Changes in bacterial isolates from burn wounds and their antibiograms: a 20-year study (1986-2005).
BACKGROUND
Our aim is to elucidate shifts in the bacterial spectrum colonising burn wounds and corresponding antibiotic susceptibilities during a 20-year study period.


METHODS
Microbiological results from burn patients collected between 1986 and 2005 were analysed retrospectively.


RESULTS
Staphylococcus aureus was isolated most frequently (20.8%), followed by Escherichia coli (13.9%), Pseudomonas aeruginosa (11.8%), coagulase-negative staphylococci (CNS) (10.9%), Enterococcus sp. (9.7%), Enterobacter cloacae (5.6%), Klebsiella pneumoniae (5%), Acinetobacter sp. (3.2%), Proteus mirabilis (2%) and Stenotrophomonas maltophilia (1.4%). Susceptibility of S. aureus to broad-spectrum substances such as ciprofloxacin or penicillinase-stable penicillins has waned, others such as cotrimoxazole or netilmicin remained effective. Not a single resistance against vancomycin was recorded. Increases in methicillin-resistant S. aureus (MRSA) were pronounced (3% in 1986-1997 (the first of the three study periods) to 16% in 1998-2001 and 13% in 2002-2005). Results for methicillin-resistant CNS (MRCNS) show an even greater increase. P. aeruginosa has shown increasing susceptibility against netilmicin (1986-1989: 84%, 2002-2005: 95%). Susceptibility of P. aeruginosa to ceftazidime has decreased markedly. S. maltophilia has shown clinically relevant susceptibility mainly against ciprofloxacin. Acinetobacter sp. have shown little susceptibility to most antibiotics. Imipenem or meropenem have been very reliable reserve antibiotics throughout the study period for the fermenting Enterobacteriaceae (E. coli, K. pneumoniae, E. cloacae and P. mirabilis), with susceptibilities of or near 100%.


CONCLUSIONS
In-depth knowledge of the bacteria causing infectious complications and of their antibiotic susceptibilities is a prerequisite for treating burn patients. Our study shows shifts in the microbial spectrum and their antibiogram, which mandate frequent reassessments.
Guggenheim
Merlin
M
Division of Hand, Plastic and Reconstructive Surgery, University Hospital Zurich, Zurich, Switzerland. Merlin@gmx.ch
Zbinden
Reinhard
R
Handschin
Alexander E
AE
Gohritz
Andreas
A
Altintas
Mehmet A
MA
Giovanoli
Pietro
P
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002056:Burns / Q000382:microbiology* / Q000401:mortality; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000302:isolation & purification*; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D012189:Retrospective Studies; D013997:Time Factors
D000900:Anti-Bacterial Agents