WEEK 10: FASTIDIOUS GRAM-NEGATIVE BACILLI Flashcards
HACEK
(Haemophilus parainfluenza, Aggregatibacter,
Cardiobacterium, Eikenella and Kingella)
) causing SBE
(subacute bacterial endocarditis)
HACEK
- Derived from the Greek word “blood-lover”
HAEMOPHILUS
- Non-pathogenic or produce opportunistic infections
- 10% of the microbiota of the upper respiratory tract
HAEMOPHILUS
what are heamophilus’ * Require performed growth factors present in the blood:
o X Factor (hemin or hematin; X for unknown) – used in
the synthesis of catalase, peroxidase, and in the
cytochrome electron transport system
o V Factor (nicotinamide-adenine dinucleotide (NAD); V
for vitamin) – NAD is a co-enzyme that transfers
electrons from one reaction to another
o Both are additives
o Both are found inside RBCs, but only X factor is directly available
o Haemophilus species with the prefix para- only
require V factor for growth
is haemophilus capnophilic?
yes . they requires 5-10% CO2
– for culture of lower respiratory tract
Bronchial washing
Direct plating on selective media at the bedside is preferred
Haemophilus spp. fast drying kasi sila
- Small, gram-negative coccobacilli to long filaments
HAEMOPHILUS
stain that help in
detecting Haemophilus spp.
Acridine orange or Methylene blue stain –
- Haemophilus spp. will not grow on
MAC agar and SBA
Produce a “clumpy” nonhomogeneous appearance when
suspended in saline
HAEMOPHILUS
Use of impregnated strips or disks – for dentification of
Haemophilus spp. and some of the Aggregatibacter spp
Carryover may produce erroneous or less than definitive
results causing H. influenzae to be misidentified as
H. parainfluenzae
WHICH REQUIRES V FACTOR, X FACTOR AND NEITHER
- H. influenzae
- H. parainfluenzae
- A. segnis
- H. influenzae – requires both X and V factors
- H. parainfluezae – requires V factor only
- A. segnis – requires only V factor, oxidase negative
- Haemophilus Quad Plate
o Four zones: media with X factor only, V factor only, X
and V factors, and X and V factors with horse red
blood cells
as a substrate to synthesize
heme factor, in the process porphyrins are created
* Performed in agar, in broth, or on a disk
delta
aminolevulinic acid (ALA)
principle of porphyrin test
Principle: Based on the ability of the organism to convert
the substrate ALA into porphyrins or porphobilinogen,
which are intermediates in the synthesis of X factor
how is porphoblinogen detected
Detected by the addition of Kovacs reagent after 35°C for 4 hours incubation
o Red color forms in the lower aqueous phase
o Kovacs reagent (p-dimethylaminobenzaldehyde)
0.5mL for inoculation
how is porphyrin detected
Detected using an ultraviolet light with a wavelength
of about 360 nm (Wood’s lamp)
o Reddish-orange or pink fluorescence form under UV
light
o Much more accurate means of determining X factor
requirement compared to X and V factor disks
o Advantage: X factor is not required (no carryover)
o Disadvantage: Primary identification is based
on a negative test result
porphyrin test result
negative poprphyrin = x factor positive
= BLUE
(uv is negative, no flourescence, no color change in addition of kovac, cant make heme)
porphyrin positive = x factor negative
= PINK
kabaliktaran
btw di naman need heme
Hemolysis is determined on HBA since it cannot
hemolyze sheep’s blood
Satellitism
Stabbing the area of inoculation
enhances the hemolytic
reaction
occurs when an organism such as
Staphylococcus aureus, Streptococcus pneumoniae, or
Neisseria spp. produces V factor as a byproduct of
metabolism (they obtain V factor from the SBA)
Satellitism
Based on the factors required for growth and the presence of hemolysis IN haemophilus spp:
o H. haemolyticus – beta hemolytic on horse blood
o H. influenzae – non hemolytic
o Misidentifying H. haemolyticus as H. influenzae may
result in overtreatment
A disk impregnated with Nitrocefin, is moistened
with a drop of water
Chromogenic cephalosporin test -
- Red color of the area develops when the β
lactam ring of Nitrocefin is broken by the β
lactamase enzyme
Occurs in 5 minutes
- Red color of the area develops when the β
A strip impregnated with benzylpenicillin and a
pH indicator, bromocresol purple, is moistened
with one or two drops of sterile distilled water
Acidometric test
If the β-lactam ring of the benzylpenicillin is broken by the β lactamase, penicilloic acid is formed, causing a drop in pH.
