease

1) Tuberculoid: Th1 stim MO to eat bacteria (cell mediated immunity), mild sx, well demarcated hairless lesions on skin 2) Lepromatous: Th2 promote humoral response, bacteria uncontained, high chance of human to human transmission, glove and stocking symmetric neuropathy, extensor surfaces with lesions, Leonine facies and deformity

tuberculoid = dapsone + rifampin for 6 mo; lepromatous = dapsone + rifampin + clofazamine for 2-5 years; Lepermans skin test wheel will form if positive; DAPSONE

Borrelia burgdorferi

Ixodes tick vector

helical, longer vs treponema, prevalent in NE US, transmitted by Ixodes tick (also Ehrlichiosis and Babesiosis), mice = larvae, deer = adults, humans incidental host, do NOT gram stain, Wright-Giemsa stain

1) Endemic relapsing fever caused by B. hermsii and B. duttonii 2) Lyme Disease = stage 1 - bull's eye rash, fever, chills stage 2 heart block (myocarditis) + bilateral Bell's palsy stage 3 migratory arthritis + CNS sx

start tx immediately doxycycline for early or mild sx, ceftriaxone for late/severe sx

Leptospirosis

question mark shaped, animal urine dog-urine contaminated water reservoir, Tropical regions; patients who do water sports

Mycobacterium Tuberculosis

Mycobacterium Leprae

cord factor - proliferates in MO and inc TNFa -> granuloma formation; sulfatides prevent phagolysosome function; glycolipids lead to clumping of bacteria into serpentine formation

fever and conjunctival redness without pus, Weil's disease, travels in bloodstream --> causes renal dysfxn, jaundice from liver doxycycline or azithromycin damage

Treponema pallidum

microaerophilic, can only be grown in rabbit testes, dark field microscopy for direct visualization, VDRL for treponema but NOT specific, RPR = low sensitivity (mono, RF, SLE, LEP also positive), FTA ABS is confirmatory

Primary syphilis: painless chancre, local invasion of small BVs, also takes out nerves Secondary syphilis: systemic disease, maculopapular rash on palms and soles of feet, months to weeks Penicillin; Jarisch Herschimer after infection, condyloma lata - dark field micro can detect confirms success - sick Tertiary syphilis - gummas, aortitis - tree barking, demyelination rxn of nerves and post spinal cord = loss of proprio, Argyle Robertson feeling + fever and chills pupils Congenital syphilis: saber shins, saddle shaped nose, Hutchinson teeth, mulberry molars, deafness

Histoplasma capsulatum

Mississippi and Ohio River Valleys (Midwestern US) bird or bat droppings, in caves, Dx via KOH or rapid serum or urine Ag test, histo shows MO with intracellular oval bodies (multiple), mold in cold (Sabouraud's agar) yeast in heat

systemic mycosis, coughing - pneumonia, granulomas which look like TB but with calcified nodes and hilar nodes, erythema azoles for mild and nodosum shows robust response in healthy indv, immunocompd amphotericin B for systemic = affects liver and spleen --> hepatosplenomegaly

Coccidioides immitis

Fungi

Blastomycoses dermatidis

spherules packed with endospores

San Joaquin Valley Fever (Southwestern US), transmitted via inhalation, common after earthquakes, mold in cold spherule in heat - larger vs RBCs

systemic mycosis but asymptomatic in most, arthralgia, cough pneumonia, fever, lung cavities/nodules, erythema nodosum in healthy pepople, bone infection in immunocompd, meningitis, IgM indicates recent infection

spores

Great Lakes and Ohio River Valley, mold in cold yeast in heat, transmitted via mycosis, patchy alveolar infiltrate on CXR, osteomyelitis, Itraconazole for local, amp B inhalation of spores, shows broad based systemic for systemic infection budding, same size as RBCs, dx via KOH damage to skin and bones prep or urine Ag test

local lung infection = azoles, systemic = amp B

Paracoccidioides brasiliensis

South America, dimorphic, multiple buds cervical lymphadenopathy in chains, granulomas in lungs, radiating out of central vacuole, large size cough, mucosal ulcers and cutaneous lesions in upper mouth vs RBCs leading to small hemorrhages

