Fastidious Gram Neg Bacilli Flashcards
The members of this group are miscellaneous,
fastidious- - they are not really easy to grow in vitro,
pleomorphic - they assume a variety of shapes,
and most of them are organisms that require
special nutrients for isolation and identification.
FASTIDIOUS GRAM-NEGATIVE BACILLI
The general characteristic of Haemophiles are:
• gram-negative, pleomorphic, coccobacilli or
bacilli
•nonmotile
•facultatively anaerobic
•ferments carbohydrates
•oxidase positive
•catalase positive
• reduces nitrates to nitrites
are obligate parasites on a mucous membrane of humans and animals
Haemophilus
most of the members of the genus Haemophilus are
non-pathogenic
Haemophilus growth factors
X Factor (Hemin or Hematin), V Factor (Vitamin)
The is considered as the unknown factor because this is what you use to differentiate the various species of Haemophilus.
X Factor (Hemin or Hematin)
V factor includes the
nicotinamide adenine dinucleotide (NAD).
Another feature of Haemophilus, specifically H.
influenzae, is a phenomenon called satellitism - in order for this to occur, it requires the ___ as a byproduct
V factor
The Haemophilus isolate obtains the X Factor from
5% Sheep Blood Agar (BAP) and obtains the V factor from the primary organism (the byproduct) that was streaked.
Salellitism
one species of Haemophilus that does not
require V factor for growth and most of the
time, would not display satellitism
H.ducreyi
H. Ducreyi is usually diagnosed through their __ pattern
gram stain
An asymptomatic colonization with this specie
Type B is rare.
HAEMOPHILUS INFLUENZAE
2 types of HAEMOPHILUS INFLUENZAE
typeable and nontypeable Haemophilus influenzae.
The most virulent and most common causative agent among the two types of Haemophilus influenzae.
H. influenzae Type B
Is h. Ducreyi a part of the normal microbiota?
No
The strains of H. influenzae are based on their
__ characteristics
capsular characteristics
The ___ h. ducreyi do not produce a
capsule and they are usually part of the
normal flora, usually in the upper respiratory
tract.
nontypeable strains
H. influenzae is also called as __
Pfeiffer’s bacillus
it causes meningitis especially in children less than 5 years old
H. influenzae
always remember the ___ of the patient that
has meningitis because it will the one that will
tell you which organism is associated with it. In
age
H. influenzae is also known to cause a condition called as
epiglottitis.
___ is the name of the sexually
transmitted disease caused by h ducreyi
Chancroid
The initial system is the development of a
painful genital ulcer and inguinal lymph
adenopathy, when we talk about this ulcer,
remember that the one caused by this specie
is painful.
Chancroid
Trenonema pallidum subspecies pallidum an agent of syphilis, they also produce an ulceration in the genitalia but this ulceration is painless, this is called as
chancre
Chancroid is more common among socially
economically disadvantaged population inhabiting ___ environments
tropical environments
Causative specie of Chancroid
HAEMOPHILUS DUCREYI
HAEMOPHILUS AEGYPTIUS also known as
Koch-Weeks Bacillus.
also known as Koch-Weeks Bacillus. This i
contagious by the fact that the infection i
transmitted when you touch an infected eye
HAEMOPHILUS AEGYPTIUS
Conditions caused by naemophilus aegyptius
conjunctivitis, contagious conjunctivitis, or pink eye.
If you are going to obtain specimens from
genital sites for H. duceryi, the genital site
must first be __ before the specimens are collected
cleansed by gauze moistened with sterile saline
After cleansing genitalia, a swab is then pre-moistened with a __ to collect the material from the base of the ulcer.
sterile phosphate buffered saline
for h ducreyi, the swab must be plated to a
special selective media within ___ of collection
10 minutes
The ideal plate or the primary plating medium
of Haemophilus is the ___, wherein wherein we can incubate it at __ with ___ carbon dioxide.
Chocolate Agar, 33-37 °C with 5-10% carbon dioxide.
If we have ____ , we can use this for the isolation of H. influenzae from respiratory secretions and patients with cystic fibrosis.
Horse Blood Bacitracin Agar
This media is designed to prevent the overgrowth of H. influenzae by another organism that is also common with cystic fibrosis patients that causes pulmonary infection and even fatal infections,
Pseudomonas aeruginosa.
Horse Blood Bacitracin Agar,
If we have Horse Rlood Bacitracin Agar , we can use this for the isolation of H. influenzae from ___ and patients with ____.
respiratory secretions, cystic fibrosis.
