Table 1.

Antibiotic concentration tested against E. coli from surface waters in northern Tanzania.

Name	Code	Source	Concentration (µg/mL)
Amoxicillin/clavulanate potassium	Amx/Clv	MP Biomedicals, Illkirch, France	32/16
Ampicillin	Amp	Fisher Scientific, Fair Lawn, New Jersey	32
Ceftazidime	Ceftaz	Sigma-Aldrich	16
Chloramphenicol	Chlo	Sigma-Aldrich	32
Ciprofloxacin	Cip	Sigma-Aldrich	4
Kanamycin	Kan	Sigma-Aldrich	64
Streptomycin	Str	Sigma-Aldrich	16
Sulfamethoxazole	Sul	MP Biomedicals	512
Tetracycline	Tet	GTS, San Diego, CA	16
Trimethoprim	Tri	MP Biomedicals	16