Bugs Flashcards
Corynebacterium diphtheriae
Toxin and mechanism
Manifestation
Diphtheria toxin (exo) - inactivates EF2 Pharyngitis with pseudomembranes in throat and severe lymphadenopathy (bull neck)
Pseudomonas aeruginosa
Toxin and mechanism
Manifestation
Exotoxin A - inactivates EF2
Host cell death
Shigella
Toxin and mechanism
Manifestation
Shiga toxin (exo) - inactivate 60S ribosome by removing adenine from rRNA GI mucosal damage causing dysentery, enhances cytokine release causing HUS
EHEC
Toxin and mechanism
Manifestation
Shiga-like toxin (exo) - inactivate 60S ribosome by removing adenine from rRNA
SLT enhances cytokine release, causing HUS but doesnt invade cells
ETEC
Toxins and mechanism
Manifestation
Heat-labile toxin (exo) - overactivates adenylate cyclase (increase cAMP) –> increase Cl- secretion in gut and H20 efflux
Heat-stable toxin (exo) - overactivates guanylate cyclase (cGMP) –> decrease resorption of NaCL and H2O in gut
Watery diarrhea: labile in the Air (adenylate) and stable on the Ground (guanylate)
Bacillus anthracis
Toxin and mechanism
Manifestation
Edema factor (exo) - mimics the adenylate cyclase enzyme (increase cAMP) Reponsible for characteristic edematous borders of black eschar in cutaneous anthrax)
Vibrio cholerae
Toxin and mechanism
Manifestation
Cholera toxin (exo) - overactivates adenylate cyclase (increase cAMP) by permanetly activating Gs --> increase Cl- secretion in gut and H2O efflux Voluminous "rice-water" diarrhea
Bordetella pertussis
Toxin and mechanism
Manifestation
Pertussis toxin (exo) - overactivates adenylate cyclase (increase cAMP) by disabling Gi, impairing phagocytosis to permit survival of microbe Whooping cough: coughs on expiration and "whoops" on inspiration
Clostridium tetani
Toxin and mechanism
Manifestation
Tetanospasmin (exo) - cleave SNARE protein required for neurotransmitter release
Muscle rigidity and “lock jaw” - prevents release of inhibitory (GABA and glycine) NT in spinal cord
Clostridium botulinum
Toxin and mechanism
Manifestation
Botulinum toxin (exo) - cleave SNARE protein required for NT release Flaccid paralysis, floppy baby - toxin prevents release of stimulatory (ACh) signals at NMJ
Clostridium perfringes
Toxin and mechanism
Manifestation
Alpha toxin (exo) - phopholipase that degrades tissue and cell membranes Degradation of phospholipid C - myonecrosis (gas gangrene) and hemolysis
Streptococcus pyogenes
Toxin and mechanism
Manifestation
Streptolysin O (exo) - Protein that degrades cell membrane Lyses RBC, contributes to B-hemolysis - host antibodies against toxin (ASO) used to diagnose rheumatic fever
Staphylococcus aureus
Toxin and mechanism
Manifestation
Toxic shock syndrome toxin (TSST-1), exo - bring MHC II and TCR in proximity to outside of antigen binding site to cause overwhelming release of IFN-gamma and IL2 –> Shock
TSS: fever, rash, shock; other toxins - scalded skin and food poisoning
Streptococcus pyogenes
Toxin and mechanism
Manifestation
Exotoxin A - bring MHC II and TCR in proximity to outside of antigen binding site to cause overwhelming release of IFN-gamma and IL2 –> Shock
Toxin shock syndrome: fever, rash, shock
What are the effects on Endotoxin?
Edema Nitric Oxide --> hypoTN DIC/Death --> from coagulation cascade Outer membrane TNF-a --> fever, hypoTN O-antigen eXtremely heat stable IL-1 --> fever Neutrophil chemotaxis
Activates complement (C3a –> hypoTN, edema and C5a –> PMN chemotaxis)
Four phases of bacterial growth
Lag: metabolic activity w/o division
Exponential/log: rapid cell division
Stationary: nutrient depletion slows growth/spore formation in some
Death: prolonged nutrient depletion and buildup of waste products lead to death
Where does penicillins and cephalosporins act in growth phase?
Exponential/lag phase - peptidoglycan is made here
Staphylococcus aureus Morph: Virulence: Dz: Toxin:
Staphylococcus aureus
Morph: gram + cocci in clusters, catalase/coagulase +
Virulence: protein A binds Fc-IgG to inhibit complement fixing and phagocytosis
Dz: (1) inflamm dz: skin infxn, organ abscess, pneumonia (2) toxin mediated: TSS, scalded skin, food poisoning (3) MRSA resistant to B lactams (4) bacterial endocarditis, osteomyelitis
Toxin: TSST-1 binds MHC-II and Tcell receptor for Tcell activation; food poisoning due to preformed enterotoxins;
Staphylococcus epidermidis
Commonly infects?
Where is it found?
Problem with taking blood?
Staphylococcus epidermidis: prosthetic devices and intravenous catheters by producing adherent biofilms.
