Podcast
Questions and Answers
What is a characteristic of Staphylococci?
What is a characteristic of Staphylococci?
- Motile
- Gram-negative
- Spore-forming
- Non-motile (correct)
Which of the following is a characteristic of Staphylococcus aureus?
Which of the following is a characteristic of Staphylococcus aureus?
- Coagulase negative
- β-hemolysin negative
- White pigmentation of colonies
- Coagulase positive (correct)
What is a normal habitat of Staphylococcus aureus?
What is a normal habitat of Staphylococcus aureus?
- Skin and mucosal surfaces (correct)
- Oral cavity
- Anterior nares
- Intestines
How do Staphylococci survive on dry surfaces?
How do Staphylococci survive on dry surfaces?
What is a common infection caused by Staphylococcus saprophyticus?
What is a common infection caused by Staphylococcus saprophyticus?
How are Staphylococci transmitted?
How are Staphylococci transmitted?
What is a characteristic of Staphylococcus epidermidis?
What is a characteristic of Staphylococcus epidermidis?
What is a common habitat of Staphylococcus epidermidis?
What is a common habitat of Staphylococcus epidermidis?
What is the effect of Teichoic Acid on Staphylococcus aureus?
What is the effect of Teichoic Acid on Staphylococcus aureus?
Which virulence factor is responsible for Staphylococcal Scalded Skin Syndrome (SSSS)?
Which virulence factor is responsible for Staphylococcal Scalded Skin Syndrome (SSSS)?
What is the effect of Peptidoglycan on Staphylococcus aureus?
What is the effect of Peptidoglycan on Staphylococcus aureus?
Which virulence factor is responsible for Necrotizing Pneumonia?
Which virulence factor is responsible for Necrotizing Pneumonia?
What is the effect of Protein A on Staphylococcus aureus?
What is the effect of Protein A on Staphylococcus aureus?
What is the effect of Enterotoxins (A-E, G-I) on the body?
What is the effect of Enterotoxins (A-E, G-I) on the body?
Which Gram Positive Cocci is most likely responsible for Scalded Skin Syndrome in neonate?
Which Gram Positive Cocci is most likely responsible for Scalded Skin Syndrome in neonate?
Which Gram Positive Cocci is most likely responsible for Neonatal meningitis?
Which Gram Positive Cocci is most likely responsible for Neonatal meningitis?
Which Gram Positive Cocci is Optochin sensitive?
Which Gram Positive Cocci is Optochin sensitive?
Which Gram Positive Cocci is most likely responsible for Endocarditis in patient with artificial heart valve?
Which Gram Positive Cocci is most likely responsible for Endocarditis in patient with artificial heart valve?
Which Gram Positive Cocci is most likely responsible for Urinary tract infection in a 25-year-old female?
Which Gram Positive Cocci is most likely responsible for Urinary tract infection in a 25-year-old female?
Which Gram Positive Cocci is most likely responsible for Pharyngitis in young adult?
Which Gram Positive Cocci is most likely responsible for Pharyngitis in young adult?
Which of the following is a risk factor for Staphylococcal infections?
Which of the following is a risk factor for Staphylococcal infections?
S. epidermidis is responsible for which of the following diseases?
S. epidermidis is responsible for which of the following diseases?
Which of the following is a common disease caused by S. aureus?
Which of the following is a common disease caused by S. aureus?
Intravenous drug abuse is a risk factor for infections with which of the following?
Intravenous drug abuse is a risk factor for infections with which of the following?
Use of antibiotics can lead to an increased risk of Staphylococcal infections due to the suppression of:
Use of antibiotics can lead to an increased risk of Staphylococcal infections due to the suppression of:
Which of the following is NOT a disease caused by S. aureus?
Which of the following is NOT a disease caused by S. aureus?
What is the main difference between folliculitis and furuncles?
What is the main difference between folliculitis and furuncles?
Which of the following is a characteristic of impetigo?
Which of the following is a characteristic of impetigo?
