Comprehensive assessment of tigecycline activity tested against a worldwide collection of Acinetobacter spp. (2005–2009)

A total of 5127 Acinetobacter spp. were collected from 140 hospitals in 32 countries in North America (17.1%), Europe (22.9%), Latin America (25.2%), and the Asia-Pacific (APAC) region (34.8%). Tigecycline MIC distributions were bimodal against isolates from North America and APAC region, while a unimodal pattern was noted for strains from Latin America. A variable MIC distribution was noted in Europe. Only tigecycline (MIC50/90, 0.5/2 μg/mL) and polymyxin B (MIC50/90, 0.5/1 μg/mL; 98.6% susceptible) exhibited high activity against Acinetobacter spp. Overall, tigecycline inhibited at least 90.0% of Acinetobacter spp. isolates from all countries evaluated at ≤2 μg/mL, as well as 95.0% of those displaying multidrug resistance. Other tested agents showed limited activity and a significant (P < 0.001) trend toward decreased susceptibility during the study period.