Component of normal skin flora Contaminates blood cultures
Streptococcus pneumoniae Morph: Virulence: Dz: Clinical presentation:
Streptococcus pneumoniae
Morph: lancet shaped, gram + diplococci, optochin sensitive
Virulence: capsule, IgA protease
Dz: MCC meningitis, otitis media, pneumonia, sinusitis
Clinical presentation: rusty sputum, sepsis in sickle cell anemia and splenectomy
Viridans group streptococci Morph: Normally found: Dz: Clinical presentation:
Viridans group streptococci
Morph: a-hemolytic, optochin resistant
Normally found: oropharynx
Dz: dental caries (mutans), subacute bacterial endocarditis (s. sanguis - sticks to damaged valves by making glycocalyx)
Not afraid of-the-chin (in mouth, optochin resistant)
Streptococcus pyogenes (group A)
Morph:
Dz:
Clinical presentation:
Streptococcus pyogenes (group A)
Morph: bacitracin sensitive
Dz: (1) pyogenic: pharyngitis, cellulitis, impetigo (2) toxigenic: scarlet fever, toxic shock like syndrome, necrotizing fasciitis (3) immunologic: rheumatic fever, acute glomerulonephritis
Clinical presentation: antibodies to M protein enhance defense but also give rise to rheumatic fever; Scarlet fever: rash sparing face, strawberry tongue, scarlet throat
Rheumatic Fever
Bug
Criteria
Cause
Streptococcus pyogenes - group A J - Joints polyarthritis O - carditis N - Nodules (subcutaneous) E - Erythema marginatum S - Sydenham's chorea Pharyngitis --> rheumatic fever from antibodies to M protein Impetigo --> glomerulonephritis
Streptococcus agalactiae (group B) Morph: Normally found: Dz: Clinical presentation:
Streptococcus agalactiae (group B) Morph: bacitracin resistant, b-hemolytic Normally found: vagina, BABIES Dz: pneumonia, meningitis, sepsis Clinical presentation: screen pregnant women at 35-7 weeks, hippurate test positive, produces CAMP factor
Enterococci (group D streptococci) Morph: Normally found: Dz: Clinical presentation:
Enterococci (group D streptococci)
Morph: penicillin G resistant, grow in 6.5% NaCl and bile
Normally found: colonic flora
Dz: UTI, biliary tract infxn, subacute endocarditis
Clinical presentation: vancomycin resistant are important cause of nosocomial infections
Streptococcus bovis
Normally found:
Dz:
Clinical presentation:
Streptococcus bovis
Normally found: the gut
Dz: bacteremia and subacute endocarditis
Clinical presentation: colon cancer patients
Corynebacterium diphtheriae Morph: Toxin: Normally found: Dz: Clinical presentation:
Corynebacterium diphtheriae
Morph: gram + rods, metachromatic granules, Elek’s test, black colonies on cystine-tellurite agar
Toxin: exotoxin by beta-prophage inhibits EF-2
Dz: diphtheria
Clinical presentation: pseudomembranous pharyngitis, lymphadenopathy, myocarditis, arrhythmias
ABCDEFG: ADP-ribosylation, Beta-prophage, Corynebacterium, Diphtheria, EF2, Granules
Spores Formed when? Properties? How to kill? Kinds of bacteria?
Form at end of stationary phase when nutrients are limited
Resistant to heat/chemicals, dipicolinic acid in core, no metabolic activity
Have to autoclave at 121 C for 15 min
Bacillus anthracis, Clostridium perfringens, C. tetani, B. cereus, C. botulinum, Coxiella burnetii
Clostridium tetani Morph: Toxin: Dz: Clinical presentation:
Clostridium tetani
Morph: Gram +, spore forming, obligate anaerobe, bacilli
Toxin: tetanus toxin (exo) - proteases cleave releasing proteins for NT
Dz: tetanic paralysis (blocks glycine and GABA release from Renshaw cells in spinal cord)
Clinical presentation: spastic paralysis, trismus (lockjaw), risus sardonicus
Clostridium botulinum Morph: Toxin: Dz: Clinical presentation:
Clostridium botulinum
Morph: gram +, spore forming, obligate anaerobic bacilli
Toxin: preformed, heat-labile toxin inhibits ACh release at NMJ
Dz: Botulism
Clinical presentation: flaccid paralysis - ingestion of preformed toxin in adults and ingestion of spores in honey in babies (floppy baby)
Clostridium perfringens Morph: Toxin: Dz: Clinical presentation:
Clostridium perfringens
Morph: gram +, spore forming, obligate anaerobic bacilli
Toxin: alpha toxin (lecithinase - phospholiapse)
Dz: myonecrosis and hemolysis
Clinical presentation: gas gangrene
Clostridium difficile Morph: Toxin: Dz: Clinical presentation:
Clostridium difficile
Morph: gram +, spore forming, obligate anaerobic bacilli
Toxin: toxin A - enterotoxin binds brush border of the gut; toxin B - cytotoxin destroys cytoskeletal structure of enterocytes
