Pathogens
Staphylococci, coagulase negative

Staphylococci, coagulase negative

Precautions

Standard Precautions

General Information

Culture

Gram-positive cocci in clusters, coagulase-negative.

A large number of coagulase negative staphylococci (CoNS) are present. In general, these are avirulent, minimally virulent or virulent mainly in compromised hosts. Infections can occur but they are more often isolated as contaminants or commensals as they are widely found as part of the commensal microbiota.

Species more likely to be involved in disease include

  • S. schleiferi
  • S. felis
  • S. haemolyticus
  • S. epidermidis
  • S. lugdunensis

Methicillin-resistance is common but does not impact virulence. Methicillin-resistant CoNS are common commensals and no more likely to cause disease than their susceptible counterparts.

While CoNS are most often found as commensals or contaminants, they can be involved in a range of opportunistic infections, mainly in compromised hosts.

These include wound infections, ear and skin infections, bloodstream infections and urinary tract infections.

Staphylococci are intrinsically susceptible to most antimicrobials. However, acquired resistance is common.

Common first line drugs include:

  • Potentiated penicillins
  • 1st generation cephalosporins
  • Clindamycin
  • Doxycycline

Also potentially effective:

  • Trimethoprim sulfa
  • Nitrofurantoin (cystitis only)
  • Fosfomycin (dogs only)
  • Penicillins can be effective but beta-lactamase-based  resistance is common

Typically susceptible to the following higher tier drugs (that should be reserved):

  • Fluoroquinolones
  • 3rd generation cephalosporins

Reserved for multidrug resistant infections where CoNS are convincingly clinically relevant:

  • Aminoglycosides
  • Chloramphenicol