Polygenes and Modifier Genes for Tetracycline and Penicillin Resistance in Neisseria gonorrhoeae

Abstract

The genetic basis for spontaneous resistance to tetracyline (Tet) and penicillin (Pen) in N. gonorrhoeae was investigated. Tet and pen are polygenes which confer small but distinct levels of resistance to Tet and Pen, respectively. Mtr is a multiple-drug resistance polygene which increases resistance to Tet and Pen (and to other unrelated antibiotics). Tem is a modifier gene affecting resistance to Tet and Pen. Pem is a modifier gene for Pen resistance. The following gene combinations code for resistance to 5 antibiotics: tet, mtr and tem for Tet; pen, mtr, pem and tem for Pen; tet, tem and mtr for doxycycline; pen and pem for ampicillin; pen, pem and mtr for nafcillin.