Streptococci

• Gram-positive cocci, in pairs or chains. 

• Main pathogens are:

  • Group A streptococcus (S. pyogenes)

  • Group B streptococcus (S. agalactiae)

  • S. pneumoniae (pneumococcus)

  • Viridans streptococci (endocarditis)

Main clinical manifestations:

• Group A strep.

  • Tonsillitis

  • Wound infection

  • Cellulitis

  • Necrotising fasciitis

  • Puerperal sepsis (now rare)

  • Septicaemia

  • Recent increase in incidence in intravenous drug users.

• Group B strep.

  • UTI

  • neonatal sepsis

  • endocarditis

  • Increase risk in diabetics.  

• S. pneumoniae

  • pneumonia

  • meningitis

  • bone/joint infections 

  • Increased risk in asplenia/myeloma. 

Usually sensitive to:

• Penicillin

  • NOTE:  increase in acquired resistance to penicillin (more common in other European countries than in UK).

• Cephalosporins

• Macrolides (erythromycin, clarithromycin) (acquired resistance common)

• Glycopeptides (vancomycin, teicoplanin)

Usually resistant to:

• Ciprofloxacin

• Gentamicin (unless in combination with penicillin / glycopeptides)

• Trimethoprim

Page last edited: 25/07/2008

Caution; the antibiotic doses recommended on this website are intended for adult patients with normal renal and liver function unless otherwise stated. Dosing advice for patients with renal impairment is available here.

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