Evidence for a reserpine-affected mechanism of resistance to tetracycline in Neisseria gonorrhoeae.
The presence of a reserpine-affected mechanism of tetracycline resistance was investigated in 17 Neisseria gonorrhoeae clinical isolates. To establish this fact the MIC of tetracycline in the presence and absence of reserpine was determined, and, in addition, mechanisms of tetracycline resistance were analyzed by PCR. The results showed that reserpine affects the MIC of tetracycline at least 4-fold in all isolates, including those containing the tetM gene. An inhibitory effect of reserpine against the MtrCDE efflux system was ruled out by using strains either with an inactive or with an unrepressed MtrCDE system. The results suggest the presence of a constitutive system of resistance to tetracycline, by a possible efflux pump, which may be inhibited by reserpine. Further studies are required to determine the exact nature of the action of reserpine on the MIC of tetracycline.
Ruiz
Joaquim
J
Servei de Microbiologia, Centre de Diagnóstic Biomèdic, IDIBAPS, Facultat de Medicina, Universitat de Barcelona, Spain. joruiz@clinic.ub.es
Ribera
Anna
A
Jurado
Angels
A
Marco
Francesc
F
Vila
Jordi
J
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D006069:Gonorrhea / Q000382:microbiology; D006801:Humans; D009344:Neisseria gonorrhoeae / Q000187:drug effects*; D012110:Reserpine / Q000494:pharmacology*; D013752:Tetracycline / Q000494:pharmacology*; D013753:Tetracycline Resistance / Q000187:drug effects
D000900:Anti-Bacterial Agents; D012110:Reserpine; D013752:Tetracycline