Lesson 8: The Gram Positive Bacilli - Endospore and Non-spore Forming Flashcards
Which of the following are spore forming and which are not-spore forming bacteria?
Bacillus
Listeria
Clostridia
Corynebacterium
Spore forming: Bacillus and Clostridia
Non-spore forming: Listeria and Corynebacterium
Which of the following is the obligate aerobe/anaerobe?
Bacillus species
Clostridium species
Obligate aerobes: Bacillus species
Obligate anaerobes: Clostridium species
Anthrax, Diphtheria, and Listeriosis are caused by what gram-type of bacillus?
Gram-positive
All Cocci are Gram-Positive except for? MANBV
Megasphera
Acidaminococcus
Neisseria
Bramhamella
Veilonella
All Bacilli are Gram-Positive except? MCCBELL
Mycobacterium
Corynebacterium
Clostridium
Bacillus
Erysipelothrix
Listeria
Lactobacillus
What agar can grow Bacillus spp? (SBA and PEA)
Sheeps Blood Agar
Phenylethyl Alcohol Agar
Spores of Bacillus can be identified with what stain? (SF Stain)
Schaeffer-Fulton stain
Round and Glass-like colonies
Bacillus spp
The spores of bacillus contain ___________ which makes them resistant to adverse environment
Calcium dipicolinate
Its antiphagocytic capsule is composed of D-glutamate
Bacillus anthracis
2 medically important Bacillus spp
Bacillus anthracis
Bacillus cereus
Where is the anthrax toxin encoded on bacillus anthracis?
Plasmid
3 forms of Anthrax
Cutaneous
Pulmonary
Gastrointestinal
It is a NON-MOTILE bacillus spp, while others are motile
Bacillus anthracis
Two exotoxins of anthrax
Edema factor and Lethal factor
Which subunit of the anthrax exotoxin has the enzymatic activity?
A or active subunit
Which subunit of the anthrax exotoxin is the protective antigen?
B or binding subunit
The smears of Bacillus anthracis are stained with? (3)
Gram Stain
Polychrome methylene blue (McFadyean’s stain)
Giemsa Stain
It is an adenylate cyclase that causes an increase in the intracellular concentration of cAMP
Similar to that of the cholera toxin
Edema factor
What Biosafety level is a precaution for anthrax toxin?
BSL II
A protease that cleaves the phosphokinase that activates the mitogen-activated protein kinase (MAPK) signal transduction pathway
Lethal Factor
Identify the agar for B. anthracis
Grayish and granular colonies
24 hour incubation
2-3 mm diameter
“Medusa head”
Nutrient agar
PMB stained smears shown an amorphous purplish material, remnant of the capsular material around the bacillus and it is used for presumptive diagnosis of anthrax in animals
McFadyean’s reaction
Identify the agar for B. anthracis
Gray or white colonies
Non-hemolytic
Dry, ground-glass appearance
3mm diameter
Sometimes have tails
Blood agar (Horse or Sheep Blood Agar)
Identify the agar for B. anthracis
Contains 0.05-0.5 U of penicillin/mL
Large, spherical colonies
“String of pearls” surface
Solid medium containing penicillin
This property is useful in differentiation of B. anthracis from B. cereus and other aerobic spore bearers
String of pearls reaction
It is a selective medium used for isolation of B. anthracis from mixtures containing other spore-bearing bacilli. The medium is composed of:
Heart infusion agar
Polymyxin
Lysozyme
Ethylene diamine tetra acetic acid(EDTA)
Thallous acetate
Knisely’s Polymyxin B-lysozyme-EDTA-thallous acetate (PLET) agar medium
B. anthracis produces acid from what sugars?
Glucose
Maltose
Sucrose
Trehalose
Dextrin
These are avirulent and lack capsule type of B. anthracis stain
Rough (R) variants
It is a test for B. anthracis used for RAPID diagnosis when tissue received is putrid and viable bacilli are unlikely to be found
Ascoli’s thermoprecipitation test
Identify the agar for B. anthracis
Growth on the stab line
Lateral spikes
“Inverted fir tree” appearance
Liquefaction is slow and late (7 days at 20C) and starts at the surface
Gelatin medium
Capsulated bacteria on serum or bicarbonate medium produce this type of colonies.
