346. Impact of Rectal Colonization with Highly Drug-resistant Enterobacteriaceae on Post-transplant Infections: The Carbapenem Resistant Enterobacteriaceae Carriage in Solid Organ Transplant (CREST) Study
Session: Poster Abstract Session: HAI: Multi Drug Resistant Gram Negatives
Thursday, October 27, 2016
Room: Poster Hall
Background:

ESBL-Enterobacteriaceae (ESBL-E) and CRE infections carry high mortality in solid organ transplant patients (SOT pts). Natural history of rectal colonization (R-COL) and subsequent disease (Dz) by ESBL-E and CRE post-SOT is unclear.

Methods:

Pts who underwent SOT from 8/15-5/16 were consented. Peri-rectal swabs were collected each week (wk) until 90 days (d) post-SOT, and cultured using KPC and ESBL CHROMagar plates. Resistance was confirmed by MIC. ESBLs and KPCs were detected by PCR. Pts were followed until 6 months (m) post-SOT. Longitudinal isolates underwent MiSeq whole genome sequencing (WGS). Primary endpoint was ESBL-E or CRE Dz.

Results:

147 pts were enrolled: 69 lung (Lu), 51 liver (Li), 17 kidney (K), 6 heart (H), 3 small bowel (SB), and 1 liver-kidney transplant. Median age was 60 years. 56% were men; 88% were white. Median time from SOT to first swab was 3 d. Median of 3 swabs/pt were collected. Among 121 pts who completed 90 d screening, 21% (26) were R-COL: 10 CRE (K. pneumoniae (Kp) most common), 16 ESBL-E (E. coli, Kp most common). One pt was R-COL with 2 CRE, and 2 pts with 2-3 ESBL-E. All CRE were KPC +. R-COL rates among Lu, Li and SB pts were 23% (16), 18% (9) and 33% (1), vs. 0% among K and H pts. 31% (2 CRE, 6 ESBL-E) were detected in the first swab. In other pts, median time from SOT to R-COL was 22 d. 76% of pts had persistent R-COL (≥2 swabs +). Among 81 Lu, Li and SB pts who reached 6 m post-SOT, 14% (11) developed Dz or COL (non-R) with ESBL-E or CRE. 9% (7) had Dz (urinary, 2; intra-abdominal, 2; bacteremia, empyema, surgical site, 1 each). 23% (6/26) of R-COL pts developed Dz vs. 2% (1/55) of non-R-COL (p=0.004). R-COL was the only significant risk factor for Dz. Dz attack rates among R-COL Li and Lu pts were 33% (3/9) and 19% (3/16), respectively. Longitudinal KPC-Kp R-COL and Dz isolates from 2 pts, and R-COL isolates from 3 pts without Dz were ST258 clones that were indisintinguishable by WGS. 17% of pts with Dz died; stay was significantly prolonged in survivors (median: 75 d).

Conclusion:

R-COL with CRE or ESBL-E was common among Lu, Li and SB pts, and a significant risk factor for subsequent Dz. Pts developed Dz due to R-COL isolates. 12% of R-COL pts carried >1 ESBL-E or CRE, suggesting horizontal transfer. 67% of R-COL pts were colonized ≥ 2 wks post-SOT. WGS revealed cryptic nosocomial acquisition of R-COL ST258 KPC-Kp, which later caused Dz. Rectal screening and infection prevention measures are merited among Lu, Li and SB pts.

M. Hong Nguyen, MD1, Ryan K. Shields, PharmD2, Liang Chen, PhD3, Barry N. Kreiswirth, PhD4 and Cornelius Clancy, MD2, (1)Infectious Disease, University of Pittsburgh, Pittsburgh, PA, (2)University of Pittsburgh, School of Medicine, Pittsburgh, PA, (3)Public Health Research Institute, Rutgers University, Newark, NJ, (4)Public Health Research Institute Tuberculosis Center, Rutgers University, Newark, NJ

Disclosures:

M. H. Nguyen, None

R. K. Shields, None

L. Chen, None

B. N. Kreiswirth, None

C. Clancy, None

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