TABLE 2.

Polyamine effects on MICs of antibiotics in clinical isolates of P. aeruginosaa

Strain no.MIC (μg/ml) for indicated antibiotic and treatment
CarbenicillinChloramphenicolCiprofloxacinPolymyxin B
NoneSpNSpDNoneSpNSpDNoneSpNSpDNoneSpNSpD
PAO1644412832320.1250.2511416
F498025681632224420.250.52
F6633625681680.520.5210.1250.50.5
H4563>1,02464321642128420.1250.50.5
M22152>1,024646416224420.512
M373101,024323216442420.1250.50.5
M38100A166432484248<0.06<0.06<0.06
M38100B1,0243232168832841641
T209525681632442440.1250.50.5
T5177>1,024646416222420.512
T626816241622444144
T15464>1,024643232822440.512
  • a Spermine (SpN; 1 mM) and spermidine (SpD; 20 mM) were used for MIC measurements. These concentrations of polyamines did not affect the growth of clinical isolates.