Mucoid or smooth(S) colony type
This test for B. anthracis is used to demonstrate serum IgG against PA
ELISA Test
This genus of Gram-positive bacilli are capable of forming endospores which are typically wider than the bodies of the bacilli resembling a spindle shape appearance
Clostridium
B. anthracis demonstrate a weak lecithinase reaction, which gives a narrow zone of opalescence around the colonies on what type of agar?
Egg-yolk agar
True or False
B. anthracis a NITRATE reducer
True
B. anthracis does not produce acid from these sugars.
Lactose
Arabinose
D-xylose
D-mannitol
It is the most important feature of clostridia
Ability to produce endospores
Bacillus cereus can be isolated from feces by using selective media such as?
MYPA (mannitol, egg yolk, polymyxin, phenol red, and agar)
PEMBA (polymyxin, egg yolk, mannitol, bromthymol blue)
Bacteria related to fried rice because it can survive steaming and rapid frying
Bacillus cereus
Identify the agar for B. cereus
Large, feathery, spreading, dull
Gray and granular
Opaque with rough matted surface
Irregular perimeters
Beta-hemolytic
Blood agar
Culture of B. cereus can is identified if there is growth on what types of agar?
5% sheep blood agar
Chocolate agar
Routine culture media
Nutrient broths
It is generally used as a toxin detection system for B. cereus
Microslide gel diffusion test
Following two weeks of incubation, aerial hyphae may develop on the surface on what media for B. cereus?
Lowenstein-Jensen medium
3 major clinical syndromes caused by Clostridium species
Tetanus
Gas gangrene
Botulism
True or False
Most species of Clostridium are harmless saprophytes and are present as normal flora in the GIT of humans and animals
True
Only 2 NON-CAPSULATED clostridia species
C. perfringens
C. butyricum
True or False
Clostridia are more associated with these:
Skin and soft tissue infections
Antibiotic-associated diarrhea
Food poisoning
True
What type of flagella does Clostridium species have?
Peritrichous flagella
Identify the clostridia species based on the spore
Central spore
“Spindle shape”
C. bifermentans
Identify the clostridia species based on the spore
Subterminal spores
“Club shape”
C. perfringens
Identify the clostridia species based on the spore
Oval terminal spores
“Tennis racket shape”
C. tertium
Identify the clostridia species based on the spore
Spherical terminal spore
C. tetani
True or False
Spores are more resistant forms than the vegetative forms of the bacilli
They show a variable degree of resistance to heat, drying, and disinfectants
True
These solutions/substances can kill spores
1% aqueous solution of iodine
2% glutaraldehyde at pH of 7.5-8.5
Spores are particularly resistant to what type of disinfectants
Phenolic disinfectants
Spores of this clostridium spp. can survive boiling at 105C for 3-4 hours
Clostridium botulinum
Spores of these clostridium spp. are rapidly destroyed by boiling for less than 5 minutes
C. perfringens
C. tetani
What strain of C. perfringens can survive boiling for several hours
C. perfringens Type-A strains
It is the most important clostridium species causing GAS GANGRENE
Also causes necrotic enteritis and food poisoning
Clostridium perfringens
Identify the Bacteria based on morphology
Large, rectangular
Gram-positive bacillus
4-6 mm in length
Straight bacillus with parallel sides
Round and truncated ends
Capsulated
Nonmotile
Clostridium perfringens
Identify the culture media of C. perfringens
Meat is NOT digested but is turned pink
Acidic reaction / sour odor in culture
Used in isolation of C. perfringens when specimens are contaminated with other clostridial species
Robertson’s cooked meat (RCM) broth
Inoculation of the specimens in RCM media
Temperature:
Time:
Temperature: 45C
Time: 4-6 minutes
Identify the culture media of C. perfringens
Prolonged incubation produces DUAL ZONE of hemolysis
Narrow zone: complete hemolysis by thetatoxin
Wider zone: incomplete hemolysis by alpha-toxin
Blood agar (Human, Sheep, or Rabbit)
In the blood agar for C. perfringens, the dual zone (narrow and wide) of hemolysis is caused by?
Narrow: Thetatoxin (complete)
Wide: Alpha-toxin (incomplete)
Does C. perfringens ferment sugar?
Yes (glucose, lactose, sucrose, and maltose)
Does C. perfringens produce H2S (Hydrogen sulfide) and reduce Nitrate to Nitrite?
Yes
Identify the bacteria based on the IMVC test
Methyl Red: Positive (+)
Voges-Proskauer: Negative (-)
Indole: Negative (-)
Clostridium perfringens
Since C. perfringens ferments lactose with the production of acid in litmus milk, the color of the medium changes from blue to red. What substance of the milk is coagulated by the production of acid?
