Multidrug-resistant Acinetobacter baumannii, Russia

Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 4, April 2007 669 levels of susceptibility because the MIC50 was only 1 dilution below the current breakpoint (7,8). Aztreonam resistance could not be transferred by conjugation between IMP-1–producing (aztreonam-resistant) P. putida and P. aeruginosa (2) and is not associated with a transposon carrying blaVIM-2 (6). No evidence of extended-spectrum β-lactamases was detected in our isolates by classic synergy assays with clavulanate plus aztreonam, ceftazidime, or cefotaxime. VIM6–producing P. putida isolates from Singapore (9) were more resistant to aztreonam (MIC >128 μg/mL), ceftazidime, and cefepime (MIC >256 μg/mL). Detection of blaVIM-2 in Pseudomonas in South America was initially reported by the SENTRY Antimicrobial Surveillance Program (10) and included 1 P. fluorescens isolate in Chile and 3 P. aeruginosa isolates in Venezuela. To the best of our knowledge, our report is the first of VIM-2 in P. putida in Latin America. VIM-2–producing P. putida, which were originally restricted to East Asia and only very recently found in France, may represent an emerging pathogen or function as reservoirs for resistance because of their widespread presence in the hospital environment.