Gram-Positive Bacilli of Medical Importance

These flashcards cover key concepts, definitions, and characteristics related to Gram-positive bacilli, their medical importance, transmission modes, and treatment methods.

What are the three general groups of medically important Gram-positive bacilli based on endospores and acid-fastness?

Endospore-formers, Non-endospore-formers, Irregular shaped and staining properties.

What is the key defining feature of endospore-forming bacilli?

They typically form spores that are resistant to heat, drying, radiation, and chemicals.

Name two species of the genus Bacillus that are medically important.

Bacillus anthracis (causes anthrax) and Bacillus cereus (causes food poisoning).

What are the virulence factors of Bacillus anthracis?

Polypeptide capsule and exotoxins (such as edema and cell death factors).

What type of anthrax is characterized by spores entering through the skin?

Cutaneous anthrax.

What is the primary treatment for anthrax infection?

A combination of ciprofloxacin and clindamycin, often along with Raxibacumab.

What distinguishes Clostridium species from Bacillus species in terms of oxygen requirements?

Clostridium species are strictly anaerobic, while Bacillus species are aerobic or facultative anaerobes.

What is the primary cause of gas gangrene?

Clostridium perfringens.

What are the two forms of gas gangrene?

Anaerobic cellulitis and true myonecrosis.

What is the neurotoxin produced by Clostridium tetani, and what effect does it have?

Tetanospasmin causes paralysis by blocking neurotransmitter release, leading to uncontrollable muscle contraction.

How is Clostridioides difficile infection commonly treated?

Mild cases are treated with fluid and electrolyte replacement, severe infections with oral vancomycin or metronidazole.

What are common sources of Clostridium botulinum?

Improperly preserved foods, particularly home-canned foods.

What happens during infant botulism?

Ingested spores germinate in the immature gut of infants, leading to `floppy baby syndrome'.

What is the primary reservoir for Listeria monocytogenes?

Soil and water; can contaminate foods like dairy products, poultry, and meat.

What is the treatment for Listeriosis?

Ampicillin, gentamicin, and trimethoprim/sulfamethoxazole.

Name two common types of non-tuberculous mycobacteria that can cause lung disease.

Mycobacterium kansasii and Mycobacterium avium complex.

What type of bacteria is Corynebacterium diphtheriae and how is it acquired?

Straight or somewhat curved rods acquired via respiratory droplets from carriers or infected individuals.

What are the main characteristics of Actinomyces species?

Nonmotile filamentous rods that can cause chronic infections, primarily actinomycosis.

What is the best prevention method against tuberculosis?

Vaccination with the attenuated 'bacille Calmette-Guérin' strain and maintaining proper hygiene.

What defines the bacteria within the Mycobacterium genus in terms of their growth and staining?

They are acid-fast bacilli, strictly aerobic, and grow slowly.