Aerobic Gram Positive Bacilli Flashcards
Non-spore forming, Non-branching Gram positive bacilli
MNEMONIC: GLECAL
* Gardnerella vaginalis
* Listeria
* Erysipelothrix
* Corynebacterium
* Arcanobacterium
* Lactobacillus
Non-spore forming, Branching, Aerobic Actinomycetes
MNEMONIC: TANGRS
* Tsukamurella, or Tropheryma whipplei
* Aerobic actinomyces
* Nocardia
* Gordonia
* Rhodoccocus
* Streptomyces
Non-spore forming, Non-branching, Catalase positive (+) Bacilli
- Corynebacterium
- Rothia
- Listeria
Non-spore forming, Non-branching, Catalase negative (-) Bacilli
- Arcanobacterium and Trueperella
- Erysipelothrix rhusiopathiae
- Gardnerella vaginalis
- Lactobacillus
It is also known as “Kleb Loeffler’s Bacillus”
Corynebacterium spp.
Corynebacterium spp. are also known as _________.
Kleb Loeffler’s Bacillus
Gram stain reaction and morphology of Corynebacterium spp.
Slightly curved, gram positive (+) rods with no parallel sides, and slightly wider ends producing a “club shape” or “coryneform” appearance
Coryne means _______.
Club or club-shaped rods
An organism characterized by its “club-shape” or “coryneform” appearance.
Corynebacterium spp.
Corynebacterium spp. are also called as _________.
Diphtheroids
_______ are also called as Diphtheroids.
Corynebacterium spp.
Diphtheroids mean _________.
Diphtheria-like
Corynebacterium spp. can be divided into _________ species.
Lipophilic and Non-lipophilic
These are fastidious organisms that grow slowly on standard culture media, and must be incubated for at least 48 hours.
Lipophilic
To enhance the growth of Lipophilic species, _______ must be added in the culture media.
Lipids
Lipophilic species should be incubated for at least ________.
48 hours
Virulence factors associated with Corynebacterium spp.
Diphtheria Toxin
TRUE OR FALSE.
Diphtheria toxin is a heat-stable toxin.
False
Answer: heat-labile
Diphtheria toxin is produced by __________.
C. diphtheriae strains that are infected with lysogenic β-phage
Diphtheria toxin is produced by strains of C. diphtheriae infected with ______.
lysogenic β-phage
__________ carries the gene “tox” for diphtheria toxin.
C. diphtheriae strains that are infected with lysogenic β-phage
C. diphtheriae strains that are infected with lysogenic β-phage carries the gene _______ for diphtheria toxin.
tox
Diphtheria toxin is a protein of _______ daltons (Da).
62,000 Da
Diphtheria toxin is composed of _____ fragments.
2
Which fragment of Diphtheria toxin functions in cytotoxicity?
Fragment A
How is Fragement A of Diphtheria toxin virulent?
It functions in cytotoxicity
Which fragment of Diphtheria toxin functions in binding to receptors and mediates the entry of the other fragment?
Fragment B
How is Fragment B of Diphtheria toxin virulent?
It binds to receptors, and mediates the entry of Fragment A into the cytoplasm
Infections caused by Corynebacterium diphtheriae
- Respiratory diphtheria
- Cutaneous diphtheria
Which organism often stains irregularly when stained with methylene blue?
Corynebacterium spp.
Corynebacterium spp. often stained irregularly when stained with ________.
methylene blue
Metachromatic areas of Corynebacterium diphtheriae are called __________.
Babes-Ernst Granules
Babes-Ernst Granules represent the _________.
accumulation of polymerizes polyphosphates
Babes-Ernst Granules is a characteristic found in ________.
Corynebacterium diphtheriae
Aerotolerance of Corynebacterium spp.
Facultative anaerobe
Optimal growth temperature of Corynebacterium spp.
37 C
Corynebacterium spp. can multiply within the temperature range _______.
15 - 40 C
Can Corynebacterium spp. grow on nutrient agar?
Yes
How can Corynebacterium spp. grow better?
By using a medium containing blood or serum such as:
* Loeffler’s serum
* Pai agar
Corynebacterium spp. produces a ______ of hemolysis.
very small zone of β-hemolysis
Which culture media is often used for Corynebacterium diphtheriae?
Cystine-Tellurite Blood Agar (CTBA)
What kind of medium is CTBA according to function?
Selective and Differential
Which inhibitor is present in CTBA?
Potassium tellurite
What does potassium tellurite do in CTBA?
Inhibits the growth of non-coryneform bacteria
It is a modification of the Tinsdale medium
Cystine-Tellurite Blood Agar (CTBA)
Cystine-Tellurite Blood Agar (CTBA) is a modification of ________.