Dz: pseudomembranous colitis (toxin B)
Clinical presentation: secondary to antibiotic use (clindamycin or ampicillin), diarrhea, tx with metronidazole or oral vanc
Anthrax - cutaneous Morph: Toxin: Dz: Clinical presentation:
Anthrax - cutaneous (contact)
Morph: bacillus anthracis - gram +, spore forming, polypeptide capsule
Toxin: anthrax toxin
Dz: black eschar caused by lethal factor and edema factor
Clinical presentation: black painless skin lesions (necrosis surrounded by edematous ring) –> bacteremia and death
Anthrax - pulmonary Morph: Toxin: Dz: Clinical presentation:
Anthrax - pulmonary (inhalation)
Morph: bacillus anthracis - gram +, spore forming, polypeptide capsule
Toxin: anthrax toxin
Dz: Woolsorters’ disease
Clinical presentation: flu-like symptoms –> fever, pulmonary hemorrhage, mediastinitis, shock
Bacillus cereus Morph: Toxin: Dz: Clinical presentation:
Bacillus cereus Morph: spore forming Toxin: cereulide a preformed toxin Dz: reheated rice syndrome Clinical presentation: food poisoning, N/V 1-5 hours and diarrheal type (watery, nonbloody)/GI pain (8-18 hrs)
Listeria monocytogenes
Morph:
Dz:
Clinical presentation:
Listeria monocytogenes
Morph: facultative intracellular microbe; tumbling motility (actin rockets)
Dz: amnionitis, septicemia, spontaneous abortion; granulomatosis infantiseptica; neonatal meningitis; meningitis in IC, gastroenteritis in healthy
Clinical presentation: ingesting unpasteurized milk/cheese/deli meats or vaginal transmission; ampicillin for infants, IC, eldery
Actinomyces Morph: Normally found: Dz: Clinical presentation:
Actinomyces
Morph: long branching filaments, gram + anaerobe
Normally found: oral flora
Dz: oral/facial abscess
Clinical presentation: drain through sinus tracts to form sulfur granules, treat with penicillin
Nocardia Morph: Normally found: Dz: Clinical presentation:
Nocardia
Morph: long branching filaments, gram + aerobe, acid fast
Normally found: soil
Dz: pulmonary infections in IC and cutaneous infections after trauma in healthy
Clinical presentation: treat with sulfonamides
Mycobacterium tuberculosis
Clinical:
Virulence:
Mycobacterium tuberculosis
Clinical: fever, night sweats, weight loss, hemoptysis
Resistant to multiple drugs
Virulence: cord factor in virulent strains inhibit macrophage maturation and induces release of TNFa. Sulfatides (surface glycolipids) inhibits phagolysosomal fusion.
Mycobacterium kansaii
Clinical:
Mycobacterium kansaii
Clinical: pulmonary TB like symptoms
Mycobacterium avium-intracellulare
Clinical:
Mycobacterium avium-intracellulare
Clinical: disseminated non-TB disease in AIDS, resistant to multiple drugs, treat prophylactically with azithro
PPD + when…
current infection, past exposure, BCG vaccinated
PPD - when…
No infection or anergic (steroids, malnutrition, immunocompromised) and sarcoidosis
Primary tuberculosis progression - 4 outcomes
Infection with Mycobacterium tuberculosis to nonimmune host –> hilar nodes and Ghon focus (Ghon complex) –>
(1) heal by fibrosis - immunity/hypersensitivity/TB +
(2) progressive lung disease - HIV/malnutrition/ –> death
(3) severe bacteremia - miliary tuberculosis –> death
(4) Preallergic lymphatic or hematogenous dissemination –> dormant tubercle bacillin in several organs –> reactivation later
Secondary tuberculosis progression
Mycobacterium tuberuclosis infection to partially immune hypersensitized host –> reinfection –> secondary TB of fibrocaseous cavitary lesion in upper lobes
Reactivation of tuberculosis outcomes - 2
(1) Secondary tuberculosis
(2) Extrapulmonary tuberculosis
CNS (parenchymal tuberculoma or meningitis)
Vertebral body (Pott’s disease)
Lymphadenitis
Renal
GI
Leprosy
Morph:
Dx: 2 types
Clinical:
Leprosy
Morph: mycobacterium leprae, acid-fast bacillus that like cool temp
Dx: (1) Lepromatous: diffusely over skin and is communicable (low cell mediated immunity with humoral Th2 reponse) (2) Tuberculoid: few hypoesthetic, hairless skin plaques (high cell mediated immunity with largely Th1 type immune response)
Clinical: infects skin and superficial nerves, glove and stocking loss of sensation; multidrug therapy of dapsone and rifampin for 6 mo for tuberculoid and dapsone, rifampin, clofazimine for 2-5 years for lepromatous
Neisseria gonorrhoeae Morph: Virulence: Transmission: Dz: Clinical:
