Gram Positive Organisms Flashcards
Why is staphylococcus resistant to the environment?
Can withstand drying, increased salt, can be inactive in dried pus, easily spread
Is staphylococcus resistant in environments?
Yes
What can staphylococcus survive in for extended periods of time?
Dried pus, boils, and skin
When is staphylococci less susceptible to antimicrobials?
When it is inactive
How does one treat a staphylococcal infection?
Debridement and draining of necrotic tissue so antimicrobials can reach the organism
What are two different types of staphylococcus?
Coagulase positive and negative
What is Coagulase positive staph?
Can clot plasma, is invasive and grouped with pneumococci and strepticocci
Coagulase + is pyogenic, what does that mean?
Causes pus forming infections from the white blood cells going to infected area and causing swelling and exudate
What are four types of toxins produced from Coagulase + staph?
Hyaluronidase, enterotoxins, hemolysins, leukocydines
What does hyaluronidase do?
Dissolves tissues, aids in the spread of bacteria
What do some Coagulase + staph produce?
Capsules to resist phagocytosis
How many kinda of coagulase - are there?
27 kinds, mostly commensuals
What is staphylococcus aureus?
Skin infection (cellulitis, boils, impetigo)
What are three types of skin infections caused by S. Aureus?
Cellulitis, boils, impetigo
What are five diseases/infections S. aureus can cause?
Skin infections, toxic shock syndrome, acute bacterial endocarditis, pneumonia, food poisoning
What is toxic shock syndrome caused by (1) and symptoms? (4$
Caused by TSST-1, fever, shock, death, septicemia
What is acute bacterial endocarditis?
Results in rapid destruction of the heart valves
What is S. Food poisoning?
Food borne intoxication
What is S. Food poisoning caused by?
Caused by the overgrowth of bacteria on food leading to the production of a toxin that causes illness
What are the symptoms in humans of s. Food poisoning? (4)
Onset of nausea, vomiting, abdominal cramps, diarrhea
What are the symptoms in animals for s. Food poisoning 2
They are sub clinical, mastitis in cows and fatal infections in rabbits
What is the incubation period for S. Food poisoning?
30min to 8 hours
What is S. Hyicus?
Exudative epidermitis (greasy pig disease)
What type of staphylococcus are commensuals but if found in the the blood are an infection (septicemia) however often mistaken for contamination?
S. Epidermitis and S. Saprophyticus
What two staph are used in fermented meats and dried fish and soy sauce and have recently found to produce enterotoxins?
S. Saprophyticus and a. Carnosus
What is MRSA?
Multiple drug resistant S. aureus and is a nosocomial pathogen
What is the reservoir for MRSA?
Health care providers
What are three ways of transportation of MRSA?
Skin contact, contaminated instruments/equipment and environment
What are the symptoms of MRSA? 5
Localized pustules, boils, inflammation, exudate, drainage
What are two symptoms that MRSA has gone systemic?
Pneumonia, septicemia
How do you treat MRSA?
Drain, culture and use correct antibiotic
How would you prevent MRSA? 2
Personal protective equipment and proper sanitation
What should be included in personal protective equipment? 4
Gloves, mouth, nose, eyes
What are 4 types of G (+) organisms?
Staphylococcus, streptococci, bacillus, clostridium
Describe streptococci
G(+) cocci in chains or pairs
What is the lance field system?
The streptococci are grouped by seri type
What is a serotype?
Antigen that binds with a particular antibody
What g(+) organism can produce hemolysins?
Streptococci
What is gamma hemolysis?
Non hemolytic, no change to color of blood agar
What is alpha hemolysis?
Partial hemolysis of blood. Green, cloudy haze around colony growth
What is beta hemolysis?
Complete hemolysis of blood, clear zone around colony growth
How can streptococci be treated?
Responds well to antibiotics or leave alone for immune system
What are five diseases or infections streptococcus pyogenes can cause?
Impetigo and other skin infections, necrotizing fascititis, rheumatic fever, scarlet fever, streptococcal pharyngitis
What happens if streptococci reach deeper tissues?
Can become necrotizing fasciitis
Why is necrotizing fasciitis so destructive?
It produces a substance that promote rapid spread of the infection
What are three things necrotizing fasciitis can produce?
Streptokinase, hyaluronidase, and DNA