Tinsdale Medium
Tinsdale medium components
- Sheep RBCs
- Bovine serum
- Cysteine
- Potassium tellurite
Describe the colonies of Corynebacterium diphtheriae when grown in CTBA
Black or Brown colonies
The black or brown colonies formed in CTBA is due to the _______.
reduction of tellurite
Which organisms form a brown halo when cultured in CTBA?
- Corynebacterium diphtheriae
- Corynebacterium ulcerans
- Corynebacterium pseudotuberculosis
The brown halo formed by some organisms in CTBA is due to the ___________.
result of cystinase activity
Catalase reaction of Corynebacterium spp.
Positive (+)
Are Corynebacterium spp. motile?
No
Urease reaction of Corynebacterium diphtheriae
Negative (-)
Which carbohydrates does Corynebacterium diphtheriae ferment?
Glucose and Maltose
Corynebacterium diphtheriae can produce ______ but not ______.
acid, not gas
Nitrate to nitrite reduction result of Corynebacterium diphtheriae
Positive (+)
Test for toxigenity of Corynebacterium spp.
In-Vitro Test
In-vitro test is also known as ________.
ELEK Test
In-vitro test is a type of ________ test.
immunodiffusion
Treatment for Corynebacterium spp.
- Administration of Antitoxins (antibodies)
- Penicillin
- Erythromycin (for penicillin sensitive patients)
Drug of Choice for Corynebacterium spp.
Penicillin
______ can be used as a treatment against Corynebacterium spp. for patients who are penicillin sensitive.
Erythromycin
Which organism is characterized by its flat and dry, matte or waxy appearance, and is non-lipophilic?
Corynebacterium amycolatum
Describe the appearance of Corynebacterium amycolatum
Flat and dry, matte or waxy
Is Corynebacterium amycolatum lipophilic?
No
Corynebacterium amycolatum is resistant to ________.
MNEMONIC: BFAMC
* β-lactams
* Fluoroquinolones
* Aminoglycosides
* Macrolides
* Clindamycin
Corynebacterium amycolatum is ______ to various antimicrobial agents such as β-lactams, Fluoroquinolones, Aminoglycosides, Macrolides, and Clindamycin
resistant
Corynebacterium amycolatum is a normal microbiota of the _______.
skin
Which organism is named after Johnson and Kaye?
Corynebacterium jeikeium
Corynebacterium jeikeium is named after _________.
Johnson and Kaye
These are the first individuals who linked C. jeikeium to human infections.
Johnson and Kaye
Johnson and Kaye contribution
The first individuals who linked C. jeikeium to human infections
Corynebacterium jeikeium is a normal microbiota of the _____.
skin
_____ is the most common cause of Corynebacterium associated prosthetic valve endocarditis in adults.
Corynebacterium jeikeium
Corynebacterium jeikeium is the most common cause of ________.
Corynebacterium associated Prosthetic Valve Endocarditis
Other than prosthetic valve endocarditis, which infections can be caused by C. jeikeium?
- Septicemia
- Meningitis
- Prosthetic joint infections
- Rash
- Subcutaneous nodules
Is Corynebacterium jeikeium lipophilic?
Yes
Aerotolerance of Corynebacterium jeikeium
Strict aerobe
Is Corynebacterium jeikeium hemolytic?
No
Urease reaction of Corynebacterium jeikeium
Negative (-)
Nitrate reduction reaction of Corynebacterium jeikeium
Negative (-)
Drug of Choice for Corynebacterium jeikeium
Vancomycin
Which organism does not show the characteristic pleomorphic morphology?
Corynebacterium pseudodiphtheriticum
Corynebacterium pseudodiphtheriticum is not ______ in terms of morphology.
pleomorphic
Corynebacterium pseudodiphtheriticum often appears in _______.
palisades
Corynebacterium pseudodiphtheriticum is a normal flora of the ______.
nasopharynx
_______ can grow on standard laboratory media.
Corynebacterium pseudodiphtheriticum
Corynebacterium pseudodiphtheriticum can grow on __________.
standard laboratory media
Urease reaction of Corynebacterium pseudodiphtheriticum
Positive (+)
Nitrate reduction reaction of Corynebacterium pseudodiphtheriticum
Positive (+)
The respiratory infection produced by Corynebacterium pseudodiphtheriticum can mimic __________.
respiratory diphtheria
The respiratory infection produced by _______ can mimic respiratory diphtheria.
Corynebacterium pseudodiphtheriticum
Which Corynebacterium sp. is a veterinary pathogen?
- Corynebacterium pseudotuberculosis
- Corynebacterium ulcerans
Corynebacterium pseudotuberculosis is a ______ pathogen.
veterinary
Corynebacterium pseudotuberculosis is the causative agent of __________.
