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GRAM-POSITIVE BACTERIA:, Slides of Microbiology

(+) quellung test (encapsulated bacteria). 1. capsule (83 serotypes). 1. pneumonia. 2. meningitis. 3. sepsis. 4. otitis media (children).

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GRAM-POSITIVE BACTERIA:
Organism Diagnostics Virulence Factors Clinical Manifestations Treatment
Staphylococcus
Staphylococcus
aureus
(nose, skin esp.
hospital staff
and pts; vagina)
1. gram stain:
a. gram (+), clustered
cocci
2. culture:
a. β-hemolytic
b. golden w/ sheep
blood
3. Metabolic:
a. catalase (+)
b. coagulase (+)
c. facultative anaerobe
1. Protective
a. microcapsule
b. Protein A: binds IgG
c. Coagulase: fibrin
formation around
organism
d. hemolysins
e. leukocidins
f. penicillinase
2. Tissue-Destroying
a. hyaluronidase
b. staphylokinase (lysis of
clots)
c. lipase
1. Exotoxin Dependent
a. enterotoxinÆ gastroenteritis (rapid
onset and recovery)
b. TSST-1 Æ toxic shock syndrome
(fever, GI sx w/diarrhea, rash,
hypotension, desquamation of palms and
soles)
c. exfoliatinÆ scalded skin syndrome
(children)
2. Direct Invasion of Organs
a. pneumonia
b. meningitis
c. osteomyelitis (children)
d. acute bacterial endocarditis
e. septic arthritis
f. skin infection
g. bacteremia/sepsis
h. UTI
1. penicillinase-resistant
penicillins (eg. methicillin,
naficillan)
2. vancomycin
3. clindamycin
* if methicillin resistant, treat w/
IV vancomycin
Staphylococcus
epidermidis
(skin, mucous
membranes)
1. gram stain:
a. gram (+), clustered
cocci
2. Metabolic:
a. catalase (+)
b. coagulase (-)
c. facultative anaerobe
1. Protective
a. polysaccharide capsule
(adherence to prosthetic
devices)
* high antibiotic resistance
1. Nosocomial Infection
a. prosthetic joints, valves
b. sepsis from intravenous lines
c. UTI
2. skin contamination in blood cultures
1. vancomycin
Staphylococcus
saprophyticus
1. gram stain:
a. gram (+), clustered
cocci
2. culture:
a. γ-hemolytic
3. Metabolic:
a. catalase (+)
b. coagulase (-)
c. facultative anaerobe
1. UTIs in sexually active women 1. penicillin
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff

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GRAM-POSITIVE BACTERIA: Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Staphylococcus Staphylococcusaureus (nose, skin esp.hospital staffand pts; vagina)

  1. gram stain:

a.^

gram (+), clusteredcocci

  1. culture:

a.^

β-hemolytic b.^

golden w/ sheepblood

  1. Metabolic:

a.^

catalase (+) b.^

coagulase (+) c.^

facultative anaerobe

  1. Protective

a.^

microcapsule b.^

Protein A: binds IgG c.^

Coagulase: fibrinformation aroundorganism d.^

hemolysins e.^

leukocidins f.^

penicillinase

  1. Tissue-Destroying

a.^

hyaluronidase b.^

staphylokinase (lysis ofclots) c.^

lipase

  1. Exotoxin Dependent

a.^

enterotoxin

Æ^ gastroenteritis

(rapid

onset and recovery) b.^

TSST-

Æ^ toxic shock syndrome (fever, GI sx w/diarrhea, rash,hypotension, desquamation of palms andsoles) c.^

exfoliatin

Æ^ scalded skin syndrome (children)

  1. Direct Invasion of Organs

a.^

pneumonia b.^

meningitis c.^

osteomyelitis (children) d.^

acute bacterial endocarditis e.^

septic arthritis f.^

skin infection g.^

bacteremia/sepsis h.^

UTI

  1. penicillinase-resistantpenicillins (eg. methicillin,naficillan) 2. vancomycin 3. clindamycin * if methicillin resistant, treat w/IV vancomycin