Neisseria gonorrhoeae
Morph: Gram - diplococci, ferment glucose, no polysaccharide capsule or maltose fermentation
Virulence: IgA proteases
Transmission: sexually
Dz: gonorrhea, septic arthritis, neonatal conjunctivitis, PID, Fitz-Hugh Curtis syndrome
Clinical: no vaccine, tx with ceftriaxone + azithromycin for possible chlamydia
Neisseria meningiditis Morph: Virulence: Transmission: Dz: Clinical:
Neisseria meningiditis
Morph: Gram - diplococci, ferment glucose, polysaccharide capsule and maltose fermenter
Virulence: IgA protease
Transmission: respiratory/oral
Dz: meningococcemia and meningitis, Waterhouse-Friederichsen syndrome
Clinical: tx ceftriaxone or penicillin G
Haemophilus infulenzae Morph: Virulence: Transmission: Dz: Clinical:
Haemophilus infulenzae
Morph: Gram - rod, culture on chocolate agar and requires V (NAD+) and X (hematin)
Virulence: capsule type B (vaccine), IgA protease
Transmission: aerosol
Dz: epiglottitis (cherry red), meningitis, otitis media, pneumonia
Clinical: tx with ceftriaxone, rifampin for close contact prophylaxis, vaccine b/t 2-18 months
Legionella pneumophila Morph: Virulence: Transmission: Dz: Clinical:
Legionella pneumophila
Morph: Gram - rod, silver stain, charcoal yeast extract with iron and cysteine
Virulence:
Transmission: aerosol from water source
Dz: (1) Legionnaires’ disease - severe pneumonia, fever, GI, CNS (2) Pontiac fever - mild flu like syndrome
Clinical: look for Ag in urine, macrolide or quinolone, hyponatremia
Pseudomonas aeruginosa Morph: Virulence: Transmission: Dz: Clinical:
Pseudomonas aeruginosa
Morph: aerobic gram - rod, non-lactose, oxidase +, pyocyanin pigment, grape-like odor
Virulence: endotoxin (fever, shock) and extoxin A (inactivates EF2)
Transmission: water source
Dz: Pneumonia, Sepsis (black lesion), external otitis (swimmer’s ear), UTI, drug use, diabetic osteomyelitis, hot tub folliculitis, malignant otitis externa (DM)
Clinical: wound and burn infxn, cystic fibrosis; tx with aminoglycoside plus extended spectrum penicillin
EIEC Morph: Virulence: Transmission: Dz: Clinical:
EIEC
Morph: gram - rod
Virulence: fimbriae (cystitis, pyelonephritis), K capsule (pneumonia, neonatal meningitis), LPS endotoxin (shock)
Transmission: invasive to intestinal mucosa
Dz: necrosis and inflammation
Clinical: dysentery
ETEC Morph: Virulence: Dz: Clinical:
ETEC Morph: gram - rod Virulence: fimbriae (cystitis, pyelonephritis), K capsule (pneumonia, neonatal meningitis), LPS endotoxin (shock), labile/stable toxin Dz: no inflammation or invasion Clinical: Traveler's diarrhea (watery)
EPEC Morph: Virulence: Dz: Clinical:
EPEC
Morph: gram - rod
Virulence: fimbriae (cystitis, pyelonephritis), K capsule (pneumonia, neonatal meningitis), LPS endotoxin (shock)
Dz: adheres to apical surface, flattens villi, prevents absorption
Clinical: diarrhea in children
EHEC Morph: Virulence: Dz: Clinical:
EHEC
Morph: gram - rod, O157:H7, doesnt ferment sorbitol
Virulence: fimbriae (cystitis, pyelonephritis), K capsule (pneumonia, neonatal meningitis), LPS endotoxin (shock), Shiga-like toxin
Dz: HUS, endothelium swells and narrows lumen leading to mechanical hemolysis and decrease renal BF
Clinical: anemia, thrombocytopenia, acute renal failure; dysentery (toxin)
Klebsiella Morph: Virulence: Dz: Clinical:
Klebsiella
Morph: gram -, lactose fermenter
Virulence: abundant polysaccharide capsule
Dz: lobar pneumonia in alcoholics/diabetics when aspirated, nosocomial UTI
Clinical: red currant jelly sputum, aspiration pneumonia, abscess in lungs/liver, alcoholics, diabetics
Salmonella Morph: Transmission: Dz: Clinical:
Salmonella
Morph: flagella, hydrogen sulfide, doesnt ferment lactose
Transmission: hematogenous, animal reservoirs
Dz: invades intestinal mucosa and cause monocytic response, blood diarrhea
Clinical: antibiotics may prolong symptoms
Shigella Morph: Transmission: Dz: Clinical:
Shigella
Morph: does not ferment lactose
Transmission: cell to cell, human reservoir
Dz: invade intestinal mucosa and cause PMN infiltration, blood diarrhea
Clinical: antibiotics prolong excretion or organisms in feces
Campylobacter jejuni Morph: Transmission: Dz: Clinical:
Campylobacter jejuni
Morph: comma or S-shaped, oxidase positive, 42 C
Transmission: fecal-oral transmission through foods (poultry, meat, unpasteurized milk)
Dz: bloody diarrhea in children