Granulomatous Lymphadenitis
________ is the causative agent of Granulomatous Lymphadenitis.
Corynebacterium pseudotuberculosis
Corynebacterium pseudotuberculosis produces how many types of toxins?
2
2 types of toxins produced by Corynebacterium pseudotuberculosis
- Dermonecrotic toxin
- Diphtheria toxin
It causes death of various cell types
Dermonecrotic toxin
What does dermonecrotic toxin do?
Cause death of various cell types
Urease reaction of Corynebacterium pseudotuberculosis
Positive (+)
Corynebacterium pseudotuberculosis, when cultured in ______ produces small, yellowish-white colonies.
SBA
Colonial appearance of Corynebacterium pseudotuberculosis in SBA
Small, yellowish-white colonies
Which organism exhibits small, yellowish-white colonies on SBA?
Corynebacterium pseudotuberculosis
Is Corynebacterium striatum lipophiilic?
No
Is Corynebacterium striatum pleomorphic?
Yes
Which organism produces small, shiny, colonies after 24 hours of incubation?
Corynebacterium striatum
Colonial appearance of Corynebacterium striatum
Small, shiny, convex colonies after 24 hours
Corynebacterium striatum is a normal flora of the _______.
skin
Corynebacterium striatum is associated with _______ infections.
nosocomial
Corynebacterium striatum is resistant to ________.
- β-lactams
- Fluoroquinolones
- Macrolides
- Penicillin
_________ is resistant to β-lactams, Fluoroquinolones, Macrolides, Penicillin
Corynebacterium striatum
Corynebacterium striatum is ________ to β-lactams, Fluoroquinolones, Macrolides, Penicillin
resistant
Corynebacterium striatum is susceptible to ________.
Vancomycin
Corynebacterium ulcerans grows well on _______.
SBA
Corynebacterium ulcerans exhibits a ________ of hemolysis on SBA.
Narrow zone of β-hemolysis
Which Corynebacterium sp. grows well on SBA and produces a narrow zone of β-hemolysis?
Corynebacterium ulcerans
Nitrate reduction reaction of Corynebacterium ulcerans
Negative (-)
Which characteristic differentiates C. ulcerans from C. diphtheriae?
(-) nitrate reduction
The nitrate reduction reaction of C. ulcerans differentiates it from ________.
Corynebacterium diphtheriae
Colonial apperance of Corynebacterium ulcerans
Grayish-white
Urease reaction of Corynebacterium ulcerans
Positive (+)
Corynebacterium ulcerans is a ______ pathogen.
veterinary
The causative agent of mastitis
Corynebacterium ulcerans
Corynebacterium ulcerans is the causative agent of _______.
Mastitis
Is Corynebacterium urealyticum lipophilic?
Yes
Aerotolerance of Corynebacterium urealyticum
Strict aerobe
Corynebacterium urealyticum is most commonly associated with _____.
UTIs
__________ is most commonly associated with UTIs.
Corynebacterium urealyticum
Colonial apperance of Corynebacterium urealyticum
Pinpoint, non-hemolytic, white colonies with coryneform apperance
Which organism exhibits pinpoint, non-hemolytic, white with coryneform appearance of colonies?
Corynebacterium urealyticum
Nitrate reduction reaction of Corynebacterium urealyticum
Negative (-)
Catalase reaction of Corynebacterium urealyticum
Positive (+)
Urease reaction of Corynebacterium urealyticum
Positive (+)
Drug of Choice for Corynebacterium urealyticum
Vancomycin
Gram stain reaction and morphology of Rothia spp.
Gram positive (+) cocci that can appear rod-shaped
Which organism is a gram positive (+) cocci that can appear rod-shaped?
Rothia spp.
Rothia spp. belong to the Family ________.
Micrococcaceae
Nitrate reaction of Rothia spp.
Positive (+)
Esculin hydrolysis reaction of Rothia spp.
Positive (+)
Urease reaction of Rothia spp.
Negative (-)
Are Rothia spp. motile?
No
Approximately 2/3 of Rothia spp. isolates are _________.
Catalase positive (+)
Approximately ______ of Rothia spp. are Catalase (+)
2/3
There are how many species of Rothia?
6
2 significant species of Rothia
- Rothia mucillaginosa
- Rothia dentocariosa
Which Rothia sp. is linked to bacteria, endocarditis, and pneumonia?
Rothia mucillaginosa
Rothia mucillaginosa is linked to _________.
Bacteremia, endocarditis, and pneumonia
Which Rothia sp. is a normal flora of the oropharynx and is found in the saliva?
Rothia dentocariosa
Rothia dentocariosa is a ________.
normal flora of the oropharnyx, and is found in the saliva
Microscopic characteristics of Rothia spp.
