In vitro antimicrobial effects of aztreonam, colistin, and the 3-drug combination of aztreonam, ceftazidime and amikacin on metallo-β-lactamase-producing Pseudomonas aeruginosa

Table 1 Antimicrobial effects of aztreonam (48 mg/l) against 23 strains of metallo-β-lactamase-producing P. aeruginosa

	No. of strains (%) showing effects^a
Time of exposure (h)	Bacteriostatic effects	Bactericidal effects
2	13 (56.5)	0 (0)
4	10 (43.5)	0 (0)
6	12 (52.2)	1 (4.3)
24	11 (47.8)	1 (4.3)

^aBacteriostatic effects, any decrease in the viable count from the starting inoculum; bactericidal effects, ≥ 3 log cfu/ml decrease in the starting inoculum.

ISSN: 1471-2334