Skin and Systemic Infections Overview

What characterizes boils and abscesses caused by Staphylococci?

Which systematic symptoms might indicate bacteremia due to Staphylococci?

What type of infection is characterized by vomiting and diarrhea after eating contaminated food?

What is the primary purpose of using Blood agar for culturing Staphylococcus species?

Which of the following accurately describes alpha hemolysis?

What type of infections are commonly linked to Staphylococci in healthcare settings?

What medium is rich and non-selective for growing Staphylococcus species?

Which of these symptoms may occur in cases of pneumonia caused by Staphylococci?

What is a common finding in a laboratory culture of S. aureus?

Skin Infections

Boils and abscesses are characterized by red, swollen, and painful lumps filled with pus
Impetigo is characterized by fluid-filled blisters that rupture and form a yellow crust

Systemic Infections

Bacteremia presents with high fever, chills, and fatigue
Pneumonia presents with difficulty breathing and chest pain
Osteomyelitis presents with bone pain and swelling

Toxigenic Syndromes

Ingesting contaminated food can lead to vomiting and diarrhea
Toxic shock syndrome symptoms include low blood pressure, fever, and rash

Healthcare-Associated Infections (HAIs)

Staphylococci are a common cause of infections in hospitals, especially in patients with surgical wounds or medical devices

Diagnosis

Staphylococci can be easily cultured on nutrient agar or blood agar
Culture: Staphylococci colonies appear golden (S.aureus) or white (S.epidermidis)
- Blood agar: is a rich, non-selective medium used to grow a wide variety of bacteria, including Staphylococcus species.
  - It helps in the identification of hemolytic activity, which is crucial for differentiating species.
  - Composition:
    - Nutrient-rich agar: Provides essential nutrients for bacterial growth.
    - Sheep blood (5-10%): Supports the growth of fastidious organisms and allows for the observation of hemolysis.
  - Hemolysis Differences:
    - Alpha (α) Hemolysis: Partial lysis of red blood cells, resulting in a greenish discoloration around colonies. This is typical for Streptococcus pneumoniae and some Staphylococcus species.

This quiz covers various types of skin infections such as boils, abscesses, and impetigo, along with systemic infections like bacteremia and pneumonia. It also discusses toxigenic syndromes caused by contaminated food and healthcare-associated infections caused by Staphylococci. Test your knowledge on diagnosis and symptoms associated with these infections.