Clinical: antecedent to GBS and active arthritis
Vibrio cholerae Morph: Virulence: Dz: Clinical:
Vibrio cholerae
Morph: comma-shaped, oxidase positive, alkaline media
Virulence: toxin permanently activates Gs –> increase cAMP
Dz: rice-water diarrhea
Clinical: rehydration necessary
Yersinia enterocolitica
Transmission:
Dz:
Clinical:
Yersinia enterocolitica
Transmission: pet feces, contaminated milk or pork
Dz: mesenteric adenitis
Clinical: mimics Crohn’s appendicitis
Helicobacter pylori
Morph:
Dz:
Clinical:
Helicobacter pylori
Morph: curved gram - rod, urease +
Dz: gastritis in duodenal ulcers (creates alkaline environment)
Clinical: RF for peptic ulcer, gastric adenocarcinoma, lymphoma; tx with PPI, clarithromycin, amoxicillin, metronidazole
Spirochetes
Morph:
Spirochetes
Morph: spiral shaped bacteria with axial filaments
Forelia, Leptospira, Treponema (BLT)
Clinical:
Leptospira interrogans Morph: Transmission: Dz: Clinical:
Leptospira interrogans
Morph: spirochete
Transmission: water contaminated with animal urine
Dz: leptospirosis (flu like symptoms, jaundice, photophobia with conjunctivitis), Weil’s disease (severe form with jaundice and azotemia from liver/kidney dysfunction; fever, hemorrhage, anemia)
Clinical: surfers in tropics
Borrelia burgdorferi Stages: Transmission: Dz: Clinical:
Borrelia burgdorferi
Stages: (1) erythema chronicum migrans (bulls eye rash), flu like symptoms (2) neurologic and cardiac (facial palsy, AV block) (3) MSK (migratory polyarthritis), neuro (encephalopathy, polyneuropathy), cutaneous manifestations
Transmission: Ixodes tick, mouse reservoir, NE USA
Dz: facial palsy, arthritis, cardiac block, erythema migrans
Clinical: tx with doxycycilne, ceftriaxone
Syphilis Morph: Screen: Dz: Clinical:
Syphilis
Morph: Treponema pallidum
Screen: VDRL screen and confirm FTA-ABS
Dz: Primary - painless chancre; Secondary - maculopapular rash (palms, soles), condylomata lata; Tertiary - gummas, aortitis (vasa vasorum), neurosyphilis (tabes dorsalis), Argyll Robertson pupil, broad based ataxia, + Romberg, Charcot joint, stroke w/o HTN; Congenital: saber shins, saddle nose, CN VIII deafness, Hutchinson’s teeth, mulberry molars
Clinical: treat with pen G, placental transmission typically occurs at first trimester
Salmonella typhi
Clinical presentation
Salmonella typhi
Clinical presentation: typhoid fever, found only in humans, rose spots on the abdomen, fever, headache, diarrhea, can remain in gallbladder as carrier state
Argyll Robertson pupil
constricts with accommodation but is not reactive to light (tertiary syphilis)
Prostitute’s pupil - accommodate but doesnt react
VDRL false positive
VDRL detects Ab that reacts with beef cardiolipin; false positive for viral infection (mono, hepatitis), some drugs, rheumatic fever, SLE, leprosy
Jarisch-Herxheimer reaction
Flu-like syndrome immediately after antibiotics are started - due to killed bacteria releasing pyrogens
Bartonella spp
Cat scratch disease from cat scratch
Borrelia burgdorferi
Lyme disease from Ixodes ticks (deer and mice)
Borrelia recurrentis
Recurrent fever from louse (variable surface antigens)
Brucella spp
Brucellosis/undulant fever from unpasteruized dairy
Campylobacter
Bloody diarrhea from puppies/livestock (fecal-oral, ingestion of undercooked meat)
Chlamydophila psittaci
Psittacosis from parrots and other birds
Coxiella burnetii
Q fever from aerosols of cattle/sheep amniotic fluid
Ehrlichia chaffeensis
Ehrlichiosis from Lone Star tick
Francisella tularensis
Tularemia from ticks/rabbits/deer fly
Leptospira spp
Leptospirosis from animal urine
Mycobacterium leprae
Leprosy from armadillos and humans with lepromatous leprosy
Pasteurella multocida
Cellulitis, osteomyelitis from animal bites, cats, and dogs
Rickettsia prowazekii
Epidemic typhus from louse
Rickettsia rickettsii
Rocky Mountain spotted fever from Dermacentor tick bite
Rickettsia typhi
Endemic typhus from fleas
Yersinia pestis
Plague from fleas (rats and prairie dogs are reservoirs)
Gardnerella vaginalis Morph: Transmission: Dz: Clinical:
Gardnerella vaginalis
Morph: pleomorphic, gram variable rod
Transmission: sexual activity but not STD
Dz: vaginosis with Clue cells or vaginal epithelial cells covered with bacteria
Clinical: gray vaginal discharge with fishy smell, non-painful; metronidazole
Rocky Mountain spotted fever
Morph:
Clinical:
Rocky Mountain spotted fever