Color change occurs from purple (negative) to yellow (positive)
Occurs 5 to 10 minu
Appear as coccobacilli, thread-like rods and high
pleomorphism is evident
HAEMOPHILUS INFLUENZAE
h influenzae ferments what
produce acid from glucose and xylose
H. aegyptius can be distinguished from H. influenzae by a
negative xylose reaction (influenzae)
- Unique polymer composed of ribose, ribitol, and
phosphate (polyribitol phosphate [PRP]) Leading
cause of meningitis in unvaccinated children
- Unique polymer composed of ribose, ribitol, and
o Serotype B strains -
Has antiphagocytic property and
anticomplementary activity
o Serotype B strains -
present in encapsulated h influenzae
is a rapid test for detection of these capsular antigens (most important - serotype B) (haemphilus influenzae to)
Latex agglutination test
o Has the ability to cleave secretory IgA
- IgA Proteases
o present on human mucosal surfaces of the respiratory tract
o H. influenzae is the only member that produces IgA
protease
have a paralyzing effect on the sweeping
motion of ciliated respiratory epithelium.
lps
Virulence Factor
of haemophilus
- capsule
disease caused by h. ducreyi
- Causes chancroid
o It is a highly communicable sexually transmitted
genital ulcer disease (GUD)
o Commonly referred to as soft chancre
o Hard chancre – syphilis
o All patients who have GUD should also be tested for
human immunodeficiency virus along with syphilis and
herpes virus
o Causes suppurative (pus forming), enlarged,
draining, inguinal lymph nodes (buboes)
Common sites of infection of h ducreyi
penis or the labia or within
the vagina
symptoms of men and women in h ducreyi
- Men have symptoms related to the inguinal tenderness
and genital lesions - Women are asymptomatic
- Nairobi bioplate medium
o First half: consist of GC agar base with 2% bovine hemoglobin and 5% fetal calf serum
o Second half: consist of MH agar with 5% chocolatized horse blood
o GC agar contains 1% hemoglobin, 5% fetal calf serum, 1% IsoVitaleX, and 3 mg/L of vancomycin
o Both sides contain vancomycin (resistant)
microscopic morphology of h ducreyi
- School of fish – arranged singly, or in groups (clusters)
- Railroad tracks – loosely coiled clusters lined up in
parallel - Fingerprints arrangement
CHOC agar: small, flat, smooth, nonmucoid, transparent to
opaque colonies, or appears tan or yellow
h ducreyi
treatment to h ducreyi
- Erythromycin – drug of choice
- Azithromycin, ceftriaxone, or ciprofloxacin, TMP-5XT-E
four subspecies or biovars of francisella
subsp. tularensis (type
A), subsp. holarctica (type B), subsp. mediasiatica, and
subsp. novicida.
very small, transparent colonies will generally appear on
cysteine-supplemented agar when incubated for 3 days at
37°C aerobically
FRANCISELLA TULARENSIS
- It is a Category A biological agent by CDC
- Organism is highly infectious and should be handled on
BSL 3 precautions
FRANCISELLA TULARENSIS
is an opportunistic pathogen,
primarily causing disease in immunocompromised
individuals
francisella
F. tularensis subsp. novicida
produce a
similar disease to F. tularensis subsp. tularensis, but
infections are rarely fatal
F. tularensis subsp. holarctica and mediasiatica
can cause infection through the
cutaneous (ulceroglandular form) or inhalation
(pneumonia) routes
francisella
francisella is present in? who are the reservoir?
