GRAM POS BACILLI Flashcards
Non-spore forming
Non-branching
Catalase Positive bacilli
Corynebacterium
Rothia
Listeria
Non-spore forming
Non-branching
Catalase negative bacilli
Gardnerella
Arcanobacterium
Lactobacillus
Erysipelothrix
Kurthia
Non-spore forming
Branching
Aerobic Actinomycetes
Nocardia
Other Actinomycetes
Spore-forming
Gram positive bacilli
Bacillus
Clostridia
Obligate aerobes, non-bulging spores
Bacillus
Obligate anaerobes, bulging spores
Clostridia
Morphology
Club shaped or coryneform like
Small pleomorphic rods
Diphtheria-like
Chinese lettering
Palisade arrangement
Corynebacteria
Corynebacterium glucose and maltose fermenters, except:
C. urealyticum
C. pseudodiphtheriticum
Toxin of C. diphtheriae
Diphtheria Toxin
Respiratory Diphtheria
exudative membrane is aka?
Pseudomembrane (gray white)
Bull Neck Appearance
Respiratory Diphtheria
DOC for C. diphtheriae
Penicillin
Erythromycin (best)
V or L shapes morphology
Corynebacterium diphtheriae
Metachromatic granules of C. diphtheriae when stained with Loeffler’s Methylene Blue
Babes-Ernst granules/Volutin granules
Media to be used for cultivation of diphtheria bacillus
Modified Tinsdale Agar
Cystine-Tellurite Blood Agar
Leoffler’s Serum Agar
Growth in Loeffler’s Serum Agar (Pai Agars)
6-8 hrs incubation
DISTINCT YELLOW TINT
*serum slant no longer recommended
CTBA growth
Black to Brownish colonies: reduction of tellurite to tellurium
Gray to Black colonies: media is differential
Brown Halo: breaking down of cystine (cystinase activity)
Positive for CTBA, brown halo
C. diphtheriae
C. ulcerans
C. pseudotuberculosis
Modified Tinsdale Agar growth
Tinsdale halo: brown colored (organism used tellurite to produce H2S)
Tests for Toxigenicity of C. diphtheriae
In-Vivo Test: guinea pig, rarely done
In-Vitro Test: immunodiffusion test by Elek
Filter paper strip impregnated with diphtheria antitoxin
Elek plate
Pos result for In-Vitro Test by Elek
Fine precipitin lines at 45 degree angle to the streaks (strain produced toxin)
Intradermal Test to find the immune status of person who received vaccine for C. diphtheriae
Schick Test
Principle: Toxin Antitoxin Neutralization
Positive result for Schick Test
Eythema and Swelling after 24 to 36 hours
(individual is susceptible)
Other medically important Corynebacteria are called:
Diphtheroid (non-diphtheria Corynebacteria)
