Gram Positive Bacilli Flashcards
All bacilli are gram Negative except
MAC DONALD
M - Mycobacterium
A - Anthracis Bacillus
C- Clostridium species
D - Corynebacterium diphtheria
N - Nocardia
A - Actinomyces
L - Listeria
D - Diphtheroids
Corynebacterium is also known as
Kleb Loeffler’s Bacillus
Features of Corynebacterium
Gram Positive
Non motile
Non sporing
Non capsulated
Types of Corynebacterium
C. Diphtheria
Others - C. Ulcerans, C. Pseudotuberculosis, C. Minitissimum
Corynebacterium Pseudotuberculosis is also known as
Preisz Nocard Bacillus
Characteristic clinical features of Corynebacterium Minitissimum
Erythrasma - Red Rash around axilla, groins
Erythrasma caused by C. Minitissimum finding under woodlamp examination
Coral red Fluorescence due to Coproporphyrin iii
Liphophilic Corynebacterium can be divided into
C. Jeikeium
C. Urealyticum
C. Jeikeium can cause
Prosthetic valve endocarditis
Immunocompromised pt
C. Urealyticum is associated with which stone
Struvite stone
Diphtheria toxin is produced by
DUP
Diphtheria
Ulcerans
Pseudotuberculosis
Diphtheria toxin is associated with which gene
TOX gene
Examples of Phage mediated Toxins
ABCDE
A and C - Strep Pyogenes
Botulinum toxin
Cholera toxin
Diphtheria toxin
EHEColi
Virulent factors of Diphtheria toxin
Fragment A - ADP phosphorylation of EF2 - Decrease protein synthesis
Fragment B - bind to cells
Strain of Diphtheria toxin used for vaccine
Park William 8 Strain
Examples of Toxin decreasing Protein Synthesis
Decreasing Protein Synthesis
DT
Exotoxin A of Pseudomonas
Shiga toxin
Verocytotoxin (Shiga like toxin)
Diphtheria toxin And Exotoxin A decreases protein synthesis by
Inhibiting ADP phosphorylation of EF2
Shiga toxin and Shiga like toxin Decreases protein synthesis by
Cleaving 60S ribosomes
Incubation period of C. Diphtheria infection
3-4 days
Forms of Diphtheria infection
Respiratory/Faucial diphtheria
Cutaneous diphtheria
Systemic diphtheria
Respiratory/Faucial form of Diphtheria is associated with
Pseudomembrane
Bull’s neck
Complications of Diphtheria infection
Myocarditis (7-10th day ) - MC cause of death
Neurological - Oculomotor paralysis
Hemorrhagic - Thrombocytopenia
Sample for C. Diphtheria infection is taken from
2 swabs under the membrane
Microscopic Finding of C. Diphtheria
Chinese letter/Cuneiform appearance
Snapping division
Volutin Granules can be seen in
Corynebacterium diphtheria
Yersinia pestis
M Tb
Gardenella
Spirillum
Volutin Granules are also termed as
Bipolar granules or Metachromatic granules or Babes ernst granules
Stains used for Volutin Granules
PLAN
Ponders stain
Loeffler Methylene Blue
Albert stain
Neissers Stain
Enriched media used for C. Diphtheria
Loeffler serum slope - 6-8 hrs
Selective media used for diagnosis of C. Diphtheria
Macleod/Hoyes/Tinsdale Medium
PTA (Potassium tellurite Agar) - Best media for Growth
Potassium tellurite Agar takes how much time to grow and shows which color colonies
Takes 48 hours
Black colonies
Test done to know toxigenicity diphtheria toxin
Eleks Gel precipitation test
Schick test is done to know
Susceptibility of person
SPIN
Positive Shick test -; Susceptible
Negative Shick test - immune
Dosage of Diphtheria antitoxin in case of Nasopharyngeal disease
40,000 to 80,000 Im/ov
Diphtheria antitoxin dose for extensive disease
80,000 to 1,20,000 im/iv
Antibiotics used for Diphtheria infection
Penicillin or Azithromycin
Difference between DTaP and TdaP vaccine
DTaP - Higher dose of Diphtheria toxin
Given to children less than 7 years
TdaP - Lower dose of DT
Given to >7 years of age
Biotyping of Corynebacterium is done on basis of
Potassium tellurite agar
Biotyping of Corynebacterium based on PTA includes
C. Gravis
C. Intermedius
C. mitis
GIM - Head Egg Egg
C. Gravis shows
Daisy head colonies
Starch fermentation
C. Intermedius shows
Frog egg appearance
Non Hemolytic
C. Mitis shows
Poached egg appearance
Least virulent
Gram Positive Filamentous Bacteria includes
Nocardia
Actinomyces
Characteristic features of Nocardia
Nocardia = Nature
Strict aerobe(O2)
Soil (exogenous)
1% acid fast (acid rain)
Characteristic features of Actinomyces
Strict Anaerobes
Found in mouth (Endogenous flora)
Non acid fast
Culture method of Nocardia
Paraffin Bait Technique
Clinical features caused by Nocardia
In immunocompetent - Cutaneous
Immunocompromised - Pulmonary manifestation (MC)
M/C extrapulmonary - Brain
Treatment of Nocardia infection
Sulphonamides
Colonies shown by Actinomyces on Solid media
Spider/molar tooth colonies
Colonies shown by Actinomyces on Liquid media
Fluffy ball
Clinical features of Actinomyces infection
Orocervical (M/C) - Lumpy jaw, Swelling of jaw, Multiple sinus discharges
Thoracic
Abdominal - following surgery
Pelvic - IUCD use
Treatment of Actinomyces Infection
Penicillin
Nocardia and Actinomyces known to cause which phenomenon
