TABLE 2.

Typing and mef element of 49 clinical pneumococci with efflux-mediated erythromycin resistance subdivided according to the mef gene carried

Isolates (total no.) bearing mef genePFGE type (no. of isolates)MLST sequence type (no. of isolates)Serotype (no. of isolates)mef element
Tn1207.1mega
mef(A) (30)A (22)ST9 (21)14 (17), 23F (2), 19A (1), 31 (1)+
ST1733a (1)23F (1)+
A1 (5)ST9 (5)14 (3), 23F (1), 33A (1)+
A2 (1)ST9 (1)3 (1)+
G (1)ST1775a (1)3 (1)+
I (1)ST9 (1)23F (1)+
mef(E) (19)A (2)ST9 (1)19F (1)+
ST448 (1)6B (1)+
A1 (1)ST199 (1)23A (1)+
B (2)ST81 (2)23F (1), 35 (1)+
B1 (1)ST81 (1)23A (1)+
C (2)bST1774a (2)11A (2)
D (2)ST490 (2)18F (1), 19A (1)+
E (1)ST180 (1)23F (1)+
E1 (1)ST180 (1)9V (1)+
F (2)ST156 (2)23F (2)+
H (1)ST218 (1)12F (1)+
J (1)ST1776a (1)3 (1)+
K (1)cNDb (1)19A (1)+
L (1)ST1250 (1)10F (1)+
M (1)ST448 (1)6B (1)+
  • a New (not previously identified) sequence type.

  • b In the course of this study, these two isolates were found to carry a novel mef gene variant, named mef(I).

  • c S. pseudopneumoniae strain. ND, sequence type not determined; being an atypical pneumococcus, this strain could not be entered into the pneumococcal MLST database.