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1

staph identification

on the staph retreat, there was NO StRESs: NOvobiocin - Saprophyticus = Resistant, Epidermidis = Sensitive

2

strep identification: Optochin

OVRPS: Optochin: Viridans = Resistant; Pneumoniae = sensitive

3

strep identification: Bacitracin

B-BRAS: Bacitracin - group B = Resistant, group A = Sensitive

4

alpha-hemolytic

green ring around colonies on blood agar: strep pneumo and viridans

5

Strep pneumo identification

catalase -, optochin sensitive, alpha-hemolytic

6

Viridens streptococci identification

catalase -, optochin resistant, alpha-hemolytic

7

beta-hemolytic

clear area of hemolysis on blood agar: staph aureus, step pyogenes, step agalactiae, listeria monocytogenes

8

staph aureus identification

catalase and coagulase +, beta-hemolytic

9

strep pyogenes identification

group A strep, catalase -, bacitracin sensitive, beta-hemolytic

10

strep agalactiae identification

group B strep, catalase -, bacitracin resistant, beta-hemolytic. produces CAMP factor (enlarges S. aureus hemolysis). Hippurate test +.

11

listeria monocytogenes

tumbling motility, meningitis in newborns, unpasteurized milk, beta-hemolytic

12

staph epidermidis

infects prosthetic devices and IV catheters by producing biofilms. component of normal skin flora, common contaminant. novobiocin sensitive

13

staph saprophyticus

2nd most common cause of UTI in young women. novobiocin resistant

14

strep pneumo

common cause of MOPS: meningitis, Otitis media, Pneumonia, Sinusitis. MOPS are Most OPtochin Sensitive. lancet-shaped, GP diplococci. encapsulated. IgA protease

15

strep pyogenes

pyogenic, toxigenic, and immunologic. bacitracin sensitive, beta-hemolytic, PYR +. Abs to M protein -> inc. host defenses and rheumatic fever. ASO titer detects recent infection

16

enterococci

group D strep. normal colonic flora. PCN G resistant. -> UTI, biliary infxns, subacute endocarditis. variable hemolysis. include VRE.

17

strep bovis

Bovis in the blood = cancer in the colon: colonizes gut,can -> bacteremia and subacute endocarditis. associated w/colon CA.

18

corynebacterium diphteriae

club-shaped. black colonies on cystine-tellurite agar. ABCDEFG: ADP-ribosylation (inhibits protein synthesis via), Beta-prophage, Corynebacterium Diptheriae, Elongation Factor 2 (what ADP-ribosylates), Granules (metachromatic). + Elek test for toxin. toxoid vaccine.

19

bacterial spores

kill w/autoclave. have dipicolonic acid in their core. no metabolic activity. dzs: anthrax, food poisoning (B. cereus), botulism, abx-associated colitis, gas gangerene, tetanus, Q fever (coxiella burnetii)

20

C. tetani

tetanospasmin: exotoxin = protease that cleaves SNARE, blocking GABA and glycine from Renshaw cells in spinal cord. -> spastic paralysis, trismus, + risus sardonicus. Tx w/vaccine, antitoxin, and diazepam

21

C. botulinum

preformed, heat-labile toxin that inhibits ACh release and NMJ. toxin in adults, spores in babies. flaccid paralysis. Tx w/antitoxin

22

C. perfringens

Perfringens Perforates a gangrenous leg. produces alpha toxin (lecithinase, a phospholipase) that can -> myconecrosis and hemolysis

23

C. difficile

2 toxins: A = enterotoxin, binds bb in gut. B = cytotoxin, -> cytoskeletal disruption via actin depolymerization -> pseudomembranous colitis. Dx by stool PCR toxin detection

24

anthrax

caused by GP, spore-forming rod that produces toxin. only bacterium w/polypeptide capsule (contains D-glutamate)

25

cutaneous anthrax

painless papule surrounded by vesicles -> ulcer w/black eschar. painless, necrotic. -> bacteremia + death = uncommon

26

pulmonary anthrax

inhalation of spores -> flu-like Sx -> fever, pulmonary hemorrhage, mediastinitis, and shock

27

B. cereus

reheated rice. spores survive cooking. keeping rice warm -> germination and toxin formation. cereulide = preformed toxin -> emetic type (w/rice + pasta). diarrheal type is slower onset

28

listeria monocytogenes

facultative intracellular microbe. unpasteurized dairy and deli meats. forms "rocket tails" via actin polymerization that -> intracellular mvmnt and cell-to-cell spread, avoiding Ab. tumbling motility. only GP that -> endotoxin. -> amnionitis, septicemia, spontaneous abortion, granulomatosis infantiseptica, meningitis, gastroenteritis. Tx. w/amp in infants, immunocompromised, and elderly w/meningitis.

