Microbiology Midterm 3(1) Staphylococcus, Streptococcus Group A and B
What is the meaning of Aureus?
Golden, characteristic yellow colonies
What traits do S. Aureus and S.epidermidis share?
Gram positive cocci, grape-like cluster arrangement, facultative anerobe.
What is the appearence of Staphylococcus?
Grape-Like Clusters
What grouping of strep is Streptococcus Pyogenes in?
Group A
How is Streptococcus grouped?
Grouped based on serotypes
What are the different diseases caused by Staph?
Septic Arthritis (joints), Endocarditis (heart), Osteomyelitis (bones), Bacteremia (infection of blood) (Septicemia)
What is Toxic Shock Syndrome?
Septic Shock without the sepsis
What are the two major species of Staphylococcus?
Staphylococcus Aureus and Staphylococcus Epidermidis
What diseases are caused by Streptococcus
Strep Throat, Scarlet fever, Impetigo, Rheumantic fever
What is Necrotizing Fasciitis, what bacteria and disease exhibit this?
Streptococcus Pyogenes releases enzymes that break down flesh in Invasive Bacteremia
What bacteria causes Rheumatic Fever?
Streptococcus pyogenes
What traits do S. Aureus and S. Epidermidis differ in? (S.Epidermidis)
Gamma-hemolytic(non-hemolytic), Coagulase negative, no exotoxins
What is the gram status of Staphylococus?
Gram Positive
What is the gram status and arrangement of Streptococcus?
Gram Positive, Forms chains of cells
How is Rheumatic fever contracted?
Contracted if strep throat infection is untreated for a long time
What percentage of microbes actually cause disease?
1%
What is used to treat S. Aureus Infections?
Antibiotics
What are M proteins?
A superantigen found in serotypes of Staphylococcus and Streptococcus
How can S.Aureus infections be prevented?
Clean cuts carefully, Aspetic and Antiseptic techniques in hospital, hangwashing
What is the long term concequence of Rheumatic fever?
Heart problems since immune system attacks M proteins attached to heart proteins
How is strep throat treated?
Penicillin
What is protein A where is it found?
Protein that binds to antibodies and prevents it from attacking cell; found in exotoxin of S. Aureus
What are the symptoms of impetigo?
Pustules that crust over and rupture
What is dangerous about S.Aureus besides its exotoxins?
Antibiotic Resistance
What is Rheumatic fever?
Autoimmune disease where immune system attacks joints (reactive arthritis) and M proteins from leftover bacteria cell walls bind to heart proteins.
What trait does Staphylococcus Aureus display in the presence of blood?
B(beta)-hemolytic
What is Staphylococcus in terms of taxonomy?
Bacterial Genus
What kind of hemolytic is Group A Streptococcus?
Beta
What kind of hemolytic is Group B Streptococcus?
Beta
How are Staph infections usually contracted?
Boils, Sweat Glands, Contaminated Surgical Wounds (Nosocomial)
What is B(beta)-hemolytic?
Breaks down red blood cells
How is Bacteremia fatal?
Can cause septic shock (lethal drop in blood pressure)
What are teichoic acids?
Acids important for bacterial attachment to infected sites
What kind of hemolytic is S. pneumoniae?
Alpha
What kind of hemolytic is S.mutans?
Alpha
What are the different toxins produced by S. Aureus?
Alpha, Beta, Gamma, Delta, Leucocidins
What is the meaning of staphylococcus in terms of what it represents?
Description of cell shape and arrangement
What are the symptoms of strep throat?
Extremely sore throat, fever, white spots on throat
What kind of bacteria is Streptococcus in the presence of oxygen?
Facultative Anaerobe
What kind of bacteria is Staphylococcus around oxygen?
Facultative anaerobe
What factor determines what exotoxin S. Aureus will have?
Its strain
What is impetigo?
Local skin infection?
What was the number one drug used to kill Staph?
Methicillin
What are primary pathogens?
Microbes that can cause disease in an healthy person.
What are opportunistic pathogens?
Microbes that cause disease only when the host's immune system has been damaged.
What is scarlet fever?
Non-invasive infection of the throat
What is Strep Throat?
Non-invasive infection of the throat- pharyngitis
What kind of infection is Staphylococcus?
Opportunisitic infections
What kind of infection Invasive Bacteremia, what bacteria causes it, what can it result in?
Oppurtunistic infection of Strep. pyogenes, produce enzymes that rapidly break down flesh, releases exotoxin A superantigento initiate massive inflammatory response, can result in death and toxic shock syndrome
What is the characteristics of S. aureus food poisoning?
Rapid onset and Rapid recovery
How does S. Aureus cause food poisoning?
Release exotoxins in food which poison GI tract
What is scalded skin syndrome?
Result of Exotoxin from S.Aureus, may indicate bacteremia, damage to skin
What does Group B streptococcus not cause versus Group A?
Rheumatic fever after infection
What traits do S. Aureus and S. Epidermidis differ in? (S.aureus)
S.Aureus- B-hemolytic, coagulase postive, produce exotoxins
What are the symptoms of Scarlet Fever?
Similar to strep throat but causes red rash on body
Where is Staphylococcus found on the human body?
Skin, In and around nose
Although Staphylococcus is contangious how is it transfered?
Skin-to-skin contact
What is the purpose of a coagulase test?
Some bacteria produce chemicals that will cause fibrin(clotting factor in test) to form clots.
Which out of the major Staphylococcus species exhibits a positive catalase test?
Staphylococcus Aureus
What specific group and species of bateria causes it Invasive Bacteremia
Streptococcus pyrogenes.
What is Toxic Shock Syndrome a direct result of?
Super tampons that accumulated exotoxin releasing S.Aureus
How do exotoxins defend Staphylococcus?
Superantigen that confuses immune system, splits immune system
What causes Toxic shock syndrome?
Superantigen that produces exaggerated immune response i.e. fever, rash, s. skin syndrome, vomiting, diarrhea
What is a rapid strep test?
Swab throat and test for group A antigens as swab is soaked in group a-antibodies
How are streptococcus serotypes determined?
Test for antibodies against teichoic acids and M protein, and capsule that prevents phagocytosis
What is the definition of Pathogen?
That which causes suffering
How can group b streptococcus be prevented from infecting infant?
Treatment of mother with antibiotics before and during birth
Where is group B Streptococcus found?
Vaginal flora, can infect infants at birth with meningitis or be transfered from mother.