Staphylococcusepidermidis (skin, mucousmembranes)

  1. gram stain:

a.^

gram (+), clusteredcocci

  1. Metabolic:

a.^

catalase (+) b.^

coagulase (-) c.^

facultative anaerobe

  1. Protective

a.^

polysaccharide capsule(adherence to prostheticdevices)

  • high antibiotic resistance
  1. Nosocomial Infection

a.^

prosthetic joints, valves b.^

sepsis from intravenous lines c.^

UTI

  1. skin contamination in blood cultures
  2. vancomycin

Staphylococcussaprophyticus

  1. gram stain:

a.^

gram (+), clusteredcocci

  1. culture:

a.^

γ-hemolytic

  1. Metabolic:

a.^

catalase (+) b.^

coagulase (-) c.^

facultative anaerobe

1.^ UTIs

in sexually active women

  1. penicillin

Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Streptococcus Streptococcuspneumoniae (oralcolonization)

  1. gram stain:

a.^

gram (+), diplococci

  1. culture:

a.^

does not grow inpresence of optochinand bile b.^

α-hemolytic

  1. Metabolic:

a.^

catalase (-) b.^

facultative anaerobe

  1. (+) quellung test (encapsulatedbacteria)
  2. capsule (83 serotypes) 1.^ pneumonia 2.^ meningitis 3. sepsis 4.^ otitis media

(children)

(secretes pneumolysins that bind cholesterol of host-cell membranes, actual effect is unknown)

  1. penicillin G (IM) 2. erythromycin 3. ceftriaxone 4. vaccine: against the 23 mostcommon capsular Ag’s

Streptococcuspyrogenes (groupA)

  1. gram stain:

a.^

gram (+), chains

  1. culture:

a.^

inhibited by bacitracin b.^

β-hemolytic(streptolysinOÆ oxygen labile, antigenic; S

Æoxygen stable, non-antigenic)

  1. Metabolic:

a.^

catalase (-) a.^

microaerophilic

  1. M-protein (adherence factor,antiphagocytic, antigenic) 2. lipoteichoic acid (adherence factor) 3. steptokinase 4. hyaluronidase 5. DNAase 6. Anti-C5a peptidase
  2. Direct Invasion/toxin

a.^

pharyngitis

(purulent exudates on tonsils, fever, swollen lymph nodes) b.^

sepsis c.^

skin infections d.^

scarlet fever e.^

toxic shock syndrome

  1. Antibody-mediated

a.^

rheumatic fever

(fever, myocarditis,

arthritis, chorea, rash, subcutaneousnodules) b.^

acute post-streptococcal glomerulonephritis

  1. Penicillin G 2. Penicillin V 3. Erythromycin 4. Penicillinase-resistant penillicin(skin infections b/c might be staph) * après RF, cont. prophylaxis forrepeat infection, if heart valvecomplications, prophylaxis avantcertain procedures (eg. dental work)

Æ

endocarditis ** invasive

Æ^ clindamycin

Steptococcusagalactiae (vaginalcolonization)

  1. gram stain:

a.^

gram (+), chains (urineor CSF)

  1. culture: (urine, CSF, blood)

a.^

β-hemolytic

  1. Metabolic:

a.^

catalase (-) b.^

facultative anaerobe

1. neonatal meningitis 2. neonatal pneumonia 3.^ neonatal sepsis

  1. penicillin G

Enterococci (group D) (normal colonflora)

  1. gram stain:

a.^

gram (+), chains

  1. culture:

a.^

bile, sodium chloride b.^

α,β, γ-hemolytic

  1. Metabolic:

a.^

catalase (-) b.^

facultative anaerobe

  1. extracellular dextran helps bind toheart valves (high intrinsic resistance)
  2. subacute bacterial

endocarditis

  1. biliary tract infections 3.^ UTI
  2. ampicillin (combined w/aminoglycosides in endocarditis) *resistance to penicillin G andemerging resistance to vancomycin