29

actinomyces and nocardia

both form long, branching filaments resembling fungi. Tx is a SNAP: Sulfonamides - Nocardia, Actinomyces - PCN

30

actinomyces

GP anaerobe, not acid fast, normal oral flora, -> oral/facial abscesses w/sinus tracts, -> yellow, sulfur granules. Tx w/PCN.

31

nocardia

GP aerobe, weakly acid fast, found in soil, -> pulm infxn in immunocompromised, cutaneous after trauma in healthies. Tx w/sulfonamides

32

primary TB

nonimmune host (often child). hilar nodes + ghon focus (usually lower-mid lung) = ghon complex. -> heals by fibrosis -> immunity + hypersensitivity -> tuberculin +. or progressive lung dz (HIV, malnutrition) -> death (rare). or severe bacteremia -> miliary TB -> death. or preallergic lymphatic or hematogenous dissemination -> dormant tubercle bacilli in several organs -> reactivation in adult life.

33

secondary TB

reinfection or reactivation in partially immune hypersensitized host (often adult). fibrocaseous cavitary lesion (upper lobes) extrapulmonary TB: CNS (parenchymal tuberculoma or meningitis), vertebral body (Pott dz), lymphadenitis, renal, GI, adrenals

34

+PPD

if current infxn or past exposure. false positives w/BCG vaccination (further w/u required)

35

-PPD

if no infection or anergic (steroids, malnutrition, immunocompromise) and in sarcoidosis.

36

mycobacteria

all are acid-fast pink rods.

37

cord factor

in virulent strains of mycobacteria. inhibits macrophage maturation and induces release of TNF-alpha. sulfatides (surface glycolipids) inhibit phagolysosomal fusion

38

leprosy

= hansen dz. caused by mycobacterium leprae. likes cool temps -> glove and stocking skin and superficial nerves. cannot be grown in vitro. armadillos. Tx w/dapsone and rifampin, adding clofazimine if lepromatous form.

39

lepromatous hansen dz

presents diffusely over the skin w/leonine facies. is communicable. characterized by low cell-mediated immunity w/humoral Th2 response

40

tuberculoid hansen dz

limited to few hypoesthetic hairless skin plaques, characterized by high cell-mediated immunity w/largely Th1 reponse

41

differentiates GN diplococci

maltose. fermenter = N. meningitidis. nonfermenter = N. gonorrhoeae

42

differentiates GN rods

1st: lactose. fermenter = fast: Klebsiella, E coli, enterobacter. slow: citrobacter, serratia

43

differentiates GN rod lactose nonfermenters

1st: oxodase. + = peudomonas. -: TSI agar: produces H2S = salmonella, proteus, yersinia. doesn't produce H2S = shigella

44

GN coccoid rods

H flu, pasteurella, brucella, bordetella pertussis

45

GN comma-shaped

oxidase +. grows in 42C = campylobacter. grows in alkaline media = v. cholerae. produces urease = H pylori.

46

lactose fermenting enterics

lactose = key. test w/macConKEE'S agar (forms pink colonies). Citrobacter, Kelbsiella, E coli, Enterobacter, Serratia (weak). grow as purple/black on EMB agar. E coli grows w/green sheen

47

Neisseria

GN diplococci. both ferment glucose and produce IgA proteases. MeninGococci ferment Maltose and Glucose. Conococci ferment Glucose.

48

Gonococci

no polysaccharide capsule. no maltose fermentation. no vaccine (Ag variation of pilus proteins). sexually or perinatally transmitted. -> gonorrhea, septic arthritis, neonatal conjunctivitis, PID, fitz-hugh-curtis. condoms help. erythromycin eye ointment for neonates. Tx: ceftriaxone (+ azythro or doxy for possible chlamydia)

49

Meningococci

polysaccharide capsule. maltose fermentation. vaccine. transmitted via respiratory + oral secretions. -> meningococcemia + meningitis, waterhouse-friderichsen syndrome (hemorrhagic adrenalitis). rifampin, cipro, or ceftriaxone PPx in close contacts. Tx: ceftriaxone or PCN G

50

H flu

small GN coccobacillus. aurosol transmittion. -> IgA protease. Cx on chocolate agar (w/factors V (NAD+) and X (hematin)) or grow w/staph aureus (-> factor V via hemolysis). haEMOPhilus -> Epiglottitis, Meningitis, Otitis media, and Pneumonia. Tx: mucosal infxns: amox +/- clav. meningitis: ceftriaxone. PPx w/rifampin (close contacts)

51

H flu vaccine

only against type b. contains capsular polysaccharide conjugated to diphtheria toxoid. given between 2-18 months.

