Methods: SMART is an on-going world-wide surveillance study that collects and tests consecutive clinical isolates from intra-abdominal, urinary, and lower respiratory tract sources since 2002. A total of 145 sequenced Kp KPC isolates were studied, 98 from SMART and an additional 47 isolates received as referrals from clinical laboratories. Susceptibility to IMI in the presence and absence of REL at a fixed concentration of 4 µg/mL was determined and the KPC sequence sub-type determined by PCR. Susceptibility results were analysed by KPC sub-type with an unpaired t-test using PRISM 6.04.
Results: Among 145 KPC-expressing Kp the % S increased from 9.9% to 98 % in the presence of REL.
Conclusion: REL restored activity to 98 % of KPC-expressing Kp. Although the geometric mean MIC of KPC-2 vs. KPC-3 producers comparison was statistically significant, the variability was within a microbroth 2-fold dilution (0.41 vs. 0.29), and the mean MICs were less than 2-fold below the CLSI MIC for IMI (1 µg/mL). Since most clinical labs do not have simple systems to determine KPC sub-type it is important that a new therapy cover equally the most widely circulating isolates. Therefore, IMI/REL represents a distinct advantage in antibacterial therapy.
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D. Tatosian, Merck & Co., Inc.: Employee and Shareholder , Salary