Microbiology

Question 1

what is the most common immunologic method?

Answer 1

latex agglutination

Question 2

what is a DNA probe?

Answer 2

identify the bug and the way to attack it

Question 3

which antibodies form first?

Answer 3

IgM (7-14 days in)

Question 4

why would you use a 2 titer approach?

Answer 4

are you in acute phase of disease or are you getting better?

Question 5

streptococci

Answer 5

gram positive in chains

Question 6

Group A beta hemolytic strep

Answer 6

S. pyogenes
DOC penicillin and amoxicillin
dx by culture and rapid ID test
serological dx by anti-treptolysin (ASO)

Question 7

what dz are assoc with S. pyogenes?

Answer 7

glomerulonephritis (rare)
rheumatic fever (rare)
pharyngitis
scarlet fever
cellulitis
TSS
necrotizing fascitis

Question 8

what happens if strep is untreated in some of the situations?

Answer 8

rheumatic fever and glomerulonephritis

Question 9

Group B beta hemolytic strep

Answer 9

S. agalactiae
causes neonatal septicemia and meningitis
source in maternal genital tract
dx with maternal vaginal culture
intradelivery antibiotics for positive mothers

Question 10

what is also assoc with group B strep?

Answer 10

post partum endometritis

Question 11

Group C beta hemolytic strep

Answer 11

primarily animal pathogens but may be normal human flora

Question 12

Group F beta hemolytic strep

Answer 12

dental abscesses, but infection uncommon

Question 13

Group G beta hemolytic strep

Answer 13

animal pathogen, but can be normal human flora

Question 14

S. viridans

Answer 14

alpha hemolytic strep
gram +
most common skin contaminant but normal in oral, throat, GI

Question 15

what is S. viridans also assoc with?

Answer 15

opportunistic infections, wounds, bacteremia

Question 16

what is the most common cause of bacterial endocarditis?

Answer 16

S. viridans

Question 17

S. pneumoniae

Answer 17

alpha hemolytic gram +
community acquired pneumonia
and pneumococcal bacteremia if left untreated
most strains sensitive to penicillin

Question 18

what is assoc with S. pneumoniae?

Answer 18

otitis media, meningitis, in children and older adults

Question 19

what do you do with S. pneumoniae infection?

Answer 19

C&S and latex agglutination of CSF

Question 20

Group D non hemolytic strep

Answer 20

S. bovis (affects animal handlers)

Question 21

Enterococcus

Answer 21

E. faecalis and E. faecium
causes 20% of bacterial endocarditis and 10% of UTI
also causes nosocomial infections producing vancomycin-resistant strains (VRE)

Question 22

staphylococci

Answer 22

gram positive in clusters

Question 23

Staph aureus

Answer 23

assoc with purulent inflammation and causes abscesses
*most common cause of bacterial endocarditis in drug users
causes endotoxin with causes TSS

Question 24

what is MRSA?

Answer 24

methicillin resistant staph aureus

-cause of nosocomial infections

Question 25

staph epidermidis

Answer 25

normal flora on skin mostly assoc with indwelling devices (catheters, vascular grafts, joint prosthetics) skin contaminant and eye surgery infection

Question 26

staph saprophyticus

Answer 26

common cause of bacterial UTI | often antibiotic resistant

Question 27

what color is gram positive?

Answer 27

blue

Question 28

what color is gram negative?

Answer 28

red

Question 29

neisseria gonorrhoeae

Answer 29

``` gram negative diplococci causes gonorrhea typically asx in females, but not in males strains are becoming resistant causes PID or salpingitis ```

Question 30

neisseria meningitidis

Answer 30

most common type of meningitis in adults | dx by C&S and agglutination of CSF

Question 31

moraxella catarrhalis

Answer 31

gram negative diplococci found in URI | most common with ear and sinus infection

Question 32

E. coli

Answer 32

most common cause of UTI | most common cause of neonatal meningitis

Question 33

E. coli O157:H7

Answer 33

hemorrhagic colitis

Question 34

Klebsiella pneumoniae

Answer 34

a/w pneumonia in alcoholics and older adults | aspirated vomit

Question 35

proteus

Answer 35

cause of UTI in pts in hospital P. mirabilis and P. vulgaris normal flora of GI

Question 36

pseudomonas aeruginosa

Answer 36

nosocomial with UTI and septicemia a/w severe burns, otitis externa and cystic fibrosis infections known for high resistance and mortality

Question 37

gardnerella vaginalis

Answer 37

causes bacterial vaginosis | dx by clue cells in wet mount of discharge

Question 38

haemophilus

Answer 38

gram negative coccobacilli

Question 39

H. influenzae

Answer 39

most important species of croup | a/w otitis media (children), sinusitis, meningitis, bacteremia and pneumonia

Question 40

H. aegyptius

Answer 40

purulent conjunctivitis

Question 41

H. ducreyi

Answer 41

causes venereal chancroid

Question 42

pasteurella multocidas

Answer 42

dogs and cat bites | cellulitis occurs if left untreated

Question 43

H. pylori

Answer 43

mucus covering gastric mucosa dx with gastric biopsy culture, urea breath test acute and chronic gastricits, duodenal ulcer and gastric CA

Question 44

corynebacteria

Answer 44

gram positive bacilli

Question 45

C. diphtheriae

Answer 45

most important corynebacteria

Question 46

lactobacillus

Answer 46

normal genital tract flora

Question 47

listeria monocytogenes

Answer 47

causes infection from contaminated food (cheese, salads) dx by culture most common presents with meningitis and bacteremia

Question 48

clostridium perfringens

Answer 48

most common cause of gas gangrene | deep tissue wounds are more susceptible

Question 49

clostridium tenani

Answer 49

``` causes tetanus (produces spores) puncture wounds are at higher risk ```

Question 50

clostridium botulinum

Answer 50

produces botulism | produces an endotoxin (spores germinate in anaerobic conditions)

Question 51

clostridium difficile

Answer 51

pseudomembraneous colitis a/w antibiotic use major nosocomial infection

Question 52

chlamydia

Answer 52

coccobacillary organism | can only be grown in living cells

Question 53

chlamydia psittaci

Answer 53

associated with birds

Question 54

chlamydia pneumoniae

Answer 54

causes about 10% of pneumonia

Question 55

chlamydia trachomatis

Answer 55

causes lymphogranuloma venereum STD huge lymph nodes in their groin serology test can cause urethritis and endocervicitis

Question 56

mycoplasma pneumoniae

Answer 56

atypical pneumonia chest x-ray is LL mottled infiltrates most common in college freshman and military recruits

Question 57

mycobacterium TB

Answer 57

acid fast bacillus

Question 58

what is the dx value of bacteria in UTI?

Answer 58

>100,000 cfu/mL

Question 59

why is sputum culture difficult?

Answer 59

can be contaminated with oropharyngeal bacteria