Twenty three trimethylammonium (TMA) derivatives were tested for their action on the multiple-drugresistance (R) transfer from the R-resistant Shigella flexneri 3a strain MZ 17R to the sensitive E. coli strain K-12 C25S, and also on the inverse R-transfer from the R-resistant E. coli K-12 C17R to the sensitive Shigella flexneri 3a MZS.
Among the compounds tested, dodecyl-TMA, myristyl-TMA, cetyl-TMA, octadecyl-TMA, dodecylbenzyl-TMA, myristoyl-choline and benzethonium chloride inhibited the both R-transfer in a concentration of 10∼40mcg/ml, and they also showed some antibacterial activity. By a new evaluation method excluding the antibacterial activity, they were regarded to have the specific actions on the R-transfer.
Although propyl-TMA, butyl-TMA, pentyl-TMA, hexyl-TMA, octyl-TMA and benzoyl choline did neither inhibited the growth of Shigella and Escherichia, nor accelerated the growth of them, put these compounds accelerated the multiple-drug-resistance transfer from MZ 17R to C25S were observed.,
As for the relationship between the chemical structure and the biological action in a serial compounds of alkyl-trimethylammonium halogenides, the following fact was worth notice.
The compounds holding from 3 to 8 carbons in the side chain have an accelerating effect on the multiple-drug-resistance transfer and these holding from 12 to 18 carbons have an inhibitory effect.