Malassezia furfur

spaghetti and meatball appearance on KOH prep of skin scrapings, thrives under hot and humid conditions

cutaneous mycosis - Pityriasis versicolor = hypo- or hyperpigmented un-itchy patchy lesions on back or chest, esp with inc sun exposure, affects only stratum corneum, caused by selenium sulfate (selsum blue) lipid degradation and destruction of melanocytes, can cause severe disease in immunocompd - pts receiving TPN, catheter of lipid infusions (neonates) causes sepsis and thrombocytopenia

Tinea (Dermatophytes)

Trichophyton, Epidermophyton, Microsporum (only these can be visualized by Woods lamp), athletes, swimmers, and wrestlers, animals also source; hyphae visible with KOH

cutaneous mycosis, Tinea capitus: head, Tinea corpus: body, Tinea cruris: groin, itchy; Onchomycosis: nails

Sporothrix schenckii

found in rose thorns "rose gardeners disease", tree bark, dimorphic fungus, cigar shaped budding yeasts, multinucleated giant cells, histiocytes, branching hyphae at 25 C

itraconazole for subcutaneous mycosis, sporotrichosis: ascending lymphadenitis, lymphocutaneous local trauma shows pustules or nodules - red bumps on skin sporotrichosis, historically KI was used

Candida albicans

yeast form with pseudohyphae in cold (25 C below), true hyphae + germ tubes at 37 C, catalase (+) - CGD susceptible, KOH prep to Dx

severe diaper rash, normal flora of GI and oral cavity = for mild, amp B contamination of sputum, oral candidiasis in steroid inhaler users, azoles nyastatin for oral or esophagitis + white pseudomembranes = AIDS defining illness - (systemic), esophageal infection, more susceptible if CD4+ < 100, diabetes, birth control pills, capsofungin for resistant antibiotics all inc susceptibility, IV drug users - endocarditis, infections tricuspid valve

Itraconazole for local, amp B for systemic infection

terbanifine, clotrimazole, griseofulvin (serious infection)

Aspergillus fumigatus

catalase (+), acute angle branching of "acute septate", conidiophores aflatoxin - associates with grain hyphae with fruiting bodies are inhaled by humans; farmers susceptible

aflatoxin produced by A. flavus, causes hepatocellular carcinoma, allergic bronchopulmonary aspergillus (ABPA) = wheezing, fever, and migratory pulmonary infiltrate, Type I hypersensitivity, IgE response; aspergillosis = susceptibility inc with TB infection aspergillomas within TB cavities; angioinvasive aspergillosis = patients with neutropenia (leukemia/lymphoma), can cause kidney failure, endocarditis, ring-enhancing lesions in brain, invades nasal sinus

Cryptococcus neoformans

urease (+), transmitted by pigeon droppings in soil --> inhaled, latex thick polysaccharide capsule = agglutination test = dx tests for repeating antiphagocytosis polysacc Ag; stains with india ink = wide encapsulated halos; mucus stains with mucicarmine red or methanamine silver

opportunistive infection - HIV, high dose steroid use, malignancies; pulmonary sx = cough, dyspnea, infection; can joint therapy with amp B and spread to CSF: meningitis, permanent neuro defect; fever, then fluconazole bronchopulmonary washing = soap bubbles; lesions in CNS dx by flucytosine, lumbar puncture -> india ink; brain has soap bubble lesions; #1 after M/C cause fungal meningitis

Mucormycoses

spores - inhaled

rhizopus = bread mold, hyphae nonseptate and branch at 90 deg angle, proliferates in BVs, invasion via cribiform plate after inhalation; bx needed for Dx

voriconazole for minor infection, amp B for invasive, surgical removal of aspergillomas

immunocompromised and DM at risk --> DKA predisposes infection --> necrosis of tissues and frontal cortex abscesses, produces black eschar and necrosis of nasal cavity (poor px at this debridement, then amp B stage), causes neuro deficits and death