What is the main difference between Staphylococcal Scalded Skin Syndrome and Staphylococcal Toxic Shock Syndrome?
What is the main difference between Staphylococcal Scalded Skin Syndrome and Staphylococcal Toxic Shock Syndrome?
Which of the following is NOT a pyrogenic infection?
Which of the following is NOT a pyrogenic infection?
What is the main cause of Staphylococcal Food poisoning?
What is the main cause of Staphylococcal Food poisoning?
Which of the following is characterized by a honey-colored crust with a moist erythematous base?
Which of the following is characterized by a honey-colored crust with a moist erythematous base?
What is the main difference between carbuncles and furuncles?
What is the main difference between carbuncles and furuncles?
Which of the following is a characteristic of Staphylococcal Scalded Skin Syndrome?
Which of the following is a characteristic of Staphylococcal Scalded Skin Syndrome?
Flashcards are hidden until you start studying
Study Notes
Gram Positive Cocci - Staphylococci
- Staphylococci are gram-positive, non-motile, non-spore forming cocci that form grape clusters or clumps.
- They are facultative anaerobes, β-haemolytic, and catalase-positive, which distinguishes them from Streptococci.
Human Pathogens
- Staphylococcus aureus is responsible for a broad spectrum of clinical syndromes.
- Staphylococcus epidermidis is associated with medical device-related infections.
- Staphylococcus saprophyticus is responsible for urinary tract infections.
Staphylococcus Species
- Staphylococcus aureus:
- Coagulase-positive
- Golden pigmentation of colonies grown on rich media
- β-hemolytic
- Staphylococcus epidermidis:
- Coagulase-negative
- White pigmentation of colonies
- Associated with medical device-related infections
- Staphylococcus saprophyticus:
- Coagulase-negative
- Colonies can be white or golden depending on the strain
- Responsible for 20% of urinary tract infections
Staphylococci as Normal Human Flora
- Staphylococci are normal flora on human skin and mucosal surfaces.
- They can survive on dry surfaces for long periods due to their thickened peptidoglycan layer and absence of outer membrane.
- Person-to-person spread can occur through direct contact or exposure to contaminated fomites.
- S. aureus is a common inhabitant of anterior nares and can also be found in other areas of the body.
- S. epidermidis is a common inhabitant of skin.
Diseases Caused by Staphylococci
- Staphylococcus aureus:
- Skin infections
- Endocarditis
- Osteomyelitis
- Pneumonia
- Meningitis
- Food-borne diseases (toxin-mediated)
- Staphylococcus epidermidis:
- Bacteraemia
- Endocarditis
- Surgical wounds
- UTIs
- Opportunistic infections of catheters, shunts, plastic implants, and prosthetic devices
- Staphylococcus saprophyticus:
- Urinary tract infections
Staphylococcus aureus Virulence Factors
- Peptidoglycan: abscess formation, inhibits phagocytosis
- Teichoic acid: helps in attachment
- Protein A: inhibits antibody-mediated clearance, inhibits phagocytosis
- Panton Valentine Leukocidin (PVL): necrotizing pneumonia
- Exfoliative Toxins (ETA, ETB): Staphylococcal Scalded Skin Syndrome (SSSS)
- Enterotoxins (A-E, G-I): superantigens, stimulating proliferation of T cells and release of cytokines
- Toxic Shock Syndrome Toxin-1: superantigen, produces leakage or cellular destruction of endothelial cells
Specific Diseases Due to S. aureus
- Cutaneous disease:
- Folliculitis
- Furuncle or boil
- Carbuncle
- Toxin-mediated disease:
- Staphylococcal Scalded Skin Syndrome (SSSS)
- Staphylococcal Toxic Shock Syndrome (STSS)
- Staphylococcal food poisoning
- Pyrogenic infections/ Invasive Staphylococcal Diseases:
- Abscesses
- Impetigo
- Wound infections
- Pneumonia
- Mastitis
- Osteomyelitis
- Septicaemia
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