Morph: Rickettsia rickettsii, obligate intracellular organisms need CoA and NAD+
Location: distributed in US
Clinical: rash at wrists and ankles spreads to trunk, palms, soles
Typhus
Morph:
Clinical:
Typhus
Morph: R. typhi and R. prowazekii
Clinical: endemic fleas = R. typhi; epidemic human body louse = R. prowazekii –> rash starts centrally and spreads out sparing palms and soles
Palm and sole rash also in Coxsackievirus A, Rocky Mountain spotted, secondary Syphilis
Ehrlichiosis
Tick - Ehrlichia
Monocytes with morula (berry-like inclusions) in cytoplasm
Anaplasmosis
Tick - anaplasma
Granulocytes with morula in cytoplasm
Q Fever
Tick feces and cattle placenta release spores that are inhaled as aerosols from Coxiella burnetii
Pneumonia
Chlamydiae Morph: Transmission: Dz: Clinical:
Chlamydiae
Morph: Chlamydia trachomatis, obligate intracellular organism; lacks muramic acid in cell wall
Transmission: Elementary body enters cell via endocytosis and reticulate body replicates in cell by fission (form seen on tissue culture)
Dz: reactive arthritis, conjunctivitis, nongonococcal urethritis, PID –> trachomatis; atypical pneumonia –> pneumoniae/psittaci;
Clinical: treat with azithromycin or doxycycline; cytoplasmic inclusions on Giemsa or fluorescent antibody stained smear
what type of chlamydiae trachomatis causes chronic infection, blindness due to follicular conjunctivits in Africa?
A, B, C
what type of Chlamydia trachomatis causes urethritis/PID, ectopic pregnancy, neonatal pneumonia (staccato cough), neonatal conjunctivitis?
D-K
What type of chlamydia trachomatis causes lymphogranuloma venereum?
L1, L2, L3
Mycoplasma pneumoniae
Morph:
Dz:
Clinical:
Mycoplasma pneumoniae
Morph: no cell wall (sterols instead), Eaton’s agar
Dz: walking pneumonia in <30 yoa
Clinical: insidious onset, headache, nonproductive cough, diffuse interstitial infiltrate; high titer of cold agglutinins (IgM); tx with macrolide or fluoroquinolone; military recruits and prisons
Histoplasmosis
Morph:
Location:
Dz:
Histoplasmosis
Morph: dimorphic fungi, Macrophage filled with Histoplasma
Location: Mississippi and Ohio River valleys
Dz: pneumonia from bird or bat droppings, treat with fluconazole or itraconazole for local and amphotericin B or systemic infections
Blastomycosis
Morph:
Location:
Dz:
Blastomycosis
Morph: dimorphic fungi, broad-base budding
Location: states E of Mississippi River and Central America
Dz: inflammatory lung disease and can disseminate to skin and bone, granulomatous nodules, treat with fluconazole or itraconazole for local and amphotericin B or systemic infections
Coccidioidomycosis
Morph:
Location:
Dz:
Coccidioidomycosis
Morph: dimorphic fungi, spherule filled with endospores
Location: SW US, California - increased after earthquake; San Joaquin Valley or desert “valley fever”
Dz: pneumonia, meningitis can disseminate to bone and skin, treat with fluconazole or itraconazole for local and amphotericin B or systemic infections
Paracoccidioidomycosis
Morph:
Location:
Dz:
Paracoccidioidomycosis
Morph: dimorphic fungi, budding yeats with captain’s wheel formation
Location: Latin America
Dz: pneumonia, treat with fluconazole or itraconazole for local and amphotericin B or systemic infections
Tinea versicolor
Morph:
Location:
Dz:
Tinea versicolor
Morph: Malassezia furfur, spaghetti&meatball on KOH prep
Location: hot, humid weather
Dz: degradation of lipids produces acids that damage melanocytes and cause hypopigmented/hyperpigmented patches; topical miconazole, selenium sulfide (Selsum)
Tinea pedis, cruris, corporis, capitis, unguium
Morph:
Location:
Dz:
Tinea pedis, cruris, corporis, capitis, unguium
Morph: dermatophytes
Location:
Dz: pruritic lesion with central clearing resembling a ring caused by dermatophytes
Candida albicans
Morph:
Dz:
Clinical:
Candida albicans - systemic or superficial fungal infection
Morph: dimorphic yeast, pseudohyphae and budding yeast
Dz: oral and esophageal thrush in IC, vulvovaginitis, diaper rash, endocarditis in IVDA, disseminated candidiasis, chronic mucocutaneous candidiasis
Clinical: tx topical azole for vaginal, fluconazole or caspofungin for oral/esophageal, fluconazole or amphotericin B or caspofungin for systemic
Aspergillus fumigatus
Morph:
Dz:
Aspergillus fumigatus
Morph: septate hyphae that branch at 45 angle
