[Antibacterial activities of monobactams against fresh clinical isolates].
Antibacterial activities of monobactam antibiotics (carumonam (CRMN) and aztreonam (AZT] against Gram-negative bacilli isolated from inpatients in the latter half of 1987 were investigated using penicillin (PC: piperacillin (PIPC], cephems (CEPs: ceftazidime (CAZ), cefotaxime (CTX), latamoxef (LMOX), cefsulodin (CFS], carbapenem (imipenem (IPM] and pyridonecarboxylic acids (norfloxacin (NFLX) and ofloxacin (OFLX] as reference antibiotics. A total of 400 strains of 13 species, i.e. Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia rettgeri, Citrobacter freundii, Enterobacter cloacae, Enterobacter aerogenes, Serratia marcescens, Pseudomonas aeruginosa and Haemophilus influenzae, were used as test strains. 1. CRMN and AZT, both monobactam antibiotics, were roughly comparable in their activities and no resistant strain to these antibiotics were found among isolates of E. coli, Klebsiella spp., Proteus spp., M. morganii, P. rettgeri or H. influenzae and few resistant strains were observed among isolates of S. marcescens. On the other hand, isolates of C. freundii, Enterobacter spp. and P. aeruginosa included rather numerous strains resistant to the monobactam antibiotics. Among these cases, whereas R strains, i.e. resistant strains showing MICs greater than or equal to 50 micrograms/ml, accounted for a large proportion of strains resistant to PC and CEPs, I strains, i.e. intermediately resistant strains showing MICs between 12.5 and 25 micrograms/ml, accounted for a large proportion of strains resistant to the monobactam antibiotics. 2. Strains resistant to PIPC, a PC, were detected with high and more or less uniform frequencies over the entire spectrum of the isolates examined. 3. Antibacterial activities of CEPs varied against different bacterial species. While strains resistant to CTX, CAZ and LMOX were commonly detected with high frequencies among isolates of C. freundii, Enterobacter spp. and S. marcescens, large percentages of LMOX-resistant strains of C. freundii and Enterobacter spp. were of the I type. CTX-resistant strains were also found among isolates of P. vulgaris and M. morganii. Proportions of CEP-resistant strains of P. aeruginosa were 28% for CFS and 12% for CAZ. 4. No or few strains among the isolates of 13 species investigated were resistant to IPM, a carbapenem antibiotic, which showed the most stable antibacterial activity, but it was less active than monobactam antibiotics and CEPs against Klebsiella spp., P. mirabilis and H. influenzae.(ABSTRACT TRUNCATED AT 400 WORDS)
Deguchi
K
K
Section of Studies, Tokyo Clinical Research Center.
Yokota
N
N
Koguchi
M
M
Nakane
Y
Y
Fukayama
S
S
Nishimura
Y
Y
Oda
S
S
Tanaka
S
S
Kato
M
M
Sato
K
K
D042462:4-Quinolones; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology; D001398:Aztreonam / Q000031:analogs & derivatives / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D001424:Bacterial Infections / Q000382:microbiology; D004352:Drug Resistance, Microbial; D006801:Humans; D008997:Monobactams / Q000494:pharmacology*
D042462:4-Quinolones; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D008997:Monobactams; C044145:carumonam; D001398:Aztreonam