TABLE 5.

Distribution of resistance mechanisms other than ESBL among enterobacterial isolates from clinical samples growing on the three selective media

Resistance mechanism, species	No. of isolates growing on:
	MCC	BM	OX	All media
Chromosomal AmpC cephalosporinase
C. freundii	2	1	2	2
E. aerogenes	4	4	3	4
E. cloacae	5	6	5	6
E. coli	3	1		3
H. alvei		2		2
M. morganii	2	1	4	4
Plasmidic AmpC cephalosporinase (CMY-type), E. coli	1	1	1	1
TEM- or SHV-derived penicillinases
E. coli		1	4	4
K. pneumoniae	1	1		2
K-OXY penicillinase, K. oxytoca		5	3	5
OXA group 3 beta-lactamase, E. coli		2	2	2
Other chromosomal beta-lactamase, C. farmeri		2	2	2
Nonenzymatic, E. coli		2		2