- Present in wide variety of wild animals, birds and even
some fishes and amphibians - Common reservoir are rabbits, muskrats, and squirrels
- Infection can occur by direct contact with a dog or cat that
has had a contact with an infected animal - Ticks and deerflies are the most common arthropod
vectors
Routes of transmission of francisella
o Bite of an arthropod
o Direct contact with an infected animal
o Ingestion of contaminated meat or water
nfection occurs most often through minute abrasions in
the skin resulting in greatly enlarged regional lymph nodes
that sometimes drain for weeks and become necrotic
FRANCISELLA TULARENSIS
Zoonotic disease aka Lemming and Water rat trapper’s
disease
Tularemia
- Biochemical tests are not used for ID and not
recommended
francisella
The organisms have a thin capsule that consists of lipid,
proteins, and carbohydrates
francisella
is used for the
identification of francisella in the tissues and sputum
specimens
Direct FAT (fluorescent antibody test)
in a single specimen is highly suggestive of francisella infection
An antibody titer of 160
A four-fold increase in antibody titer in paired serum
samples taken 2 weeks apart is strongly indicative of active
disease
BIOTYPE A
- Found in US and North
America - Highly virulent
- Transmission is through
the bite of a tick that has
acquired the organism
from infected wild
rabbits
BIOTYPE B
- More widespread
- Found in Western and
Eastern hemispheres
and is associated with
water and rodents
treatment of francisella
- Streptomycin is the drug of choice or Gentamicin over a
period of 10 days. - Vaccine provides partial immunity
francisella is resistant to
beta-lactamase like Ceftraixone
Ubiquitous gram-negative bacilli acquired by humans
primarily through inhalation
legionella
- Produce a spectrum of symptoms from mild upper
respiratory tract infections to pneumonia - Associated with nosocomial infections
LEGIONELLA
Most human cases of legionellosis are caused by
L.
pneumophila
Legionella spp. are transmitted to human hosts from these
environmental sources primarily via
aerosolized particles,
such as those produced by normal tap water pressure.
factors that contribute to the ability of Legionella spp.
to colonize these sources include:
The ability to multiply over the temperature range of 20° to 43° C and survive for varying periods at 40° to 60° C
The capacity to adhere to pipes, rubber, plastics, and
sediment and persist in piped water systems even
when flushed
The ability to survive and multiply within free-living
protozoa and in the presence of commensal bacteria
and algae
vf of legionella
- proteolytic enzymes
- Organism’s ability to enter, survive, and multiply within the host’s cells, especially bronchoalveolar macrophages
should not be used in processing or
transporting specimens because of the inhibitory effects of
sodium
Saline or buffer
Transport specimens to a reference laboratory on wet ice, and freeze specimens at −70° C if processing will be delayed for several days
legionella
Extending the safranin counterstaining time to at least 10
minutes can enhance the staining intensity of the
organisms.
legionella
is weakly acid-fast in tissue and stains best
with the modified Kinyoun procedure
L. micdadei
The faint-staining, pleomorphic gram-negative bacilli may
be found
(legionella)
outside of and within macrophages and
segmented neutrophils
- provides a
useful method of confirming that an isolate is a Legionella
sp. and for identifying the more common species and
serogroups of the genus
Direct fluorescent antibody (DFA) test
isolation method oof legionella
o In this procedure, an aliquot of the specimen is first
diluted 1: 10 with 0.2 N KCl-HCl and allowed to stand
for 5 minutes.
o Inoculated medium is incubated at 35° to 37° C in air
for at least 7 days.
o Usually within 3 to 5 days, Legionella spp. colonies
are visible.
is best for Legionella isolation
Buffered charcoal yeast extract (BCYE) agar with L
cysteine
Fastidious, aerobic bacteria that will not grow on sheep
blood agar (SBA) and require L-cysteine for growth
legionella and francisella ??