Casein of the milk
When C. perfringens ferments lactose, there is a formation of a clot and it breaks which adheres to the sides of the glass tube. This reaction is known as?
Stormy fermentation
Identify the test used for C. perfringens
Rapid Detection
Uses “Lecithinase”
Produces “opalescence” in the serum and in the egg yolk media
Nagler reaction
This test for C. perfringens contains:
6% agar
5% Fildes peptic digest of sheep blood
20% human serum
Antibiotic neomycin sulfate
1/2 with antitoxin
1/2 without antitoxin
Nagler Test
True or False
C. perfringens are sensitive to metronidazole and penicillin
True
4 major toxins produced by C. perfringens
alpha
beta
epsilon
iota-toxin
5 strains of C. perfringens
A, B, C, D, E strains
It is the most important toxin produced by all strains of C. perfringens
Alpha-toxin
Largest volumes of alpha-toxin are provided by what strain of C. perfringens?
Type A strain
This toxin of C. perfringens is responsible for toxemia typically observed during gas gangrene
Alpha-toxin
This toxin of C. perfringens causes lysis of RBCs, WBCS, platelets, and endothelial cells
Alpha-toxin
This toxin of C. perfringens is observed best on incubation at 37C followed by re-incubation at 4C (hot-cold lysis)
Alpha toxin
This toxin of C. perfringens causes necrotic lesions in necrotizing enteritis
Beta-toxin
This toxin of C. perfringens is a lethal toxin, which produces necrotic lesions and increases vascular permeability
Iotta-toxin
This toxin of C. perfringens is a prototoxin, which is activated by trypsin. This toxin increases vascular permeability of the wall of gastrointestinal tract
Epsilon-toxin
Minor toxins of C. perfringens
Delta
Theta
Kappa
Lambda
Mu
Nu
It is a toxin of C. perfringens:
Lethal
Hemolytic to sheep, goat, cattle, red cells, and etc
Delta Toxin
It is a toxin of C. perfringens:
Oxygen-labile hemolysin
Cytolytic toxin
Theta-toxin
It is a toxin of C. perfringens:
Collagenase
Kappa-toxin
It is a toxin of C. perfringens:
A proteinase
A gelatinase
Lambda-toxin
It is a toxin of C. perfringens:
A hyaluronidase
Mu toxin
It is a toxin of C. perfringens:
A deoxyribonuclease
Nu-toxin
This toxin is produced by type A strain of C. perfringens
Heat-labile
Produced during the stage of sporulation of vegetative cells to form spores, which is stimulated by alkaline environment of the small intestine
Enterotoxin
It is the most important enzyme of C. perfringens that alters the cell surface ganglioside receptors and promotes capillary permeability
Hint: Ganglioside = ganglia = brain related
Neuraminidase
This soluble substance produced by C. perfringens acts specifically on muscle tissue and may be responsible for typical muscle lesions observed in GAS GANGRENE
Bursting factor
This soluble substance produced by C. perfringens increases ADRENALINE sensitivity of the capillary membrane and also inhibits phagocytosis
Circulatory factor
It is a rapidly spreading edematous myonecrotic life-threatening condition caused by C. perfringens in association with extensive muscle trauma contaminated with C. perfringens or other pathogenic clostridia
Gas Gangrene or Clostridial Myonecrosis
Other name of Gas Gangrene
Clostridial Myonecrosis
It is caused by C. perfringens TYPE C and is an acute necrotizing condition of the jejunum
Characterized by abdominal pain, bloody diarrhea, shock, and peritonitis
Necrotizing enteritis
Necrotizing enteritis is known as what in Papa New Guinea?
Pigbel
Necrotizing enteritis is known as what in Germany?
Darmbrand (fire bowels)
Strain of C. perfringens that is part of the normal flora where they are found in soil, dust, and air
Type A
Strain of C. perfringens that colonize the intestinal tracts of animals and occasionally humans. Their spores do not survive in soil.
Type B, C, D and F
Identify the bacteria
Obligate anaerobe
Gram-positive
Causes tetanus
Clostridium tetani
It is an infectious disorder characterized by an increased muscle tone and spasms caused by the release of a neurotoxin, “tetanospasmin”, produced by C. tetani when it gets inoculated into humans
Tetanus
What strain of C. tetani is non-motile because it does not have a flagella?