Streptococcusviridans (normal orophrynx flora & GI)

  1. gram stain:

a.^

gram (+), chains

  1. culture:

a.^

resistant to optochin b.^

α-hemolytic (green)

  1. Metabolic:

a.^

catalase (-) b.^

facultative anaerobe

  1. subacute bacterial

endocarditis

  1. dental cavities 3. brain or liver abcesses
  2. penicillin G

Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Listeria Listeriamonocytogenes (ingestion ofcontaminatedraw milk orcheese; vaginaltransmission)

  1. gram stain:

a.^

gram (+), non-spore-forming rods

  1. culture:

a.^

low temperature(2.

°C)

  1. metabolism:

a.^

catalase (+) b.^

β-hemolysis c.^

facultativeintracellularanaerobic parasite

  1. flagella (H-Ag (+)) 2. hemolysin

a.^

heat labile b.^

antigenic

1.^ neonatal meningitis 2.^ meningitis

in immuno-suppressed pts*

3.^ septicemia * cell-mediated immunity protective ** only gram (+) w/endotoxin (LPS-Lipid A)—clinical significance is ambiguous

  1. ampicillin 2. trimethoprim/sulfamethoxazole

GRAM-NEGATIVE BACTERIA: Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Enterobacteriaceae Salmonella species (zoonotic: turtles,chicken, uncookedeggs)

  1. gram stain:

a.^

gram(-) rods

  1. culture: (EMB/MacConkey)

a.^

HS production^2

  1. metabolism:

a.^

catalase (+) b.^

oxidase (-) c.^

glucose fermenter d.^

does not fermentlactose e.^

facultative anaerobe

  1. flagella (H antigen) 2.^ capsule

(Vi antigen): protects from intracellular killing 3. siderophore *^ lives in M

φ^ in lymph nodes ** asplenic or non-fxn splenic

pts are

at increased risk

  1. paratyphoid fever (similar to typhoid fever) 2.^ gastroenteritis 3.^ sepsis 4.^ osteromyelitis

(esp SS pts)

  1. ciprofloxacin 2. ceftriaxone 3. trimethoprim & sulfamethoxazole 4. azithromycin 5.^ diarrhea: only fluid andelectrolyte replacement

Salmonella typhi (fecal-oraltransmission)

  1. gram stain:

a.^

gram(-) rods

  1. culture: (urine, blood, CSF;EMB/MacConkey agar)

a.^

HS production^2

  1. metabolism:

a.^

catalase (+) b.^

oxidase (-) c.^

glucose fermenter d.^

does not fermentlactose e.^

facultative anaerobe

  1. flagella (H antigen) 2.^ capsule

(Vi antigen): protects from intracellular killing 3. siderophore *^ lives in M

φ^ in lymph nodes **can live in

gall bladder

for years

*** asplenic or non-fxn splenic ptsare at increased risk

1.^ typhoid fever

a.^

fever b.^

abdominal pain c.^

hepatosplenomegaly d.^

rose spots on abdomen (light skinned pts)

2.^ chronic carrier state 1.^ ciprofloxacin 2.^ ceftriaxone 3. trimethoprim & sulfamethoxazole 4. azithromycin

Shigelladysenteriae (humans; fecal-oraltransmission)

  1. gram stain:

a.^

gram(-) rods

  1. culture: (stool;EMB/MacConkey agar)

a.^

no H

S production 2

  1. metabolism:

a.^

catalase (+) b.^

oxidase (-) c.^

glucose fermenter d.^

does not fermentlactose e.^

facultative anaerobe

1.^ non-motile

(no H antigen)