central portion of young colonies has a “ground
glass” appearance, light gray and granular
francisella
periphery of the colony has pink and/or light blue or
bottle green bands with a furrowed appearance
francisella
legionella treatment
- Treated with a macrolide such as azithromycin or a
fluoroquinolone - An alternate drug is doxycycline
Discovered after an outbreak of severe respiratory illness
at an American Legion convention that took place in 1976
in Philadelphia
LEGIONELLA PNEUMOPHILIA
e Pontiac fever
LEGIONELLA PNEUMOPHILIA
Ubiquitous in the environment where warm and moist
condition prevail
LEGIONELLA PNEUMOPHILIA
- Have been recovered from lakes, streams, mud, and soil
- No known animal reservoir
LEGIONELLA PNEUMOPHILIA
Aerobic, gram-negative rods that can be isolated on
BCYE supplemented with 1% α-ketoglutarate
LEGIONELLA PNEUMOPHILIA
Best growth is obtained at a pH of 6, 9, 37°C and 90%
humidity
LEGIONELLA PNEUMOPHILIA
The organism requires iron salts, cysteine, and high
humidity (moist) for growth
LEGIONELLA PNEUMOPHILIA
Specimens for culture include bronchial washings, lung
biopsies, pleural fluid, and blood
LEGIONELLA PNEUMOPHILIA
how to diagnose legionella neumophilia
Many patients are diagnosed retrospectively by an
indirect FAT a 4-fold rise in anti-Legionella antibody to a
titer of 128 or greater is considered positive
Basic fuchsin is often used as a counterstain for 3
minutes
l. pneumophilia
y appear to have ground glass speckling like a
shattered windshield
legionella pneumophilia
- Pigmentation can vary from colorless, grayish, pale green
to indescent pink or blue - Colonies may be translucen
legionella pneumophilia
L pneumophilia diseases
Legionnaire’s disease
a mild, short-term febrile illness to an
acute purulent pneumonia with an intra alveolar exudate
Organisms are acquired through inhalation of aerosols
created by contaminated air conditioners to destruction by
PMNs
l pneumophilia
- Febrile disease with pneumonia
Legionnaire’s Disease
3 patterns of legionnaire’s disease
Typically presents in three major patterns:
o Sporadic cases – most common and usually occur
in the community
o Epidemic outbreaks – characterized by short
duration and low attack rates
o Nosocomial clusters – occurring in compromised
patient populations
is the predominant manifestation of
legionellosis
Pneumonia
– caused by Mycoplasma
pneumoniae, Chlamydophila pneumoniae, and
Legionella
Atypical pneumonia
S/s: non-productive cough, fever, headache, and
myalgia, rales, dyspnea, and shaking chills
Legionnaire’s disease
Febrile disease without pulmonary involvement or non-
pneumonic form legionellosi
Pontiac fever
are primary
human pathogens of the respiratory tract, causing
whooping cough or pertussis
Bordetella pertussis and B. parapertussis
are primary
human pathogens of the respiratory tract, causing
whooping cough or pertussis
Bordetella pertussis and B. parapertussis
are respiratory tract
pathogens of wild and domestic birds and mammals
B. bronchiseptica and B. avium
appears to be an avian commensal
B. hinzii
is an opportunistic human pathogen,
causing respiratory and wound infections
are respective agents of
immune-compromised bacteremia and wound or ear
infection.
B. holmesii and B. trematum
Best culture on media containing charcoal to neutralize
inhibitory effects (charcoal will inhibit other commensals)
B pertussis
Regan- Lowe is often used as transport medium
B pertussis
Vf of bordatella pertussis
-filamentous hemagglutinin and pertactin = attach to epi cell
- pertussis toxin : modifies adp robosyl transferase
- adynelate cyclase toxin= inhibits host epithelial and
immune effector cells
-tracheal cytotoxin = causing ciliostasis, inhibiting DNA synthesis, and
promoting cell death.
facilitate attachment to
ciliated epithelial cells
Filamentous hemagglutinin (FHA) and pertactin (a 69
kDa outer membrane protein)
protein exotoxin that produces a wide variety of responses in vivo
o Main activity: Modification of host proteins by ADP ribosyl (adenosine diphosphate) transferase, which interferes with signal transduction
Pertussis toxin (PT) –
inhibits host epithelial and
immune effector cells by inducing supraphysiologic
concentrations of cyclic adenosine monophosphate
(cAMP)
Adenylate cyclase toxin
contributes to pathogenesis by
causing ciliostasis, inhibiting DNA synthesis, and
promoting cell death.
Tracheal cytotoxin –
Catarrhal phase
Catarrhal phase – initial phase
o Symptoms are insidious and nonspecific
o Include sneezing, mild cough, runny nose, and perhaps conjunctivitis, although infants can develop apnea and/or respiratory distress.
o Infection is highly communicable because of the large number of organisms in the respiratory tract.