52

legionella mnemonic

think of a french soldier (legionnaire) w/silver helmet, sitting around a campfire (charcoal) w/his iron dagger. he is no sitty (cysteine).

53

legionella

GNR (poorly) so use silver stain. grow on charcoal yeast extract culture w/iron and cysteine. Dx: Ag in urine. hyponatremia. aurosol transmission from environmental water source (e.g. airconditioning). no person-person transmission. Tx: macrolide or quinolone.

54

legionnaire's dz

severe pna, often unilateral and lobar, fever, GI + CNS Sx

55

pontiac fever

mild flu-like syndrome caused by legionella

56

pseudomonas mnemonic

PSEUDDOmonas: Pneumonia, Sepsis, otitis Externa, UTIs, Drug use, Diabetics, Osteomyelitis (e.g. puncture wounds).

57

pseudomonas

aerobic, motile, GNR. non-lactose fermenting. oxidase +. produces pyocyanin (blue-green pigment). has grape-like odor. produces endotoxin (fever, shock) and exotoxin A (inactivates EF-2). burn victims. mucoid polysaccharide capsule -> chronic pna in CF (forms biofilms). hot tub folliculitis

58

pseudomonas Tx

extended spectrum beta-lactams: pip-tazo, ticarcillin, cefepime
carbapenems
monobactams: aztreonam
fluoroquinolones
aminoglycosides: gent, tobramycin
for multidrug resistent: colistin, polymyxin B

59

ecthyma gangrenosum

rapidly progressive, necrotic cutaneous lesion caused by pseudomonas. typically seen in immunocompromised.

60

EIEC

Invasive. dysentery. microbe invades intestinal mucosa -> intestinal necrosis + inflammation. similar to shigella

61

ETEC

Traveler's diarrhea (watery). produces heat-labile and heat-stable enteroToxins. no inflammation/invasion

62

EPEC

Pediatrics. no toxin. adheres to apical surface, flattens villi, prevents absorption -> diarrhea

63

EHEC

shiga toxin. O157:H7 = most common serotype in US.
-> dysentery. doesn't germent sorbitol (unlike other E coli)
causes HUS: anemia, thrombocytopenia, acute renal failure: microthrombi form on damaged endothelium -> mechanical hemolysis (schistocytes), plt consumption, dec. renal blood flow.

64

klebsiella mnemonic

4 As: Aspiration pna, Abscess in lungs + liver, Alcoholics, di-A-betics

65

klebsiella

intestinal flora -> lobar pna in alcoholics and diabetics when aspirated. very mucoid colonies caused by abundant polysaccharide capsules. currant jelly sputum. also -> nosocomial UTIs

66

campylobacter jejunum

major cause of bloody diarrhea, esp. children. fecal-oral transmission or from poultry, meat, unpasteurized dairy or contact w/infected animals. comma or S-shaped, oxidase +, grows at 42C. common cause of GBS and reactive arthritis

67

salmonella typhi

humans only. hematogenous dissemination. produces H2S. has flagella (salmon swim). virulence factors: endotoxin + Vi capsule. high infectious dose. abx prolong duration of fecal excretion. monocyte-predominant response. -> constipation, then diarrhea. live attenuated oral vaccine. -> typhoid fever. Tx w/ceftriaxone or fluoroquinolone. carrier state w/gallbladder colonization.

68

typhoid fever

rose spots on abdomen, constipation, abd. pain, fever

69

salmonella except typhi

humans and animals. hematogenous dissemination. produces H2S. has flagella (salmon swim). virulence factor: endotoxin. high infectious dose. abx prolong duration of fecal excretion. PMN-predominant response (in disseminated dz). -> bloody diarrhea. no vaccine. found in poultry, eggs, pets, and turtles. more common cause of gastroenteritis

70

shigella

humans only. cell to cell, not hematogenous spread. no H2S. no flagella. virulence factors: endotoxin, shiga toxin. low infectious dose. abx shortens duration of fecal excretion. PMN-predominant response. -> bloody diarrhea (bacillary dysentery). no vaccine. 4 Fs: Fingers, Flies, Food, Feces. Severity: dysenteriae > boydii > sonnei. invasion = key to pathogenicity in organisms that produce less toxin

71

v. cholera

produces profuse rice-water diarrhea via enterotoxin that permanently activates Gs -> inc. cAMP. comma-shaped, oxidase +, grows in alkaline media. endemic to developing countries. requires prompt oral rehydration

72

salmonella and shigella..

