Table 4.

Etest MICs for the three organisms used in the urine assays^*

Antibiotic	Minimum Inhibitory Concentration (MIC) ug/mL
	E. coli ATCC 25922	B. stearothermophilus ATCC 7953	S. pyogenes ATCC 19615
Ampicillin	6	< 0.016	0.023
Amoxicillin	8	< 0.016	0.016
Ceftriaxone	0.094	0.032	0.032
Chloramphenicol	4	6	2
Ciprofloxacin	0.016	0.25	0.25
Co-trimoxazole	0.094	0.004	0.75
Doxycycline	1.5	0.023	0.19
Erythromycin	96	0.38	0.125
Ofloxacin	0.094	0.5	0.75
Penicillin	> 32	0.002	0.032
Trimethoprim	0.5	0.047	> 32

^*Minimum inhibitory concentrations (MIC) were determined by the Etest method according to the manufacturers' instructions, with the exception that those for B. stearothermophilus were performed at 56°C. Quality control was undertaken using E. coli ATCC 25922 as both a test and control organism, along with Staphylococcus aureus ATCC 29213 and Pseudomonas aeruginosa ATCC 27853 as appropriate, with reference to the manufacturers' instructions and relevant Clinical and Laboratory Standards Institute reference ranges.³²