Gram Positive Bugs
Staphylococcus
Enterococcus







Staphylococcus aureus (Skin)
MSSA – Methicillin Susceptible S. aureus (Skin)
MRSA – Methicillin Resistant S. aureus (Skin)
Staphylococcus epidermis (Skin)
Staphylococcus saprophyticus (Urinary tract, Vagina)
Streptococcus




Streptococcus pyrogens – Group A (Throat)
Streptococcus pneumoniae (Lungs)
Streptococcus viridans (Dental access, Endocarditis)
Streptococcus agalactiae (Group B Strep)
Enterococcus faecalis (Urinary tract)
Enterococcus faecium (Urinary tract)
Other Gram Positives







Listeria monocytogenes (listeriosis)
Corynebacterium diphtheriae (diphtheria)
Clostridium botulinum (botulism)
Clostridium tetani (tetanus)
Clostridium difficile (C. diff)
Bacillus anthracis (anthrax)
Propionibacterium acne (acne)
Gram Negative Bugs (Just about Everything else!)








Neisseria mengingitidis
Shigella
Campylobacter
Salmonella
Common Beta-Lactamase Producers



Haemophilus influenza
Neisseria gonorrheae
Moraxella catarrhalis




Atypical Pathogens
Pasteurella
Rickettsia
Borrelia
Pseudomonas
Escherichia coli (E. coli)
Proteus
Klebsiella
Bacterioides fragilis



Mycoplasma pneumoniae
Chlamydia pneumoniae
Legionella pneumophila
Allergic to Penicillin?


90% - 98% of PCN allergic Pts can take Cephalosporins
2% - 10% of PCN allergic Pts are allergic to β-lactam ring and can
not take Cephalosporins
Who can I give a Cephalosporin to?



Never give Cephalosporin if PCN RXN was Anaphylaxis
Never give Cephalosporin if PCN RXN was Hives
o Hives = IgE mediated, Type I RXN (Real allergic RXN)
 Raised, red, highly pruritic
o IgE RXNs escalate with repeated exposures
Give Cephalosporin if PCN RXN was Morbiliform Rash
o Morbiliform Rash not IgE mediated (usually T-cell
mediated)
 Viral infection with ABX treatment for example:
Mono c̅ PCN, or HIV c̅ Sulfa drug