o Cultures are not often performed at this stage because the symptoms are nonspecific
o May last 1 to 2 weeks
The hallmark of this phase is the sudden onset of
severe, repetitive coughing followed by the
characteristic “whoop” at the end of the coughing
spell
paroxysmal phase
o Begins within 4 weeks of onset with a decrease in
frequency and severity of the coughing spells
o Recovery is gradual
o Coughing lessens but fits of coughing may return
- Convalescent phase – third phase
– two components signal transduction system to
sense the environment and regulate gene expression
BygAS
treatment of b pertussis
- Erythromycin
- Vaccine
o Killed bacterial cell suspension-DPT vaccine
o Vaccine- Induced immunity after five to ten years - Acellular vaccines
ntracellular bacteria that are usually found in animals with
humans being accidental hosts
BRUCELLA
Brucellosis or also known as
Malta fever or
undulant fever
grow on well-defined media containing amino
acids, vitamins, salts, and glucose
brucellosis
- Grow slowly on sheep’s BAP or CAP with 5-10% CO2
- It stains irregularly and pale with Gram’s stain
- Inactive metabolically
brucella
Short, coccobacillary forms, bipolar staining sometimes
eviden
brucella
In the animals, they localize in the pregnant uterus
because of the presence of Erythritol in allantoic and
amniotic fluids
brucella
- Abortion is a major manifestation of the disease in animals
brucella
localize in mammary glands of animals can
be shed in milk or cheeses or other products
brucella
It can be difficult to diagnose brucellosis through direct
examination of a clinical sample, most often , and the ability for direct isolation and culture can
vary between acute and chronic manifestations
blood or bone
marrow
3 clinical stages of Brucellosis:
- acute infection
- are non-specific (fever, malaise, headache, anorexia, myalgia, and back pain)
- occur within 8 weeks of exposure. - Sub chronic or undulant form
- appear after a year of exposure with undulating fevers (characterized by
normal temperatures in the morning followed by high temperatures in the afternoon and evening), arthritis, and epididymoorchitis (inflammation of the epididymis and testis) in males. - Chronic form
- presents after 1 year of exposure with
symptoms such as depression, arthritis and chronic fatigue
Farmers, vets and abattoir or slaughterhouse workers
are at greatest risks for infection
brucella
Onset is slow and insidious and disseminated via the
lymphatics and the blood stream
brucella
Proliferation of mononuclear cells is a major histologic
finding
brucella
Fever may have a daily, periodicity, rising in the
afternoon and falling at night, malaise, weakness and
non-specific aches and pains
brucella
onsists of 5-serogroups (A, B, C, D, E)
defined by capsular antigens
P. multocida
Colonizes mucous membranes of the upper respiratory
tract and gastrointestinal tracts of mammals and birds
pasteurella
- Most common isolates are Pasteurella
p. multocida
disease caused by pasteurella
- Systemic, pneumonic, cutaneous form of infections
- Localized infection after a bite or scratch
- Respiratory tract infection
- Life-threatening systemic diseases (e.g., meningitis,
bacteremia) - Colonizes mucous membranes of the URT and GIT of
mammals and birds - Human infections occur from bites and scratches inflicted
by animals
- Growth on 5% blood or chocolate shows small, smooth,
convex colonies - “Musty” odor
pasteurella
- In TSIA, a weak glucose fermentation reaction appears.
pasteurella
Growth on SBA in the absence of satellitism or in pure
culture combined with bipolar staining
differentiate
Pasteurella from Haemophilus
non-hemolytic colonies on SBA
that may appear mucoid after 24 hours of incubation at
37° C followed by the production of a narrow green-to
brown halo around the colony after 48 hours
P. multocida
- Bipolar staining with Giemsa or Methylene blue
- “Safety-pin” appearance when the poles of the cells are
more intensely stained
pasteurella
- Has been isolated from placenta, amniotic fluid, blood,
rectal sites, abscesses, and urogenital specimens
PASTEURELLA BETTYAE
PASTEURELLA BETTYAE ferments what
gf
diff of pasteurella bettyae and multocida
growth in macconkey (bettyae)
multocida glucose only betyyae glucose and fructose
o Has similar requirements as the HACEK group
o Has similar requirements as the HACEK group
HACEK is an old term, but it’s now called
AACEK
The latter four members of the HACEK group are
considered to be more dysgonic (slower or poorer
growing) – in contrast to eugonic
ewan
aacek causes
endocarditis (infective and bacterial)
sbe
