[Study on antibiotics susceptibility and mechanism of carbapenem-resistance in clinical isolates of Pseudomonas aeruginosa].
The susceptibility of 260 strains of Pseudomonas aeruginosa to several antibiotics and the mechanism of resistance to carbapenems were investigated. The number of strains of P. aeruginosa moderately resistant or resistant to ofloxacin, ceftazidime and imipenem (IPM) were 76 (29.2%), 31 (11.9%) and 30 (11.5%), respectively. There was no clear relationship between the drug resistance of P. aeruginosa and serum type. Fourteen strains (46.6%) out of 30 IPM-resistant strains were susceptible to meropenem (MEPM). Twenty seven (90.0%) IPM-resistant strains showed cross resistant to panipenem (PAPM), and 12 strains (44.4%) out of the 27 strains showed high susceptibility to MEPM. P. aeruginosa becomes resistant to IPM and PAPM only by the decrease in the outer membrane permeability of these carbapenems. In contrast, P. aeruginosa becomes equally resistant to MEPM by concurrent occurrence of the increase in the efflux of the antibiotics and the decrease in the outer membrane permeability of the antibiotics. The possibility that both mechanisms are taken place concurrently in P. aeruginosa is considered to be low, and it was also supported by the results of the present study.
Arita
K
K
Department of Respiratory Disease, Hiroshima Red Cross Hospital.
Daido
K
K
Ohashi
N
N
Nakamura
K
K
Takeshima
Y
Y
Kohara
T
T
D000890:Anti-Infective Agents / Q000494:pharmacology; D015780:Carbapenems / Q000494:pharmacology*; D002442:Ceftazidime / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D015378:Imipenem / Q000494:pharmacology; D000077731:Meropenem; D015242:Ofloxacin / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D013845:Thienamycins / Q000494:pharmacology; D018440:beta-Lactam Resistance
D000890:Anti-Infective Agents; D015780:Carbapenems; D002511:Cephalosporins; D013845:Thienamycins; D015378:Imipenem; D002442:Ceftazidime; D015242:Ofloxacin; D000077731:Meropenem; C039536:panipenem