TY - JOUR
T1 - A novel chromosomal TEM derivative and alterations in outer membrane proteins together mediate selective ceftazidime resistance in escherichia coli
AU - Weber, David A.
AU - Sanders, Christine C.
AU - Bakken, Johan S.
AU - Quinn, John P.
PY - 1990/8
Y1 - 1990/8
N2 - A clinical Escherichia coli isolate (MG32) resistant to ceftazidime but susceptible to other third-generation cephalosporins was previously examined and found to harbor TEM-1 and exhibit alterations in outer membrane proteins. Reexamination of this isolate revealed the additional presence of a novel TEM-1 derivative, now designated TEM-12. Evaluation of ceftazidime and cefotaxime minimum inhibitory concentrations for isogenic derivatives demonstrated a major role for TEM-12 in the decreased susceptibility observed. This was selectively enhanced for ceftazidime resistance by the altered porins of E. coli MG32. TEM-12 appeared identical to TEM-101, an in vitro TEM derivative, in both isoelectric point (pI 5.25) and substrate profile. Hybridization and cloning of the TEM-12 determinant revealed that, unlike other TEM derivatives, TEM-12 is chromosomally encoded, not plasmid-encoded.
AB - A clinical Escherichia coli isolate (MG32) resistant to ceftazidime but susceptible to other third-generation cephalosporins was previously examined and found to harbor TEM-1 and exhibit alterations in outer membrane proteins. Reexamination of this isolate revealed the additional presence of a novel TEM-1 derivative, now designated TEM-12. Evaluation of ceftazidime and cefotaxime minimum inhibitory concentrations for isogenic derivatives demonstrated a major role for TEM-12 in the decreased susceptibility observed. This was selectively enhanced for ceftazidime resistance by the altered porins of E. coli MG32. TEM-12 appeared identical to TEM-101, an in vitro TEM derivative, in both isoelectric point (pI 5.25) and substrate profile. Hybridization and cloning of the TEM-12 determinant revealed that, unlike other TEM derivatives, TEM-12 is chromosomally encoded, not plasmid-encoded.
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U2 - 10.1093/infdis/162.2.460
DO - 10.1093/infdis/162.2.460
M3 - Article
C2 - 2197339
AN - SCOPUS:0025333164
VL - 162
SP - 460
EP - 465
JO - Journal of Infectious Diseases
JF - Journal of Infectious Diseases
SN - 0022-1899
IS - 2
ER -