BIO 265L Clinical Microbiology Lab Week 11: Clostridium

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Questions and Answers

What is the purpose of using reducing agents in anaerobic bacterial cultures?

To enhance the growth of microaerophiles

To remove oxygen from the media (correct)

To promote the growth of aerobes

To inhibit the growth of facultative anaerobes

Which of the following bacteria is an obligate aerobe?

Pseudomonas aeruginosa (correct)

Bacillus subtilis

Staphylococcus epidermidis

Clostridium perfringens

What is the purpose of an anaerobic jar with Gaspak?

To isolate obligate anaerobes

To culture microaerobic bacteria

To remove oxygen from the media (correct)

To provide oxygen for aerobic bacteria

Which media is commonly used for the primary cultivation of anaerobic bacteria from clinical specimens?

Cooked meat broth Signup and view all the answers

What is the Gram stain reaction of Clostridium perfringens?

Gram-positive endospore-forming rod Signup and view all the answers

What is the classification of Staphylococcus epidermidis based on oxygen requirements?

Facultative anaerobe Signup and view all the answers

Which of the following anaerobic bacteria is typically found in the human colon?

Bacteroides Signup and view all the answers

Which Clostridium species is associated with food poisoning?

C.perfringens Signup and view all the answers

What is the characteristic hemolytic pattern of Clostridium perfringens on Blood Agar?

Double zone of hemolysis Signup and view all the answers

What is the disease caused by Clostridium tetani?

Tetanus Signup and view all the answers

Which of the following is a characteristic of Clostridium perfringens?

Gram-positive, endospore-forming anaerobic bacilli Signup and view all the answers

What is the term for the disease caused by Clostridium perfringens, which is characterized by the production of enzymes that destroy host cells?

Gas gangrene Signup and view all the answers

What is the result of the action of the neurotoxin produced by Clostridium tetani?

Permanent muscle contraction Signup and view all the answers

What is the common route of transmission of Clostridium difficile?

Fecal-oral Signup and view all the answers

What is the condition characterized by a lack of intestinal microbiota, making it possible for Clostridium botulinum to germinate in the gut?

Infant botulism Signup and view all the answers

What is the combination of vaccines usually given to children to protect against tetanus?

DTaP (diphtheria, tetanus, and pertussis) Signup and view all the answers

What is the disease caused by Clostridium botulinum, characterized by rapidly progressing paralysis?

Botulism Signup and view all the answers

What is the condition that allows Clostridium difficile to proliferate in the large intestine?

Antimicrobial treatment Signup and view all the answers

Study Notes

Clostridium: Clinical Significance and Laboratory Diagnosis

Clostridium species are Gram-positive, endospore-forming anaerobic bacilli that are commonly found in the intestinal tract of humans and animals, as well as in soil.
Four Clostridium species are important in human disease: C. perfringens, C. tetani, C. botulinum, and C. difficile.

Methods to Culture Anaerobes

Anaerobes require a proper atmosphere to grow, and specimens from patients must be incubated in a suitable environment.
Factors affecting bacterial growth include oxygen availability, with aerobes, anaerobes, microaerophiles, facultative anaerobes, and aerotolerant anaerobes having different oxygen requirements.

Media for Anaerobe Culture

Cooked meat broth contains reducing agents and nutrients, making it suitable for the primary cultivation of anaerobic bacteria from clinical specimens.
Thioglycollate broth contains sodium thioglycolate and cystine, which remove oxygen from the media, allowing anaerobes to grow.
Anaerobic jars with Gaspak and anaerobic plastic pouches can be used to create an oxygen-free environment for anaerobe growth.

Clostridium Species

C. perfringens is a Gram-positive, endospore-forming anaerobic bacillus that causes food poisoning and "gas gangrene".
C. tetani causes tetanus, a disease characterized by permanent muscle contraction, and can be prevented with a toxoid vaccine.
C. botulinum causes botulism, a disease with two forms: foodborne botulism and infant botulism, which can lead to rapidly progressing paralysis.
C. difficile causes pseudomembranous colitis, a life-threatening disease, and is the most common nosocomial cause of diarrhea.

Laboratory Diagnosis

Gram stain and endospore stain can be used to identify Clostridium species.
Hemolytic patterns on blood agar can be used to differentiate between Clostridium species.

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Description

This quiz covers the clinical significance of Clostridium, Gram stain reaction and morphology, and methods to culture anaerobes. It also explores factors affecting bacterial growth, including oxygen requirements and different types of anaerobes.