- Resembles coryneform bacilli
- Produces coccoid cells
Which microscopic characteristic of Rothia differentiates it from Actinomycetes?
Production of coccoid cells
Listeria monocytogenes is the causative agent of _________.
Listeriosis
________ is the causative agent of Listeriosis.
Listeria monocytogenes
It is an uncommon, but serious infection primarily of neonates, pregnant women, older patients, and immunocompromised hosts.
Listeriosis
Where can Listeriosis be recovered?
soil, water, and animal products
Virulence factors of Listeria monocytogenes
- Hemolysin (Listeriolysin O)
- Catalase
- Superoxide dismutase
- Phospholipase C
- Surface protein (p60)
Which virulence factor of L. monocytogenes damages the phagosome membrane, and prevents killing of organism by macrophages?
Hemolysin (Listeriolysin O)
How is hemolysin (listeriolysin O) virulent?
It damages the phagosome membrane, and prevents killing of the organism by macrophages
Which virulence factor of L. monocytogenes inhibits phagocytosis?
Surface protein (p60)
How is surface protein (p60) virulent?
It inhibits phagocytosis
Which stage of pregnancy can Listeriosis be identified?
Third trimester
How can Listeriosis affect pregnant women?
It can lead to spontaneous abortion and still-born neonates
Listeriosis in newborns is similar to the newborn infection of which bacterium?
Streptococcus agalactiae
Two Kinds of Listeriosis in Newborns
- Early-onset Listeriosis
- Late-onset Listeriosis
Which Kind of Listeriosis in Newborns?
It causes illness shortly after birth (can form intrauterine infection, sepsis, amniotic fluid infection)
Early-onset Listeriosis
What can be the possible effects of Early-onset Listeriosis?
- Intrauterine infection
- Sepsis
- Infection within amniotic fluid
Which Kind of Listeriosis in Newborns?
The disease can occur from several days to weeks
Late-onset Listeriosis
What can be the possible effects of Late-onset Listeriosis?
Meningitis
Microscopy of Listeria monocytogenes
Gram positive (+) coccobacilli arranged in singly, short chains, or palisades
Culture Medium of Choice for Listeria monocytogenes
McBride Medium
Listeria monocytogenes grows well on ________.
SBA, CAP, Nutrient Agar, BHI, and Thioglycolate Broth
Which organism is typically cultured in McBride Medium?
Listeria monocytogenes
Which organism is typically cultured in Cystine-Tellurite Blood Agar (CTBA)?
Corynebacterium spp.
Listeria monocytogenes prefers a __________.
slightly increased CO2
________ prefers a slightly increased CO2.
Listeria monocytogenes
Colonial apperance of Listeria monocytogenes
Small, round, smooth, and transluscent colonies surrounded by a narrow zone of β-hemolysis (can be seen after the colony has been removed)
Which organism exhibits the colonial characteristic of small, round, smooth, transluscent colonies surrounded by a narrow zone of β-hemolysis?
Listeria monocytogenes
The hemolytic pattern produced by Listeria monocytogenes can only be visualized _________.
if the colony is removed
Optimum growth temperature of Listeria monocytogenes
30 - 35 C
But growth occurs over a wide range of 0.5 - 45 C
A technique which is used to isolate the organism from polymicrobial clinical specimens.
Cold Enrichment
Cold Enrichment is a technique used in the isolation of _________.
Listeria monocytogenes
Listeria monocytogenes can survive refrigerator temperature or 4 C under the condition of __________.
low pH and high salt concentration
Hippurate hydrolysis reaction of Listeria monocytogenes
Positive (+)
Which organism is (+) for Hippurate Hydrolysis test similar to S. agalactiae?
Listeria monocytogenes
Catalase reaction of Listeria monocytogenes
Positive (+)
Bile esculin hydrolysis reaction of Listeria monocytogenes
Positive (+)
Is Listeria monocytogenes motile?
Yes, at room temperature
Describe the motility of Listeria monocytogenes in wet mount preparations
Tumbling Motility (end-over-end motility)
It is an organism characterized by it “tumbling motility (end-over-end motility)” in wet mount preparations
Listeria monocytogenes
In motility medium, Listeria monocytogenes produces _________ pattern.
Umbrella
_______ produces an “umbrella” pattern in motility medium.
Listeria monocytogenes
How can we see the “umbrella” pattern made by Listeria monocytogenes?
By incubating the organism at 22 - 25 C (room temperature)
CAMP reaction of Listeria monocytogenes
Positive (+)
A pleomorphic rod that has a tendency to form long filaments.
Erysipelothrix rhusiopathiae
Morphology of Erysipelothrix rhusiopathiae
Pleomorphic rod that tends to form long filaments
The usual route of infection of Erysipelothrix rhusiopathiae is through __________.
cuts or scratches on the skin
There are how many species in the genus Erysipelothrix?