Horse Blood Bacitracin Agar is generally for all
Haemophilus species except:
H. Aegyptius, H. ducreyi
H. Aegyptius requires an enriched ___ Agar with 1% Iso VitaleX or what we call the ____.
Chocolate Agar with 1% Iso VitaleX / Nairobi Biplate
most fastidious organism
H. ducreyi
H. ducreyi needs high humidity, which should have _____ atmosphere with ___ as the
optimal temperature for cultivation
5-10% carbon dioxide, 33 °C
The Nairobi Biplate is called as a “biplate” because it has two bases:
GC Agar Base and the Mueller Hinton (MH) Agar.
h. ducreyi is resistant with ___ and it helps reduce the growth of commensal microbiota from genital specimens and improves the detection of H. ducreyi.
vancomycin
GC Agar contains
1% hemoglobin
5% fetal calf serum
1% IsoVitaleX,
3 mg/L of vancomycin
MH agar has
• 5% chocolatized horse pool
• 3% mg/L of vancomycin.
H. aegyptius should be held for ___before releasing a negative result.
4 days
H. ducreyi should be held for ___ before releasing a negative result.
7 days
has a translucent, tannish, moist,
smooth. and convex colony
Haemophilus
Haemophilus distinct odor
“mousy” or bleach like odor.
Also remember that Haemophilus, although it
is a gram negative, does not grow on?
MacConkey
Haemophilus, sometimes grow on ____ around colonies of other bacteria species to produce satellitism. Thus, it may grow together with ___
SBA plates, S. aureus.
appear as small, flat, smooth, nonmucoid,
transparent to opaque colonies or appear tan
or yellow in Chocolate Agar.
H. ducreyi
h. ducreyi are difficult to pick up and produce a
____appearance when suspended in saline.
clumpy nonhomogeneous
You can also use ____ (fluorescent
stain) or ___ for Haemophilus
acridine orange or methylene blue
As mentioned, sometimes for H. duceryi, since
they are very fastidious, ____ is only done
gram staining
The genital specimen for haemophilus is gram stained, and this specie will appear as ___ or ___ in appearance.
school of fish or railroad tracks
gram-negative. So, your first clue that an isolate might belong to the genus Haemophilus is the growth of gram- negative pleomorphic coccobacilli on ____
CHOC agar (not on SBA & MAC)
To establish the X and V factor requirements, you
are going to:
place discs impregnated with each factor on
a supplemented media - which is usually ___
Agar or _____ Agar - inoculated with
a light suspension of the organism
MH Agar or Trypticase Soy Agar
(X & V factor requirements) After an overnight incubation in ___ °C in ____ air, the plate is examined for growth around each disc.
35 °C in ambient air
in x and v test there are only 3 discs:
V, X, and both the X and V factor.
If you do not want to use the discs, you can also use a plate through the __ that we can use to determine X and v factor requirements, as well as hemolysis
on the Horse Blood Agar.
Specialized Haemophilus Quad
is the one with Brain Heart Infusion Agar that is supplemented with Hemin for the X factor
Quadrant 1
is the Brain Heart Infusion as the base, supplemented by the IsoVitaleX for the
V factor.
Quadrant 2
Quadrant that has both the X and V factor
Quadrant 3
Quadrant ___ is Horse Blood Agar (X factor) and
is supplemented with the V factor, used to speciate the Haemophilus isolate.
Quadrant 4
test where it converts the substrate delta-aminolaevulinic acid (ALA) into porphyrins or porphobilinogen. This could be an intermediate then for the synthesis of the X factor.
Porphyrin Test
Porphyrin Test converts the substrate ____ into __ or ___.
delta-aminolaevulinic acid (ALA) into porphyrins or porphobilinogen.
to perform porphyrin test a microbial group or colonies taken and ___ is added at ___ for ___ hours and is placed under ___
p- dimethylaminobenzaldehyde (Kovac reagent) is added and is incubated at 35 °C for 4 hours and is placed under UV light
end result color of porphyrin test
red color or reddish-orange color.
This test is a sensitive method to determine
only the X factor requirement. So, those
species that do not require the X factor will
yield a positive result in test.
porphyrin test
requires X factor, is negative for porphyrin test test.
H. influenzae
characteristics on isolates identified as H. influenzae.
• gram neg rods/coccobacilli
• grow on CHOC and CO2
• not on blood agar
• porphyrin neg
• non-hemolytic on rabbit or horse blood,
growth factor for h. ducreyi
x factor
Haemophilus influenzae Biotypes infects Ear, respiratory tract
Biotype V
Haemophilus influenzae Biotypes infects Eye, respiratory tract
II, III
Haemophilus influenzae Biotypes Meningitis, epiglottis, respiratory tract
Biotype I
Eye, respirators tract
Biotype II and III
Ear, respiratory tract
Biotype v
All H. influenzae, from cases of invasive infections
should be ___ to determine whether or
not Type B is the cause of the infection.
serotyped
serotyping and molecular methods for haemophilus is done through the ____ where it detects the outer membrane protein D gene (g|pQ) from the capsule (cap) locus, the capsule producing gene (bexA), and the 165 RNA, as well as the insertion-like sequence.
