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.