Pneumocystis jirovecii

CD4+ < 200 start prophylactic tx; immunocompromised susceptible, esp HIV and elderly, healthy bronchoalveolar lavage for dx, can be asx, pulmonary sx = ground glass appearance in both methamine silver stain to ID fungus that indv lungs lookse like disc shaped yeasts

bactrim (TMP/SMX) = higher risk of allergy for HIV pts! Pentadamine for sulfa allergy, also DAPSONE

Picornavirus

naked (+)ssRNA, requires only host cell machinery, replication in the cytosol fecal-oral transmission

aseptic meningitis = normal glucose, no cultures, elevated protein

Poliovirus (Picornovirus)

"" acid stable (fecal-oral transmission), replication in Peyer's patches in submucosa of ileum - 2-3 weeks, infection of anterior horn of LMN cell bodies

no tx only vaccine: Salk = killed, used in US produces asymetric paralysis in lower legs, myalgias, respiratory deficiency IgG; Sabin = live, shed in feces = M/C cause of death; aseptic meningitis and used in 3rd world countries - can also cause Polio, makes IgM

Coxsackie virus (Picornovirus)

"" A and B type

A type = Hand-Foot-Mouth disease (vesicular rash), aseptic meningitis, summertime; B type = dilated cardiomyopathy* and devil's grip/Bornholm's disease - extreme unilateral chest pain (pleurodynia)

supportive care

RNA (+) Viruses

Rhinovirus (picornovirus)

"" acid labile, transmitted through resp droplets and fomites, attaches to ICAM-1 common cold to enter host cells, grows best at 33 C (in nares), 113 total serotypes = NO VACCINE

no vax, supportive

Hepatitis A virus (picornovirus)

in traveler's in endemic areas, esp Southern "" acid stable (fecal-oral), contaminated common water (developing countries) and shellfish hemisphere, causes hepatomegaly, jaundice (adults only), vomiting, smoking aversion, one month duration - self-limiting, (developed countries) no carrier or chronic state

inactivated vaccine for travelers, prevention by chlorination, bleaching, UV/irradiated, or boiled water

Norwalk virus (Calicivirus)

(+)ssRNA, naked, produced one long single protein that is cleaved by viral proteases into smaller constituents; replicates in cytoplasm

diarrhea outbreaks on cruises, common in daycare centers, foods in buffets - esp seafood/shellfish, causes explosive diarrheal illness

Flavivirus

(+)ssRNA, nonsegmented, enveloped, sometimes vector transmission

Dengue fever (Aedes egyptei) - renal failure, septic shock, infection of bone marrow, bleeding, hemorrhagic fever; Yellow fever (Aedes egyptei) - back pain, bloody diarrhea, jaundice, vomiting, West Nile Virus (Culex spp.): birds are reservoir, encephalitis, seizures, coma, flaccid paralysis

Hepatitis C (flavivirus)

"" transmission by blood transfusion, IV drug use, placentally, sex, breast feeding; high antigenic variation d/t virion exonuclease lack of proofreading in 3-5' so RNA is prone to freq mut's, cryoglobulins (IgM)

jaundice, inc LFT's, hepatomegaly, causes chronic hepatitis, lymphocyte infilatrion of portal tract kills hepatocytes and causes + IFN-alpha + fibrosis and cirrhosis, can lead to hepatocellular carcinoma, acute ribavirin protease inhibitor infection = RNA in serum in 1st 6 mo, ALT rises and falls; **leading cause of liver failure and transplant**

Rubella (Togavirus)

(+) ssRNA, enveloped, one long polyprotein precursor cleaved by proteases, usually unvaccinated immigrants; replication in cytosol