  1. invades submucosa not laminapropria *IgA best defense 1.^ Shiga toxin

: inactivates the 60S ribosome,

inhibiting protein synthesis and killing intestinal cells a.^ bloody diarrhea

with mucus and pus

  1. fluoroquinolones 2. trimethoprim & sulfamethoxazole

Klebsiellapneumoniae

  1. gram stain:

a.^

gram(-) rods

  1. culture: (EMB/MacConkey) 3. metabolism:

a.^

indole, oxidase (-) b.^

glucose , lactosefermenter c.^

facultative anaerobe

  1. capsule 2. non-motile 1.^ pneumonia

, with significant lung necrosis and

bloody sputum, commonly in alcoholics, or those withunderlying lung disease 2.^ hospital acquired UTI and sepsis

rd 1. 3 generation cephalosporins

  1. ciprofloxacin

Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Vibrionaceae Vibrio cholera (fecal-oraltransmission)

  1. gram stain:

a.^

short, commashaped, gram(-)rods

w/ single polar flagellum

  1. culture: (TCBS agar)

a.^

flat yellow colonies

3.^ dark field microscopy

of

stool

a.^

motile organismsimmobilized withantiserum

  1. metabolism:

a.^

ferments sugar(except lactose)

  1. flagellum (H antigen) 2. mucinase: digests mucous layerto attach to cells 3. fimbriae: helps with attachmentto cells 4.^ noninvasive 1.^ cholergen

(enterotoxin): like LT,

↑^ cAMP

Æ

secretion of electrolytes from the intestinalepithelium (secretion of fluid into intestinal tract)

a.^

cholera

: severe diarrhea with rice water stools, no pus^ (death by dehydration)

  • epidemics

1991 Latin America 1993 Bangladesh and India

  1. replace fluids 2. doxycycline 3. fluoroquinolone

Campylobacterjejuni (zoonotic: wildand domesticanimals andpoultry;transmitted byuncooked meatand fecal-oral)

  1. gram stain:

a.^

curved

gram(-) rods w/^ singular polarflagellum

  1. culture: (stool;EMB/MacConkey agar)

a. optimum temp is 42

°C

  1. metabolism:

a.^

oxidase (+) b.^

does not fermentlactose c.^

microphilic aerobe

  1. flagella (H antigen) 2. invasiveness
  2. enterotoxin: similar to cholera toxin and LT 2. cytotoxin: destroys mucosal cells Î^ secretory or bloody diarrhea * one of the three most common causes ofdiarrhea in the world
  3. fluoroquinolone 2. erythromycin

Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Pseudomonadaceae Pseudomonasaeruginosa (opportunistic)

  1. gram stain:

a.^

gram(-) rods

  1. culture: (blood agar)

a.^

greenish-metallicappearance w/ fruitysmell

  1. metabolism:

a.^

oxidase (+) b.^

non-lactosefermenter c.^

obligate aerobe

  1. polar flagellum (H antigen) 2. hemolysin 3. collagenase 4. elastase 5. fibrinolysin 6. phospholipase C 7. DNAase 8. some strains possess anantiphagocytic capsule
  2. exotoxin A (similar to diptheria toxin):inhibits protein synthesis by blocking EF

a.^

pneumonia (cystic fibrosis andimmunosuppressed pts) b.^

osteomyelitis (diabetics, IV drug users,children) c.^

burn wound infections d.^

sepsis e.^

UTI

f.^

endocarditis (IV drug users) g.^

malignant external otitis h.^

corneal infections in contact lenswearers

  1. ticarcillin 2. timentin 3. carbenicillin 4. piperacillin 5. mezlocillin 6. ciprofloxacin 7. imipenem 8. tobramycin 9. aztreonam

Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Bacteroidaceae Bacteroidesfragilis (normal GI flora)

  1. gram stain:

a.^

gram(-) rods b.^

non-spore forming c.^

polysaccharidecapsule

  1. metabolism:

a.^

anaerobe

  • infection when organism entersperitoneal cavity
  1. does not contain Lipid A

a.^

abcesses in GI tract, pelvis, lungs

  1. metronidazole 2. clindamycin 3. chloramphenicol 4. surgically drain abcess

Actinomyces

GRAM-NEGATIVE RODS RELATED TO RESPIRATORY TRACT INFECTIONS: Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Hemophilus Hemophilusinfluenzae (humans;respiratorytransmission)

