Small Pleo Gram (-ve) Rods 🈵 Flashcards
3 genus of small pleo gram (-) rods related to the Respiratory system
HLB
Haemophilus spp.
Legionella spp.
Bordetella spp.
side note:
Haemophilus spp.
✅ Non – motile
✅No toxins
🦠
Haemophilus spp. are fastidious therefore they need these 2 essential growth requirements on CAP?
(V-factor) NAD – from yeast extract or Staphylococcus aureus
(X-factor) Hematin – from blood
(4) Haemophilus spp.
H. influenzae
H. ducreyi
H. aegypticus
H. vaginalis
Haemophilus spp. aka?
Pfeiffer’s Bacillus
how many types of capsules Haemophilus spp. have?
and what is the most virulent type?
Capsule – 6 types
type B – most virulent
Haemophilus spp. type B – most virulent capsule is made of?
polyribitol ribose phosphate (PRP)
Haemophilus spp. exhibits “Satellite phenomenon”
Haemophilus influenzae
Sexually transmitted and causes Clinical Presentation
Chancroid/Soft chancre
Haemophilus ducreyi
Gram stain – small pleomorphic gram negative bacilli in clusters - “school of fish”
Haemophilus ducreyi
for culture: requires Fresh Clotted Rabbit Blood - preferred
20 – 30% Defibrinated Rabbit Blood agar
Sheep or Horse Blood
Haemophilus ducreyi
aka Kock-Week’s Bacillus
Haemophilus aegyptius
small pleomorphic gram negative rods:
🔬🧑⚕️Clinical Presentation
- Pink eye conjunctivitis
- Resembles H. influenzae biotype III
Haemophilus aegyptius
AKA: Kock-Week’s Bacillus
- because it takes a week to recover under antibiotic therapy
Formerly Haemophilus vaginalis
Gardnerella vaginalis
(Gardnerella vaginalis/Haemophilus vaginalis)
-same ra
bahog bilat fishy odor with discharge syndrome causative agent???
Gardnerella vaginalis/Haemophilus vaginalis
“clue cells” - epithelial cells with tiny bacilli covered is indicative of?
Gardnerella vaginalis or bacterial vaginosis
POSITIVE ON
✅Human Blood Tween Agar at 48 hours in 5 – 10% CO2 – Beta hemolysis
✅Whiff Test or Sniff Tests – vaginal discharge + 10% KOH
Positive test – Fishy- amine like odor
G. vaginalis/ H. vaginalis
stain used for Gardnerella vaginalis clue cells?
Papanicolaou’s stain
all Haemophilus spp. need V-factor (NADH nicotinamide) except
H. ducreyi
-only needs X-factor
(2) Haemophilus spp. that does not require X-factor (Hematin) but requires V-factor
✅H. parainfluenzae
✅H. parahaemolyticus
causes Pittsburg pneumonia
Legionella micdadei
causes Legionnaire’s Pneumonia
Pontiac Fever
Legionella pneumophila
causative agent?
-gram stain: stains faintly
-intracellular organism
-Immunofluoresacence
-Dieterle Silver Stain
Legionella pneumophila
requires Dieterle Silver Stain
Legionella pneumophila
side note:
Legionella pneumophila
- Does not grow on ordinary media
- Requires high concentration of Iron and Cysteine
REMEMBER Requires high concentration of Iron and Cysteine!!! - Legionella pneumophila
again: high Iron and Cysteine concentration - Legionella pneumophila
grows on
✅(BCYE) Buffered Charcoal Yeast Extract Agar
✅CAP
✅ 🟤Feeley-Gorman Medium🟤 (BROWN pigment)🤎
Legionella pneumophila
4 phases of whooping cough?
✅Incubation Period
7-10 days
✅Catarrhal Period
7-10 days
✅Paroxysmal phase
2-4 weeks
✅Convalescent stage
3-4 weeks (or longer)
causative agent:
- Gram – negative coccobacilli
- Direct examination of smears stained with fourescein conjugated monoclonal or polyclonal antibodies
– slow grower; should be held for 7 to 12 days - requires CALCIUM AGINATE TIPPED APPLICATOR
Bordetella pertussis
specimen culture for Bordetella pertussis should be collected at what phase?