Type VI C. tetani
Identify the media used for C. tetani
Produces turbidity with production of some gas in the medium
Meat is not digested, but turns “BLACK”
Robertson’s Cooked Medium (RCM)
What hemolysin is produced by C. tetani that converts alpha-hemolysis to beta-hemolysis on prolonged incubation?
Tetanolysin
Identify the media used for C. tetani
produces “Alpha-hemolysis” which becomes “Beta-hemolytic” on prolonged incubation due to the production of TETANOLYSIS
Surface colonies tend to swarm over the entire surface of the agar
Fine translucent film of growth, which is difficult to visualize except at the edges of the colonies
Blood agar
C. tetani are classified into how many serological types based on AGGLUTINATION?
10 serological types (Types I to X)
Identify the media of C. tetani
Bacillus produces a “Fir-tree” type of growth under anaerobic incubation
Gelatin Stab Culture
True or False
C. tetani is NOT a sugar fermenter
True
It is the toxin responsible for the clinical manifestation of tetanus
Tetanospasmin
True or False
C. tetani has mild proteolytic activity BUT completely lacks saccharolytic activity
True
Identify the media of C. tetani:
Inoculation at bottom of the slope
Anaerobic incubation for 24 hours
Yields a “Pure” colony at top of the slope
Method: Fildes technique
Nutrient agar slope
It is a routine method for isolating pure colonies of C. tetani
Fildes Technique (Nutrient agar slope)
C. tetani spores are killed by what solution/chemical substance?
1% aqueous solution of iodine
10% hydrogen peroxide
True or False
C. tetani can be killed by:
- 5% phenol
- 0.1 mercuric chloride solution
False, they can only be killed by 1% iodine solution or 10% hydrogen peroxide
True or False
C. tetani does not produce H2S and does not reduce nitrates
True
Identify the bacteria based on IMVC test
Indole: Positive (+)
Methyl Red: Negative (-)
Voges Proskauer: Negative (-)
C. tetani
Tetanus toxin is made into toxoid by treating it with?
Formaldehyde
These are the two major toxins of C. tetani which are pharmacologically and antigenically distinct
Tetanolysin
Tetanospasmin
Identify the bacteria based on the medium
Produces a greenish fluorescence on MacConkey medium, which contains NEUTRAL RED
C. tetani
It is a recently identified toxin of C. tetani
Non-spasmogenic toxin or Neurotoxin
Identify the toxin of C. tetani
3rd toxin recently identified
Non-spasmogenic
Neurotoxin
This toxin acts by preventing the release of Neurotransmitters, such as Gamma-aminobutyric acid(GABA), glycine, etc, thereby specifically blocking synaptic inhibition in the spinal cord
Tetanospasmin
True or False
Tetanus toxoid is antigen but nontoxic
True
Identify the toxin of C. tetani
Oxygen and heat-labile hemolysin
Related to clostridial hemolysins and streptolysin O
Does not play any role in the pathogenesis of tetanus
Tetanolysin
Function of each chains of Tetanospasmin
Heavy chain:
Light chain:
Heavy chain: responsible for specific binding to neural cells and for protein transport
Light chain: blocks the release of two major inhibitory neurotransmitters (GABA and glycine)
Common incubation period of tetanus
6-12 days
Type of tetanus (4)
Generalized tetanus
Neonatal tetanus
Localized tetanus
Cephalic tetanus
Are swabs from the wounds good specimens for C. tetani identification?
NO
Identify the bacteria
Heterogenous group of spore-forming bacteria
Anaerobic
Gram-positive
Causes “botulism”
Clostridium botulinum
It is a paralytic disease with the presentation of food poisoning
Botulism
C. botulinum is gram-positive(+) in young cultures less than how many hours?
Less than 18 hours old
True or False
C. botulinum is motile by the presence of peritrichous flagella, and possesses subterminal and oval bulging spores
It is also NON-CAPSULATED
True
Identify the agar of C. botulinum
produces large, irregular, and semitransparent colonies
“Irregular fimbriated” border
Blood agar
What sugar does C. botulinum ferment?
Glucose
What enzyme is produced by the formation of iridescent film on C. botulinum colonies grown on EGG YOLK AGAR?
Lipase
How many types of C. botulinum are there on the basis of the antigenic specificities of their toxins?
7 types (A to G)
It is the major virulence factor of C. botulinum
Botulinum toxin (exotoxin)
The botulinum toxin is inactivated for how many minutes?
