microbes

Question 1

gram + cocci in chains

grows in salt

Answer 1

Enteroccocus (group D strep)
Note: unlike strep, these are relatively resistant to PCN
Enterococci have both an intrinsic and acquired resistance to antibiotics, making them important nosocomial pathogens. Intrinsically, enterococci tolerate or resist beta-lactam antibiotics because they contain penicillin-binding proteins (PBPs); therefore, they are still able to synthesize some cell-wall components. They are intrinsically resistant to penicillinase-susceptible penicillin (low level), penicillinase-resistant penicillins, cephalosporins, nalidixic acid, aztreonam, macrolides, and low levels of clindamycin and aminoglycosides. They use already-formed folic acid, which allows them to bypass the inhibition of folate synthesis, resulting in resistance to trimethoprim-sulfamethoxazole.

Question 2

antibiotics prescribed for newborn pneumonia

Answer 2

ampicillin and gentamicin OR

ampicillin and cefotaxime

Question 3

young infant with stacatto cough, tachypnea & conjuctivitis
eosinophilia
bilateral infiltrates with hyperinflation

Answer 3

chlamydia pneumonia

Tx: erythromycin

Question 4

pediatric patient > 5 yr with lower resp tract infection signs

Answer 4

mycoplasma pneumonia

Tx: azithromycin

Question 5

refractory asthma

fungal ball on CXR

Answer 5

Aspergillus

Question 6

5 mm induration in a known exposure, abnormal CXR or immunodeficiency

Answer 6

positive PPD