[Alteration of serotype and drug susceptibility of some Pseudomonas aeruginosa isolates by exposure to human serum and polymorphonuclear leukocytes].
In the presence of 40% human serum plus polymorphonuclear leukocytes (PMNs, 10(7) cells/ml), changes in the surface properties of clinical isolates of P. aeruginosa were investigated by determining their serotypes and pyocin types as the markers. Furthermore, three isolates were tested for their susceptibility to anti-pseudomonal drugs and profiles of outer membrane proteins by the SDS-PAGE analysis. P. aeruginosa No. 21 which did not change in serotype and pyocin type after exposure to serum plus PMNs did not alter their susceptibility to all the drugs tested or their profiles of OMPs. In the case of P. aeruginosa No. 1-S, the variants with different serotypes were formed after the exposure, and increased their susceptibilities to some beta-lactams and norfloxacin which could penetrate into the bacterial cells through the porin channels of the outer membrane. Furthermore, two of the three type variants formed decreased their susceptibilities to gentamicin and polymyxin B which penetrated into the cells by the self-promoted uptake pathway. P. aeruginosa No. 1-R formed the serotype A and G variants with different pyocin types, only when exposed to serum plus PMNs for 24 hours, and the results were accompanied by the appearance of the porin D2 which was not detected in the parent cells. A small number of P. aeruginosa formed the variants with different serotypes and pyocin types owing to the alteration of their surface structures, when the cells were exposed to serum plus PMNs. The alterations were accompanied by the changes in some outer membrane proteins and the drug susceptibility to anti-pseudomonal drugs.(ABSTRACT TRUNCATED AT 250 WORDS)
Chemotherapy Division, Mitsubishi Yuka Bio Clinical Laboratories, Inc. Tokyo.
I
I
Kobayashi
M
M
Hasegawa
M
M
Nishida
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001790:Blood Physiological Phenomena; D006801:Humans; D008826:Microbial Sensitivity Tests; D009504:Neutrophils / Q000502:physiology*; D011550:Pseudomonas aeruginosa / Q000145:classification* / Q000187:drug effects; D012703:Serotyping
D000900:Anti-Bacterial Agents