Chapter 19: Gram + Bacilli of Medical Importance

02/24/2025- Started Flashcard set ~X

Do gram + bacteria produce endotoxins?

No.

Is Bacillus aerobic or anaerobic? What 2 species are of medical importance?

Aerobic and catalase positive. The 2 species of medical importance are:

• Bacillus anthracis

• Bacillus cereus

Who used a species of the Bacillus genus to prove the germ theory?

Robert Koch

Where do most cases of Bacillus anthracis occur? inside the USA or outside the USA? What products are high risk? What occupations have a heightened risk?

Most cases occur in herbivores from Africa, Asia, Haiti, and Middle Eastern countries. Hence outside the USA. High risk products are animal products. High risk occupations are workers involved in industrial processing of imported animal products and fibers of animal origin.

Regarding Bacillus anthracis, what preventative measures are taken for workers in the industry?

Vaccination of workers involved in the industrial processing of imported animal products and the decline in using fibers of animal origin.

What antibiotics are used to treat Bacillus anthracis?

Penicillin, tetracycline, or ciprofloxacin.

Are there vaccinations against Bacillus anthracis for both livestock and humans?

Yes

• Live spores and toxoid to protect livestock.

• Purified toxoid; for high risk occupations and military personnel; toxoid 6 inoculations over 1.5 years; annual boosters.

What are the 3 manifestations of Bacillus anthracis? What initial way do they differ?

• Cutaneous Anthrax – spores enter through skin

• Pulmonary Anthrax – inhalation of spores

• Gastrointestinal Anthrax – ingested spores

They differ depending on POE.

What is POE?

Poral of entry

In cutaneous Anthrax, what enters the skin? Where are they from? What characteristic symptoms are seen? In what scenario would this form of anthrax be fatal?

• Spores enter skin through small cuts when handling animal hides or hair

• Symptoms: growth of microbe in skin causes a small papule that progresses to a black, swollen, crusty ulcer =eschar

• Can be fatal with toxemia and septicemia

What is pulmonary Bacillus anthracis known as? What is the POE? What is being inhaled? What do the germinated cells produce?

Pulmonary anthrax:

• POE: inhaled spores which germinate in the lungs.

  • vegetative cells grow and produce exotoxins.

  • resulting toxemia causing capillary thrombosis and cardiovascular shock.

  • Septicemia causes death within a few hours.

What antibiotic is administered for pulmonary anthrax? What toxoid is administered? What preventative measures are taken to eliminate exposure?

• Antibiotic: Ciprofloxacin – antibiotics does not counteract the toxin.

• Toxoid (Biothrax) to humans

• Preventative:            

  • Sterilization of hides, hair, & bone products of herbivorous livestock; burn carcasses of livestock which die of anthrax.

  • administer immunization to susceptible hosts.

How common is the gastrointestinal Bacillus anthracis? where are the toxins produced?

Rare. Exotoxins produced in the digestive tract causes necrotic lesion of ileum and or large intestine.

What disease does Bacillus cereus cause? Where can you find this bacterium? What type of exotoxin is produced? What specific type of infections can this also cause?

Causes: food poisoning

Causes:  large, spore-forming, Gram-positive saprobe that lives in the soil

• common airborne and dust-borne contaminant

• Prefers cooked foods such as rice, potato, and meat dishes = grow and produce enterotoxin

Symptoms:  vomiting and diarrhea

• Causes Nosocomial infections, progressive pneumonia, fulminant sepsis, and central nervous system in the immunosuppressed, IV drug users, and neonate

Where is the species Clostridium found? Can it live in oxygen? What type of infections are caused?

• Common soil inhabitants

• Strict Anaerobe

• Catalase negative

• Oval or spherical spores produced only under anaerobic conditions

• Synthesize organic acids, alcohols, and exotoxins

• Cause wound infections, tissue infections, and food intoxications

What 4 common pathogenic species of Clostridium are discussed?

• Clostridium perfringens

• Clostridium tetani

• Clostridium botulinum

• Clostridium difficile