TABLE 1.
Features of the four qnr-positive diarrheagenic Escherichia coli strainsa
| Strain | Pathotype | Origin | Serotype | qnr gene | Resistance phenotype or genotype | MIC (μg/ml) of NAL, CIP | Plasmid size (kb), incompatibility group |
|---|---|---|---|---|---|---|---|
| 2384/12 | EAEC | TD | O65/O71:H1b | qnrB19 | AMP CHL TET AMC | 12, 0.38 | 3, ColETp |
| 4425/12 | STEC | CD | O157:H7 | qnrB19 | AMP SSS STR TET SXT | 16, 0.38 | 3.5, ColETp |
| 4472/12 | aEPEC | NCD | O49:H− | qnrS1 | AMP SSS NAL TET blaTEM1 | >256, 1.5 | 48, NT |
| 2113/13 | EIEC | TD | O96:H19 | qnrS1 | AMP SSS STR CEF CTX SXT AMC blaTEM1 blaCTX-M-15 | 6, 0.38 | 97, IncK |
a
NAL, nalidixic acid; CIP, ciprofloxacin; EAEC, enteroaggregative E. coli; STEC, Shiga toxin-producing E. coli; aEPEC, atypical enteropathogenic E. coli; EIEC, enteroinvasive E. coli; TD, traveler's diarrhea; CD, complicated endemic diarrhea; NCD, noncomplicated endemic diarrhea; H−, nonmotile; AMP, ampicillin; CHL, chloramphenicol; TET, tetracycline; AMC, amoxicillin-clavulanic acid; SSS, sulfonamides; STR, streptomycin; SXT, trimethoprim-sulfamethoxazole; CEF, cephalothin; CTX, cefotaxime; NT, nontypeable.
b
This strain cross-reacted with the respective O antisera.