2102. Common co-occurence in the respiratory tract of Mucorales with Gram-negative rods in patients with hematologic malignancy and sinopulmonary mucormycosis

Abstract

Abstract Background Mucorales (MCR) and Gram-negative rods (GNR) commonly infect patients (pts) with hematological malignancies (HM); however, their co-occurrence is understudied. Methods We retrospectively reviewed the records of 63 pts with HM and sinopulmonary MCR (proven or probable, EORTC/MSG criteria) at MD Anderson Cancer Center (Houston, TX) from 2008-2016. Co-occurrence was defined as a culture positive for GNR taken from sinuses or the lungs within 90 days (d) of a positive Mucorales culture or histology demonstrating Mucorales spp. Results Ninety percent of the 63 pts with MCR had leukemia or myelodysplastic syndrome (54% AML) and 10% had lymphoma/myeloma. Sixty-eight percent had undergone hematopoietic stem cell transplant. Sixty-seven percent were neutropenic at the time of MCR diagnosis. Thirty-five percent had received > 600mg of prednisone within 30 days (d) prior to MCR diagnosis. Thirty-five percent were admitted to the ICU during the time of MCR treatment. MCR pts had sinusitis (42.9%), pneumonia (38.1%) and disseminated sinopulmonary disease (19.0%). Nearly all pts (92%) received empiric antimicrobials with activity against Pseudomonas prior to collection of their positive fungal cultures. Twenty-three pts (37%) had concurrent detection of GNRs (Pseudomonas in 10, Stenotrophomonas in 8) in samples from the sinopulmonary tract. Eight of 23 co-isolations of GNRs and Mucorales (35%) were found in same-day samples. Demographic and clinical characteristics of pts with and without co-occurrence of GNR were comparable. Pts with co-occurrence had less frequently received antibiotics with activity against Stenotrophomonas 7 (30.4%) vs 23 (60%, p=0.024). Ninety-day all-cause mortality was high and comparable in pts with (83%) and without (78%) GNR detection (p = 0.75). Conclusion Over a third of heavily immunosuppressed pts with sinopulmonary MCR harbor GNRs in their respiratory tract, most commonly Pseudomonas. Although no impact on survival outcomes was seen in a background of high mortality, pathogenesis studies are needed to understand the mutualistic interplay of GNR and Mucorales spp. and their influence on host responses. Disclosures William R. Miller, MD, Entasis Therapeutics: Grant/Research Support|UpToDate: Royalties - Topic Contributor Dimiitrios P. Kontoyiannis, MD, ScD, PhD (hon), AbbVie: Advisor/Consultant|Astellas Pharma: Advisor/Consultant|Astellas Pharma: Grant/Research Support|Astellas Pharma: Honoraria|Cidara Therapeutics: Advisor/Consultant|Gilead Sciences: Advisor/Consultant|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria|Merck: Advisor/Consultant.