  1. gram (-) rods 2. culture: (blood agar heatedto 80

°C for 15 min) a.^ high CO

2 environment

  1. Fluorescent Ab’s 4. (+) Quellung test
  2. capsule (6 types, b mostvirulent) 2. attachment pili (FHA) 3. IgA

protease 1

I. encapsulated 1.^ meningitis

(type b): infants 3 – 36 m/o

cx: retardation, seizures, deafness, and death 2. acute epiglottis 3. septic arthritis in infants 4. sepsis esp pts w/o functioning spleens 5.^ pneumonia II. nonencapsulated 1.^ otitis media 2.^ sinusitis

nd 1. 2 or 3

rd^ generation c’sporins

  1. Hib vaccines: DTP 3. passive immunization (

↑^ mother

transfer of immunity )

Hemophilusdureyi (STD)

  1. gram (-) rods 2. culture: (ulcer exudates &pus from lymph node)
  2. no capsule 1.^ chancroid

: painful genital ulcer, often

associated w/ unilateral swollen lymph nodes thatrupture releasing pus

  1. azithromycin or erythromycin 2. ceftriaxone 3. ciprofloxacin

Bordetella Bordetellapertussis (man; highlycontagious;resptransmission)

  1. gram (-) rod 2. culture: (Bordet-Gengoumedia) 3.^ serologic tests

(ELISA)

a. specimen from post.pharynx (does not grow oncotton) 4. direct flourescein-labeledAb’s

1.^ pertussis toxin

: activate G

proteins that

↑^ cAMP

Æ^ ↑

histamine sensitivity,

↑^ insulin

release,

↑^ lymphocytes in blood

  1. extracytoplasmic AC:“weakens” PMNs, lymphocytes,and monocytes 3. FHA: binding to ciliated epicells 4. tracheal cytotoxin: kills ciliatedepi cells 1.^ whooping cough

a.^

catarrhal phase

: 1-2wks; pt is high

contagious (low grade fever, runny nose,& mild cough) b.^

paroxymal phase

: 2-10wks (whoop,

lyphocytes in blood smear,

antibiotics

ineffective

c.^

convalescent phase

  1. erythromycin (before paroxymalstage) 2. Vaccine: DPT (may cause rash& fever, rarely systemic disease) 3. newer-acellular vaccinew/pertussis toxin, FHA, pertactin,and frimbrial Ag 4. treat household contacts w/erythromycin

Legionella Legionellapneumophilia (ubiquitous inman & naturalwater environ.;airconditioning,cooling towers)

  1. gram (-) rod (faint) 2. culture: (buffered charcoalyeast extract) 3.^ serologic tests (IFA,ELISA) 4.^ urinary Ag

can be detected

by radioimmunoassay;remains (+) for months afterinfection 5. facultative intracellularparasite

  1. capsule 2. flagella & multiple fimbriae) 3. hemolysin
  2. cytotoxin 2.^ Pontiac fever

: headache, fever, myalgia (self-

limiting) 3.^ Legionnaires’ Disease

: pneumonia (atypical),

fever, non-productive cough *compromised immune systems, greater risk

  1. erythromycin 2. rifampin

GRAM-NEGATIVE RODS RELATED TO THE ENTERIC TRACT: Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Enterobacteriaceae Salmonella species (zoonotic: turtles,chicken, uncookedeggs)

  1. gram stain:

a.^

gram(-) rods

  1. culture: (EMB/MacConkey)

a.^

HS production^2

  1. metabolism:

a.^

catalase (+) b.^

oxidase (-) c.^

glucose fermenter d.^

does not fermentlactose e.^

facultative anaerobe

  1. flagella (H antigen) 2.^ capsule

(Vi antigen): protects from intracellular killing 3. siderophore *^ lives in M

φ^ in lymph nodes ** asplenic or non-fxn splenic

pts are

at increased risk

  1. paratyphoid fever (similar to typhoid fever) 2.^ gastroenteritis 3.^ sepsis 4.^ osteromyelitis

