Gram positive

• Streptococci species

• Staphylococcus aureus

• Staphylococcus epidermitdis

• Clostridium species (excluding C. difficile)

Gram negative

• E. coli

• Klebsiella species

• haemophilus influenzae

• Proteus mirabilis

• Providencia species

Anaerobes

• Bacteroides species (resistance increasing to B. fragilis)