Congenital (TORCHeS): crosses placenta, mental retardation, sensorineural deafness, blueberry muffin skin rash, jaundice, cataracts, PDA, pulmonic stenosis; Childhood rubella: postauricular and occipital lymphadenopathy, transmitted through resp droplet, descending maculopapular rash lasting 3 days, arthritis Adult rubella: lymphadenopathy and seizures

no tx, vax = MMR live attenuated, do NOT give pregnant or immunocompd, HIV pts need CD4+ > 200 before admin

Arbovirus (Togavirus)

" and arthropod vector - mosquitos

Western equine encephalitis (Western US), Eastern encephalitis (Eastern US), Venezuelan encephalitis (South America)]

no tx, can only avoid mosquito bites

Coronavirus

(+)ssRNA, replicates in cytoplasm, encapsulated, helical

SARS and MERS: acute bronchitis that can progress to ARDS, also common cold

Dengue fever - supportive, Yellow fever - live attenuated vaccine

HIV (Retrovirus)

infects MO and Th cells via CCR5 (early stage) and CXCR4 (late stage)

(+)ssRNA, enveloped, dipoid nature, 3 genes = Gag (p24, capsule), Env (gp41 transmembrane protein and gp120 sticks out of membrane), Pol (reverse transcriptase), transmittion through sex and blood transfusion; screening test is ELISA, confirm with Western blot; can measure viral load and CD4 via PCR neonates can be falsely positive so use HIV RNA or HIV DNA amp test

Orthomyxovirus

NA and HA - glycoprotein that binds sialic acid in upper resp mucosa, also binds RBCs and causes clumping, H1,2,3; M2 = uncoating

(-)ssRNA, brings own polymerase, enveloped, replications in NUCLEUS!!! cause of flu*, strains ABC, can get Guillane-Barre from antigenic drift (point mut in NA and HA) M/C vaccination, also S. aureus pneumonia, Reye's syndrome assoc and antigenic shift (new species), 8 segments = 8 places to mutate; spread by with aspirin admin to children with flu by parents resp droplets

fusion protein, NA, and HA

(-)ssRNA, brings own polymerase, repl in cytosol, enveloped, resp droplet transmission, fusion protein causes multinuc giant cells in lymphoid tissue, causes red inclusion bodies, HA causes RBCs to stick together

RNA (-) Viruses

Paramyxovirus

NRTIs (backbone of therapy, nucleotide analog, stops initially prodromal flu - cervical lymphadenopathy, enlarged prolongation, Zidovudine tonsils, fever; latency for 10 years replicating in LNs, CD4 < 200 good for preg), NNRTIs (inh precipitates AIDS, can cause B cell lymphomas (i.e. diffuse large B reverse transcriptase), cell lymphoma) protease inh (prevent cleavage of viral prot), CCR5 inh (Miravoroc)

Measles = 4C's, cough, coryza, conjunctivitis, Koplik spots, also fever (104 C), descending maculopapular rash, pneumonia, SSPE look for anti measles Abs in CSF; Mumps = replication in salivary glands, can cause orchitis, infertility, meningitis, RSV = ataches to G protein to infect resp epi cells, causes bronchiolitis*, pneumonia*, Parainfluenza virus = croup/laryngeotracheobronchitis, steeple sign on Xray

Rhabdovirus

(-)ssRNA, enveloped, capsule appears bullet-shaped, helical nucleocapsid, transmitted by bats (#1 M/C), foxes, squirrels, glycoprotein binds Nicotinic ach rec at NMJ and replicates in motor rabies, encephalopathy neurons, retrograde movement, Negri bodies (eosinophilic) in hippocampus pyramidal cells or perkinje cells (have Negri bodies)

Filovirus

(-)ssRNA, helical, repl in cytosol, enveloped by Golgi, monkeys and fruit bats are vectors, healthcare workers more likely to get virus

Ebola and Marburg viruses - hemorrhagic fever, end organ failure, severe blood loss, shock

amantadine, rimantadine = inh M2 and prevent uncoating, allows inc DA in CNS (also PD tx), Tamiflu/Seltamivir/Anamivir = block NA and release of virus, vaccine = killed IM, live nasal spray

