2665. Intestinal Microbiome of Patients Submitted to Hematopoietic Stem Cell Transplantation Using Lactobacillus plantarum to Decolonized Multidrug-Resistant Bacteria

BACKGROUND: Patients colonized by multidrug-resistant bacteria (MDR) have high risk for infection after hematopoietic stem cell transplantation (HSCT). Probiotic is a strategy that can be used to decolonize patients. Our aim was to describe the impact of use of Lactobacillus plantarum (LP) on decolonization, MDR infections and intestinal microbiome (IM) of autologous HSCT patients colonized by vancomycin-resistant Enterococcus (VRE) and carbapenem-resistant Gram-negative (CRGN). METHODS: A prospective study was conducted at Hospital das Clinicas of University of Sao Paulo Brazil from 2017 to 2018. Candidates for auto-HSCT colonized by MDR received LP in capsules, 5 × 10(9) CFU twice daily until neutropenia (NP). Rectal swabs were performed and cultured using selective media as well as PCR for carbapenemases, vanA and vanB. Stool samples for IM analysis were collected weekly as baseline (before LB use) until the NP. The V4 region of 16S rDNA gene were sequenced by Ion Torrent PGM and analyzed using alpha and β diversities by Qiime. Demographic and clinical data including previous antibiotics use were evaluated; CDC criteria was applied for colonization and infection. RESULTS: All of seven patients were colonized by VRE and CRGN (Table 1). Only one patient remained colonized by CRGN after 61 days of LP. Four patients developed seven bloodstream infections (BSI) during the NP, two of them by CRGN. There was no infection caused by VRE neither by LP. One patient, with low adherence to LP use (66%), died due to MDR K. pneumoniae BSI. We observed a decrease of Clostridia, Verrucomicrobiae, Blautia and an increase of Enterobacteriaceae. Baseline samples from patients who used TMP/SMX had higher concentrations of Bacteroidetes when compared with those who had not use it. The Shannon index in controls ranged 1.98–5.55 and during NP 1.15–5.99. The β diversity analysis showed no clear patterns between patients. CONCLUSION: We observed a heterogeneity among IM of auto-HSCT patients prior and after LP. It was not possible to establish an IM pattern, probably, because of small number of patients. Although, clinical infections by CRGN occurred despite of LP use, no cases of colonization and infection by VRE were identified. Thus, it seems that LP is a good and safe strategy to decolonized HSCT. [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.