Paroxysmal phase
2-4 weeks
-Whoop (burst of non-productive
coughs)
side note:
Bordetella pertussis in lab diagnosis is usually associated with Lymphocytosis
🦠
B. pertussis phase when the px is highly contagious and antibiotics most effective?
Catarrhal phase
B. pertussis phase when 2-10 weeks
✅Whoop (burst of non-productive
coughs)
✅Increased number of lymphocytes
in blood smear
Paroxysmal phase
B. pertussis phase when there is a development of secondary
complications (pneumonia, seizure, encephalopathy)
Convalescent stage
Growth on:
✅Regan – Lowe
>charcoal, blood, and antibiotic
✅Bordet – Gengou:
>Composed of: Potato
20 – 30 % blood Glycerol
Bordetella pertussis
may give the appearance of “drop of mercury” on Regan – Lowe agar
Bordetella pertussis
📒Side note:
🦠B. parapertussis
🦠B. bronchiseptica
Culture media:
✅MacConkey Agar (MAC)
✅Sheep Blood agar (SBA)
✅
The only motile Bordetella spp.?
also positive for catalase, urease and oxidase
B. bronchiseptica
3 Gram – Negative Zoonotic Rods
✅Brucella spp
✅Pasteurella spp
✅Francisella spp.
✅Yersinia
Brucella spp. is a facultative intracellular parasite.
Give two (2) facultative intracellular parasite bacteria under the small gram neg pleomorphic rods
(HBL)
🦠Haemophilus influenzae
🦠Legionella pneumophila
(Brucella spp. and Haemophilus ilnfluenzae are facultative intracellular parasite)
capsulated and shows Tropism to erythritol
Brucella spp.
- aka Bang’s Disease?
- what bacteria genus?
- Brucellosis
- Brucella spp.
shows:
✅ “Undulant fever”
✅ Non – specific signs and symptoms
✅ Organomegaly – splenomegaly, ✅Hepatomegaly and lymphadenopathy
✅Induces abortion in animals
Brucella spp.
Rod to coccoid – shaped, arranged singly or in pairs –“appearance of a sand”
Brucella spp.
the only Thionine sensitive and requires 5 % CO2 for growth Brucella spp?
B. abortus
(abortion on cows)
Minimum titer of ____in a standard tube agglutination test for Brucella spp.
1:160 titer
✅Recent brucellosis – 4 fold or greater during the the first two months of illness
Found as commensals in the upper respiratory tract of fowl and mammals
Pasteurella spp.
Aerobic, motile, and nutritionally fastidious pleomorphic poorly gram-negative rods; visualized with ______
silver stain
What bacteria?
Aerobic, motile, and nutritionally fastidious pleomorphic poorly gram-negative rods; visualized with silver stain
Legionella pneumophila
Pasteurella spp. most important human pathogen.
-Found as commensals in the upper respiratory tract of fowl and mammals
Pasteurella multocida
Transmission:
- From dog or cat bites
what bacteria:
Laboratory diagnosis:
- gram – negative short rod with BIPOLAR STAINING (safety pin)
-Px got bit by a cat/dog
-Musty or mousy odor on BAP
Pasteurella multocida
what bacteria:
✅Cottontail rabbit – primary reservoir
✅both wild and domesticated animals - birds
✅arthropods
Transmission:
1. Tick bites
2. Inhalation
3. Ingestion
4. Direct contact with infected animals
Francisella tularensis
what bacteria:
🧑⚕️Clinical manifestations:
✅Tularemia (tularensis) wink
✅Pneumonic Tularemia
✅Oculoglandular – conjunctivitis (with papule on the lower lid)
✅Typhoidal - Gastrointestinal
✅Ulceroglandular – at the site of inoculation (swollen lymph nodes)
Francisella tularensis
✅small pleomorphic gram – negative rods with faint bipolar staining
what bacteria:
✅cotton tail rabbit natural reservoir
✅slow grower (usually within 2 – 4 days)
✅Glucose – cyteine agar supplemented with 5% defibrinated rabbit blood
✅Chocolate Agar with IsolVitalX
✅Buffered charcoal yeast extract agar (BYCE)
Note that Legionella pneumophila also grows on BCY
Francisella tularensis