Slide agglutination test
HACEK group
Haemophilus
Aggregatibacter
Cardiobacterium
Eikenella
Kingella
What is common with HACEK?
are slow growing gram-negative bacilli associated
with endocarditis.
usually involves the heart valves where there are lesions found called vegetations -
Endocarditis
HACEk is a normal biota of the?
Oral cavity
- It is one of the most prevalent species in the
HACEK groups - usually found in dental plaque and gingival
scrapings
AGGREGATIBACTER APHROPHILUS.
These can be both V Factor-dependent or V
Factor-independent.
AGGREGATIBACTER APHROPHILUS.
In addition, aside from endocarditis, aggregatibacter aphrophilus are the major cause of ___
periodontitis
aggregatibacter is a major cause of periodontitis infection of the gums because their virulence factor as ___ and ____
collagenase and alphaleukotoxin.
AGGREGATIBACTER APHROPHILUS is Already transferred to the genus
Haemophilus
Produces star-shaped colonies and are
catalase positive
AGGREGATIBACTER ACTINOMYCETEMCOMITANS
AGGREGATIBACTER ACTINOMYCETEMCOMITANS does not grow on _ agar
MacConkey agar
AGGREGATIBACTER ACTINOMYCETEMCOMITANS urease ____ and ___ to ferment
alucose
urease negative and are able to ferment
alucose
normal microbiota of the nose, mouth, and
throat and may be present even in the
gastrointestinal tract
CARDIOBACTERIUM HOMINIS
CARDIOBACTERIUM HOMINIS often show ____ reactions in part of the cells
false gram positive reactions
infects the dortic valves more frequently
compared to the other HACEK organisms
CARDIOBACTERIUM HOMINIS
form rosettes, swellings, long filaments or
sticklike structures in yeast extract - thus it
could be in Broth Dextrose Agar
CARDIOBACTERIUM HOMINIS
CARDIOBACTERIUM HOMINIS require _ atmosphere
humid atmosphere (either aerobic or
anaerobic with 5% carbon dioxide)
a member of normal biota of the oral and
bowel cavities
EIKENELLA CORRODENS
infections are associated with this organism
have been mixed and often occur as a result
of trauma, especially after human bites - we
sometimes call it as clenched fists wounds or
after the skin has been broken by human
teeth, especially among children
EIKENELLA CORRODENS
EIKENELLA CORRODENS is associated with people with ___ which cause cellulitis as result of direct
inoculation of organism unto the skin after oral
contamination of the needle paraphernalia.
drug addiction
this specie is the least common
isolate of the HACEK group when it comes to
infectious endocarditis
EIKENELLA CORRODENS
- fastidious, gram-negative coccobacilli that
requires carbon dioxide with hemin - In broth media, this organism may adhere to
the sides of the tube and produce granules.
EIKENELLA CORRODENS
The greening effect should not be confused
with the greenish metallic sheen on the _____ because E. corrodens will not grow on the said medium, and will also not grow on MacConkey
Eosin Methylene Blue Agar
EIKENELLA CORRODEN produces a _____ on the other media
chlorine bleach-like odor
Main characteristic of 45% of E. Corrodens’ isolates
make pits , depression, or corrode the surface of the agar
KINGELLA SPECIES is composed of 4 species
K. Kingae
K.denitrificans
K.oralis
K.potus
recognized as important pathogens in the
pediatric population and have a predilection
for bones and joints - causing osteoarthritis
infections in young children (< 4 years old).
K. kingae
also a member of the normal oropharynx
microbiota and the one that is associated
with ACEK
K. kingae
one that is associated with endocarditis like
Kingae but it is usually associated with the
poor hygiene or oral surgery - thus history
should also be considered
K. denitrificans
K. denitrificans are are ____ to _____ with squared ends that occur in pairs or short chain
coccobacillary to short bacilli
Difference of kingella spp. from neisseria gonorrhoeae
- Kingella is gram negative rods with square ends and in chains and catalase negative
- Neisseria is gram negative diplococci and catalase positive
- N. gonorrhode does not pit the agar as such
many strains of K. denitrificans.
This specie yield smooth, convex, and beta-hemolytic colonies that are characterized as spreading, corroding colonies with yellowbrown pigment.
Kingella kingae
Kingella denitrificans grows on
42°C
C. canimorsus cause a fulminant, life threatening ____ in humans- particularly in patients with asplenia or alcoholism after a dog or cat bite or through continuous contact
Septicemia
has a flagella sometimes, but it is usually
absent and is associated with gliding motility
on surfaces
CAPNOCYTOPHAGA
Capnocytophaga can be confused with
Eikenella.
Capnocytophaga is also negative in most of biochemical reactions including ____ - wherein many bacteria are positive for this test.
Capnocytophaga
a zoonotic infection that
humans acquire from exposure to infected
animal or products made from infected
animals
Pasteurellosis
