Multicenter studies of tigecycline disk diffusion susceptibility results for Acinetobacter spp.
Acinetobacter sp. isolates having multidrug resistance (MDR) patterns have become common in many medical centers worldwide, limiting therapeutic options. A five-center study tested 103 contemporary clinical Acinetobacter spp., including MDR strains, by reference broth microdilution and disk diffusion (15-mug disk content) methods against tigecycline. Applying U.S. Food and Drug Administration tigecycline breakpoint criteria for Enterobacteriaceae (susceptibility at < or =2 microg/ml [< or =1 microg/ml by the European Committee on Antimicrobial Susceptibility Testing]; disk diffusion breakpoints at > or =19 mm and < or =14 mm) to Acinetobacter spp. led to an unacceptable error rate (23.3%). However, an adjustment of tigecycline disk diffusion breakpoints (susceptible/resistant) to > or =16/ < or =12 mm reduced intermethod errors to an acceptable level (only 9.7%, all minor).
Jones
Ronald N
RN
JMI Laboratories, North Liberty, IA 52317, USA. ronald-jones@jmilabs.com
Ferraro
Mary Jane
MJ
Reller
L Barth
LB
Schreckenberger
Paul C
PC
Swenson
Jana M
JM
Sader
Helio S
HS
D000150:Acinetobacter / Q000145:classification / Q000187:drug effects*; D000151:Acinetobacter Infections / Q000382:microbiology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D008911:Minocycline / Q000031:analogs & derivatives* / Q000494:pharmacology; D000078304:Tigecycline
D000900:Anti-Bacterial Agents; D000078304:Tigecycline; D008911:Minocycline