[Influences of %T>MIC achievement probability due to the difference of the MIC measurement concentration range-analysis of meropenem for Pseudomonas aeruginosa-].

We attempted to analyze any influences to %T>MIC achievement probability due to the difference of the MIC measurement concentration range of MEPM for 613 strains of Pseudomonas aeruginosa by the Monte Carlo simulation method. As for the analysis, we calculated the achievement probability of 30% and 50% for MEPM %T>MIC by the administration volume of MEPM: 250 mg, 500 mg, and 1,000 mg, the administration time: 0.5 h, and 3 h, the administration frequency: 2 times, and 3 times, and the renal excretion capability: Normal, Slight, Moderate, and High abnormal with the 3 types of MIC concentration measurement level 1) <=0.06~>=256 µg/ml: 13 levels, 2) <=0.5~>=32 µg/ml: 7 levels, and 3) <=1~>=16 µg/ml: 5 levels. As the result, we found the following findings; 1. In terms of the administration of normal renal excretion capability, 250 mg, in comparison with 500 mg and 1,000 mg, indicated the differential due to the difference of MIC measurement concentration range. 2. The administration volume of MEPM 500 mg which has been recommended shown the less differential of the achievement probability due to the difference of MIC measurement concentration range. As the renal excretion was shifted through Normal to Slight to Moderate to High abnormal, the differential of the achievement probability due to the difference of MIC measurement concentration range was gradually decreased. With these results, PK/PD analysis is possible for the 5 levels measurement concentration. It is significant that the facility using the automated microbiology analyzer can provide not only the MIC report, but also the information on the appropriate administration method for antibacterial drug by PK/PD analysis.

[Clinical significance on MicroScan Rapid plus series using various antibiotic-resistant bacteria].

MicroScan Rapid plus Neg II Series and MicroScan Rapid plus Pos Series by Siemens Healthcare Diagnostics K.K. are the panels which enable to measure identification and antimicrobial susceptibility testing quickly and we have confirmed that it is useful for detecting drug resistance bacteria. As the identification result of comparing Rapid plus series with the current panel by using 143 strains of various drug resistance bacteria, Gram positive cocci was 87. 7%, glucose fermenter was 100% and glucose non-fermenter was 77.3 in Gram negative bacilli. On the evaluation of antimicrobial susceptibility testing, Rapid plus series, in comparison with the current panel, confirmed the lower tendency of MIC value on some drugs, but it basically presented the good concordance rate. In terms of the reporting time of antimicrobial agent, non-fermenter or MRCNS reported the result as needed after 8 hours and it took a little longer time for the report of antimicrobial agent. On the other hand, 80% or higher of antimicrobial agent on panel was reported for intestinal bacteria in 4.5 hours and for MRSA in 6.5 hours. It enabled to report the testing result on the same day. Due to the results above, Rapid plus series was highly valued on the usability, such as the early detection of drug resistance bacteria and the selection of therapeutic agents.

[The isolation frequency and antimicrobial susceptibility of Haemophilus influenzae isolated in Saga University Hospital].

Isolation frequency and antimicrobial susceptibility of Haemophilus influenzae isolated in Saga University hospital from October 2002 to September 2003 were investigated. Out of 155 H. influenzae strains subjected 77 were isolated from pediatrics specimens. beta-Lactamase negative ampicillin (ABPC)-resistant H. influenzae (BLNAR), against which MICs of ABPC were higher than 4 microg/mL, were 32 strains (20.6%), and it became 63 strains (41.3%) when Low-BLNAR, against which MICs of ABPC were higher than 2 microg/mL, were included. beta-Lactamase positive ABPC-resistant H. influenzae (BLPAR) were 8 strains (5.2%). Although those BLNAR were also resistant to variety of beta-lactams, fluoroquinolones and other antibiotics were not affected by the level of ABPC-resistance. Resistant strains of BLPAR against SBT/ABPC, a combination of a beta-lactamase inhibitor, were detected but all of them were sensitive to TAZ/PIPC, an another combination. Those strains were able to be considered as beta-lactamase positive amoxicillin-clavulanate resistant H. influenzae (BLPACR). PIPC, TAZ/PIPC, CTRX, CDTR, MEPM, LVFX and CPFX showed good activity among tested antibiotics.

[Antibacterial activity of oral Cephems against various clinically isolated strains].

We determined the antibacterial activities of oral Cephems against isolated from the patients with the respiratory infections, the urinary tract infections, and infections in the obstetrics field of an adult and a child, during the period from 2002 to 2003; Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, Branhamella catarrhalis, Klebsiella pneumoniae and Escherichia coli of 40 strains of each, and Peptostreptococcus spp. 22 strains. S. pneumoniae and H. influenzae strains that resistant is regarded were collected mainly, penicillin-intermediate S. pneumoniae (PISP), penicillin-resistant S. pneumoniae (PRSP) and beta-lactamase negative ampicillin-resistant H. influenzae (BLNAR) strains. The MICs of Cephems except cefaclor (CCL) were < or = 0.03 microgram/mL against all strains of S. pyogenes. The MICs of cefteram (CFTM) and cefditoren (CDTR) were < or = 0.0125 microgram/mL activity against 7 strains penicillin-susceptible S. pneumoniae (PSSP). However the MIC90s of cefditoren (CDTR) was 1 microgram/mL, cefteram (CFTM), and cefcapene (CFPN) were 2 micrograms/mL against PISP and PRSP, were higher than those of other drugs, but showed slightly higher than PSSP. The MIC90s of Cephems. were 0.5-4 micrograms/mL against strains of E. coli. The MIC90s of CFTM was 0.5 microgram/mL, and CDTR, CFPN were 1 microgram/mL against E. coli were higher than those of other drugs. The four strains of E. coli however were highly-resistant which MIC90s of CCL were more than 32 micrograms/mL were obtains. Furthermore it is necessary to pay much attention to the trend of resistant such as E. coli of Cephems. Although all strains showed resistant to AMPC, MIC90 of Cephems were 0.25-1 microgram/mL, good activities against K. pneumoniae. Against beta-lactamase negative ampicillin-susceptible H. influenzae (BLNAS) 23 strains the MIC90s of CCL and other Cephems were 64 micrograms/mL and 0.25-8 micrograms/mL. The MIC90s of CDTR and CFTM were < or = 1 microgram/mL of BLNAR (15 strains). However there of CFDN and CPDX were 8 micrograms/mL and CCL were > or = 16 micrograms/mL. Two strains which were produced beta-lactamase were highly--ABPC resistant. Although B. catarrhalis all strains were produced beta-lactamase and Cephems except for CCL showed better susceptibility than AMPC. The MIC90s of Cephems were 0.25-2 micrograms/mL against Peptostreptococcus spp.