Vit A can reduce mortality in measles, Ribavarion for RSV (not for babies or preg), Palivisumab (IgG vs fusion protein)

passive preformed IgG Abs + killed vaccine

RN Bunyavirus

(-)ssRNA, enveloped with Golgi membrane, 3 circular segments, mosquito vector same as arbovirus, transmission via deer and mouse urine and pellets,

Arenavirus

(-)ssRNA, repl in cytoplasm, enveloped, can encode both neg and pos, helical capsid, segmented, granular sandy outer febrile aseptic meningitis, fever capsid on EM, rodent transmits disease

Reovirus

HSV-1 and HSV-2

EBV

CMV

NSP4 = inc Cl-permeability --> (-)dsRNA, repl in cytoplasm, naked, 11 secretory diarrhea segments,

dsDNA, enveloped, repl in nucleus, ds and linear, Cowdry bodies = intranuclear inclusions, look like targets, ToRCHES, transmission via sex and saliva; Tzanck smear = multinucleated giant cells

dsDNA, spread via oral secretions, latent EBV envelope (glycoprotein) B cells, causes T cell proliferation binds CD21 on B cells (receptor in (CD8+); monospot/heterophile test for CD3) - infects detects agglutination using sheep Abs

dsDNA, repl in nucleus, latent in mononuclear cells (MO, lymphocytes), ToRCHES, Owl's eye inclusion bodies, herpesvirus

Hantavirus - can cause death, pulmonary edema via capillary leak and prerenal azotemia, hemorrhagic fever; Rift Valley fever, California encephalitis - via Aedes spp mosquito, seizures, encephalitis

can be inactivated with heat, low pH, irradiation and detergents

supportive care, oral Rotavirus - toxin-mediated secretory diarrhea; winter outbreaks, rehydration, live attenuative children most at risk, #1 M/C cause severe diarrhea in children, oral vaccine - 1st dose before Colorado tick virus - myalgia, fever, vomiting 3 mo, may dec intussuseception

HSV-1 = upper half of body: primary infection = gingivitis stomatitis, then herpes labialis, snake-like ulcers and keratoconjunctivitis in eyes, temporal lobe encephalitis with bizarre behavior and personality change, M/C cause sporatic encephalitis*, latent in trigeminal ganglia, finger herpes = Herpetic Whitlow; Erythema multiform; HSV-2 = lower half, genital legionsm inguinal lymphadenopathy, latent in sacral ganglia, causes aseptic meningitis

no cure, prevent breakouts with valcyclovir and acyclovir

infectious mononucleosis, tender lymphadenopathy in posterior cervical, reactive lymphocytosis - Downy cell, causes splenomegaly, pharyngitis seen in kids, mono in late teens and adults; inc cancer risk: 1) Asians = nasopharyngeal carcinoma 2) African children - Burkitt's lymphoma 3) immunocomp'd pts = B cell lymphoma, Hodgkin's lymphoma; can also cause hairy leukoplakia in HIV (not precancerous)

if incorrectly treated with penicillin - maculopapular rash (NOT allergic rxn); supportive care, avoid contact sports

M/C fetal viral infection - #1 cause sensorineural deafness, #1 cause mental retardation, get blueberry muffin rash, hepatomegaly, jaundice, ventriculomegaly, periventricular Foscarnet if UL97 calcifications; **usually 80-90% asyx**, can cause hydrops fetalis, Gancyclovir, immunocomp'd pts (AIDS CD4 < 50, organ transplant recipients); mutation CMV retinitis (pizza pie), esophagolitis and colitis (deep and linear), CMV mono (neg monospot test)

DNA viruses

VZV

dsDNA, enveloped, spread via resp droplets,Tzanck smear shows multinucleated giant cells, latent in DRG, TORCHeS, herpesvirus