Formerly CDC Group JK
C. jeikeium
- named after Johnson and Kaye
- DOC: Vancomycin
Formerly CDC Group D-2
C. urealyticum
Has metachromatic granules and does not ferment sucrose like C. diphtheriae
C. xerosis
veterinary pathogen causing mastitis in CATTLES
C. ulcerans
vet pathogen producing dermonecrotic toxin causing lymphadenitis in SHEEP
C. pseudotuberculosis
C. diphtheriae, ulcerans, and pseudotuberculosis have POSITIVE CTBA, differentiate them.
C. diphtheriae is UREASE NEGATIVE
C. ulcerans and C. tuberculosis are UREASE POSITIVE
Also known as Hoffman’s Bacillus
Does not show pleomorphic morphology
C. pseudodiphtheriticum
Produces yellowish green soluble pigment
C. striatum
Undesignated CDC Coryneform Groups
CDC Group G
Immunization sched for DPT
6th week
10th week
14th week
Boosters: (2)
16-24th months
5 years
Found in saliva and supragingival plague
Rothia dentocariosa
R. dentocariosa in BROTH and SOLID MEDIA
Broth: coccoid and bacilli
Solid Media: branched filaments
Biochem tests for R. dentocariosa
Nitrate P
Esculin Hydrolysis P
Urease N
Listeria are motile at what temp
25 degree C
Only pathogenic Listeria
L. monocytogenes
Virulence Factors of Listeria and their functions (4)
HIAP
- Hemolysin (Listeriolysin O)
- major
- survival within pathocytes - Internalin
- cell surface protein
- induces phagocytosis - Act A
- induces actin polymerization
- cell to cell spread - Phospholipases
- escape from WBCs
Listeriosis in pregnant women is at what trimester
3rd
Tumbling motility, end over end
L. monocytogenes
Listeria monocytogenes growth pattern in SIM medium at 22-25C overnight
Umbrella Pattern Growth
Differentiates L. monocytogenes from other beta-hemolytic listeria species
CAMP Test
what bacteria is used in CAMP Test for L. monocytogenes
Rhodococcus equi
Pos res for CAMP Test for L. monocytogenes
Block pattern type of hemolysis
(+) L. monocytogenes
Differentiation of pathogenic Listeria species from the nonpathogenic ones
ID is based on enzyme phospholipases activity
New Oxoid Chromogenic Listeria Agar
Pos res for NOCLA
Turquoise colonies with halo
(+) L. monocytogenes
Differentiate L. monocytogenes and Corynebacterium spp.
Catalase Test
Esculin Hydrolysis
Motility
CAMP Test
6.5% NaCl
L. monocytogenes: +++++
Corynebacteria: +-VVV
Only considered human pathogenic Erysipelothrix
Erysipelothrix rhusiopathiae
Erysipelothrix: red skin, thread
Rhusiopathiae: red disease
Localized infection usually in the hands or fingers
Resembles streptococcal erysipelas
Self limiting
Erysipeloid
Differentiates Erysipelothrix from Lactobacillus Listeria Kurthia
H2S POSITIVE
Differentiate E. rhusiopathiae from E. tonsillarum
E. rhusiopathiae: SUCROSE NEGATIVE
morphology of E. rhusiopathiae in GELATIN STAB
Test-tube brush appearance at 22C
E. rhusiopathiae is susceptible to:
Penicillin
Erythromycin
Cephalosporin
Clindamycin
Kurthia benssonnii may appear ___ in cultures more than 3 days old
Coccoid cells
Describe Kurthia benssonnii
Motile by peritrichous flagella
Non hemolytic colonies
Oxidase NEGATIVE
3 significant spp of Arcanobacterium
Happy Birthday (Ha Py Ber-diae)
A. haemolyticum
A. pyogenes
A. bernardiae
Recovered from 10-20 yo patients with pharyngitis
Arcanobacterium haemolyticum
Pleomorphic, GP rods, RUDIMENTARY BRANCHING
Arcanobacterium haemolyticum
These are observed when the colony of Arcanobacterium haemolyticum is SCRAPED
Black Opaque Dots (pitting of the agar)
The CAMP Test for Arcanobacterium haemolyticum uses ______
Group B Streptococcus (S. agalactiae)
*CAMP Test for Group B Strep: S. aureus
*CAMP Test for L. monocytogenes: Rhodococcus equi
Created to accommodate non beta hemolytic lancefield group N strep
Genus Lactococcus
Important for maintaining proper pH balance in vaginal secretions
Aerotolerant anaerobe, non motile
Low pathogenicity, probiotic bacteria
Lactobacillus
Growth of Lactobacillus acidophilus on 5% SBA
Pinpoint, Alpha hemolytic (resembling Strep)
Rough gray colonies
Lactobacillus acidophilus grow at what pH
3-4
Lactobacillus acidophilus ferments:
MSG Vetsin
Maltose
Sucrose
Glucose
Gram Positive but with THINNER PEPTIDOGLYCAN (significantly)
Gardnerella vaginalis
Disease: polymicrobial, normal lactobacilli in the vagina are replaced by high conc of bacteria
Lactobacilli are either absent or few
Bacterial Vaginosis
Gardnerella vaginalis increases the vaginal pH greater than _
4.5
One of the most common causes of vaginal discharge
Bacterial Vaginosis
Characterized by FOUL SMELLING, EXCESSIVE PURULENT VAGINAL DISCHARGE (MALODOROUS)
Bacterial Vaginosis
Characteristic finding of G. vaginalis
CLUE CELLS
Large squamous vaginal epithelial cell to which bacteria have attached
CLUE CELLS
Scoring system for gram stain of vaginal smears
Nugent Scoring System
Nugent Scoring System is a scoring for:
Lactobacillus
Gardnerella
Mobiluncus spp.