(esp SS pts)

  1. pneumonia and meningitis

indicated for neonates or pts at riskfor septicemia or dissemination 1. ciprofloxacin (sepsis) 2. ceftriaxone (sepsis) 3. trimethoprim & sulfamethoxazole 4. azithromycin 5.^ diarrhea: only fluid andelectrolyte replacement

Salmonella typhi (fecal-oraltransmission)

  1. gram stain:

a.^

gram(-) rods

  1. culture: (urine, blood, CSF;EMB/MacConkey agar)

a.^

HS production^2

  1. metabolism:

a.^

catalase (+) b.^

oxidase (-) c.^

glucose fermenter d.^

does not fermentlactose e.^

facultative anaerobe

  1. flagella (H antigen) 2.^ capsule

(Vi antigen): protects from intracellular killing 3. siderophore *^ lives in M

φ^ in lymph nodes **can live in

gall bladder

for years

*** asplenic or non-fxn splenic ptsare at increased risk

1.^ typhoid fever

a.^

fever b.^

abdominal pain c.^

hepatosplenomegaly d.^

rose spots on abdomen (light skinned pts)

2.^ chronic carrier state 1.^ ciprofloxacin 2.^ ceftriaxone 3. trimethoprim & sulfamethoxazole 4. azithromycin 5. ampicillin (carriers)

Shigelladysenteriae (humans; fecal-oraltransmission)

  1. gram stain:

a.^

gram(-) rods

  1. culture: (stool;EMB/MacConkey agar)

a.^

no H

S production 2

  1. metabolism:

a.^

catalase (+) b.^

oxidase (-) c.^

glucose fermenter d.^

does not fermentlactose e.^

facultative anaerobe

1.^ non-motile

(no H antigen)

  1. invades submucosa not laminapropria *IgA best defense ** very low ID

50

1.^ Shiga toxin

: inactivates the 60S ribosome,

inhibiting protein synthesis and killing intestinal cells a.^ bloody diarrhea

with mucus and pus (

dysentery

)

  1. fluid and electrolyte replacement 2. fluoroquinolone (severe cases) 3. trimethoprim & sulfamethoxazole

Klebsiellapneumoniae (colon, soil,water)

  1. gram stain:

a.^

gram(-) rods

  1. culture: (EMB/MacConkey)

a.^

vicous colonies

  1. metabolism:

a.^

indole, oxidase (-) b.^

glucose , lactosefermenter c.^

facultative anaerobe

  1. capsule 2. non-motile 1.^ pneumonia

, with significant lung

necrosis

and

bloody sputum

, commonly in alcoholics, or those

with underlying lung disease 2.^ hospital acquired UTI and sepsis

rd 1. 3 generation cephalosporins

  1. ciprofloxacin

Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Vibrionaceae Vibrio cholera (fecal-oraltransmission)

  1. gram stain:

a.^

short, commashaped, gram(-)rods

w/ single polar flagellum

  1. culture: (TCBS agar)

a.^

flat yellow colonies

3.^ dark field microscopy

of

stool

a.^

motile organismsimmobilized withantiserum

  1. metabolism:

a.^

ferments sugar(except lactose)

  1. flagellum (H antigen) 2. mucinase: digests mucous layerto attach to cells 3. fimbriae: helps with attachmentto cells 4.^ noninvasive 1.^ cholergen

(enterotoxin): like LT,

↑^ cAMP

Æ

secretion of electrolytes from the intestinalepithelium (secretion of fluid into intestinal tract)

a.^

cholera

: severe diarrhea with

rice water

stools

, no pus (death by dehydration)

  • epidemics

1991 Latin America 1993 Bangladesh and India

  1. replace fluids 2. doxycycline 3. fluoroquinolone

Campylobacterjejuni (zoonotic: wildand domesticanimals andpoultry;transmitted byuncooked meatand fecal-oral)

