Serratia marcescens endocarditis: a regional illness associated with intravenous drug abuse

Ann Intern Med. 1976 Jan;84(1):29-35. doi: 10.7326/0003-4819-84-1-29.


From 1969 to 1974, 19 cases of Serratia marcescens endocarditis were observed in the San Francisco Bay Area. Seventeen patients were intravenous drug users, and Serratia caused 14% of all addict-associated endocarditis in San Francisco. Serratia strains were nonpigmented and had typical antibiotic sensitivities, except that 9 of the isolates exhibited colonial variation, with each variant having different antibiotic sensitivities. Aortic or mitral valves were involved in 13 patients, and heart failure developed in 9 of these. Twelve patients had embolic episodes to brain, iliofemoral arteries, or lung. Five of 6 patients with tricuspid valvulitis were cured by antibiotics either with (1) or without excision of the valve. All 12 patients with aortic or mitral valvulitis treated medically died; 11 had unremitting sepsis. Aortic valve replacement and antibiotics were effective in 1. Gentamicin combined with either carbenicillin or chloramphenicol was the most effective treatment regimen.

MeSH terms

  • Adult
  • Aged
  • Aortic Valve
  • California
  • Carbenicillin / therapeutic use
  • Chloramphenicol / therapeutic use
  • Drug Therapy, Combination
  • Endocarditis, Bacterial / drug therapy
  • Endocarditis, Bacterial / epidemiology
  • Endocarditis, Bacterial / etiology*
  • Female
  • Gentamicins / therapeutic use
  • Heart Valve Prosthesis
  • Humans
  • Kanamycin / therapeutic use
  • Male
  • Middle Aged
  • Serratia marcescens / isolation & purification*
  • Substance-Related Disorders / complications*


  • Gentamicins
  • Kanamycin
  • Chloramphenicol
  • Carbenicillin