Pos res for Amine Test/Whiff Test
Fishy amine-like odor
Solution used in Amine Test or Whiff Test
10% KOH
Gardnerella vaginalis
Grows on:
Does not grow on:
Grows on 5% SBA, CAP
Does not grow on MAC
Columbia CNA contains these antibiotics to prevent ____
Colistin
Nalidixic Acid
prevent overgrowth of GN orgs
This is a CNA Medium with the addition of AMPHOTERICIN B
HBT (Human Blood Bilayer Tween) - beta - hemolytic
This media is a selective medium used to isolate G. vaginalis
HBT (Human Blood Bilayer Tween) - beta - hemolytic
Function of amphotericin B in HBT medium
Prevent the overgrowth of Yeasts and Filamentous fungi
What diseases have POSITIVE WHIFF TEST
Bacterial Vaginosis
Vaginalis Trichomonas
Normal vaginal pH
Normal discharge
Microscopic
3.8-4.2
White, thin, flocculent
Lactobacilli, epithelial cells
pH in
- Bacterial Vaginosis
- Vaginalis Trichomonas
- Candida Vulvovaginitis
- > 4.5
- 4.5
- <4.5
Discharge of
- Bacterial Vaginosis
- Vaginalis Trichomonas
- Candida Vulvovaginitis
- Thin, white (milky), gray
- Yellow, green, frothy
- White, curdy, “cottage cheese”
Microscopic findings in Bacterial Vaginosis
Clue Cells
Adherent cocci
NO WBCS
Microscopic findings of Vaginalis Trichomonas
- Trichomonads
- WBC >10/hpf
Microscopic findings in Candida Vulvovaginitis
- Budding Yeast
- Hyphae
- Pseudohyphae
Partially acid fast or modified acid fast positive bacteria
Nocardia
Cell wall of Nocardia have _________ (shorter than mycobacteria)
Mycolic Acids
*stain with routine acid fast rgt carbolfuchsin
*able to retain carbolfuchsin dye when decolorized with 1-4% SULFURIC ACID
Virulence of Nocardia is associated with the production of large amounts of
Cord Factor (trehalose 6-6’ dimycolate)
Most notable Nocardia spp
Nocardia asteroides
Colonies of Nocardia asteroides
Star-shaped colonies
Pulmonary Infection
Common manifestations of Nocardia infection among immunocompromised patients
Confluent bronchopneumonia (usually chronic but my also be acute or relapsing)
Cutaneous Infections
Associated with most primary cutaneous infections that usually result from trauma
Nocardia brasiliensis
Chronic subcutaneous infection caused by fungi
Mycetoma
*Actinomycetoma: if caused by actinomycetes
Colonial appearance of Nocardia in routine agar
Chalky, matte/velvety, dry and crumbly like breadcrumbs
Nocardia asteroides grow on this agar at 37C
7H10 agar medium
Due to the growth of ______, colony color of Nocardia ranges from chalky white to orange and salmon pink
Aerial hyphae
This actinomycetes resembles Klebsiella spp. colonies on SBA
Rhodococcus (salmon pink pigment)
These actinomycetes can be detected using 16srRNA gene sequencing
- Tsukamurella
- Tropheryma whipplei
This actinomycetes is not culturable on artificial media
It is also a facultative INTRACELLULAR pathogen
Tropheryma whipplei
CA of Whipple’s Disease
Tropheryma whipplei
Characteristic findings of Whipple’s Disease
Periodic Acid Schiff staining macrophages
3 classes of endospores
I : oval, central
II : oval, swollen, central
III : round, swollen, terminal
Catalase Test of Bacillus and Clostridia
Bacillus catalase POSITIVE
Clostridia catalase NEGATIVE
Largest genus within GP Bacilli
Contains the most important medically relevant organisms
Bacillus
Bacillus are motile because of peritrichous flagella EXCEPT
Bacillus anthracis
Bacillus mycoides
What are the two primary virulence factors (exotoxins) of Bacillus anthracis
- EF (Edema Factor/Toxin)
- LF (Lethal Factor/Toxin)
This virulence factor of B. anthracis causes local edema and interferes with phagocytosis
EF (Edema Factor/Toxin)
This virulence factor of B. anthracis targets and kills macrophages - > disables immune defense