  1. gram stain:

a.^

curved

gram(-) rods w/^ singular polarflagellum

  1. culture: (stool;EMB/MacConkey agar)

a. optimum temp is 42

°C

  1. metabolism:

a.^

oxidase (+) b.^

does not fermentlactose c.^

microphilic aerobe

  1. flagella (H antigen) 2. invasiveness
  2. enterotoxin: similar to cholera toxin and LT 2. cytotoxin: destroys mucosal cells Î^ secretory or

bloody diarrhea

(associated with Guillain-Barre syndrome—acuteneuromuscular paralysis; autoimmune) * one of the three most common causes ofdiarrhea in the world

  1. fluoroquinolone 2. erythromycin 3. ciprofloxacin

Helicobacterpylori

  1. gram stain:

a.^

curved

gram(-) rods w/^ tuft of flagella

  1. metabolism:

a.^

urease (+) b.^

microaerobe

1.^ duodenal ulcers 2.^ chronic gastritis

  1. bismuth, ampicillin,metronidazole & tetracycline 2. clarithromycin & omeprazole * both reduce duodenal ulcerrelapse

Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Pseudomonadaceae Pseudomonasaeruginosa ( opportunistic

soil, water; usuallynosocomial)

  1. gram stain:

a.^

gram(-) rods

  1. culture: (blood agar)

a.^

greenish-metallicappearance w/ fruitysmell

  1. metabolism:

a.^

oxidase (+) b.^

non-lactosefermenter c.^

obligate aerobe

  1. polar flagellum (H antigen) 2. hemolysin 3. collagenase 4. elastase 5. fibrinolysin 6. phospholipase C 7. DNAase 8. some strains possess anantiphagocytic capsule * high antibiotic resistance
  2. exotoxin A (similar to diptheria toxin):inhibits protein synthesis by blocking EF

a.^

pneumonia

( cystic fibrosis

and

immunosuppressed pts) b.^

osteomyelitis (diabetics, IV drug users,children) c.^

burn wound infections d.^

sepsis e.^

UTI

f.^

endocarditis (IV drug users) g.^

malignant external otitis h.^

corneal infections in contact lenswearers

1.^ ticarcillin 2. timentin 3. carbenicillin 4.^ piperacillin 5. mezlocillin 6. ciprofloxacin 7. imipenem 8. tobramycin 9. aztreonam

Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Bacteroidaceae Bacteroidesfragilis (normal GI flora)

  1. gram stain:

a.^

gram(-) rods b.^

non-spore forming c.^

polysaccharidecapsule

  1. metabolism:

a.^

anaerobe

  • infection when organism entersperitoneal cavity (resistant to penicillins, 1

st

generation cephalosporins,aminoglycosides)

  1. does not contain Lipid A

a.^

abcesses in GI tract, pelvis, lungs (disease below the diaphragm)

1.^ metronidazole 2. clindamycin 3. chloramphenicol 4. surgically drain abcess

Actinomyces

GRAM-NEGATIVE OBLIGATE INTRACELLULAR PARASITES: Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Chlamydia Chlamydiatrachomatis (humans, directcontact)

  1. gram stain:

a.^

gram (-), lackspeptidoglycan layer

  1. culture: (conjunctiva surface,genital secretions)

a.^

no gram(-) diplococci

3.^ immunofluorescent slidetest 4. serologies

  1. resistant to lysozyme 2.^ prevents phagosome-lysosomefusion 3. nonmotile 4. no pili 5. no exotoxins Cell Cycle: 1.^ elementary body

infects cells

Æ

reticulate body

that replicates (

req’

host ATP

Æelementary body that leaves cell and infects other cells 2. tropism for endothelial columnarcells

  1. serotypes A, B, C:

a.^

trachoma

: scarring of inside of eyelid

Æ

redirection of eyelashes onto cornealsurface (corneal scarring and blindness)

  1. serotypes D-K:

a.^

inclusion conjunctivitis (opthalmianeonatorum) b.^

infant pneumonia c.^

urethritis, cervicitis, PID in women d.^

nongonoccal urethritis, epididymitis,prostatitis in men cx: sterility, ectopic pregnancy, chronic pain,reiter’s syndrome, perihepatitis (Fitz-Hugh-Curtis Syndrome)

