Division of Infectious Diseases, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Diagn Microbiol Infect Dis. 2013 Aug;76(4):491-6. doi: 10.1016/j.diagmicrobio.2013.04.018. Epub 2013 May 27.
The objective of this study was to characterize the temporal variability of fluoroquinolone resistance mechanisms among Escherichia coli colonizing the gastrointestinal tract of hospitalized patients. Patients with new fluoroquinolone-resistant E. coli (FQREC) colonization were followed with serial fecal sampling until discharge or death. Genetic mechanism(s) of resistance for all FQREC isolates was characterized, including mutations in gyrA and parC and efflux pump overexpression. Of 451 subjects, 73 (16.2%) became newly colonized with FQREC. There was significant variability in regard to temporal changes in resistance mechanisms and levofloxacin MICs among isolates from individual patients. Compared to patients with transient colonization, patients with persistent colonization were more likely to have a urinary catheter (P = 0.04), diarrhea (P = 0.04), and a longer duration of hospitalization (22 and 9.0 mean days, respectively; P = 0.01) prior to sampling. Our data demonstrate the significant variability of resistance mechanisms in colonizing E. coli isolates among hospitalized patients.
本研究旨在描述住院患者肠道定植的大肠埃希菌中氟喹诺酮耐药机制的时间变异性。对新定植氟喹诺酮耐药大肠埃希菌（FQREC）的患者进行连续粪便采样，直至出院或死亡。对所有 FQREC 分离株的耐药遗传机制进行了特征描述，包括 gyrA 和 parC 突变以及外排泵过表达。在 451 名患者中，73 名（16.2%）新定植 FQREC。单个患者分离株的耐药机制和左氧氟沙星 MIC 值的时间变化存在显著差异。与一过性定植患者相比，持续性定植患者在采样前更有可能有导尿管（P = 0.04）、腹泻（P = 0.04）和更长的住院时间（分别为 22 和 9.0 天，P = 0.01）。我们的数据表明，住院患者肠道定植大肠埃希菌分离株的耐药机制存在显著的变异性。
