[In vitro antibacterial activities of carbapenems and other antibiotics against Pseudomonas aeruginosa determined using low-amino-acid agar].
MICs of imipenem (IPM), panipenem (PAPM), cefozopran (CZOP), cefpirome (CPR), gentamicin (GM), tobramycin (TOB) and amikacin (AMK) against Pseudomonas aeruginosa were determined using Mueller-Hinton agar and low-amino-acid agar. On Mueller-Hinton agar, the antibacterial activity of TOB was superlative, followed in order by GM, CZOP, IPM, AMK, PAPM and CPR, whereas on low-amino-acid agar, the order changed to IPM, PAPM, TOB, CZOP, GM, AMK and CPR. The largest decrease of MICs was seen with PAPM on low-amino-acid agar, and the antibacterial activity of PAPM was not stronger than that of IPM. The growth of P. aeruginosa on the low-amino-acid agar were significantly weaker than that on Mueller-Hinton agar, hence the evaluation of appearance colonies was difficult and misjudgement may result. Based on the above observations, we believe further investigations are needed before the application of low-amino-acid agar becomes routine.
Department of Central Clinical Laboratories, Tokyo Metropolitan Police Hospital.
M
M
Kouda
I
I
Udagawa
J
J
Fukuhara
K
K
Tamura
H
H
Matsuzaki
D000362:Agar; D000596:Amino Acids; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015780:Carbapenems / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology; D003470:Culture Media; D004352:Drug Resistance, Microbial; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification
D000596:Amino Acids; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D015780:Carbapenems; D002511:Cephalosporins; D003470:Culture Media; D000362:Agar