Significant cause of endocarditis (infective and bacterial)
o Involves the heart valves; the lesion (referred to as
vegetation) is composed of fibrin, platelets,
polymorphonuclear cells, monocytes, and
microorganism
o Include tooth extraction, history of endocarditis,
gingival surgery, mitral valve prolapse
Aphros “foam loving” or needing high concentration of
CO2
AGGREGATIBACTER APHROPHILUS
- Found in dental plaque and gingival scrapings
AGGREGATIBACTER APHROPHILUS
Found in dental plaque and gingival scrapings
* Most prevalent cause of endocarditis
AGGREGATIBACTER APHROPHILUS
Growth is star-shape with 4-6 points at the center of the
colonies after 48 hours
AGGREGATIBACTER
ACTINOMYCETEMCOMITANS q
Clinical features of infections: fever, heart murmur, CHF,
and embolism
AGGREGATIBACTER APHROPHILUS
- Fermenter when serum is added to the carbohydrate
AGGREGATIBACTER
ACTINOMYCETEMCOMITANS
nclude collagenase, leukotoxin that is toxic to
polymorphonuclear cells and monocytes
AGGREGATIBACTER
ACTINOMYCETEMCOMITANS
Normal oral microbiota of humans
* Human tissue infections attributed to cattle, sheep, pig,
and horse bites
* Has been isolated from blood, lung tissue, abscesses of
the mouth and brain and sinuses
* Causes SBE and periodontitis
AGGREGATIBACTER
ACTINOMYCETEMCOMITANSAGGREGATIBACTER
ACTINOMYCETEMCOMITANS
AGGREGATIBACTER
ACTINOMYCETEMCOMITANS
teatment
- P. aminoglycosides, 3rd gen
- Cephalosphorins, quinolones, C and Te sensitive
- Resistance to ampicillin, vancomycin and erythromycin is
common - Usual treatment for endocarditis is with penicillin and an
aminoglycoside
show false gram-positive
reactions in parts of the cell
CARDIOBACTERIUM HOMINIS
organisms tend to form rosette swellings,
long filaments, or stick-like structures in yeast extract
CARDIOBACTERIUM HOMINIS
incubation in a humid atmosphere with 5% CO2 enhances
growth
c. HOMINIS
c hominis disease
- Usual manifestation is endocarditis often presenting with
large vegetations and no demonstrable fever - Infects the aortic valve
- Associated with meningitis
antibacterial susceptibility of CARDIOBACTERIUM HOMINIS
Sensitivity can be seen to β-lactams, chloramphenicol,
and tetracycline with variable response to
aminoglycosides, erythromycin, clindamycin, and
vancomycin.
* Usual therapy includes Penicillin and aminoglycosides
- A bleach-like odor from the agar surface may be obvious
EIKENELLA CORRODENS
- Corrodes (pits) the surface of agar
- Non-hemolytic but may show greening around the
colonies on SBA
EIKENELLA CORRODENS
- Associated with poor dental hygiene or oral surgery
- Reported as a cause of meningitis, empyema,
pneumonia, osteomyelitis, arthritis, and post-op
infections - Shows least predilection for attachment to heart valves
among HACEK
EIKENELLA CORRODENS
- Normal microbiota of the oral and bowel cavities
- Human bites or fights infection
EIKENELLA CORRODENS
Antibacterial Susceptibility EIKENELLA
Resistant to Clindamycin and aminoglycosides and
narrow spectrum cephalosporins
* In vitro, isolates demonstrate sensitivity to penicillin,
ampicillin, cefoxitin, chloramphenicol, carbenicillin,
and imipenem
Coccobacillary to short bacilli with squared ends that
occur in pairs or short chains
KINGELLA
row in MTM, resemble colonies of Neisseria when
they do not pit agars which many usually
KINGELLA
- Associated with poor dental hygiene or oral surgery
- Very important in pediatric patients, it can create
diseases that will present as bone diseases, septicemia
KINGELLA
s two types of colonies: smooth, convex type and a
spreading corroding type
KINGELLA DENITRIFICANS
- Major green negative bacterium isolated from
degenerative joint and bone infection in children <3
years - Causes endocarditis in adults and school-age children
- Most isolates are susceptible to most antibiotics
KINGELLA KINGAE
Belongs to the the family Flavobacteriaceae and includes
dysgonic fermenter called DF-1 and DF-2
CAPNOCYTOPHAGA
- Thin, and often fusiform (pointed ends) resembling
Fusobacterium spp. - Spindle-shaped, coccoid, and curved filaments may be
also seen - Flagella are absent but produce gliding mostly on solid
capnocytophaga
Not commonly involved in endocarditis but is associated in
septicemia with patients with neutropenia
capnocytophaga
can cause a fulminant, life-threatening
infection in humans following a dog or cat bite
C. canimorsus
is the most common clinical isolate of capnocytophaga
C. ochracea
Antibacterial Susceptibility
of capnocytophaga
- Susceptible to imipenem, erythromycin, clindamycin,
tetracycline, chloramphenicol, quinolones, and β-lactams - Resistant to the aminoglycosides
- Penicillin is the drug of choice