  1. serotypes L

:(1-3)

a.^ lymphogranuloma venereum

  1. doxycycline (adults) 2. erythromycin (infants andpregnant women) 3. azithromycin * systemic tx needed for any eyeinfection

Æ^ pneumonia

Chlamydiapneumoniae (humans;respiratoryroute; TWAR)

  1. gram stain:

a.^

gram (-), lackspeptidoglycan layer

  1. culture: (conjunctiva surface,genital secretions)

b.^

no gram(-) diplococci

  1. immunofluorescent slide test 4.^ serologies

cell cycle similar to above

1.^ atypical pneumonia

: viral-like atypical

pneumonia, with fever and dry, non-productivecough in young adults

  1. doxycycline 2. erythromycin

Rickettsia Rickettsiarickettsii (transmitted bydog and woodticks;southeasterntick belt)

  1. clinical exam 2. ELISA of skin biopsy fromrash site 3. serology 4. Weil-Felix reaction: (

x-rxn to

proteus

Ag ), OX-2,19 (+)

1.^ Rocky Mountain Spotted Fever

a.^

fever b.^

conjunctival injection c.^

severe headaches d.^

rash on wrists, ankles, soles, and plamsinitially, becomes more generalized later(centrifugal)

  1. doxycycline 2. chloramphenicol

Rickettsia akari (transmitted bymites on housemice)

  1. clinical exam 2. weil-felix reaction (-) 1.^ Rickettsial Pox: a. vesicular rash similar to chicken pox (resolvesover 2 wks)
  2. doxycycline 2. chloramphenicol

Ehrlichia Ehrlicihiacanis/chaffeenis (dog ticks)

  1. rise in acute and convalescentAb titers 2. morula bodies in leukocyteblood smears 1.^ Human Ehrlichiosis a. similar to Rocky Mountain spotted Fever, butrash is rare
  2. doxycycline 2. rifampin (resistant to chloramphenicol)

MISCELLANEOUS BACTERIA: Organism

Diagnostics

Virulence Factors

Clinical Manifestations

Treatment

Actinomycetes Actinomycesisraelli (normal oralflora)

  1. gram (+),

long branching filaments 2. hard, yellow granules( sulfur granules

) formed in

pus 3. culture of pus or tissue 4.^ anaerobe 5. immunofluorescence

1.^ Actinomycosis

a.^

abscess with draining sinuses b.^

initial lesion involves face and neck(rest

Æ^ chest and abdomen) c.^

not communicable

  1. prolonged penicillin G w/surgical drainage

Nocardiaasteroids (soil)

  1. gram (+) filaments, acid fast 2. aerobic 1.^ Nocardiosis

a.^

abscesses in brain and kidneys inimmunodeficient pts b.^

pneumonia c.^

not communicable

  1. trimethoprim-sulfamethoxazole 2. surgical drainage may benecessary

Mycoplasma Mycoplasmapneumoniae (humans, respdroplets

1.^ absence of cell wall 2. bacterial membranecontains cholesterol 3. grown on artificial mediareq’ lots of different lipids;characteristic “fried egg”colonies w/raised center 4. rod-shaped w/ pointed tip 5.^ serologies; cold-aglutinintiter

(IgM autoAb’s against type O blood cells)—non-specific

  1. produces hydrogen peroxidedamages resp tract cells 2. Ab’s against RBCs (coldagglutinins), brain, lung, and livercells produced during infection 1.^ Atypical Pneumonia

a.^

most common cause of pneumonia inyoung adults b.^

gradual onset with non-productivecough, sore throat, ear ache c.^

constitutional sx of fever, headache,malaise, and myalgias pronounced d.^

minimal chest x-ray findings e.^

resolves spontaneously in 10-14 days

  1. macrolide (erythromycin,azithromycin) 2. tetracycline (doxycycline) (penicillins and c’sporinsineffective b/c no cell wall)