LF (Lethal Factor/Toxin)
Where is the largest and lomgest outbreak of B. anthracis
Zimbabwe
Three clinical manifestations of B. anthracis infection
- Cutaneous anthrax
- Pulmonary anthrax
- Gastrointestinal anthrax
Cutaneous Anthrax
Small papule -> Ring of vesicles -> Ulceration
- The typical presentation of ulceration is a BLACK NECROTIC LESIONS known as
- The answer in #2 is also referred to as
- Ring of vesicles coalesces is termed as
- Eschars/Black Eschars
- Malignant pustules
- Erythematous Ring
Pulmonary/Respiratory/Inhalation Anthrax
Used to describe respiratory infections that result from the exposure to endospores during handling of animal products
Wool Sorter’s Disease
The mortality rate of this type of anthrax is higher than cutaneous anthrax
GI Anthrax
Microscopic feature of B. anthracis resembles
STRING OF PEARLS
B. anthracis unstained spores with end fit snugly together like a ____
Bamboo rods
Staining color of vegetative cell and the spore of B. anthracis
Cells: red
Spore: green
This stain is used to stain the capsule of B. anthracis
India Ink Stain
B. anthracis Lecithinase Test growth on Egg Yolk Agar (EYA)
Opaque zone around colonies
CHO Fermentation of B. anthracis
G, MAX
Glucose POSITIVE
Maltose, Arabinose, Xylose NEGATIVE
Colonies of B. anthracis on BAP
Non hemolytic
GROUNDGLASS APPEARANCE
Colonies of B. anthracis look like hairy projections or comma shaped and are termed as
Medusa Head
Colonies of B. anthracis are described as ____ because they are tenacious when lifted with a loop and they have sticky colony phenomenon
Beaten Egg Whites
Growth of B. anthracis on SBAP
this is very important because other Bacillus spp. have different hemolysis pattern
NON HEMOLYTIC
Other Bacillus spp. are BETA HEMOLYTIC
This agar is used for the cultivation of B. anthracis when the specimen is stool
Phenylethyl Alcohol Agar (PEA)
stool weak growth on SBAP, CAP, NB
Agar used to demonstrate B. anthracis capsule
Bicarbonate Agar with 5-7% CO2
Post exposure prophylaxis for B. anthracis
Ciprofloxacin (2000)
Post exposure prophylaxis for B. anthracis. It is preferred if the strain is penicillin sensitive
Doxycycline
What type of toxin are the virulence factors of B. anthracis?
Exotoxin
The virulence factors of Bacillus cereus are what type of toxin?
Enterotoxin spores
This bacillus is associated with reheated rice and potatoes
B. cereus
2 types of B. cereus toxin
Diarrheal Toxin
Emetic Toxin
- B. cereus secretes this toxin only AFTER entering the intestine
- This toxin of B. cereus acts IMMEDIATELY on intestine
- Diarrheal Toxin (8-16 hrs)
- Emetic Toxin (1-6 hrs)
B. cereus
MOT of Diarrheal Toxin
MOT of Emetic Toxin
- Ingestion of MEAT or POULTRY
- Ingestion of FRIED RICE / CHINESE FRIED RICE
B. cereus
Heat labile toxin
Heat stable toxin
- Diarrheal Toxin
- Emetic Toxin
B. cereus is resistant to
Penicillin
How many organisms is the diagnosis of B. cereus infection
10^5 per gram
Differentiates B. anthracis and B. cereus in motility
Anthracis: NON MOTILE
Cereus: MOTILE
This bacillus has FROSTED GLASS APPEARING COLONY
B. cereus
B. anthracis: GROUND GLASS
Treatment for B. cereus
ClinVan
Clindamycin
Vancomycin
Lab diagnosis differentiation of B. anthracis and B. cereus
B. anthracis: POSITIVE only on LECITHINASE and STRING OF PEARL TEST
B. cereus: NEGATIVE only on STRING OF PEARL TEST
An autoclave indicator bacteria
Bacillus stearothermophilus
Autoclave Test Results
Yellow Color Change
- failed, bacterial growth
No color change
- successful
Common laboratory contaminant
B. subtilis
This genus is saprophytes
Clostridia
Why are spores of Clostridia wider than vegetative bacteria