GN bacilli, non-lactose fermenting, oxidase -.

73

yersinia enterocolitica

transmitted from pet feces (e.g. puppies), contaminated milk, pork. -> acute diarrhea or pseudoappendicitis (RLQ pain due to mesenteric adenitis and/or terminal ileitis)

74

H pylori

-> gastritis + peptic ulcers (esp. duodenal). risk factor for peptic ulcer, gastric adenocarcinoma, + MALT lymphoma. curved GNR. catalase, oxidase, and urease +. Dx: urea breath test or fecal Ag test. creates alkaline environment. Tx: PPI + clarithromycin + amoxicillin (or flagyl if PCN allergy)

75

spirochetes

BLT: Borrelia (big), Leptospira, Treponema. only borrelia can be seen using aniline dyes (wright or giemsa) in light microscopy due to size. treponema is seen on dark-field microscopy

76

leptospira interrogans

found in water containing animal urine. -> leptospirosis and weil dz

77

leptospirosis

flu-like Sx, myalgias (classically calves), jaundice, photophobia w/conjuctival suffusion (erythema w/o exudate). prevalent among surfers and in tropics

78

weil dz

icterhemorrhagic leptospirosis = severe form w/jaundice + azotemia from liver and kidney dysfxn, fever, hemorrhage, and anemia.

79

lyme mnemonic

key lime pie to the FACE: Facial nerve palsy (typically b/l), Arthritis, Cardiac block, Erythema chronicum migrans

80

lyme dz

caused by borrelia burgdorferi. transmitted by Ixodes deer tick (same as babesia). mouse = natural reservoir. common in NE united states. initial Sx: erythema chrocum migrans, flu-like Sx, +/- facial nerve palsy. later Sx: monoarthritis (large joints), AAV nodal block, neurologic (meningitis, facial palsy, polyneuropathy). Tx: doxycycline, ceftriaxone.

81

primary syphilis

painless chancre. Dx: dark-field microscopy of chancre-fluid. VDRL + in 80%

82

secondary syphilis

disseminated dz w/constitutional Sx, maculopapular rash including palms and soles, condylomata lata. Dx: can still use dark-field microscopy

83

tertiary syphilis

gummas, aortitis (vasa vasorum destruction), neurosyphilis (tabes doraslis ,"general paresis"), argyll robertson pupil. signs: board-based ataxia, + romberg, charcot joint, stroke w/o HTN. Dx for neurosyphilis: test CSF w/VDRL and PCR

84

congenital syphilis

facial abnormalities: rhagades (linear scars at mouth angle), snuffles, saddle nose, notched hutchinson teeth, mulberry molars, short maxilla, saber shins, CN VIII deafness. PPx: treat mother early in pregnancy: transmission usually occurs after 1st trimester

85

VDRL false positives

VDRL: Viral infection (mono, hepatitis), Drugs, Rheumatic fever, Lupus/Leprosy. inexpensive, widely available, quantitative. sensitive but not specific. Ab reacts w/beef cardiolipin

86

jarisch-herxheimer reaction

flu-like Sx after Abx started due to killed bacteria (usually spirochetes) releasing endotoxins

87

anaplasma

zoonotic bacteria -> anaplasmosis (anemia, hematuria, diarrhea, B Sx). source: ixodes ticks (live on deer + mice)

88

bartonella

zoonotic bacteria -> cat scratch dz (tender lymphadenitis, B Sx), bacillary angiomatosis (tumor-like blood vessels), source: cat scratch

89

borrelia burgdorferi

zoonotic bacteria -> lyme dz. source: ixodes ticks (deer + mice)

90

borrelia recurrentis

zoonotic bacteria -> relapsing fever. source: louse. recurrent due to variable surface Ags

91

brucella

zoonotic bacteria -> brucellosis/undulant fever (sweating, migratory arthralgia/myalgia, fever). source: unpasteurized dairy

92

campylobacter

zoonotic bacteria -> bloody diarrhea. source: puppies, livestock (fecal-oral, ingestion of undercooked meat)

93

chlamydophila psittaci

zoonotic bacteria -> psittacosis (atypical pna that mimics typhoid fever). source: parrots, other birds

94

coxiella burnetii

zoonotic bacteria -> Q fever (fever, malaise, sweating, pain, dry cough, headache, confusion, GI Sx). source: aerosols of cattle/sheep amniotic fluid

95

ehrlichia chaffeensis

zoonotic bacteria -> ehlichiosis (headache, myalgia, fatigue +/- rash. can -> opportunistic infxns). source: ambylomma (lone star tick)

