Table 2. Frequency of ESBL, AmpC β-lactamases and carbapenemase among Enterobacteriaceae members detected by different phenotypic laboratory methods.

DDST: Double-disk synergy test; ESBL: Extended-spectrum β-lactamase; MHT: Modified Hodge test; ND: Not determined.

Isolates	ESBL	AmpC β-lactamases	Carbapenemase
	DDST	AmpC disk test	MHT
E. coli	37 (30/81)	29 (9/31)	67 (4/6)
K. pneumoniae	61.5 (30/52)	52.4 (11/21)	78 (14/18)
Acinetobacter baumannii	25 (3/9)	83.3 (10/12)	89 (8/9)
Proteus mirabilis	50 (5/10)	ND	0.0 (0/1)
Other Gram-negative rods	40 (2/5)	33.3 (1/3)	50 (1/2)
Enterobacter cloacae	50 (4/8)	75 (6/8)	67 (2/3)
Total	45.2 (76/168)	49.3 (37/75)	74.4 (29/39)