3
What are the species under Erysipelothrix?
- Erysipelothrix rhusiopathiae
- Erysipelothrix tonsillarum
- Erysipelothrix inopinata
Which Erysipelothrix sp. is the only species that causes disease in humans?
Erysipelothrix rhusiopathiae
Erysipelothrix rhusiopathiae is the causative agent of _________.
Erysipeloid
________ is the causative agent of Erysipeloid.
Erysipelothrix rhusiopathiae
An infection caused by Erysipelothrix rhusiopathiae, which is associated with endocarditis.
Septicemia
Infections caused by Erysipelothrix rhusiopathiae
- Erysipeloid
- Septicemia
- Diffused cutaneous infections
Microscopy of Erysipelothrix rhusiopathiae
- Thin rod-shaped, gram positive (+) organism that can form long filaments.
- Arranged in singly, short chains, or in a “V” shape
- Decolorizes easily, so it may appear gram variable
_______ decolorizes easily, so it may appear as gram variable.
Erysipelothrix rhusiopathiae
Erysipelothrix rhusiopathiae grows well on _________.
SBA and CAP
Colonial appearance of Erysipelothrix rhusiopathiae
Non-hemolytic and pinpoint
Colonial appearance of Erysipelothrix rhusiopathiae after 48 hours
- Small, smooth, transparent, glistening, convex colonies with entire edges
- Large, rough colonies with a flat and matte surface, curled structure, and irregular edges
Hemolytic pattern of Erysipelothrix rhusiopathiae
α-hemolysis
Erysipeloid is also known as _______.
Whale finger or Seal finger
Catalase reaction of Erysipelothrix rhusiopathiae
Negative (-)
Is Erysipelothrix rhusiopathiae motile?
No
Aerotolerance of Erysipelothrix rhusiopathiae
Aerobic or Facultative Anaerobic
H2S production of Erysipelothrix rhusiopathiae
Positive (+)
Voges-Proskauer result of Erysipelothrix rhusiopathiae
Negative (-)
Which pattern does Erysipelothrix rhusiopathiae produce in gelatin stab culture?
Test tube brush-like
_____ produces a “test tube brush-like” pattern at 22 C in gelatin stab culture.
Erysipelothrix rhusiopathiae
Erysipelothrix rhusiopathiae produces a “test tube brush-like” pattern at what temperature in gelatin stab culture?
22 C
Erysipelothrix rhusiopathiae produces a “test tube brush-like” pattern at 22 C in which culture media?
gelatin stab culture
Arcanobacterium haemolyticum is formerly known as ___________.
Corynebacterium haemolyticum
________ is formerly known as Corynebacterium haemolyticum
Arcanobacterium haemolyticum
Trueperella pyogenes is previously known as _________.
Arcanobacterium pyogenes
__________ is previously known as Arcanobacterium pyogenes
Trueperella pyogenes
An animal pathogen that is best known for causing infections in cattles.
Trueperella pyogenes
Trueperella pyogenes is an ______ pathogen.
animal
Trueperella pyogenes causes infections in _______.
cattles
Trueperella bernardiae is previously known as _________.
Arcanobacterium bernardiae
_______ is previously known as Arcanobacterium bernardiae
Trueperella bernardiae
Colonial appearance of Arcanobacterium haemolyticum on BAP
Small colonies surrounded by a narrow zone of β-hemolysis after 24 to 48 hours of incubation
A _______ is observed in A. haemolyticum when the colony is scraped.
black opaque dot
The distinct black opaque dot feature is seen in ________.
Arcanobacterium haemolyticum
How can we see the black opaque dot exhibited by Arcanobacterium haemolyticum?
By scraping the colonies
________ is capable of pitting the agar.
Arcanobacterium haemolyticum
Lipase reaction of Arcanobacterium haemolyticum
Positive (+)
Lecithinase reaction of Arcanobacterium haemolyticum
Positive (+)
Can Arcanobacterium haemolyticum exhibit a reverse CAMP reaction?
Yes
Gram stain reaction and morphology of Gardnerella vaginalis
Short, pleomorphic, gram positive rods, or coccobacillus
Is Gardnerella vaginalis gram variable?
Yes
Gardnerella vaginalis is a normal flora of the __________.
urogenital tract
Gardnerella vaginalis is the causative agent of _______.
Bacterial Vaginosis
________ is the causative agent of Bacterial Vaginosis
Gardnerella vaginalis
Bacterial vaginosis results from _______.
reduction of Lactobacillus in the vagina
Bacterial vaginosis is characterized by _________.
- Malodorous discharge
- pH >4.5
Microscopy of Gardnerella vaginalis
Clue Cells
Large squamous epithelial cells with gram positive/variable bacilli
Gardnerella vaginalis
Morphology of clue cells
Large squamous epithelial cells that are gram (+) or variable bacilli
Clue cells are a characteristic of ___________.
Gardnerella vaginalis
The presence of _______ aids in the diagnosis of BV.
clue cells
Which is used for the diagnosis of Bacterial Vaginosis?
Amsel’s Clinical Criteria
Indications under Amsel’s Clinical Criteria
- Homogenous, thin, white discharge
- Clue cells
- pH >4.5
- Fishy odor before and after the addition of 10% potassium hydroxide (whiff test)
How is whiff test performed?
10% potassium hydroxide is added to the vaginal discharge to note its fishy odor
Gardnerella vaginalis grows best in ___________.
5-7% CO2 at 35-37 C
Colonial appearance of Gardnerella vaginalis on SBA
Pinpoint, non-hemolytic
Culture media of choice for Gardnerella vaginalis
Human Blood Bilayer Tween Agar (HBT)
Aerobic, branching, beaded, gram positive (+) bacilli
Nocardia spp.
Nocardia spp. gram stain and morphology
Aerobic, branching, beaded, gram positive (+) bacilli
Are Nocardia spp. acid-fast organisms?
Yes, they are partially acid-fast
The colonies and microscopic morphology of Nocardia spp. resemble _______.
fungi
The colonies and microscopic morphology of _____ resemble fungi.
Nocardia spp.
Virulence factors of Nocardia spp.
No identified virulence factors, but virulence has been associated with alterations in the cell wall:
* Superoxide dismutase and Catalase
* Iron-chelating compound called Nocobactin
How is the superoxide dismutase and catalase of Nocardia spp. virulent?
They provide resistance to oxidative killing by phagocytes
It is an iron-chelating compound found in Nocardia spp.
Nocobactin
Nocobactin is found in ________.
Nocardia spp.
Nocobactin is an _____ compound.
iron-chelating
Infections caused by Nocardia spp.
- Pulmonary Infection (confluent bronchopneumonia)
- Cutaneous infection (nocardiosis and actinomycotic mycetomas)
Describe the appearance of sputum when infected with bronchopneumonia
Thick and purulent
_______ is the most common frequent cause of cutaneous nocardiosis and actinomycotic mycetomas.
Nocardia brasiliensis
Nocardia brasiliensis is the most common frequent cause of ___________.
Cutaneous nocardiosis and Actinomycotic mycetomas
Describe the appearance of pus of the cutaneous infection caused by Nocardia spp.
Pigmented and contains yellow or orange sulfur granules
Microscopy of Nocardia spp.
Gram positive (+), beaded, branching filaments
Culture medium for Nocardia spp.
- Modified Thayer-Martin Agar
- Buffered Charcoal Yeast Extract Agar
Buffered Charcoal Yeast Extract Agar is a _______ medium.
non-selective
Colonial apperance of Nocardia spp.
- Chalky, matte, velvety, or powdery appearance and may be white, yellow, pink, orange, peach, tan, and gray
- Dry and crumbly appearance, similar to breadcrumbs
Actinomadura spp. is the causative agent of ______.
Mycetomas
________ is the causative agent of Mycetomas.
Actinomadura spp.
The microscopic and colonial morphology of Actinomadura spp. are very similar to those of ______.
Nocardia spp.
The microscopic and colonial morphology of ________ are very similar to those of Nocardia spp.
Actinomadura spp.
What differentiates Actinomadura spp. from Nocardia spp.?
Actinomadura spp. are cellobiose and xylose (+), while Nocardia spp. aren’t
Species under Actinomadura
- Actinomadura madurae
- Actinomadura pelletieri
These are primarily saprophytes found as soil inhabitants and resemble other aerobic actinomycetes with regard to morphology and the diseases they cause.
Streptomyces spp.
Streptomyces spp. are ______ found as soil inhabitants.
saprophytes
Streptomyces somaliensis is associated with ________.
Actinomycotic Mycetoma
____________ is associated with Actinomycotic Mycetoma.
Streptomyces somaliensis
Streptomyces anulatus is formerly known as ________.
Streptomyces griseus
_______ is formerly known as Streptomyces griseus
Streptomyces anulatus
Streptomyces anulatus has been increasingly isolated from many clinical specimens including ________.
sputum, wound, blood, brain
Catalase reaction of Gordonia spp.
Positive (+)
Are Gordonia spp. gram variable?
Yes
Are Gordonia spp. acid-fast?
Yes, partially
Are Gordonia spp. motile?
No
_____ grows with mycelial form that fragment into rod-shaped or coccoid elements.
Gordonia spp.
They are termed as “Nocardioform”
Gordonia spp.
Gordonia spp. are termed as ________.
Nocardioform
Why are Gordonia spp. termed as “nocardioform”?
Because they grow with mycelial forms that fragment into rod-shaped or coccoid elements
How are Gordonia spp. different from Mycobacteria spp.?
Due to their weak acid-fastness and absence of arylsulfatase
It is found in soil and causes respiratory tract infections in animals.
Rhodococcus equi
Rhodococcus equi is found in ______.
soil
Rhodococcus equi causes ______.
respiratory tract infections in animals
Human infections caused by _______ is rare.
Rhodococcus equi
Is Rhodococcus equi acid-fast?
Yes (or partially)
______ is the causative agent of Whipple Disease.
Tropheryma whipplei
Tropheryma whipplei is the causative agent of _________.
Whipple Disease
A rare bacterial disease which often affects the joints and digestive system.
Whipple Disease
Whipple disease is a rare bacterial disease which often affects the ______.
joints and digestive system
Tropheryma whipplei is a _______ pathogen.
facultative intracellular
When and how is Tropheryma whipplei identified?
1991, with the use of PCR from duodenal biopsy specimen
Tropheryma whipplei is detected in _______.
human feces, saliva, and gastric secretions
Spore-forming, Non-branching, Catalase positive (+) Bacilli
Bacillus
Are Bacillus spp. gram-variable?
Yes
Aerotolerance of Bacillus spp.
Aerobic or Facultative Anaerobic
Some Bacillus spp. are ______ that grow best at 55 C or higher.
thermophiles
Bacillus spp. grow best at ______.
55 C or higher
Bacillus anthracis is the causative agent of _______.
Anthrax
______ is the causative agent of Anthrax.
Bacillus anthracis
Virulence factors of Bacillus anthracis
- Capsule
- Anthrax Toxin
How is the capsule of Bacillus anthracis virulent?
It protects from phagocytosis
The capsule of B. anthracis is a polypeptide of ________.
D-glutamic acid
The capsule of B. anthracis is a ________ of D-glutamic acid.
polypeptide
The capsule of ________ is a polypeptide of D-glutamic acid.
Bacillus anthracis
The ____ of B. anthracis is a polypeptide of D-glutamic acid.
capsule
Anthrax toxin contains how many proteins?
3
Proteins under Anthrax toxin
- Protective Antigen (PA)
- Edema Toxin (EF)
- Lethal Toxin (LF)
How is the PA of B. anthracis virulent?
It combines with EF and LF to produce a cytotoxic and immunomodulating effect.
It combines with EF and LF to produce a cytotoxic and immunomodulating effect.
Protective Antigen (PA)
Infections caused by Bacillus anthracis
- Cutaneous Anthrax
- Inhalation Anthrax
- Gastrointestinal Anthrax
- Injectional Anthrax
It occurs when wounds are contaminated with anthrax spores acquired through skin cuts, abrasion, or insect bites.
Wound Anthrax
How is cutaneous anthrax developed?
When the wound is contaminated by anthrax spores
How are cutaneous anthrax spores transmitted?
Through skin cuts, abrasion, and insect bites
Cutaneous Anthrax
A small pimple or papule appears ____ after exposure.
2-3 days
Cutaneous Anthrax
A ________ appears 2-3 days after exposure.
small pimple or papule
Cutaneous Anthrax
A ring vesicle develops, forming _______.
erythematous ring
The depressed black necrotic central area that forms when the small dark area of the ring ulcerates and dries is called _______.
Eschar or Black Eschar or Malignant Pustule
How is Eschar formed?
When the small dark area of the erythematous ring ulcerates and dries
Usually, the lesions of cutaneous anthrax is _______.
painless and does not produce pus
Inhalation anthrax is also known as ______.
Whoolsorter’s Disease
________ is also known as Whoolsorter’s Disease.
Inhalation anthrax
It is acquired when spores are inhaled into the pulmonary parenchyma.
Inhalation Anthrax
How is Inhalation Anthrax acquired?
It is acquired when spores are inhaled into the pulmonary parenchyma
It occurs when spores are inoculated into a lesion in the intestinal mucosa after ingestion of spores.
Gastrointestinal Anthrax
How is Gastrointestinal Anthrax acquired?
Through the inoculation of spores in the intestinal mucosa after ingestion
It is characterized by soft tissue infection associated with “skin popping” or other forms of injection drug use and results from the direct injection of the spores into the tissue.
Injectional Anthrax
How is Injectional Anthrax acquired?
Through the direct injection of the spore into the tissue
Microscopy of Bacillus anthracis
Large, square-ended, gram positive to variable rods (bamboo rods)
What happens when B. anthracis is sub-cultured?
