Micro 4 - Streptococcus

Question 1

What is the most common community acquired pnemonia and bacterial meningitis in adults?

Answer 1

Streptococcus pneumoniae.

Question 2

What are the symptoms pneumococcal pneumonia?

Answer 2

Sudden onset of chills, lobar consolidation, “rust colored” sputum.

Question 3

What can patients with splenectomy patient infected with streptococcus pneumoniae develop?

Answer 3

Fulminant septicemia because streptococcus has a capsule.

Question 4

What three bacteria are encapsulated?

Answer 4

Strep pneumo, haemophilus influenzae, neisseria meningitidis.

Question 5

What are the 2 vaccines available in the US against strep pneumo?

Answer 5

Pneumococcal conjugate vaccine (PCV13) given to infants, pneumococcal polysaccharide vaccine (PPSV23) given to adults.

Question 6

What are the indications for a strep pneumo vaccine?

Answer 6

65 or older, 2 to 64 with a chronic illness, disease that lowers immune response, medication that lowers immune response, smokes or asthma.

Question 7

What are two virulence factors for strep pneumo?

Answer 7

Capsule, IgA protease.

Question 8

What are the five different viridans group streptococci?

Answer 8

S.salivarius, S.sanguinis, S.mitis, S.intermedius, S.mutans.

Question 9

Which organism is the most prominent in dental plaque?

Answer 9

S.mutans.

Question 10

Which viridans group streptococci can cause subacute endocarditis and how?

Answer 10

S.sanguinis can enter circulation during dental procedures and cause subacute endocarditis in those with turbulent flow heart problems (pre-existing endothelial damage).

Question 11

What should be given to patients with turbulent flow heart problems before a dental procedure?

Answer 11

Prophylaxis amoxicillin.

Question 12

What are three diseases that Strep pyogenes can cause?

Answer 12

I)Superficial/deep infections: acute pharyngitis, cellulitis, invasive infections (bacteremia, pneumonia, necrotizing fasciitis). II)Immunologic illness: acute post-streptococcal glomerulonephritis, rheumatic fever. III)Toxin-mediated illness: streptococcal toxic-shock syndrome, necrotizing fasciitis.

Question 13

What skin infections can be caused by both strep pyogenes and Staph aureus?

Answer 13

I) Cellulitis: deep skin infection. II) Impetigo: Superficial skin infection characterized by redness and small vesicles or blisters, that can rupture and leak yellowish fluid (honey crusted lesions) that usually affects the face, nose, mouth and cheeks.

Question 14

What criteria do we use to diagnose rheumatic fever?

Answer 14

Jones criteria.

Question 15

Describe the Jones criteria.

Answer 15

First we have to prove that there was a recent group A strep infection. They need to have 2 major criteria or 1 major and 2 minor criteria. Major Criteria: [JONES]Joints, heart (pancarditis), Nodules (subcutaneous nodules Ashoff), Erythema marginatum (appear and disappear in a few hours), Sydenham chorea (St. Vitus dance, uncoordinated movement of face and limbs). Minor criteria: arthralgia, fever, elevated ESR or CRP, prolonged PR interval on EKG.

Question 16

What does group B strep cause?

Answer 16

Infants: pneumonia, sepsis, meningitis. Pregnant women: asymptomatic bacteruria, UTI, post-partum endometritis, bacteremia. Nonpregnant adults: Bacteremia, skin and soft tissue infections.

Question 17

Why is group B streptococcus (Strep agalactiae) so common in neonates?

Answer 17

Because it is normal vagina flora in about 25% of women (asymptomatic carriers). Infants born to women colonized with GBS are more likely to develop infection.

Question 18

What do we do to check Group B strep on pregnant women? What do we do if it is positive?

Answer 18

Vaginal and rectal swab to detect GBS colonization at 35-37 weeks. If positive, use prophylactic penicillin during labor.

Question 19

What three organisms are important causes of neonatal sepsis?

Answer 19

Group B strep, E.coli, Listeria monocytogenes.

Question 20

What does VRE stand for?

Answer 20

Vancomycin Resistant Enterococci.

Question 21

What is the difference between Enterobacter and Enterococcus?

Answer 21

Enterobacter is a G(-) rod. Enterococcus is a G(+) coccus.

Question 22

What is another name for Group D strep?

Answer 22

Streptococcus bovis and there are 4 subspecies: Strep gallolyticus, Strep lutetiensis, Strep infantarius, Strep pasteuranus.

Question 23

What does Group D strep cause? And what do we have to do when found in the bloodstream?

Answer 23

Found in the gut, can cause endocarditis. When found in the blood or cause of endocarditis, patient must be evaluated with colon cancer with colonoscopy because there is an association between them (15-30% will have colon cancer).

Question 24

What is the organism most common associated with subacute endocarditis?

Answer 24

Viridans group streptococci. Can also be enterococci, strep bovis, coagulase (-) staph, HACEK organisms.

Question 25

What are the HACEK organisms?

Answer 25

Haemophilus aphrophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae.

Question 26

RFF: Gram (+) diplococci.

Answer 26

Streptococcus pneumoniae.