ROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a worldwide epidemiologic survey for investigating drug susceptibility against major bacterial pathogens in respiratory tract infections, and that is also designed to identify the action mechanism of telithromycin (TEL), a ketolide antibacterial agent, on the resistant Streptococcus pneumoniae and the resistance mechanism for TEL on the TEL-resistant S. pneumoniae strain, in addition to determine macrolide/ketolide resistant S. pneumoniaeactivities of TEL using molecular analysis.
TEL exerted the antibacterial action on the macrolide-resistant S. pneumoniae regardless maintaining the macrolide-resistant mechanism and exhibited the potent antibacterial activity against all of ermB gene-positive strains, mefA gene-positive strains and ribosome variants. This result was considered to reflect the fact that TEL did not induce resistance to ermB and had extremely low ability to select resistant strain by mutation. These actions of TEL were considered to be derived from its novel chemical structure and might be characteristics of ketolides not possessed by macrolides.
In the survey of PROTEKT in 1999 to 2002, among 13,864 strains of S. pneumoniae isolated worldwide, ketolide-resistant strain (TEL MIC≥4μg/ml) was observed in 10 strains (0.07%). MIC of these 10 strains was 4 or 8ug/mL and all of these strains were ermB-positive strains. Based on this fact, potential involvement of adenine demethylase (ermB gene product) was considered in the background of development of ketolide-resistant S. pneumoniae.

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Antimicrobial susceptibility of Pseudomonas aeruginosa isolated at Kochi Municipal Central Hospital between 2001 and 2003 was assessed according to the NCCLS interpretive criteria.
1. The piperacillin-susceptible rate was 92.9%.
2. Among cephem antibiotics, the ceftazidime-susceptible rate was the highest (96.0%).
3. As for aminoglycosides, susceptibility to tobramycin and amikacin remained with a susceptible rate of 93.2% and 94.8%, respectively.
4. The carbapenem-susceptibility remained high. The susceptible rate for meropenem (94.1%) was higher than that for imipenem (88.3%).
5. Acquisition of resistance was observed in urinary isolates. Four multi-drug resistant P aeruginosa, which are resistant to all of imipenem, amikacin and ofloxacin were isolated in this study and all were isolated from urine.
6. Of 388 isolates, 34 isolates were resistant to imipenem, but no positive isolate was found in screening of metallo-β-lactamase-producing bacteria.

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The minimum inhibitory concentration (MIC) and bactericidal activity of chlorhexidine gluconate (CHG) were determined for methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Escherichia coli, Serratia marcescens, Eterobacter cloacae, Pseudomonas aeruginosa and Burkholderia cepacia, isolated from patients in medical institutions all over Japan between 2000 and 2002.
The following findings were obtained.
1. The MICs of CHG against MSSA, MRSA, E. coli and B. cepacia were 0.002% or less, and those against S. marcescens, E. cloacae and P. aeruginosa were 0.008% or less.
2. Rapid and strong bactericidal effects of CHG were observed against all clinical isolates of E. coli, E. cloacae and P. aeruginosa tested even at relatively low concentrations (0.02 to 0.05%).
3. Relatively high concentration or prolonged treatment time was required to achieve sufficient bactericidal effect of CHG against some isolates of S. aureus, S. marcescens and B. cepacia.
These results suggest that CHG is useful antiseptic agent or disinfectant for recent clinical isolates of various bacterial pathogens. In addition, the selection of treatment concentrationand treatment time for each organism and purpose was important to obtain sufficient bactericidal effect.

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