2025 – PAGE 303 – INFECTIOUS DISEASES

Treating Newborns with GBS Disease

In general, ampicillin and gentamicin are good empiric treatments when GBS is suspected but not confirmed. If meningitis is suspected, add on an expanded-spectrum cephalosporin (eg, cefotaxime, ceftazidime, or cefepime). If the culture results are known, the definitive treatment is penicillin G since GBS is uniformly sensitive to penicillin and ampicillin. For specific antibiotic regimens in situations where culture results are not yet available, empiric treatment is based on the site of the infection and whether the infection is early onset” (birth to DOL 6) or late onset (DOL 6+):

• EARLY ONSET
  • Bacteremia, sepsis or pneumonia: ampicillin IV + gentamicin IV
  • Meningitis: ampicillin + gentamicin + cefotaxime
• LATE ONSET
  • Bacteremia: ampicillin (or vancomycin) + gentamicin (or cefotaxime)
  • Meningitis: ampicillin (or vancomycin) + gentamicin + cefotaxime
  • Cellulitis/adenitis: nafcillin (or vancomycin) + gentamicin (or cefotaxime)
  • UTI: ampicillin (or vancomycin) + gentamicin (or cefotaxime)
• Septic arthritis or osteomyelitis: nafcillin (or vancomycin) + cefotaxime

STAPHYLOCOCCUS AUREUS & EPIDERMIDIS

* STAPHYLOCOCCUS AUREUS: Look for gram-positive organisms in CLUSTERS on Gram staining. If Staph aureus is growing in the BLOOD, it requires prolonged IV antibiotics and an ECHOCARDIOGRAM to look for endocarditis! Please refer to the chart below for everything else you need to know about Staph aureus.

* COAGULASE NEGATIVE STAPHYLOCOCCUS (AKA CONS): STAPHYLOCOCCUS EPIDERMIDIS is a CONS. Regardless of what you learned in residency, if a blood culture comes back with “Coagulase negative Staphylococcus,” TREAT! And treat BIG, with VANCOMYCIN. Staph epi is extremely resistant to common antibiotics. Also, the final culture results may actually show MRSA, so never assume that it’s CONS until the identification comes back. Even then, make sure you have multiple blood cultures and a good clinical condition to force you to stop antibiotics!

PEARL: For SECONDARY BACTERIAL PERITONITIS in a patient on peritoneal dialysis, and for patients with a VENTRICULOPERITONEAL SHUNT (VPS) INFECTION, assume the organism causing the infection is methicillin-resistant Staphylococcus epidermidis. Treat with VANCOMYCIN until the culture results come back.

MNEMONIC: Don’t let CONS “con” you into leaving it alone. TREAT!