Ribotypes Matter, Significance of Clostridium difficile Ribotypes in Cancer Patients with Diarrhea

BACKGROUND: Cancer patients are at increased risk for Clostridium difficile infection (CDI) due to frequent health care contact, chemotherapy, use of antibiotics, and immunosuppression. Distinct ribotypes are associated with CDI adverse outcomes. Ribotypes 14-020 are the predominant ribotypes in many hospitals. We examined the contribution of C. difficile ribotypes to CDI severity, response to therapy and outcomes in this population. METHODS: Demographic and clinical data were collected from 90 cancer patients with a first episode or first recurrence of CDI identified by two-step PCR followed by EIA for A/B toxins. Fluorescent PCR ribotyping (FPCR) was performed on fecal isolates. We identified 27 distinct ribotypes between October 2016 and January 2017. Clinical outcomes were studied in three FPCR subgroups. Group I (GI, n = 27) included F014-020, group II (GII, n = 17) included virulent types 002, 027, 078–126, 244 and group III (GIII, n = 46) included the rest. Treatment failure was defined as no response after at least 3 days of a CDI treatment regimen. CDI severity was determined using Zar’s criteria, presence of bacteremia and ICU stay. RESULTS: The proportion of patients >50 yrs. old, with health care onset CDI (31%), primary CDI (92.2%), and on active chemotherapy (70%) was similar across the three groups. At presentation, disease severity was similar in all groups; However, patients in GII were more likely to have detectable toxin A/B by EIA compared with GI and GIII (53% vs. 23%, P = 0.015) and higher treatment failure rates (56%) when compared with GI (15% P = 0.007) and GIII (16%, P = 0.004). Bacteremia was more common in GIII (28%) compared with GII (0%) P = 0.041 and GI 7% P = 0.007. Patients in GI experienced fewer complications when compared with those in GIII P = 0.025. No differences in sustained clinical response, recurrence, ICU stay or all cause 90-day mortality were found between the groups. CONCLUSION: Cancer patients with CDI due to GII ribotypes are more likely to excrete fecal toxin A/B and fail conventional therapy. In contrast, patients in GI and GIII were more likely to respond to therapy. GI was associated with fewer complications. Of interest, GIII was associated with bacteremia. Evaluation of C. difficile ribotypes is clinically relevant in cancer patients with CDI. DISCLOSURES: All authors: No reported disclosures.