Volume 18, Number 5—May 2012
Research
Antimicrobial Drug Resistance in Escherichia coli from Humans and Food Animals, United States, 1950–2002
Daniel A. Tadesse, Shaohua Zhao, Emily Tong, Sherry Ayers, Aparna Singh, Mary J. Bartholomew, and Patrick F. McDermott
Table 2
Antimicrobial drug resistance phenotypes of Escherichia coli isolates from different sources, United States, 1950–2002*
| Drug class | Drug | Resistance breakpoint, µg/mL | % Resistance |
Timeline for clinical use of drugs (reference) | ||||
|---|---|---|---|---|---|---|---|---|
| Overall, n = 1,729 | Human, n = 983 | Cattle, n = 323 | Chickens, n = 138 | Pigs, n = 285 | ||||
| Penicillins | AMP | >32 | 24.1 | 16.5 | 35 | 34.1 | 33.3 | 1961 (17) |
| β-lactam/β-lactamase inhibitor combinations | AUG | >32 | 5.6 | 2.4 | 12.7 | 7.3 | 7.4 | 1984 (17) |
| Cephems | CEP | >32 | 12.9 | 8.8 | 20.1 | 12.3 | 19.3 | 1964 (18) |
| FOX | >32 | 4.4 | 1.5 | 9.3 | 5.1 | 8.4 | 1977 (19) | |
| TIO | >8 | 2.3 | 0.1 | 7.4 | 1.5 | 4.2 | 1988 (FDA Green Book)† | |
| AXO | >4 | 2.4 | 0.1 | 7.7 | 1.5 | 4.6 | 1984 (FDA Orange Book)‡ | |
| Phenicols | CHL | >32 | 8.1 | 3.7 | 18 | 8.7 | 11.9 | 1947 (17) |
| Aminoglycosides | GEN | >16 | 6.7 | 0.1 | 16.1 | 16.7 | 14 | 1963 (17) |
| KAN | >64 | 19.3 | 5.7 | 39.9 | 29.7 | 37.5 | 1957 (17) | |
| STR§ | >64 | 34.2 | 15.3 | 61.3 | 58 | 57.2 | 1943 (17) | |
| Quinolones | CIP | >4 | 0.4 | 0 | 1.9 | 0.7 | 0 | 1987 (17) |
| NAL | >32 | 1.7 | 1 | 3.7 | 1.5 | 1.8 | 1962 (19) | |
| Tetracyclines | TET | >16 | 40.9 | 18 | 71.2 | 68.8 | 72.3 | 1948 (17) |
| Folate pathway inhibitors | SUL | >512 | 36.2 | 19.9 | 61 | 60.9 | 52.6 | 1936 (19) |
| TMP/SMX | >4 | 7 | 2.2 | 16.1 | 13.8 | 9.8 | 1968 (19) | |
*AMP, ampicillin; AUG, amoxicillin/clavulanic acid; CEP, cephalothin; FOX, cefoxitin; TIO, ceftiofur; FDA, Food and Drug Administration; AXO, ceftriaxone; CHL, chloramphenicol; GEN, gentamicin; KAN, kanamycin; STR, streptomycin; CIP, ciprofloxacin; NAL, nalidixic acid; TET, tetracycline; SUL, sulfonamide; TMP/SMX, trimethoprim/sulfamethoxazole.
†www.fda.gov/AnimalVeterinary/Products/ApprovedAnimalDrugProducts
‡www.fda.gov/drugs/developmentapprovalprocess/ucm079068.htm
§No Clinical and Laboratory Standards Institute breakpoint. The National Antimicrobials Resistance Monitoring System breakpoint was used.