Chicken pox, Shingles in adults - can also get pneumonia --> major cause of mortality in adults; postherpetic neuralgia, trigeminal nerve involvement = herpes zoster opthalmicus; congenital varicella syndrome = limb hypoplasia, cutaneous scarring in dermatomal pattern, blindness

Zoster vaccine for adults > 60 and healthy, no preg or immunocompd, Famcyclovir, Valcyclovir

HHV-6

dsDNA, infects CD4+ cells and kills them off, herpesvirus, 6mo - 2 years old

Roseola - 6th disease, 4 day high fever (104 F), after fever subsides, a rash appears on face vs Measles - rash during fever that starts on face and descends

keep patient cool, supportive care

HHV-8

dsDNA, herpesvirus, affects immunosuppressed, don't confuse with Bartonella - bacillary angiomatosis = neutrophil infiltrate (bacterial origin) vs Kaposi = lymphocytic infiltrate (viral origin)

Kaposi's sarcoma - erythematous violaceous lesions on nose, extremities, and mucous membranes: #1 location is hard palate; also intraintestinal lesions; can cause B cell lymphoma (primary enfusion lymphoma), more common in elderly Russian men and MSM (kissing), endemic areas of Africa

dsDNA, naked virus, CD4 < 200 in AIDS

JC virus: causes progressive multifocal leukencephalopathy (PML) - demyelination, multifocal non-enhancing lesions in white matter (vs toxo = ring-enhancing), causes motor neuropathy; BK virus: nephropathy, hemorrhagic cystitis, transplant pts, hematuria

serotypes 1-4,6,11,16,18,31,33; dsDNA, naked; Pap smear = screening, immunosuppression is major risk factor

1-4 = verruca vulgaris (common wart), 6,11 = laryngeal papillomatosis and anogenital warts, 16,18 = anogenital carcinoma (squamous cell carcinoma), 31,33 = carcinoma; common sx = bleeding after sex

VEGF dysregulation

Polyomavirus

HPV

E6 and E7 --> proteolysis of p53 and Rb, respectively; overactivation of G1 --> S phase

Parvovirus B19

Slapped cheek/fifth disease/erythema infectiosum = low grade fever for 1 wk, then lacy reticular patterned rash that starts on ssDNA, naked, smallest virus, and is descending; joint pain, arthritis, soreness, leads to transmission via resp droplets, TORCHeS face anaplastic anemia (mostly affects RBCs) - esp SCD***, causes hydrops fetalis in utero

Adenovirus

dsDNA, naked, transmission via resp droplets and fecal-oral; children, military tonsillitis, hemorrhagic cystitis, viral conjunctivitis recruits most at risk, public pools harbor virus

Pox virus

dsDNA, contains everything it needs within itself, makes own envelope, repl in cytoplasm and brings RNA pol to make small pox - same aged lesions, general redness like sunburn, other proteins and DNA pol, Guarneri molluscum contageosum virus - umbilicated lesions on trunk, inclusion bodies, dumbbell shaped core, cow pox - like smallpox LARGEST DNA virus; sexual transmission in adults

Gardasil = 6,11,16,18 inactivated quadrivalent vaccine

live vaccine for military recruits

Hepatitis B virus

"SPECIES": 1) HbSAg - active infection 2) HbEAg 3) AntiHbCAg = (+) in window period NOT IN IMMUNIZED 4) AntiHbE = low infectivity, NOT IMMUNIZED 5) Anti-HbSAg = recovery - in immunized and prev infected indv

incomplete circular and partially dsDNA, enveloped, repl in nucleus and outside of it, ssDNA -> ssRNA -> dsDNA, has own + arthralgia, kidneys damaged by polyarteritis nodosa, also reverse transcriptase, spread via sex and rash MGN and MPGN; can lead to hepatocellular carcinoma drugs, TORCHeS; ground glass appearance, ALT rises in acute infection (except normal in neonates)

co-infection or superinfection with Hepatitis D virus (req existing or prev existing Hep B virus) ; Lamivudine, NRTI's, IFN-alpha, Ig with Hep B vaccine to at-risk neonates