TABLE 1.

Cephalosporin resistance in E. coli isolates from sick and healthy cattle

Cattle group (no.) and cephalosporin resistance mechanism	No. of E. coli isolates	% in cattle
Sick (657)
CTX-M alone	14	2.1
CTX-M + TEM	2	0.3
Other ESBL alone	1	0.2
All ESBLs	17	2.6
CMY	2	0.3
Non-CMYa	22	3.4
All non-ESBLs	24	3.7
All acquired cephalosporin resistance mechanisms	41	6.2
Healthy (607)
CTX-M alone	17	2.8
CTX-M + TEM	6	1.0
Other ESBL alone	2	0.3
All ESBLs	25	4.1
Non-CMYa	10	1.6
All non-ESBLs	10	1.6
All acquired cephalosporin resistance mechanisms	35	5.8

^aAnother chromosomal or plasmidic AmpC mechanism, as deduced from resistance to cefoxitin, cefotaxime, and ceftazidime, but not cefepime, cefpirome, and imipenem, and without cephalosporin-clavulanate synergy.