1. HACEK GROUP
GROUP 1

2. • H-aemophilus spp.,
– Aggregatibacter aphrophilus
– H. paraphrophilus
• Aggregatibacter
actinomycetemcomitans
• Cardiobacterium hominis
• Eikenella corodens
• Kingella spp.

3. • Gram (-) rods
• Capnophilic
• Non-motile
• Fastidious
• More dysgonic- slower or poorer growing
(Except Haemophilus spp.)
• Endocarditis-involved in heart valves
• Non/fermentative
• Normal biota of the oral cavity
• Opportunistic and required a compromised
host

4. • Foaming lover or needing high [CO2]
• Most prevalent species in the group producing
endocarditis
• H.aphrophilus and H.paraphrophilus have been
recently reclassified as a single specie
• Contains V factor in/dependent
– Clinical features
• Fever
• Heart murmur
• Congestive heart failure
• Embolism

5. Cultural
characteristics Culture Media
• Raised, convex,
granular and
yellowish
• Small cocobacillus
• Ferments glucose,
maltose, sucrose
and lactose
• Trypticase Soy
Agar
• Chocolate Agar

6. • Formerly known as Actinobacillus
• Small bacilli to coccoid gram-negative bacilli
• 6 serotypes (a-f)
– a,b & c are the most common
• Normal oral microbiota
• Subacute bacterial endocarditis
Virulence factors:
 Collagenase- toxic to polymorphonuclear cells and
 Leukotoxin monocytes

7. Cultural Characteristics
• Ferments glucose, maltose,
manitol & xylose
• Catalase +
• “Star shape with 4-6
points” in the center of the
colonies
• Very small cocobacillus in
Gram stain
• Small colonies that adhere
to agar
Culture media:
 BHI
 Trypticase soy agar

8. – MOT
• ENTERS IN DEEPER TISSUE BY MINOR
TRAUMA TO MOUTH, SUCH AS DURING
DENTAL PROCEDURES
– DISEASE
• Causative agent of SUBACUTE BACTERIAL
ENDOCARDITIS with an insidious and protracted
presentation, usually treated by penicillin
• PERIODONTITIS- “Inflammation around the tooth
and gum”

9. Sensitivity to penicillin
Isolates are susceptible to:
 Aminoglycosides
 Cephalosporins
 Quinolones
 Chloramphenicol
 Tetracycline
Resistance to vancomycin and
erythromycin

10. HAVE TWO SPECIES
Cardiobacterium hominis
Cardiobacterium valvarum

12. Pleomorphic
Gram-negative bacillus
Normal microbiota of the nose
Mouth
Throat
DISEASE acquired is ENDOCARDITIS

14. Gram stains of the bacilli often show
false gram-positive reactions in the
parts of the cells.
The organisms tend to form
rosettes,swellings,long filaments or in
yeast extract, stick like
structures.
They grow slowly on SBS and CHOC
agar but not at all on MAC agar.

15. • Sensitive to B-lactams,
Chloramphenicol & tetracycline
• Therapy: penicillin and an
aminoglycoside

16. • Gram-negative cocobacilli
• CO2 with hemin
• Oxidase positive
• Asacchrolytic
• Catalize negative
• Chloride bleach odor
• Normal biota oral and bowel cavity
• Colony: Pits the agar
• Broth medium: adhere to the side medium produce
granules

17. • Clenched fist wounds due to trauma,
human bites or fights
• Meningitis, empyema (collection of pus in
space between the lungs), pneumonia,
osteomyelitis, arthiritis, and postoperative
tissue infection
• In drug addicts produce cellulitis

18. • RESISTANT TO clindamycin and
aminoglycosides
• IN-VITRO SENSITIVITY to penicillin,
ampicillin, cefoxitin, chloramphenicol,
carbenicilin, imipenem, cephalosphorins, &
trimethoprim-sulfamethoxazole

20. • Cocobacilli “short bacilli with squared ends
that occur in pairs or short chain”
• They tend to resist decolorization in the gram
staining
Note: if the isolate does not pit the agar
as many strains do can resemble Neisseria
gonorrhoeae.
• They are tend nutritionally fastidious
• Fermenters of glucose and other sugar with
no gas
• Oxidases positive
• Catalase negative

21. • Cultural
morphology
– may grow on
Neisseria
selective
agar(Thayer
Martin Medium)
– usually susceptible
to most agents ,
including
PENICILIN
• Infection
– They colonize
the upper
respiratory
tract specially
the tonsils
– Poor dental
hygiene or oral
surgery
associated with
infection

22. 1. Kingella kingae
-are recognized as an important pathogen in
the pediatric population.
- weakly ferments glucose and maltose but
negative in sucrose
-produces yellow brown pigments
- Two types of colony morphology
- spreading corroding colony or smooth ,
- convex and ß-hemolytic colony

23. -The hemolysis may appear beneath the
colony or in close proximity
after24hrs.after 48hrs of incubation
-it is major gram negative bacterium
isolated from denegrative joint and
bone infection (osteoarthritis)

24. -positive for glucose fermentation and nitrate
reduction and might grow at 46°C
-Both catalase and superoxol are negative.
-It is negative for
-urease
-indole esculin gelatin citrate
-Does not grow on MAC agar
-Two types of colonies morphology
- smooth and convex type and Spreading
corroding type
- This spp. is rarely isolated as a pathogen but has
been associated with bacteremia

26. Periodontitis-Most common disease
because of HACEK bacteria
“inflammation around the tooth" - it is a serious
gum infection that damages the soft tissue and
bone that supports the tooth.

28. Organism
catalase
oxidase
glucose
maltose
sucrose
lactose
Gram
staining
Colony
Morphology
COMMENTS
A. Aphrophilus - V + + + +
Small
coccobacillus
Raised,
convex,
granular,
yellowish
A.
actinomycetem
comitans
+ V + + - -
Very small
coccobacillus
Small
colonies that
adhere to
agar
C. Hominis - + + + + -
Straight bacillis,
spindle, rosettes
Smooth,
opaque,
adherent to
agar
Indole (+)
Eikenella
corrodens
- + - - - - Straight
rods
Usually pits
the agar
Smell like
bleach
Ornithine (+)
Kingella kingae - + + + - - Coccoid to
straight bacili,
chains and
pairs
2 types: spreading
& corroiding or
smooth & convex
beta hemolysis
Nitrate (-)