Characterizing Clinical Demographics, Susceptibility Patterns, and Development of Resistance in Raoultella ornitholytica Infections in Southern Virginia

Abstract

Background Raoultella ornitholytica (R. ornitholytica) is a waterborne Gram-negative bacilli increasingly found in hospitals. Multi-drug resistance has been reported, including to carbapenems. Our objective was to identify demographics of R. ornitholytica at Danville Regional Medical Center (DRMC) to determine predisposing factors to infection and potential antibiotic resistance.MethodsCultures positive for R. ornitholytica were identified through DRMC’s electronic medical records (EMR) from 1/2010 to 3/2017. Site of infection, concurrent infections, isolate susceptibilities, prior antibiotic exposure, and appropriateness of treatment were extracted from the EMR. Healthcare associated was defined as occurring in the hospital, nursing home, long-term acute care, or inpatient rehabilitation facility within the past 90 days. Those with diabetes, cancer, and end stage renal disease (ESRD) were qualified as immunosuppressed.ResultsThirty-two cases were isolated, of which 20 had associated clinical data. One urine isolate was consistent with colonization. Of the 19 infections, the majority (n = 15) were urinary tract infections (UTIs) and one case each from bronchial washing, heel wound, blood culture, and vulvar lesion. Clinical demographics are shown in Figure 1. Thirteen (65%) had concurrent infections, of which 5 (26%) were co-infected with Enterococcus faecalis, one which was vancomycin resistant. Three had chronic Foley catheters, constituting 20% of the UTIs. Susceptibilities are reported in Figure 2. Prior antibiotic use is shown in Figure 3.ConclusionMost of the isolates from our institution were relatively sensitive, with most resistance to ampicillin. Two isolates were pansensitive, however one case was sensitive only to nitrofurantoin and ertapenem. All isolates which were resistant to cefazolin and ceftriaxone had prior exposure. The elderly and diabetics had the greatest association with infection. A majority of patients had a concurrent infection, which may suggest this as an opportunistic organism. Our findings warrant further studies to better characterize clinical associations and development of resistance in response to prior antibiotic exposure.Disclosures All authors: No reported disclosures.