Long-Term Care Facilities Are Reservoirs for Antimicrobial-Resistant Sequence Type 131 Escherichia coli. (17th February 2015)

• Record Type: Journal Article
• Authors: Burgess, Mary J.; Johnson, James R.; Porter, Stephen B.; Johnston, Brian; Clabots, Connie; Lahr, Brian D.; Uhl, James R.; Banerjee, Ritu
• Is Part Of: Open forum infectious diseases. Volume 2:Number 1(2015)
• Publication Date: 2015-02-17
• Subjects: E. coli -- E. coli resistance -- long-term care facilities -- ST131; Communicable diseases -- Periodicals; Medical microbiology -- Periodicals; Infection -- Periodicals; 616.9
• DOI: 10.1093/ofid/ofv011
• Languages: English
• ISSNs: 2328-8957

Abstract

Abstract : In this cross sectional study, one-fourth of LTCF residents were colonized intestinally with ST131 E. coli . The most dependent residents were at highest risk. Strain transmission occurred within and between LTCFs. Molecular typing showed similarities to clinical isolates. Abstract: Background. Emerging data implicate long-term care facilities (LTCFs) as reservoirs of fluoroquinolone-resistant (FQ-R) Escherichia coli of sequence type 131 (ST131). We screened for ST131 among LTCF residents, characterized isolates molecularly, and identified risk factors for colonization. Methods. We conducted a cross-sectional study using a single perianal swab or stool sample per resident in 2 LTCFs in Olmsted County, Minnesota, from April to July 2013. Confirmed FQ-R E. coli isolates underwent polymerase chain reaction-based phylotyping, detection of ST131 and its H 30 and H 30-Rx subclones, extended virulence genotyping, and pulsed-field gel electrophoresis (PFGE) analysis. Epidemiological data were collected from medical records. Results. Of 133 fecal samples, 33 (25%) yielded FQ-R E. coli, 32 (97%) of which were ST131. The overall proportion with ST131 intestinal colonization was 32 of 133 (24%), which differed by facility: 17 of 41 (42%) in facility 1 vs 15 of 92 (16%) in facility 2 ( P = .002) . All ST131 isolates represented the H 30 subclone, with virulence gene and PFGE profiles resembling those of previously described ST131 clinical isolates. By PFGE, certain isolates clustered both within and across LTCFs. Multivariable predictors of ST131 colonization included inability to sign consent (odds ratio [OR], 4.16 [ P = .005]), decubitus ulcer (OR, 4.87 [ P = .04]), and fecal incontinence (OR, 2.59 [ P = .06]). Conclusions. Approximately one fourth of LTCF residents carried FQ-R ST131 E. coli resembling ST131 clinical isolates. Pulsed-field gel electrophoresis suggested intra- and interfacility transmission. The identified risk factors suggest that LTCF residents who require increased nursing care are at greatest risk for ST131 colonization, possibly due to healthcare-associated transmission.