Gram negative bacteria

Question 1

Enterobacteriaceae

Answer 1

gram negative rods
ferment glucose
reduce nitrate
catalase positive
oxidase negative
antigen: H -flagellar; O-somatic; K-capsular
virulence factor: endotoxin(LPS); capsule; antigenic phase variation

Question 2

E. Coli

Answer 2

ETEC-exotoxins
EPEC- intestinal epithelium
EAEC”stacked brick”, biofilm
EHEC- intestinal epithelium + shiga-like toxin; O157:H7; bloody stools; hemolytic uremic; antimicrobials contraindicated; most common of diarrheic in US
EIEC- intestinal epithelium, lead to tissue distraction; disease mimics bacillary dysentery (shigellosis)
normal E. Coli- most common UTI

Question 3

Salmonella Typhi

Answer 3

enteric fever

“typhoid fever”

Question 4

Shigella

Answer 4

S. dysenteriae
S. sonnei
S. boydii
S. flexneri
Shiga toxin- cell damage, cell death, HUS
Shigellosis (bacillary dysentery)-bloody diarrhea, pus, dead tissue

Question 5

Yersinia pestis

Answer 5

Select agent!
Plague: bubonic, pneumonic, septicemic
Bubonic- flea bites; buboes in groin and axillae; 75% mortality
Pneumonic- droplets; 90% mortality
Septicemic- progressive disease from bubonic, pneumonic forms

Question 6

Yersinia enterocolitica

Answer 6

refrigerated blood products (grows at 4C)

can be transfused

Question 7

Klebsiella

Answer 7

K. pneumoniae, K. oxytoca
bloody sputum
mucoid- thick capsule

Question 8

Proteus

Answer 8

P. mirabilis, P. vulgaris
swarming motility
causes UTI

Question 9

Neisseria

Answer 9

gram negative diplococci

Question 10

Neisseria gonorrhoeae

Answer 10

STD; urethral in men, cervical in women
ophthalmia neo- eye infection of newborn
caused when newborn passes through the birth canal of infected mother

Question 11

Neisseria meningitides

Answer 11

bacterial meningitis
waterhouse-friderichsen syndrome
destruction of adrenal glands

Question 12

Vibrio cholerae

Answer 12

Gram negative rods, comma shaped
salt concentration
Serogroups O1 and O139: cholera toxin
Cholera toxin- cellular cAMP, expel chloride ions and massive amounts of water, leading to characteristic diarrhea
Disease: cholera, profuse diarrhea, “rice-water stool”

Question 13

Vibrio vulnificus

Answer 13

raw shellfish
wound infection-contaminated sea water
worse with underlying medical condition or immunocompromised state

Question 14

Campylobacter jejuni

Answer 14

gram negative rod
“gull-wing” shape
42C
most common cause of gastroenteritis in US

Question 15

Helicobacter pylori

Answer 15

gram negative, helical shaped
stomach ulcers
gastric cancer

Question 16

Pseudomonas aeruginosa

Answer 16

pyocaynin: blue-green pigment
pyoverdin: yellow-green pigment
mucoid in cystic fibrosis
burn patients
“hot tub folliculitis”
“swimmer’s ear”
Ecthyma gangrenosum

Question 17

Haemophilus influenzae

Answer 17

fastidious bacteria
X factor (hemin)
V factor (NAD)
HIB-most common cause of pediatric meningitis

Question 18

Haemophilus aegyptius

Answer 18

conjuntivitis

pink eye

Question 19

Haemophilus ducreyi

Answer 19

chancroid- painful, flcerated lesion on genitalia; STD

Question 20

Bordetella pertussis

Answer 20

Fragile! fastidious bacteria, requires special media
pertussis toxin-cholera toxin; causes increase in cellular cAMP leading to increased respiratory secretions and mucus production
Pertussis-“whooping cough”
catarrhal stage-similar to common cold
paroxysmal stage- paroxysms; “whoop”
lymphocytes present viral infection, also in bacterial infection
Convalescent phase- decrease in number of paroxysms, recovery

Question 21

Francislla tularensis

Answer 21

Select agent!
ulceroglandular tularemia-“rabbit fever”
oculoglandular tularemia- painful conjunctivitis; exposure of eye to splash or aerosol
Pneumonic tularemia- infection via inhalation of aerosol; bioterror

Question 22

Brucella

Answer 22

Select agent!
four species cause illness in human
most serious- Brucella melitensis
undulant fever (brucellosis)- repeating of fever until treated

Question 23

Legionella pneumophila

Answer 23

warm springs, A/C cooling towers
Pontiac fever- milder form of disease, no pneumonia
Legionnaire disease (legionellosis)-mutilobar pneumonia

Question 24

Treponema pallidum

Answer 24

gram negative spirochete
STD
Primary syphilis- chancre (lesion) at initial site of infection
Secondary syphilis- skin rash
Tertiary syphilis- gummas; disease dependent affected organs

Question 25

Borrelia burgdorferi

Answer 25

Lyme disease
“Target” rash
vector-tick

Question 26

Borrelia recurrentis

Answer 26

Relapsing fever
vector-body louse
recurrent fever episode after a week of remission

Question 27

Leptospira interrogans

Answer 27

Leptospirosis

Weill syndrome- kidney and liver failure

Question 28

Mycoplasma pneumoniae

Answer 28

smallest free-living bacteria

“walking pneumonia”- milder form of pneumonia; “atypical pneumonia”

Question 29

Rickettsia rickettsii

Answer 29

Rocky Mountain spotted fever

vector-tick

Question 30

Rickettsia prowazekii

Answer 30

Epidemic typhus
vector- body louse
Brill-Zinsser disease-recrudescence of typhus
spontaneously when people live together in large group in unsanitary condition
(war, famine, natural disaster, refugee camps)

Question 31

Rickettsia Typhi

Answer 31

Endemic typhus- disease always present

Vector- tick

Question 32

Ehrlichia chaffeensis

Answer 32

obligate intracellular bacteria
vector- tick
human monocytic ehrlichiosis(HME)- bacteria infect and multiply in monocytes

Question 33

Anaplasma phagocytophilum

Answer 33

Obligate intracellular bacteria
vector-tick
human anaplasmosis: similar to HME, infects granulocytes (neutrophils, eosinophils, basophils)

Question 34

Coxiella burnetii

Answer 34

Obligate intracellular bacteria
Q fever
tick-borne, but tick infect livestock
human illness upon inhalation of bacteria in dried animal feces, urine

Question 35

Chlamydia trachomatis

Answer 35

obligate intracellular bacteria
STD
Elementary bodies- infectious, no replication
Reticulate bodies- non-infectious, replicative form of bacteria
Trachoma-eye infection
Urogenital infection

Lymphogranuloma venereum:
Primary stage- lesion at site of infection
Secondary stage- inflammation of regional lymph nodes; buboes

Question 36

Chlamydophila psittaci

Answer 36

Psittacosis (“parrot fever”)
infection due to inhalation of dried bird droppings, feather dust
can be found in all kinds of birds, commonly with psittacine birds (cockatiels, parakeets, etc.)