TABLE 3.

Resistance phenotypes of E. coli and K. pneumoniae isolates producing CTX-M-type ESBLs

Species	Enzyme (no. of isolates)	% Susceptible toa,b:
		AMC	PTZ	IMI	GEN	AMK	CIP
E. colic	CTX-M-1 (35)	77	100	100	89	97	54
	CTX-M-15 (64)	22	89	100	46	98	2
	CTX-M-32 (4)	0	100	100	100	100	0
K. pneumoniae	CTX-M-1 (3)	67	100	100	100	100	100
	CTX-M-15 (5)	20	80	100	0	80	100
	CTX-M-32 (2)	0	100	100	100	100	100

^aBased on disk diffusion testing.

^bAMC, amoxicillin-clavulanate; PTZ, piperacillin-tazobactam; IMI, imipenem; GEN, gentamicin; AMK, amikacin; CIP, ciprofloxacin.

^cChi-squared test (CTX-M-1 and CTX-M-15): AMC, P < 0.001; PTZ, P < 0.05; GEN, P < 0.001; AMK, not significant; CIP, P < 0.001.