week12 Flashcards
(40 cards)
Is Bacillus Gram positive or gram variable?
Gram positive
What type of bacilli are Bacillus species?
Aerobic or facultative anaerobic bacilli
Do Bacillus species form spores?
Yes, they are spore formers to survive harsh environments or lack of nutrients
What is the catalase status of Bacillus?
Catalase positive
Are Bacillus species motile?
Motile, except for B. anthracis
How do Bacillus and Clostridium differ in spore formation?
Bacillus forms spores aerobically and is catalase-positive, while Clostridium does not.
What is the causative agent of anthrax?
Bacillus anthracis
What are the virulence factors of Bacillus anthracis?
Glutamic acid capsule and anthrax toxin
What are the components of anthrax toxin?
Protective antigen (PA), edema factor (EF), and lethal factor (LF)
What does PA + EF cause?
Edema
What does PA + LF cause?
Death of host cells
What is a common disease of livestock caused by Bacillus anthracis?
Anthrax
What is another name for inhalation anthrax?
Woolsorter’s disease or ragpicker’s disease
How is human infection with Bacillus anthracis acquired?
From exposure to animals or animal products
What are the four forms of anthrax seen in humans?
Cutaneous, inhalation/pulmonary, gastrointestinal, and injectional anthrax
What is cutaneous anthrax?
Occurs when wounds are contaminated with spores acquired through skin cuts, abrasions, or insect bites
What are the initial symptoms of cutaneous anthrax?
Starts as a small pimple or papule at the site of inoculation 2-3 days after exposure
What is the appearance of the lesion in cutaneous anthrax?
An erythematous ring develops, with a small dark area that ulcerates and dries (eschar or black eschar)
What are the symptoms of inhalation anthrax?
Mild fever, fatigue, malaise, respiratory problems, disorientation, coma, and death
What are the symptoms of gastrointestinal anthrax?
Abdominal pain, nausea, anorexia, vomiting, and bloody diarrhea
What characterizes injectional anthrax?
Soft tissue infection associated with injection of drugs of abuse
What are the complications of anthrax?
Approximately 5% of patients develop meningitis, unconsciousness, and death may occur within 1 to 6 days after exposure
What specimens can be used for diagnosing anthrax?
Malignant pustule, sputum, and blood
How does Bacillus anthracis appear under microscopy?
Large, square-ended, gram positive or gram variable rod found single or in chains, resembling bamboo rods
