Gram positive:
Streptococci group A/B/C/G
S. pneumoniae
S. anginosus group
E. faecalis
Oral Anaerobes:
Actinomyces
Prevotella melaninogenica
Peptostreptococci
Syphilis: Penicillin G should not be substituted for Penicillin G benzathine as IM therapy for syphilis.