Cooking at 80C:
Boiling at 100C:
Cooking: 30-40 minutes
Boiling: 10 minutes
Botulinum toxin consists of two subunits A and B, what is their function?
Subunit A: light chain, a neurotoxin
Subunit B: heavy chain, prevents the neurotoxin(chain A) from being inactivated by stomach acid
It is the most potent NATURALLY occurring toxin known to mankind
Botulinum toxin
Lethal does of botulinum toxin in humans?
1-2g
All toxins of C. botulinum are “neurotoxins” except for?
C2
The neurotoxin of C. botulinum acts specifically on cholinergic nerves. It acts by preventing the release of a neurotransmitter, which is?
Acetylcholine
What are the 2 most potent toxins of C. botulinum?
Toxins A and B
What toxins of C. botulinum appears to be mediated by bacteriophages?
Types C and D
It is a type of botulism caused by toxins produced by C. botulinum present in the intestine
Infant botulism
It is a type of botulism caused by toxins produced in a C. botulinum contaminated wound
Wound botulism
A type of botulism where food poisoning occurs on ingestion of “preformed” toxins in food contaminated with C. botulinum
Death is due to respiratory paralysis and occurs in 1-7 days after onset of the disease
Food-borne botulism
It is a type of botulism caused by neurotoxins produced in vivo by C. botulinum that have colonized the gastrointestinal tract of the infants
Infant botulism
A type of botulism from heavy contamination of wounds with soil or water containing C. botulinum spores
Incubation period: 4-14 days
Wound botulism
True or False
Wound botulism is similar to Food-borne botulism except that the incubation period is longer
True
What type of botulinum cause avian and nonhuman mammalian disease?
Types C and D
True or False
Food-borne botulism is more common than infant botulism
False, Infant botulism is more common
Food-borne botulism is caused by what types?
Types A, B, and F
Wound botulism is very rare and is caused by what type of strain?
Type A
Infant botulism occurs following ingestion of C. botulinum spores present in infant food such as?
Honey
Identify the type of botulinum based on the specimen type:
Wound pus and exudates
Wound botulism
Identify the type of botulinum based on the specimen type:
Food by culture
Toxin in food or feces
Food-borne botulism
Identify the type of botulinum based on the specimen type:
Isolation of bacilli and detection of botulinum toxin in feces of the patient
Infant botulism
It was first described in 1935 from the feces of healthy newborns and was initially not thought to be a pathogen
Clostridium difficile
Identify the bacteria:
Long slender
Gram-positive
Anaerobic
Large, oval, and terminal spores
Non-hemolytic
Saccharolytic
Mild proteolytic
Clostridium difficile
It is the causative agent of antibiotic-associated diarrhea and colitis
C. difficile
What are the 2 antigenically distinct toxin of C. difficile?
Toxin A - enterotoxin
Toxin B - cytotoxin
It is a test that has been employed to detect the presence of “Glutamate Dehydrogenase”, produced by C. difficile, for the diagnosis of C. difficile diarrhea
Latex agglutination test
Identify the bacteria:
Normal flora in skin, URT, and Urogenital tract
Gram-positive
Aerobic or Facultative anaerobe
Non-motile
Non-spore forming
Club-shaped, irregular-shaped, v-shaped arrangements in normal growth
Believed to be “mainly contaminants”
Corynebacterium spp.
Is corynebacteria catalase positive or negative?
Catalase-positive
In Gram stain, it shows bacteria in short chains or clumps resembling “CHINESE LETTERS”
Corynebacterium
A bacteria from the greek word, koryne, meaning club, and bacterion, meaning little rod
Corynebacteria
It is the most widely studied species of Corynebacteria and is the causal agent of “Diphtheria”
Corynebacterium diphtheriae
Non-diphtherial corynebacteria are collectively referred to as?
Diphtheroids
It is an acute respiratory tract illness characterized by sore throat, low-grade fever, and an adherent membrane on the tonsils, pharynx, and nose
Diphtheria
It is a Gram-positive bacillus showing maximum “pleomorphism” on Gram-staining
Palisades appearance or V and L formation
C. diphtheria
This pattern formation of C. diphtheria is caused by the incomplete separation of the daughter cells during division when the organism is grown on nutritionally inadequate media, such as “Coagulated Egg Medium” or “Loeffler’s Coagulated Serum”
Chinese letter pattern or Cuneiform Arrangement
C. diphtheria have 2-3 granules at the swollen ends, which gives “reddish purple color” when stained with?
Loeffler alkaline methylene blue
Granules of C. diphtheria are also known as?
