title: Specific role of sex pili in the effective eliminatory action of sodium dodecyl sulfate on sex and drug resistance factors in Escherichia coli.
abstract: Evidence is presented for the specific role of sex pili in the eliminatory action of sodium dodecyl sulfate (SDS) on sex (F) and drug resistance (R) factors in Escherichia coli K-12 strains leading to their loss. SDS at 0.03% concentration lysed JE3100 F(8) (+) (F-gal)/gal(-)fla(-)pil(-) in Penassay broth after they had grown exponentially and reached maximum growth to the extent that the agent at concentrations higher than 1% did. However, the agent was only effective in eliminating sex factors from JE3100 in high frequencies at concentrations higher than 1%. Increase of osmotic pressure of the culture with SDS at concentrations as low as 0.03 to 0.1% by addition of sucrose led to the substantial increase of elimination efficiency. Reconstruction experiments between F(8) (+) and F(-) cells in the SDS culture revealed the selective growth of F(-) cells as well as a delay of maximum growth of F(-) variants derived from F(8) (+) cells, compared with those of F(8) (+) cells, as well as F(-) cells originally added to the culture. The agent was not very effective in eliminating sex factors from JE3427 F(8)m(+)5/fla(-)pil(-) cells which lack the function of production of F pili. F(8)m(+)5 cells showed a sensitivity toward SDS intermediate between those of F(8) (+) and F(-) cells. SDS was further effective in eliminating R factors from KE132 R(100-1) (+)/fla(-)pil(-) cells in high efficiency; however, the action was not efficient with KE133 F(100) (+) cells possibly with fewer sex pili than R(100-1) (+). Action of acridine orange on these F(+) or R(+) strains was found to be different in some aspects from that of SDS.
mesh_terms: D000166:Acridines / Q000494:pharmacology; D001431:Bacteriological Techniques; D001433:Bacteriolysis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003090:Coliphages; D003227:Conjugation, Genetic / Q000187:drug effects; D003470:Culture Media; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development; D005233:Fatty Alcohols / Q000494:pharmacology; D005407:Flagella; D014644:Genetic Variation; D008242:Lysogeny; D008297:Male; D009154:Mutation; D009997:Osmotic Pressure; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013395:Sucrose; D013501:Surface-Active Agents / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000166:Acridines; D003470:Culture Media; D005233:Fatty Alcohols; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate; D013395:Sucrose