Spleudore Hoepplei phenomenon
Combination of Nocardia and Actinomyces causes
Actinomycetoma
Which Actinomyces species can be acid fast sometimes
Actinomyces Israelli
Actinomyces shows which granules on Israel yellow sand
Yellow sulphur granules
Virulence factor of Listeria monocytogenes
Listeriolysin O
Motility shown by Listeria monocytogenes
Tumbling motility - motile @22°C, non motile at 37°C
Mnemonic for Listeria monocytogenes
ABCDEFG
A- Anton test
B - Beta hemolysis (Listeriolysin O)
C - contact, Contaminated food, cheese (Dairy), Cold enrichment, CAMP +ve, Catalase +ve
D - Diarrhea
E - Flagella (Peritrichous) , Females, pregnancy, neonates (sepsis)
G - Granulomatous Infanti septicum
Clinical features of Listeria monocytogenes
Gasteroenteritis
Pregnant females - Abortion/still birth
Early neonatal period - Sepsis
Late neonatal period - Meningitis
Granulomatous Infanti septicum
Specimen taken for Listeria monocytogenes diagnosis
Cervical/vaginal
Meconium/cord blood
CSF
Anton test is positive in
Listeria monocytogenes
Animal (Rabbit eye) - On injecting listeria - cause Keratoconjunctivitis
CAMP test and Catalase in Listeria monocytogenes
Positive
Examples of Spore forming Bacteria
Bacillus
Clostridium
All bacillus are motile, unencapsulated and Hemolytic except
Bacillus anthracis
Bacillus family includes
B. Stearothermophilus - Autoclave, Plasma sterilization
B. Subtilis - Hot air oven
B. Pumilus - Radiation
B. Globigri - Gas sterilization
First pathogenic bacteria seen under Microscope
B. Anthracis
First pathogenic bacteria having live attenuated vaccine
B. Anthracis
First pathogenic bacteria isolated in pure culture
B. Anthracis
Virulence factors of B. Anthracis
Capsule - Polypeptide made of Polyglutamate - PxO2 plasmid
Anthrax toxin - PxO2 plasmid
Why anthrax toxin is called Tripartite
EPL
3 Factors
E - Edema factor - increases cAMP
P - Protective Factor - attachment
L - Lethal factor - Death
Ways to spread Bacillus anthracis
Cutaneous (M/C)
Inhalational
Ingestion
Clinical features of Cutaneous anthrax
Hide Porter’s disease - Malignant Eschar (Black)
Clinical features of Pulmonary anthrax
Wool sorter’s disease
Results in hemorrhagic mediastinitis
Pericarditis
Septicemia
Associated with Bioterrorism
Clinical features of Intestinal anthrax
Undercooked meat
Hemorrhagic enteritis
Complications of Anthrax
CSF/Meningitis/Meningoencephalitis
Hemorrhagic CSF
Microscopic Finding of Bacillus anthracis
Bamboo stick appearance or Box car appearance
Demonstration of Capsule is done in case Bacillus anthrax infection
Mc Fadyeans Reaction - Smear+ Polychrome Methylene blue - Purple color around capsule
Culture findings in Bacillus anthracis infection
Forsted glass @edge of colony - Medussa head appearance
Comet tail
Beaten egg
B. anthracis is susceptible to penicillin and incubation on medium containing low levels of penicillin causes the bacterium to
swell and form a chain of cells that resemble a String of pearls
Bacillus Anthrax on Gelatin liquifaction
Shows Inverted Fir tree appearance
Selective media used for diagnosis of Bacillus anthrax
PLED (Polymxin lysosome EDTA thallous acetate)
Serology exams for Bacillus anthrax infection
Ascoli’s ring therompercipitin
ELISA
Duckering means
Disinfection of wool by 2% Formaldehyde at 30-40°C for 20 min
According to CDC, when to give presumptive diagnosis of Anthrax
Any gram +ve bacillus, non motile, non Hemolytic, Catalse +ve
Which vaccine is given to vets/occupational exposure against Bacillus anthrax
AVA biothrax
Vaccines given to animals against Bacillus anthrax
PSM
Pasteurs anthrax vaccine
Sterne vaccine
Mazzucchi vaccine
Treatment of Uncomplicated Cutaneous anthrax
Ciprofloxacin or Doxycycline (7 to 10day)
Treatment of Sytemic anthrax
Ciprofloxacin or Doxycycline
Add Antoxin (Raxibacumab)
In case of Anthrax meningitis - 60 Days antibiotics (Ciprofloxacin+ Meropenem + Clindamycin)
Post exposure prophylaxis for System anthrax
AVA Biothrax+ 60 days antibiotics
Bacillus cereus habitat
Soil
Bacillus cereus causes
Food poisioning
Types of Food poisoning caused by Bacillus cereus
Emetic type
Diarrheal type
Incubation period of Emetic type and Diarrheal type
Emetic - 1 to 5 hours
Diarrheal - 8 to 16 hrs
Food responsible for Emetic type and Diarrheal type of Bacillus cereus infection
Emetic - Chinese fried rice
Diarrheal - Meat and milk
Which one is heat stable - Emetic type or diarrheal type
Emetic type
Mechanism of action of Emetic type Bacillus cereus
Increases cGMP - Vagomimetic action
Mechanism of action of diarrheal type of Bacillus cereus infection
Increases cAMP
Nhe toxin - Secretory diarrhea
Features of Bacillus cereus
Motile
Hemolytic
Non encapsulated
Selective media used for bacillus cereus
MYPA (Mannitol, Yolky, Polymyxin Agar)
PEMBA ( Polymyxin, Mannitol, Bromothymol blue Agar)