Babes-Ernst granules/ Metachromatic granules/
Volutin Granules
Granules of C. diphtheria are the accumulation of polymerized ________, which are responsible for the “BEADED” appearance of the bacteria
Phosphates
3 special stains used for granule demonstration of C. diphtheria
Albert stain
Neisser stain
Ponder stain
Identify the culture media for C. diphtheria
Enriched medium
Characteristic morphology is best seen here
Produces a “luxuriant growth” in 4-6 hours at 37C
Initial incubation: (White, circular, opaque colony)
Prolonged incubation: (Large, Yellow Tint)
Loeffler’s serum slope
2 examples of selective media used for diphtheria culture
Macleod’s or Hoyle’s tellurite blood agar media
Concentration of tellurite present in the media that inhibits growth of other contaminant bacteria
0.04%
Identify the culture media for C. diphtheria
Gray or Black colored colonies
48 hours of incubation
Tellurite agar
C. diphtheria reduces tellurite to ___________, which is incorporated in the colonies that gives a “Gray” or “Black” color
Metallic tellurium
3 distinct biotypes of C. diphtheria based on colony morphologies on “CYSTEINE-TELLURITE AGAR”
Mitis
Intermedius
Gravis
Identify the C. diphtheria biotype (mitis, intermedius, gravis)
Small, round
Convex
Black
Mitis
Identify the C. diphtheria biotype (mitis, intermedius, gravis)
Small, Flat
Gray
Intermedius
Identify the C. diphtheria biotype (mitis, intermedius, gravis)
Large, Irregular
Gray
Gravis
Identify the C. diphtheria biotype
Daisy head colony
Uniform staining
Malt surface
Brittle consistency
Gravis
Identify the C. diphtheria biotype
Frog’s egg colony
Irregular staining
Shining surface
Weak buttery consistency
Intermedius
Identify the C. diphtheria biotype
Poached egg colony
Irregular staining
Glossy surface
Buttery consistency
Mitis
Only biotype of C. diphtheria that is not a starch fermenter
Intermedius
What sugars does C. diphtheria ferment?
Glucose
Galactose
Maltose
Dextrin
What is always used for testing fermentation of sugars for C. diphtheria?
Hiss’s serum water
Which sugars are not fermented by C. diphtheria?
Lactose
Mannitol
Sucrose
True or False
Diphtheria bacilli are readily killed by heating at 58C for 10 minutes and at 100C for 1 minute
True
A type of bacilli that is destroyed by the usual strengths of antiseptics
C. diphtheria
Diphtheria toxin is produced only by strains of C. diphtheria that are lysogenized with bacteriophages that contain the structural gene (________) for the toxin molecule(________)
Structural gene: Tox gene
Toxin molecule: Tox1 strains
How can iron influence toxin production in diphtheria?
When DNA of the phage becomes integrated into the genetic material of C. diphtheriae, the bacteria develop the capability of producing the polypeptide toxin. The gene for toxin production occurs on the chromosome of the prophage, but a bacterial repressor protein controls the expression of this gene. The repressor is activated by iron, and it is in this way that iron influences toxin production.
Identify the bacteria:
Causes nosocomial infections
Pyrazidamidase positive
Produces infections after prosthetic device implants
Resistant to most antimicrobial agents
Corynebacterium jeikeium
Identify the bacteria:
Causes UTI
Slow grower
Rapid urease producer
Corynebacterium urealyticum
Differential Tests for Corynebacterium Spp. (Identify)
CTBA Halo: +
Esculin Hydrolysis: -
Gelatinase: -
Nitrate: +
Urease: -
C. diphtheria
Differential Tests for Corynebacterium Spp. (Identify)
CTBA Halo: -
Esculin Hydrolysis: -
Gelatinase: -
Nitrate: -
Urease: -
All are negative
C. jeikeium
Differential Tests for Corynebacterium Spp. (Identify)
CTBA Halo: +
Esculin Hydrolysis: -
Gelatinase: +
Nitrate: -
Urease: +
C. ulcerans
Differential Tests for Corynebacterium Spp. (Identify)
CTBA Halo: +
Esculin Hydrolysis: -
Gelatinase: -
Nitrate: -/+
Urease: +
C. pseudotuberculosis
Differential Tests for Corynebacterium Spp. (Identify)
CTBA Halo: -
Esculin Hydrolysis: -
Gelatinase: -
Nitrate: -
Urease: +
Only positive for urease (Hint: it has urea in the name)
C. urealyticum
Differential Tests for Corynebacterium Spp. (Identify)
CTBA Halo: -
Esculin Hydrolysis: -
Gelatinase: -
Nitrate: +
Urease: +
C. pseudodipthericum
Identify the bacteria
Gram-positive rod
Resembles corynebacteria and streptococci
Resemble diphtheroids in stained smears
Beta-hemolytic colonies on blood agar
Catalase-positive
Can grow slowly in cold temperatures (1C)
Listeria monocytogenes
Tumbling motility in fluid media at 25C that distinguishes them from corynebacteria
Listeria monocytogenes
3 serotypes of Listeria that are majority in human cases
1/2a
1/2b
4b
What major component of the cell wall of listeria differentiates the serotypes?
