Heterogeneity of lipopolysaccharide chain size of Pseudomonas aeruginosa isolated from different clinical sources--with reference to gentamicin-susceptibility and serotype

Abstract

Lipopolysaccharide (LPS) compositions of P. aeruginosa isolated from from clinical sources such as blood, urine, pus, sputum, and feces were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and aminoglycoside-susceptibility and serotype of these isolates were investigated in this study. Fifty-nine isolates tested were divided into three groups according to the difference in their LPS compositions; 35 strains with the long-LPS chain (B-band LPS), 14 strains with the short chain (A-band LPS) and 10 LPS-deficient strains. The relationship between the LPS compositions and their sources of 59 strains were investigated. The majority of clinical isolates (12 of the 13 strains) from the blood samples possessed the long-LPS chain (B-band LPS) and the remaining possessed the short-LPS chain (A-band LPS). About 67% each of the isolates from urine and feces possessed the long-LPS chain, and the minor part of both groups possessed the short-LPS chain. In isolates from both sputum and pus samples, the long- and short-LPS chains were found at almost the same rate, and the LPS-deficient isolates were found in the sputum samples at a considerably high rate of 42%. The 19 of the 35 isolates with the long-LPS chain were susceptible to gentamicin (54%) and 12 isolates were resistant (34%). On the other hand, the 14 isolates with the short chain were divided roughly into three groups, gentamicin-resistant, and -susceptible groups and intermediate groups. It was also notable that 7 of the 10 LPS-deficient isolates were resistant to gentamicin.(ABSTRACT TRUNCATED AT 250 WORDS)