Dz: invasive aspergillosis in IC and chronic granulomatous dz; allergic bronchopulmonary aspergillosis in asthma; aspergillomas in lung cavities especially after TB infection, produce aflatoxins assocaited with HCC
Cryptococcus neoformans
Morph:
Dz:
Clinical:
Cryptococcus neoformans
Morph: yeasts with wide capsular halos and unequal budding in India ink, encapsulated
Dz: meningitis, cryptococcosis
Clinical: soil and pigeon droppings through inhalation w/ hematogenous dissemination to meninges; Sabouraud’s agar, stains with India ink, latex agglutination test detects polysaccharide capsular antigen; Soap bubble lesions
Mucor and Rhizopus
Morph:
Dz:
Clinical:
Mucor and Rhizopus
Morph: irregular, borad, nonseptate hyphae branching at wide angles
Dz: mucormycosis, rhinocerebral and frontal lobe abscesses
Clinical: ketoacidotic diabetic and leukemic patients - proliferate in blood vessel walls when excess ketone and glucose –> penetrate cribriform plate and enter brain; presents with HA, facial pain, black necrotic eschar on face, cranial nerve involvement
Pneumocystis jirovecii
Morph:
Dz:
Clinical:
Pneumocystis jirovecii
Morph: disc shaped yeast on methenamine silver stain, diffuse bilateral CXR appearance
Dz: pneumocystis pneumonia (PCP) - diffuse interstitial pneumonia
Clinical: inhaled, most are asymptomatic but IC predisposes to disease. Lung biopsy or lavage and tx with TMP-SMX, pentamidine ,dapsone
Sporothrix schenckii
Morph:
Dz:
Clinical:
Sporothrix schenckii
Morph: dimorphic, cigar shaped budding yeast leives on vegetation, spores
Dz: sporotrichosis
Clinical: traumaticaly introduced into the skin (thorn), causes local pustule or ulcer with nodules draining along lymphatics; tx with itraconazole or potassium iodide
Giardia lambli Morph: Transmission: Dz: Clinical:
Giardia lambli
Morph: protozoa; trophozoites or cysts in stool
Transmission: cysts in water
Dz: Giardiasis
Clinical: bloating, flatulence, foul-smelling, fatty diarrhea; tx with metronidazole
Entamoeba histolytica Morph: Transmission: Dz: Clinical:
Entamoeba histolytica
Morph: protozoa, flask shaped ulcers, trophozoites with RBC in cytoplasm or cysts in stool
Transmission: cysts in water
Dz: amebiasis
Clinical: bloody diarrhea, liver abscess (anchovy paste exudate), RUQ pain (flask shaped ulcer); tx with metronidazole, iodoquinol for asymptomatic cyst passers
Cryptosporidium Morph: Transmission: Dz: Clinical:
Cryptosporidium Morph: cysts on acid-fast stain Transmission: cysts in water Dz: diarrhea Clinical: severe diarrhea in AIDS or mild in healthy; prevention by filtering water; nitazoxanide in healthy hosts
Toxoplasma gondii Morph: Transmission: Dz: Clinical:
Toxoplasma gondii
Morph: protozoa, ring enhancing lesion
Transmission: cysts in meat or cat feces, crosses placenta
Dz: brain abscess in HIV
Clinical: congenital - chorioretinitis, hydrocephalus, intracranial calcifications; dx by biopsy/serology; tx with sulfadiazine and pyrimethamine
Naegleria fowleri Morph: Transmission: Dz: Clinical:
Naegleria fowleri
Morph: amoebas
Transmission: swimming in freshwater lakes enters through cribriform plate
Dz: rapidly fatal meningoencephalitis
Clinical: seen in spinal fluid, amphotericin has been effective for few survivors
Trypanosoma brucei/gambiense/rhodesiense Morph: Transmission: Dz: Clinical:
Trypanosoma brucei/gambiense/rhodesiense Morph: Transmission: Tsetse fly - painful bite Dz: African sleeping sickness Clinical: enlarged lymph nodes, recurring fever, somnolence, coma; detect in blood smear; tx with Suramin for blood borne disease or melarsoprol for CNS penetration
Plasmodium 4 types and characteristics Transmission: Dz: Clinical:
Plasmodium
(1) vivax - 48 hr w/ fever 1&3 days, dormant in liver (2) ovale - same as vivax (3) falciparum - sever, irregular, parasitized RBC occlude capillaries in brain/kidney/lungs (4) malariae - 72 hr cycle
Transmission: anopheles mosquito
Dz: malaria
Clinical: fever, headache, anemia, splenomegaly; dx w/ blood smear - trophozoite ring, RBC schizont with merozoites;
tx with chloroquine - blocks heme polymerase or mefloquine, life threatening –> IV quinidine, vivax/ovale –> primaquine for hypnozoite
Babesia Morph: Transmission: Dz: Clinical:
Babesia Morph: protozoa Transmission: NE USA, Ixodes tick Dz: Babesiosis Clinical: fever, hemolytic anemia; asplenia increase risk of severe illness; blood smear - ring form with maltese cross; tx with atovaquone + azithromycin