They are BULGING, SWOLLEN
Causative agent of botulism
Clostridium botulinum
What toxin are ingested to have Botulism
Botulinum Toxin A B E
C. botulinum is described as ______ bcs it is used to treat involuntary muscle disorders and anti-aging remedy to improve frown lines
Beauty Enhancer (temporary improvement)
Infant Botulism is also known as
Floppy Baby Syndrome
Common among 2 weeks to 6 months baby
They dont havr the ability to suck and swallow
Floppy Baby Syndrome
Botulinum toxin induces _______, there are 7 main types _______, the most common are _________
- Muscle paralysis
- A to G
- A B E
Purified form of Botulinum Toxin Type A is used to treat
Strabismus (wandering eyes)
Appearance or Clostridium tetani due to its spores
Drumstick Appearance
An acute disease manifested by skeletal muscle spasm and autonomic nervous system disturbance
This is characterized by RIGIDITY and CONVULSIVE SPASMS of skeletal muscle
Tetanus
Tetanos (Greek) to stretch
In tetanus, the spores germinate within wounds producing ____
This neurotoxin also prevents the release of neurotransmitter in spinal cord
Tetanospasmin
First symptoms of tetanus leads to ______ aka ______
Trismus
Locked Jaw
This is a common complication of tetanus as if you are smiling all throughout
Risus sardonicus
2 exotoxins of C. tetani
Tetanolysin
Tetanospasmin (Aka Tetanus Toxin)
This vaccine is the most effective method of prophylaxis for Tetanus
DPT Vaccine
Cultural characteristics of C. tetani that are like Proteus spp.
Swarming growth
Where are the spores of C. perfringes
Subterminal
Four major toxins of C. perfringens
Alpha
Beta
Epsilon
Iota
This toxin of C. perfringens destroys cell membranes
Alpha toxin
This is described as rapidly spreading edematous myonecrosis and alpha toxin is the principal virulence factor
GAS GANGRENE
This is caused by C. perfringens Type A Enterotoxin
Food Poisoning
Microscopic appearance of C. perfringens
BOXCAR-SHAPED
Hemolysis of C. perfringens on SBA
Target Hemolysis/Double Zone Hemolysis
(beta hemolysis surrounded by alpha hemolysis)
This test differentiates C. perfringens from other Clostridia spp.
Direct Nagler Test
Principle: Neutralization of Lecithinase Activity
Pos and Neg res of Direct Nagler Test
Pos: Disappearance or a reduction in the opacity of the antitoxin side
- C. perfringens
Neg: Presence of opacity
- C. difficile
Major cause of hospital acquired infection
Clostridium difficile
C. difficile is responsible for a unique colonic disease known as
Pseudomembranous Colitis
aka ANTIBIOTIC ASSOCIATED PSEUDOMEMBRANOUS COLITIS
2 powerful exotoxins of C. difficile
- Toxin A or enterotoxin
- Toxin B or cytotoxin
Both toxins A and B are secreted in the intestine
Which toxin results in watery diarrhea
Which toxin damaged colonic mucosa
- Toxin A or Enterotoxin
- Toxin B or Cytotoxin
Pink staining bacilli
C. difficile
This agar is a selective and differential medium for C. difficile
CCFA - Cycloserine Cefoxitin Fructose Agar
Pos growth for CCFA of C. difficile
YELLOW COLONIES
pink agar turns to yellow in the vicinity of colonies
Most effective antibiotic for C. diphtheriae
Erythromycin
DOC for C. jeikeium and C. urealyticum
Vancomycin
DOC for Listeria monocytogenes
Penicillin with or wo aminoglycosides
DOC for Gardnerella vaginalis
Metronidazole
SXT is effective among __
Nocardia
Tropheryma whipplei
The only motile spp in MODULE 9 GRAM POSITIVE BACILLI
- Listeria monocytogenes (25°C)
- Kurthia benssonnii
- Bacillus (except anthracis and mycoides)
- Clostridium botulinum
the GRAM VARIABLE team
BEG
Bacillus anthracis (old cultures)
Erysipelothrix rhusiopathiae
Gardnerella vaginalis