title: Antibiotic resistance of Escherichia coli O157:H7 and O157:NM isolated from animals, food, and humans.
abstract: Antibiotic resistance was determined for 118 E. coli O157:H7 and 7 O157:NM isolates from animals, foods, and humans. Among the 125 isolates, 30 (24%) were resistant to at least one antibiotic and 24 (19%) were resistant to three or more antibiotics. Cattle isolates had the highest rate (34%) of antibiotic resistance. The seven resistant food isolates were all from ground beef. The most frequent resistance type overall was streptomycin-sulfisoxazole-tetracycline, which accounted for over 70% of the resistant strains. Two E. coli O157:NM isolates from cattle were resistant to six antibiotics: ampicillin, kanamycin, sulfisoxazole, streptomycin, tetracycline, and ticarcillin. Streptomycin was the most common antibiotic to which E. coli O157:H7 and O157:NM were resistant (29 out of 30 isolates), followed by tetracycline (26 isolates). This study suggests that E. coli O157:H7 and O157:NM have developed resistance to antibiotics. Research is needed to define mechanisms of antibiotic resistance in E. coli O157:H7 and to minimize the development of resistance.
authors.affiliation: Department of Nutrition and Food Science, University of Maryland, College Park 20742, USA. jm332@umail.umd.edu
authors.forename: J
authors.initials: J
authors.lastname: Meng
authors.forename: S
authors.initials: S
authors.lastname: Zhao
authors.forename: M P
authors.initials: MP
authors.lastname: Doyle
authors.forename: S W
authors.initials: SW
authors.lastname: Joseph
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002417:Cattle; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D004927:Escherichia coli Infections / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000302:isolation & purification*; D005516:Food Microbiology; D006801:Humans; D008460:Meat / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000382:microbiology; D012756:Sheep / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents