SPORE FORMING GRAM POSITIVE BACILLI Flashcards
are responsible for the resistance to extreme conditions.
SPORES
BACILLUS
O2 Requirement
Catalase
Gas production
Aerobic
Positive
Negative
CLOSTRIDIUM
O2 Requirement
Catalase
Gas production
Anaerobic
Negative
Positive
Members of the genus Bacillus are metabolically diverse, and some species are______ that grow best at_____
thermophiles
55° C or higher
Members of the genus Bacillus are metabolically diverse, and some species are______ that grow best at_____
thermophiles
55° C or higher
LARGEST pathogenic bacteria
Also known as “______”
BACILLUS ANTHRACIS
Anthrax Bacillus
VIRULENCE FACTOR (Bacillus anthracis)
D-GLUTAMIC ACID CAPSULE
ANTHRAX TOXIN
Anthracis virulence factor
This particular isomer of glutamic acid is resistant to_____ by host proteolytic enzymes because it is the “unnatural” form of the amino acid
D-GLUTAMIC ACID CAPSULE
hydrolysis
Resistant to hydrolysis
At some point, it can resist proteolytic enzyme produced by our body
NOTE: Although the capsule is necessary for virulence, antibodies against the capsule do not confer immunity
D-GLUTAMIC ACID CAPSULE
Each of which individually is nontoxic but which together act synergistically to produce damaging effects.
ANTHRAX TOXIN
Anthrax toxin (3)
Protective antigen (PA)
Edema factor (EF)
Lethal factor (LF)
Serves as a necessary binding molecule for EF and LF, permitting their attachment to specific receptors on the host cell’s surface
Protective antigen (PA)
Is an adenylate cyclase, release of water and electrolytes
Edema factor (EF)
is a protease that inhibits protein synthesis.
Lethal factor (LF)
PA + EF =
PA + LF =
EDEMA
DEATH
DISEASE ASSOCIATION (Bacillus anthracis)
Cutaneous Anthrax
Inhalation Anthrax
Gastrointestinal Anthrax
Injectional Anthrax
• A small pimple (2 to 3 days after exposure) → eventually ulcerates and dries, forming a depressed black necrotic central area known as an eschar or black eschar.
Cutaneous Anthrax
• Also known as_______; is acquired when spores are inhaled into the pulmonary parenchyma.
Inhalation Anthrax
Woolsorter’s disease
• Acquired by means of ingestion of the spores.
Most fatal
Gastrointestinal Anthrax
If the spores are being ingested, the anthrax spores can affect the_________ (throat, esophagus, stomach, intestine) causing a wide variety of symptoms
upper gastrointestinal tract
is characterized by soft tissue infection associated with “skin popping”
Injectional Anthrax
• Lack of eschar, severity of disease, and increased mortality rate make this form clinically distinct from the cutaneous form.
Injectional Anthrax
Injectional anthrax
First discovered in
Northern Europe
Symptoms is somehow similar to that cutaneous anthrax but, there may be infection that is DEEP UNDER the skin or in the muscle where the drug is injected; Can spread throughout the body FASTER and be harder to recognize and treat unlike the cutaneous anthrax which is visible because it is located at the upper part of the skin.
Injectional anthrax
TREATMENT (Bacillus anthracis)
Most isolates of B. anthracis are______ to penicillin, but______ can occur in the absence of B-lactamase production
SUSCEPTIBLE
resistance
B-lactam drug - Antibiotic that specifically target the…
cell wall synthesis of the bacteria
The CDC recommends that______ or ______ be used for initial intravenous therapy until antimicrobial susceptibility results are known.
•_____ - to identify what is the most effective drug against B. anthracis.
ciprofloxacin or doxycycline
AST
is a large, square ended, gram-positive rod found singly or in chains.
B. anthracis
• Gives the appearance of bamboo pole arrangement because of the location of its spore (centrally located)
Anthracis
Anthracis
Spores can be observed with a SPORE STAIN
With this technique, vegetative cells stain
______, and the spores stain_____.
However, the color depends on the stains used
red
green
CULTURE (Bacillus anthracis)
• The term_________ has been used to describe the colony morphology of B. anthracis on BAP.
Can only be observed on BAP
Medusa head/ beaten egg whites
CULTURE (Bacillus anthracis)
•________ on MHA with penicillin
MHA - usually used on AST (Kirby-Bauer
Disk Test)
String of pearls
is a relatively common cause of fried rice poisoning and opportunistic infections in susceptible hosts.
• B. cereus
• Food poisoning caused by B. cereus takes two forms:
diarrheal & emetic
Defecation
Meat & Poultry
8-16 hours
Heat-Labile
DIARRHEAL TYPE
Defecation and Vomiting
Most common cause of food poisoning toxin of B. cereus
1-6 hours
Heat-Stable Enterotoxin
EMETIC TYPE
DIAGNOSIS (Bacillus cereus)
• Culture of suspected food from a food poisoning incident may be done to quantify and isolate B. cereus
Count how many bacteria are present on a one gram of food that causes the incident.
__________ food poisoning by this organism is confirmed.
To confirm the organism as the cause of the disease, viable counts from the stool should also be at least ______
100,000 cereus/gram
T or F
TREATMENT (Bacillus cereus)
Most food poisoning cases caused by B. cereus DO NOT REQUIRE ANTIMICROBIAL TREATMENT
True
B. cereus is_______ to penicillin and all of the other B-lactam antibiotics except for the_____
RESISTANT
carbapenems
B. cereus
Treatment with_____ or ______ with or without an aminoglycoside has been successful.
vancomycin or clindamycin
B cereus
• Bacillus cereus bacteria stained with_______ to display their flagella.
Leifson dye
B anthracis
Catalase
Lecithinase
Motility
BAP Hemolysis
Positive
Positive
Non motile
Gamma
B cereus
Catalase
Lecithinase
Motility
BAP Hemolysis
Positive
Positive
Motile
Beta