Trypansoma cruzi Morph: Transmission: Dz: Clinical:
Trypansoma cruzi
Morph: protozan
Transmission: S. America, Reduviid bug (kissing bug w/ painless bite)
Dz: Chagas disease
Clinical: dilated cardiomyopathy, megacolon, megaesophagus; blood smear for dx; tx with nifurtimox
Leishmania donovani Morph: Transmission: Dz: Clinical:
Leishmania donovani Morph: Transmission: sandfly Dz: visceral leishmaniasis (kala-azar) Clinical: spiking fevers, hepatosplenomegaly, pancytopenia; dx macrophages containing amastigotes; tx with sodium stibogluconate
Trichomonas vaginalis Morph: Transmission: Dz: Clinical:
Trichomonas vaginalis Morph: trophozoites on wet mount Transmission: STD Dz: vaginitis Clinical: foul-smelling, greenish discharge; itching and burning; tx with metronidazole for patient and partner
Enterobius vermicularis
Transmission:
Dz:
Treat:
Enterobius vermicularis (pinworm)
Transmission: food contaminated w/ eggs
Dz: intestinal infection causing anal pruritius (scotch tape test)
Treat: Bendazole or pyrantel pamoate
Ascaris lumbricoides
Transmission:
Dz:
Treat:
Ascaris lumbricoides
Transmission: fecal-oral, eggs visible in feces
Dz: intestinal infection
Treat: Bendazoles
Strongyloides stercoralis
Transmission:
Dz:
Treat:
Strongyloides stercoralis
Transmission: larvae in soil penetrate skin
Dz: intestinal infection causing vomiting, diarrhea, anemia
Treat: Ivermectin or albendazole
Ancylostoma duodenale Necator americanus Transmission: Dz: Treat:
Ancylostoma duodenale Necator americanus Transmission: larvae penetrate skin Dz: intestinal infection causing anemia by sucking blood from intestinal walls Treat: Bendazoles or pyrantel pamoate
Dracunculus medinensis
Transmission:
Dz:
Treat:
Dracunculus medinensis
Transmission: drinking water
Dz: skin inflammation and ulceration
Treat: slow extraction of worm
Onchocerca volvulus
Transmission:
Dz:
Treat:
Onchocerca volvulus
Transmission: female blackfly bite
Dz: hyperpigmented skin and river blindness; allergic reaction to microfilaria
Treat: ivermectin
Loa loa
Transmission:
Dz:
Treat:
Loa loa
Transmission: deer fly, horse fly, mango fly
Dz: swelling in skin, worm in conjunctiva
Treat: diethylcarbamazine
Wuchereria bancrofti
Transmission:
Dz:
Treat:
Wuchereria bancrofti
Transmission: female mosquito
Dz: blocks lymphatic vessels, elephantiasis (9 mos to 1 yr to become symptomatic)
Treat: diethylcarbamazine
Toxocara canis
Transmission:
Dz:
Treat:
Toxocara canis
Transmission: food contaminated with eggs
Dz: visceral larva migrans
Treat: albendazole or mebendazole
Taenia solium
Transmission:
Dz:
Treat:
Taenia solium
Transmission: ingestion of larvae encysted in undercooked pork OR ingestion of eggs
Dz: intestinal infection OR cysticercosis, neurocysticercosis
Treat: Praziquantel or that plus bendazoles for neurocysticercosis
Diphyllobothrium latum
Transmission:
Dz:
Treat:
Diphyllobothrium latum
Transmission: ingestion of larvae from raw freshwater fish
Dz: Vitamin B12 deficiency –> anemia
Treat: Praziquantel
Echinococcus granulosus
Transmission:
Dz:
Treat:
Echinococcus granulosus
Transmission: ingestion of eggs from dog feces
Dz: cysts in liver, causing anaphylasix if antigens released
Treat: -bendazoles
Schistosoma
Transmission:
Dz:
Treat:
Schistosoma
Transmission: snails host, cercariae penetrate skin of humans
Dz: liver and spleen granulomas, fibrosis, inflammation; chronic infection with S. haematobium can lead to SCC of bladder
Treat: Praziquantel
Clonorchis sinensis
Transmission:
Dz:
Treat:
Clonorchis sinensis
Transmission: undercooked fish
Dz: biliary tract inflammation –> pigmented gallstones and associated with cholangiocarcinoma
Treat: praziquantel
Paragonimus westermani
Transmission:
Dz:
Treat:
Paragonimus westermani
Transmission: undercooked crab meat
Dz: lung inflammation and secondary bacterial infection, hemoptysis
Treat: praziquantel
Parasite - brain cysts, seizure
Taenia solium (cysticercosis)
Parasite - liver cysts
Echinococcus granulosus
Parasite - Vitamin B12 deficiency
Diphyllobothrium latum
Parasite - Biliary tract disease, cholangiocarcinoma
Clonorchis sinensis
Parasite - hemoptysis
Paragonimus westermani
Parasite - portal HTN
Schistosoma mansoni
Parasite - hematuria, bladder cancer
Schistosoma haematobium
Parasite - microcytic anemia
Ancylostoma, Necator
Parasite - perianal pruritus
Enterobius