Techoic acid composition
What serotype of Listeria accounts for almost all “food-borne” listeriosis outbreaks
There are BOTH galactose and glucose substituents in its N-acetylglucosamine
4b
A gram-positive bacilli that can be transmitted transplacentally to the fetus
Listeria monocytogenes
It is a surface protein of Listeria that causes a local reorganization of the cytoskeleton of the cell and stimulates its own entry in a membrane-bound vacuole.
Internalin
In Listeria monocytogenes, the invading bacteria rapidly escape into the host cell cytosol by elaborating this cytotoxin similar to streptolysin O
Listeriolysin O (LLO)
Identify the bacteria:
Slender, straight, slightly curved
Gram-positive bacillus
Non-motile
Non-spore forming
Non-capsulated
Catalase-negative (-)
H2S negative
Negative for IMVC
Natural parasite of swines, mice, rabbit, turkeys, and etc
Erysipelothrix rhusiopathiae
Identify the media used for E. rhusiopathiae:
24-48 hrs incubation
Convex and Translucent colony
Variable zone of “a-hemolysis”
Blood agar
On tellurite agar, E. rhusiopathiae produces what color of colonies?
Black colonies
It is the pathogenic agent causing pharyngitis and cutaneous infections among US service members and indigenous people in South Pacific
Arcanobacterium haemolyticum
It was named as the ‘Secretive Bacteria”
Arcanobacterium
What is the major human pathogen in the Arcanobacterium group?
A. haemolyticum
What does A. haemolyticum lack which would indicate that it is a non-streptococcal origin even though it has a beta-hemolytic effect?
Lancefield group antigen
An arcanobacterium spp. which is an animal pathogen and as a major cause of “MASTITIS” in lovestock
Arcanobacterium pyogenes
An arcanobacterium spp. which is non-branching on Gram-stain and have rare occurrences described causing:
-bacteremia
-musculoskeletal
-eye infections
Arcanobacterium bernardiae
Identify the bacteria:
Gram-positive
Non-acid fast
Composed of “coccoid cells”
Non-spore forming
Non-encapsulated
Kurthia gibsonii
Kurthia zopfii
Identify the bacteria:
- Yeast Nutrient Agar
- rhizoid colonies
- loops and whorls of chains of rods at the edge
- “Medusa head” appearance similar to B. anthracis - Nutrient Gelatin Slant
- “Bird’s Feather” appearance
Kurthia gibsonii
Kurthia zopfii
True or False
K. gibsonii and K. zopfii are:
Catalase-positive
Oxidase-negative
True
True or False
Kurthia species are aerobic and are non-fermenters
True
This species have been implicated as “opportunistic” pathogens reported to cause ENDOCARDITIS
Kurthia spp.
Identify the bacteria:
Gram-positive
Catalase-positive
Non-motile bacilli
Considered to be transitional forms between bacteria and fungi
Actinomycetes
Bacteria that possess cell walls containing muramic acid but are also similar to fungi that form delicate filaments called “Hyphae” similar to the hyphal form in fungi
Actinomycetes
Aerobic actinomycetes can be classified into two groups which are?
