Molecular epidemiology of gram-negative bacteremia.
We did pulsed field gel electrophoresis (PFGE) and antibiotic susceptibility testing on 202 gram-negative isolates obtained from blood cultures between 1 January 1989 and 31 December 1993. Seventy-eight patients had at least two gram-negative isolates of the same species recovered from blood drawn one or more days apart and met the other study criteria. Twenty patients had only 1 bloodstream infection, 48 patients had 1 recurrence of bacteremia, and 10 patients had > 1 recurrence of bacteremia. Of 80 recurrences of bacteremia, 52 (65%) were relapses and 28 (35%) were reinfections. Seventy-eight percent of the episodes of bacteremia occurring < or = 300 days apart were relapses, and 100% occurring > 300 days apart were reinfections (P < .001). Organisms causing recurrent bacteremia were not more resistant than those causing initial episodes. In conclusion, most episodes of recurrent gram-negative bacteremia were relapses. Relapses and reinfections could not be distinguished only by the length of time between episodes or by antimicrobial susceptibility patterns.
Wendt
C
C
Department of Internal Medicine, University of Iowa Hospitals and Clinics, and The Veterans Affairs Medical Center, Iowa City 52242-1081, USA.
Messer
S A
SA
Hollis
R J
RJ
Pfaller
M A
MA
Wenzel
R P
RP
Herwaldt
L A
LA
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D015373:Bacterial Typing Techniques; D001769:Blood / Q000382:microbiology; D016521:Electrophoresis, Gel, Pulsed-Field; D006090:Gram-Negative Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D012008:Recurrence
D000900:Anti-Bacterial Agents