Capsule production ceases
Capsule production ceases when _____ is sub-cultured.
Bacillus anthracis
Incubation of Bacillus anthracis
In an atmosphere with increased CO2
What happens when B. anthracis is incubated in an atmosphere with increased CO2?
Capsule production is stimulated
Capsule production is stimulated when _____ is incubated in an atmosphere with increased CO2.
Bacillus anthracis
Colonial characteristics of Bacillus anthracis on SBA
Non-hemolytic, large, gray, and flat with irregular margins due to outgrowth of long, filamentous projections
“Medusa head”
Bacillus anthracis
“Beaten egg whites”
Bacillus anthracis
Consistency of Bacillus anthracis colonies
Tenacious
It exhibits a “cut-glass” appearance in transmitted light
Bacillus anthracis
Bacillus anthracis exhibits a _____ in transmitted light.
cut-glass appearance
Catalase reaction of Bacillus anthracis
Positive (+)
Is Bacillus anthracis motile?
No
Which carbohydrate/s can be fermented by Bacillus anthracis?
glucose
It produces an opaque zone around the colonies growing on egg yolk agar
Bacillus anthracis
Bacillus anthracis produces an ____ around the colonies growing on egg yolk agar.
opaque zone
Salt concentration of Bacillus anthracis
7%
Bacillus anthracis has a ____ pH
low
Bacillus anthracis is susceptible to ____.
penicillin (10 U/mL)
Bacillus anthracis is _____ to penicillin (10 U/mL).
susceptible
Bacillus anthracis capsule production can be detected by _______.
India Ink Staining
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus anthracis
Hemolysis on SBA
-
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus cereus
Hemolysis on SBA
+
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus anthracis
Motility
-
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus cereus
Motility
+
Differentiation of Bacillus anthracis and Bacillus cereus
Bacillus anthracis
Penicillin susceptibility
S
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus cereus
Penicillin susceptibility
R
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus anthracis
Lecithinase production
+
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus cereus
Lecithinase production
+
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus anthracis
Fermentation of salicin
-
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus cereus
Fermentation of salicin
+/-
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus anthracis
Growth in penicillin (10 U/mL) agar
-
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus cereus
Growth in penicillin (10 U/mL) agar
+
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus anthracis
Gelatin hydrolysis
-
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus cereus
Gelatin hydrolysis
+
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus anthracis
Growth on phenylethyl alcohol agar
-
Differentiation of Bacillus antracis and Bacillus cereus
Bacillus cereus
Growth on phenylethyl alcohol agar
+
A common cause of food poisoning and opportunistic infections.
Bacillus cereus
An important cause of eye infections
Bacillus cereus
Virulence factor of Bacillus cereus
Enterotoxin
* Diarrheal
* Emetic
Bacillus cereus is grown ______ at 37 C on SBA
anaerobically
Bacillus cereus culture medium and incubation period
Grown anaerobically at 37 C on SBA
Colonial appearance of Bacillus cereus
β-hemolytic, frosted glass appearing colonies
Is Bacillus cereus motile?
Yes
“Frosted-glass” colonies
Bacillus cereus
Comparison of Enterotoxins Produced by Bacillus cereus
- Characteristic: Incubation period
- Type of Enterotoxin: Diarrheal
8-16 hours
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Incubation period
Type of Enterotoxin: Emetic
1-5 hours
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Diarrhea
Type of Enterotoxin: Diarrheal
Very common
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Diarrhea
Type of Enterotoxin: Emetic
Fairly common
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Vomiting
Type of Enterotoxin: Diarrheal
Occasional
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Vomiting
Type of Enterotoxin: Emetic
Very common
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Duration of illness
Type of Enterotoxin: Diarrheal
12-24 hours
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Duration of illness
Type of Enterotoxin: Emetic
6-24 hours
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Foods implicated
Type of Enterotoxin: Diarrheal
- Meat
- Soups
- Vegetables
- Puddings
- Sauces
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Foods implicated
Type of Enterotoxin: Emetic
Fried or Boiled rice
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Molecular weight
Type of Enterotoxin: Diarrheal
= 50,000
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Molecular weight
Type of Enterotoxin: Emetic
<5000
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Stability to heat
Type of Enterotoxin: Diarrheal
-
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Stability to heat
Type of Enterotoxin: Emetic
+
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Stimulation of adenylate cyclase-cAMP system
Type of Enterotoxin: Diarrheal
+
Comparison of Enterotoxins Produced by Bacillus cereus
Characteristic: Stimulation of adenylate cyclase-cAMP system
Type of Enterotoxin: Emetic
-
Other Bacillus species
- B. subtilis
- B. licheniformis
- B. circulans
- B. pumilus
- B. sphaericus