Actinomycetes with Mycolic acid
Actinomycetes without Mycolic acid
Actinomycetes with Mycolic Acid includes 3 families which are? (CoMyNo)
Corynebacteriaceae
Mycobacteriaceae
Nocardiaceae
The family Nocardiaceae consists of 4 genera which are? (NoRhoTsuGo)
Nocardia
Rhodococcus
Tsukamurella
Gordonia
Actinomycetes without Mycolic Acid includes opportunistic pathogens such as? (TT AND SOR)
Tropheryma
Thermophilic actinomycetes
Actinomadura
Nocardiopsis
Dermatophilus
Streptomyces
Oerskovia
Rothia
3 Thermophilic actinomycetes
Saccharopolyspora
Saccharomonospora
Thermoactinomyces
Most common actinomyces causing human infection
Actinomyces Israeli
Identify the bacteria:
Gram-positive
Non-motile
Non-sporing
Non-acid fast bacilli
Grow in filaments
Separate into “bacillary and coccoid” filaments
Actinomyces israeli
Identify the culture for A. israeli:
Enriched medium used frequently for Actinomyces
“Molar-tooth appearance”
Brain Heart Infusion (BHI) agar
Heart infusion agar supplemented with 5% defibrinated rabbit, sheep, or horse blood
Identify the culture media used for A. israeli:
Heart infusion blood and thioglycolate blood supplemented with 0.1-0.2% sterile rabbit serum
Liquid media
These bacteria are present as normal flora of the “ORAL CAVITY” and also in the lower GIT and female genital tract of human hosts
Actinomyces spp.
It is a subacute and chronic bacterial infection characterized by contiguous spread and suppurative and granulomatous inflammation
Actinomycosis
Actinomycosis is associated with the formation of multiple abscesses and development of sinus tracts discharging “WHITE TO YELLOWISH GRANULES” known as?
Sulphur granules
What is the color of Sulphur granules?
White to Yellowish
Sulfur granules of Actinomyces are crushed between two slides and are stained by ______ or _______ staining method using 1% sulfuric acid for decolorization
Gram staining or Ziehl-Neelsen staining method
Stained smears on Microscopic examination showing a “Sun-ray” appearance or “Ray of sun” appearance
Actinomyces
Identify the bacteria:
Gram-positive
Rod-shaped
Shows “True branching”
Nocardia spp.
Nocardia species most common in human infections and are “WEAKLY ACID FAST”
Nocardia asteroides
Nocardia brasiliensis
Colonies initially have:
Dry, wrinkled
“chalk-like” appearance
Adherent to the agar
White to Orange pigment
Nocardia spp
2 forms of Nocardiosis
Pulmonary and Cutaneous
Developed colonies of Nocardia give off the aroma of?
Wet dirt aroma
Identify the bacteria:
Gram-positive
Strict aerobic actinomycetes
Cell wall contains mycolic acid and Tuberculostearic acid
Acid fast bacteria
Rhodococcus
It is formerly known as Corynebacterium equi
Rhodococcus equi
The most important human pathogen of Rhodococcus
Rhodococcus equi
A pleomorphic gram-positive coccobacillus showing some degrees of branching and is weakly acid fast
Rhodococcus equi
On blood agar, on prolonged incubation at room temperature, the bacteria produce colonies resembling Klebsiella, with production of “PINK PIGMENTS”
Rhodococcus equi
It is an intracellular pathogen, which multiplies in macrophages
Rhodococcus equi
True or False
Rhodococci are difficult to treat because they are resistant to penicillin and cephalosporins
True
True or False
Treatment with:
Vancomycin or Combination of erythromycin and rifampicin is effective for Rhodococci
True
These 2 Genera were earlier classified with Rhodococcus, because of their morphological similarities to it
Gordonia
Tsukamurella
Identify the bacteria:
Gram-positive
Aerobic of complex form
Form a “Threadlike net” called a mycelium that bears chains of spores at maturiy
Streptomyces
Streptomyces spp. that produce antibiotics
S. aureofaciens (chlortetracycline)
S. rimosis (oxytetracycline)
S. griseus (streptomycin)
S. erythraeus (erythromycin)
S. venezuelae (chloramphenicol)
It is one of the most common causes of actinomycotic mycetoma (maduramycosis or madura foot)
Actinomadura
Identify the bacteria:
Aerobic actinomycetes
Filamentous bacterium found in soil
Once believed to be a fungus
Actinomadura
The colony of this bacteria has a:
Glabrous
Waxy
Membranous or mucoid
Heaped and “folded” appearance
Red, pink, yellow, orange, white, or tan colony color
Actinomadura
What medium is used for Actinomadura that shows aerial hyphae on the surface following 2 weeks of incubation?
Lowenstein-Jensen medium
