Neisseria, Haemophilus, AACEK Flashcards
Neisseria general characteristics
aerobic
GNDC like coffee beans
ox +
cat+
non motile
acid from oxidation of carbs not fermentation
Neisserria gonorrhoeae overview
sexual transmitted
fastidious
capnophilic
GNDC like coffee beans
acid from glucose not other sugars
intracellular in PMNs
requires special media
Neisseria gonorrhoeae clinical symptoms
2nd STD after Chlamydia
year 2000 increase in homeless/prostitute population
.5-3% dissemination: skin lesions, arthritis, joint fluid
Neisseria meningitidis overview
capsule
small GNDC
2nd cause of comm. aquired meningitis
swift progression
Neisseria meningitidis disease states
meningitis
septicemia
meningoencephalitis
arthritis
urethritis
young adult peak incidence (college dorms); most common in kids under 5
babies can get and develop symp later
Is Neisseria meningitidis normal flora?
yes in the nasopharynx
treatment of meningitis
IV penicillin (can cross blood brain barrier when meninges are acutely inflammed)
chloramphenicol or 3rd gen cephalosporin
Neisseria lactamica
normal flora of nasopharnyx
more common in kids
Moraxella catarrhalis overview
NF
GNDC
causes otitis media, sinusitis, bacteremia, endocarditis
looks like Neisseria but not in same group
Moraxella catarrhalis treatment
most prod. beta lactamase
penicillin resistant; some trimethoprim also
susceptible to: fluroquinolone, trimethoprim-sulfamethoxazole, 2 and 3rd gen cephalosporins, erythromycin, amoxicillin-clavulana
Neisseria general lab characteristics
GNDC
capnophilic- 3-7%Nacl
special media: CHOC
NURF grows on BAP & CHOC
ox+
cat+
nit=
nonmotile
Neisseria gonorrhoeae lab characteristics
collection: urethral discharge, vaginal swab, rectal
transport media: Stuart’s or Annies, transgrow bottles: 5%CO2, Jembec plate
sm gry translucent raised opaque glistening on CHOC
Modified Thayer Martin media, Martin Lewis agar
modified Thayer Martin media
selective enrichment
suppress vaginal/rectal flora
denatured hgb, vitamins, L-cysteine, cornstarch (ab inhib. substances)
Ab- vancomycin (inhibit GPC), colistin (inh. GNR), trimethoprim (inh. Proteus swarm.), nystatin (inh. fungi)
Marin lewis agar
similar to MTM
[ ] vancomycin increased (gpc better supressed)
anisomycin instead of nystatin (inh. fungi and C. albicans)
Neisseria gonorrheae key tests
ox+
superoxol+ (30%H2O2)
glu+, mal=, suc=, lac=
latex aggl., FA tech., rapid enzyme panel, DNA probe- beta lactamase test (use 2 to confirm)
Neisseria meningitidis key tests
ox+
glu+, mal+, lac=, suc=
latex aggl.
not tested for beta lactamase
Neisseria lactamica key tests
rare cause of meningitis
gluc+, mal+, lac+, suc=
grow on CHOC/BA
Non pathogenic Neisseria
N. flavescens
N. polysaccharea
N. sicca
N. flava
N. subflava
N. perflava
N. mucosa
N. elongata
Non pathogenic Neisseria lab characteristics
colonies dry wrinkled opaque yellow self-adherant
Non pathogenic Neisseria key tests
N. sicca: grow CHOC/BA, glu+, mal+, suc+, fru+, nit=
N. mucosa: grow CHOC/BA, glu+, mal+, suc+, fru+ , nit+
N. flavescens: grow CHOC/BA, no carb acid
Moraxella catarrhalis key tests
GNDC
colony buff opaque smooth slide like hockey puck
ox+
=carb
DNase+,
butyrate esterase+
catarrhalis disk+ (blue)
beta lactamase=
Haemophilus general characteristics
pleomorphic GNCB
require media w/ X,V, XV factors
needs increased CO2
non motile
Haemophilus influenzae key tests
ALA=
Requires x and V
no hem. on BA
Haemophilus aegypitius key tests
ala=
Needs xv
no hem on BA
Haemophilus parainfluenzae key tests
ala+
x=, v+, V only
no hem on BA
Haemophilus ducreyi key tests
ala=
x+, v=, x only
no hem on BA
Haemophilus haemolyticus key tests
ala=
Requires x & v factors
hemolysis on BA
Haemophilus parahaemolyticus key tests
ala+
x=, v+, v only
hemolysis on BA
Aggregatibacter aphrophilua key tests
ox+ w
cat=
indole=
ferm.: glu+, lac+, mal+, suc+
GNCB
endocarditis assoc. w/ tongue piercing
Aggregatibacter actinomycetemcomitans key tests
ox+
cat+
indole=
ferm.: glu+, lac=, mal+, suc=
GNCB slow grow 48-72 hrs
Cardibacterium hominis key tests
ox+
cat=
indole+
ferm: glu+, lac=, mal+, suc+
GNR w/ rosette, teardrop, dumbbell form
may pit agar
Eikinella corrodens key tests
ox+
cat=
indole=
ferm: glu=, lac=, mal=, suc=
thin GNR or CB
pits agar
smells like bleach
ornithine+
Kingella kingae key tests
ox+
cat=
indole=
ferm: glu+, lac=, mal+, suc=
short rod w/ square ends
Capnocytophaga key tests
ox+
cat v
indole=
ferm: glu+, lac=, mal+, suc+
gliding motility
colony sweats
esculin= (usually+)
nit+
catarrhalis disk
brom-chloro-indolyl buturate ——–buturate esterase —- > purple/indigo color change
beta-lactamase test should be tested on what organisms?
Haemophilus influenzae, Neisseria gonorrheae, Moraxella catarrhalis
beta lactamase test
disk contains the chromogenic cephalosporin known as nitrocefin which changes from yellow to red
when the organism is inoculated with a penicillin resistant organism
Modified Thayer Martin (MTM)
Vancomycin – GPC
Colistin – GNR
Trimethoprim – Proteus
Nystain – fungi including yeast
Martin Lewis (ML)
increased Vancomycin
Colistin - GNR
Trimethoprim - Proteus
Anisomycin - yeast
Superoxol test
30% H2O2
to distinguish N. gonorrheae (+) from other Neisseria spp.
(neg)
ALA-porphyrin test
The test medium contains delta aminolevulinic acid (ALA). The unknown organism is inoculated onto the medium and incubated for the appropriate amount of time. Growth is then observed under a Wood’s lamp (UV light). The organism fluoresces a “brick-red” color
What does a positive ALA test tell us?
That it is able to synthesize X factor and does not require a source of exogenous X factor for growth.
Which organism shows a school of fish morphology on gram stain?
Haemophilus ducreyi
a group of heat-stable tetrapyrrole
compounds that are provided by several iron-containing pigments such as hemin and hematin
x factor
nicotinamide adenine dinucleotide phosphate (NAD) is what factor?
v factor
What agar is V factor in?
Chocolate agar serves as a source of this substance in the growth of Haemophilus spp. It is normally present in 5% TSA Sheep Blood Agar as nicotinamide adenine dinucleotide phosphate (NAD) but is inactivated by NADase enzymes in the agar. Gentle heating of the blood during the production of chocolate agar inactivates the enzymes that hydrolyze this substance and makes it more readily available for use by these bacteria
Isovitalex, an exogenous source of V-Factor is also added
The AACEK group is made up of:
Aggregatibacter aphrophilus Aggregatibacter actinomycetemcomitans
Cardiobacterium Eikinella Kingella
