Dissemination of carbapenem-resistant Enterobacteriaceae (CRE) poses a considerable threat to public health. Infections caused by CRE have limited treatment options and have been associated with high mortality rates. This resistance is largely the consequence of acquisition of carbapenemase genes. The genotypes in the geographical areas were initially different, as the Japanese epidemic was related to the IMP type (Class B), whereas the US epidemic was related to the KPC type( Class A). Thus, clinical detection of carbapenemase producers remains difficult based on each genotypes has specific screening method. CRE has many problems: some carbapenemase producers were susceptible to the carbapenems and some CRE were not producing carbapenemase which is associated with porin loss or efflux pomp. This review describes the current situation of CRE. It would facilitate accurate detection of CRE and approaches to prevention and treatment.

The balance of “Host-Pathogen-Antimicrobials” is crucial for the establishment of infectious diseases. Recently the ineffective cases, even though the appropriate antibiotics use, have been increasing since the several ineludible problems are rising, such as varied patient’s background and the epidemic of the drug resistant pathogens, etc. Despite of the medical progression and the development of novel antimicrobials, the mortality of pneumonia has increased gradually and been the third cause of death in Japan. The conventional treatment depended on only bactericidal effect of antimicrobials faces a limit and the alternative strategies are required to overcome the current situation. This review addresses the potency of non-antibiotic antimicrobial agents as an alternative therapeutic strategy, especially focused on the activation of the innate host immunity induced by the macrolides and toll-like receptor agonist.

A study was conducted of the 1,225 Pseudomonas aeruginosa strains that were isolated at 20 medical institutions in the Kinki district between 2011 and 2013 to determine their antimicrobial susceptibility and to characterize the strains of multidrug-resistant Pseudomonas aeruginosa (MDRP) and the metallo-β-lactamase (MBL)-producing strains. The MIC₅₀/MIC⁹⁰ values (μg/mL) of the various antimicrobial agents were as follows: imipenem, 2/>8; meropenem, 1/>8; doripenem, 0.5/8; biapenem, 1/>8; tazobactam/piperacillin, 8/>64; piperacillin, 8/>64; sulbactam/cefoperazone, 8/64; cefepime, 4/16; cefozopran, 2/>16; aztreonam, 8/>16; amikacin, 4/16; levofloxacin, 1/>4; and ciprofloxacin, 0.25/>2. From the viewpoint of the annual changes in the susceptibility rates (according to the CLSI guidelines [M100-S22]), the susceptibility to tazobactam/piperacillin, piperacillin, cefepime, cefozopran and aztreonam decreased in 2013. On the other hand, two antimicrobial agents showed high susceptibility rates each year; amikacin (94.0–95.6%) showed the highest rate, followed by doripenem (80.3–82.6%). With the exception of amikacin, there were substantial inter-institutional differences in antimicrobial susceptibility. In comparison to the previous CLSI guidelines (M100-S21), the new CLSI guidelines (M100-S22) on the use of carbapenems and penicillins show that the MIC⁸⁰ has been affected. The MDRP detection rates in 2011, 2012 and 2013 were 1.8% (8 strains), 1.8% (8 strains), and 2.8% (10 strains), respectively. The MBL detection rates were as follows: bla_VIM-2, 0.2% (1 strain) in 2011; bla_IMP-1, 0.9% (4 strains) in 2012, and 1.7% (6 strains, including bla_IMP-1[3 strains], bla_IMP-2[2 strains] and bla_VIM-2[1 strain]) in 2013.

We herein discovered a highly resistant clinical isolate of Pseudomonas aeruginosa with MICs to amikacin, gentamicin, and arbekacin of 128 μg/mL or higher in a drug sensitivity survey of 92 strains isolated from the specimens of Yoka hospital patients between January 2009 and October 2010, and Achromobacter xylosoxidans was separated from this P. aeruginosa isolate. The sensitivity of this bacterium to 29 antibiotics was investigated. The MICs of this A. xylosoxidans strain to 9 aminoglycoside antibiotics were: amikacin, gentamicin, arbekacin, streptomycin, kanamycin, neomycin, and spectinomycin, 1,024 μg/mL or ≧1,024 μg/mL; netilmicin, 512 μg/mL; and tobramycin, 256 μg/mL. This strain was also resistant to dibekacin. This aminoglycoside antibiotic resistant phenotype is very rare, and we are the first report the emergence of A. xylosoxidans with this characteristic.