Carbapenems are the most potent real estate agents for treating attacks by Gram-negative bacterias because of the stability with regards to the most -lactamases and their higher rate of penetration through the bacterial outer membranes. (5, 8, 9), as well as the PCR items from the metallo–lactamase gene had been sequenced. All 54 isolates had been positive for the IMP-1 type but adverse for IMP-2, VIM-1, and VIM-2 types by PCR. Sequencing exposed that 49 from the 54 isolates transported IMP-6 and five transported IMP-1. From the 49 IMP-6-positive isolates, all had been positive for CTX-M, 23 had been positive for TEM, and non-e had been positive for SHV by PCR. All IMP-6-positive isolates demonstrated 100% susceptibility to imipenem and 71.4% susceptibility to meropenem based on the criteria from the Clinical and Lab Specifications Institute (Desk 1) (3). Desk 1 Activity of varied antimicrobial agents against 49 IMP-6-positive isolates of were isolated in Japan and that those strains were also resistant to meropenem but susceptible to imipenem (10). In our study, the susceptibility rate of IMP-6-positive was higher for imipenem than meropenem (100% versus 71.4%). In Japan, imipenem is often used as a representative carbapenem for susceptibility testing (10), so IMP-6-producing isolates may be falsely categorized as susceptible if imipenem is tested. Weisenberg et al. reported that KPC-producing strains seem susceptible to carbapenems according to routine testing, although clinical and microbiological failure Atosiban are frequent when these agents are chosen (11). Therefore, when IMP-6-producing isolates are falsely categorized as susceptible and treated with carbapenems, clinical and microbiological failure may occur, as happens with KPC producers. Meropenem is widely used for the treatment of severe Gram-negative infections, because it is slightly more active than imipenem against Gram-negative bacteria (1). Accordingly, IMP-6-producing isolates may be selected by use of carbapenems, especially meropenem, becoming a major problem for antimicrobial therapy in Japan. Therefore, it is necessary to establish a laboratory Atosiban screening method for these isolates, and further research, including keying in of evaluation and integrons using multilocus series keying in, is needed. June 2012 Contributor Info Shiro Endo Footnotes Released before printing 4, Division of Disease Lab and Control Diagnostics Internal Medication Tohoku College or university Graduate College of Medication Miyagi, Japan. Risako Kakuta, Division of Otolaryngology Throat and Mind Operation Tohoku College or university Graduate College of Medication Miyagi, Japan. Masumitsu Hatta, Division of Disease Control and Lab Diagnostics Internal Medication Tohoku College or university Graduate College of Medication Miyagi, Japan. Mitsuhiro Yamada, Division of Regional Assistance for Infectious Illnesses Tohoku University Graduate School of Medicine Miyagi, Japan. Koichi Tokuda, Department of Contamination Control and Laboratory Diagnostics Internal Medicine Tohoku University Graduate School of Medicine Miyagi, Japan. Mitsuo Kaku, Department of Contamination Control and Laboratory Diagnostics Internal Medicine Tohoku University Graduate School of Medicine Miyagi, Japan. REFERENCES 1. Baldwin CM, Lyseng-Williamson KA, Keam SJ. 2008. Meropenem: a review of its use in the treatment of serious bacterial infections. Drugs 68:803C838 [PubMed] 2. Clinical and Laboratory Standards Institute 2009. Methods for dilution antimicrobial susceptibility assessments for bacteria that grow aerobically; approved standard8th edition. M07-A8 Clinical and Laboratory Standards Institute, Wayne, PA 3. Clinical and Laboratory Standards Institute 2011. Performance standards for antimicrobial susceptibility testing: 21st informational supplement. M100-S21 Clinical and Laboratory Standards Institute, Wayne, PA 4. Hirakata Y, et al. 1998. Rapid detection and evaluation of clinical characteristics of emerging multiple-drug-resistant gram-negative rods carrying the metallo–lactamase gene blaIMP. Antimicrob. Brokers Chemother. 42:2006C2011 [PMC free article] [PubMed] 5. Kanamori H, et al. 2011. High prevalence of extended-spectrum -lactamases and qnr determinants in Citrobacter species from Japan: dissemination of CTX-M-2. J. Antimicrob. Chemother. 66:2255C2262 [PubMed] 6. Kurokawa H, Yagi T, Shibata N, Shibayama K, Arakawa Y. 1999. Worldwide proliferation LIPB1 antibody of carbapenem-resistant gram-negative bacteria. Lancet 354:955 doi:10.1016/S0140-6736(05)75707-X [PubMed] 7. Nishio H, et al. 2004. Metallo–lactamase-producing gram-negative bacilli: laboratory-based surveillance in cooperation with 13 clinical laboratories in the Kinki region of Japan. J. Clin. Microbiol. 42:5256C5263 [PMC free article] [PubMed] 8. Queenan AM, Bush K. 2007. Carbapenemases: the versatile -lactamases. Clin. Microbiol. Rev. 20:440C458 [PMC free article] [PubMed] 9. Seok Y, et al. 2011. Dissemination of IMP-6 metallo–lactamase-producing Pseudomonas aeruginosa sequence type 235 in Korea. J. Antimicrob. Chemother. 66:2791C2796 [PubMed] 10. Shigemoto N, et al. 2012. Emergence in Japan of an imipenem-susceptible, meropenem-resistant Klebsiella pneumoniae carrying blaIMP-6. Diagn. Microbiol. Atosiban Infect. Dis. 72:109C112 [PubMed] 11. Weisenberg SA, Morgan DJ, Espinal-Witter R, Larone DH. 2009. Clinical outcomes of patients with Klebsiella pneumoniae carbapenemase-producing K. pneumoniae after treatment with imipenem or meropenem. Diagn. Microbiol. Infect. Dis. 64:233C235 [PMC free article] [PubMed] 12. Yano H, et al. 2001. Plasmid-encoded metallo–lactamase (IMP-6) conferring resistance Atosiban to carbapenems, especially meropenem. Antimicrob. Brokers Chemother. 45:1343C1348 [PMC free.