96

francisella tularensis

zoonotic bacteria -> tularemia (high fever, lethargy, dec. appetite, rash, supporative lymphadenopathy, septicemia). source: ticks, rabbits, deer fly

97

leptospira

zoonotic bacteria -> leptospirosis (headache, myalgia, fever, hemoptisis, meningitis, jaundice, azotemia. source: animal urine

98

mycobacterium leprae

zoonotic bacteria -> leprosy. source: humans w/lepromatous leprosy, armadillo

99

pasteurella multocida

zoonotic bacteria -> cellulitis, osteomyelitis. source: animal bite: cats/dogs

100

rickettsia prowazekii

zoonotic bacteria -> epidemic typhus (sustained high fever, cough, rash, severe muscle pain, chills, falling blood pressure, stupor, sensitivity to light, delirium and death). source: louse

101

ricketssia rickettsii

zoonotic bacteria -> rocky mountain spotted fever (fever, headache, centripetal rash). source: dermacentor (dog tick).

102

Rickettsia typhi

zoonotic bacteria -> endemic typhus. source: fleas (on rats)

103

salmonella

zoonotic bacteria -> diarrhea (can be bloody), vomiting, fever, abd cramps. source: reptiles + poultry

104

yersinia pestis

zoonotic bacteria -> plague (bubonic, septicemic, pneumonic). source: fleas (rats + prairie dogs = reservoirs)

105

gardnerella vaginalis

-> BV. Tx: flagyl or clinda

106

rocky mountain spotted fever

rickettsia rickettsii. tick vector. found in/near north carolina. Sx: classic triad = headache, fever, rash. rash starts on wrists/ankles, spreads to trunk, palms, soles. Tx: doxycycline

107

palms + soles rash mnemonic

you drive CARS with your palms + soles: Coxsackievirus A (hand, foot, mouth), Rocky mountain spotted fever, secondary Syphilis.

108

typhus

endemic (fleas): R. typhi. epidemic (lice): R. prowazekii. rash starts centrally and spreads out, sparing palms + soles. Tx: doxy

109

centripetal/centrifugal rash mnemonic

Rickettsii on the wRists, Typhus on the Trunk.

110

ehrlichiosis

vector = tick. rash is rare. monocytes w/morulae (berry-like inclusions) in cytoplasm. Tx: doxy

111

anaplasmosis

vector = tick. granulocytes w/morulae in cytoplams. Tx: doxy

112

Q fever

coxiella burnetii. no arthropod vector. spores inhaled from cattle-sheep amniotic fluid. presents as pna. most common cause of Cx neg endocarditis. Q fever = Queer: no rash, no vector, organism can survive outside (as endospore).

113

chlamydia

cannot make ATP so they are obligate intracellular pathogens. chamys = cloak (intracellular). lab Dx: cytoplasmic inclusions seen on giemsa or fluorescent Ab-stained smear. cell wall lacks classic peptidoglycan (less muramic acid) so beta-lactams are less effective.

114

chlamydia forms

Elementary body (small, dense) = Enfectious, Enters cell via Endocytosis. transforms into retuculate body
Reticulate body Replicates in cell by fission; Reorganizes into elementary bodies

115

C. trachomatic

-> reactive arthritis (reiter syndrome), follicular conjunctivitis, nongonococcal urethritis, PID. Tx: azythromycin (1 dose) or doxy

116

C. pneumoniae/C. psittaci

-> atypical pna. transmitted via aerosol. Tx: azythromycin (1 dose) or doxy. psittaci has avian reservoir

117

chlamydia trachomatis serotypes A, B, C

-> chronic infection, blindness 2/2 follicular conjunctivitis (mostly in africa). ABC: Africa, Blindness, Chronic infection

118

chlamydia trachomatis serotypes D-K

-> everything else: urethritis/PID, ectopic pregnancy, neonatal pna (staccato cough) w/eosinophilia, neonatal conjuctivitis.

119

chlamydia trachomatis serotypes L1, L2, L3

-> lymphogranuloma venereum: small, painless genital ulcers -> swollen, painful inguinal lymph nodes that ulcerate (buboes). Tx: doxy

120

mycoplasma pneumonia

no cell wall. not seen on gram stain. pleomorphic. bacterial membrane contains sterols for stability. more common in young people, military recruits, prisons. -> atypical, walking pna. X-ray is worse that Sx. high titer of cold agglutinins (IgM): can agglutinate or lyse RBCs. grown on eaton agar. Tx: macrolides, doxy, or fluoroquinolones