Dysgonomonas capnocytophagoides Bacteremia in a Patient With Stage IV Colon Adenocarcinoma.

Dysgonomonas capnocytophagoides bacteremia is a rare clinical entity described in only five case reports. Difficulties in the identification and intrinsic multidrug resistance (MDR) of the organism make diagnosis and treatment challenging. We present a case of D. capnocytophagoides bacteremia which highlights the diagnostic and treatment challenges posed by this organism. The case also contributes to the nascent understanding of the clinical profile of patients with D. capnocytophagoides infection and the antimicrobial susceptibility of the organism. A 56-year-old male with advanced colon adenocarcinoma on palliative fluorouracil, leucovorin, and irinotecan (FOLFIRI) presented with abdominal pain. He had been discharged recently following an ICU admission for neutropenic fever with diarrhea and polymicrobial bacteremia resulting in sepsis. Diarrhea resolved during hospitalization. Mediport was retained, surveillance blood cultures remained negative, and he completed 14 days of levofloxacin. Upon readmission for abdominal pain, vital signs were normal and neutropenia had resolved. A Gram-negative rod grew from blood cultures drawn peripherally and from the port with no differential time-to-positivity. Multiple testing platforms were used in an attempt to identify the organism, to include the VERIGENE® Gram-negative blood culture test, matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, VITEK ® 2 GN ID, and the Thermo Scientific™ RapID™ NH System (Thermo Scientific, Waltham, MA). Test results from all platforms were either inconclusive or contradictory in their identification of the organism, making the determination of appropriate treatment difficult. Given inconsistent results on multiple testing platforms, the isolate was sent for whole genome sequencing (WGS). Additional workup performed during the hospitalization included a diagnostic paracentesis without evidence of spontaneous bacterial peritonitis, transesophageal echocardiogram without evidence of infective endocarditis, and dental evaluation without evidence of the infectious source. Abdominal CT showed nonspecific terminal ileitis. He was treated for presumed HACEK bacteremia and was transitioned from piperacillin-tazobactam to ceftriaxone to complete a two-week course at hospital discharge. He also received a seven-day course of doxycycline for concomitant, mild lower extremity cellulitis which resolved during hospitalization. Ultimately, antimicrobial susceptibility testing which resulted following discharge was not consistent with the HACEK organism. Testing demonstrated resistance to multiple antimicrobials including ceftriaxone, as well as susceptibility to trimethoprim-sulfamethoxazole (TMP/SMX). WGS ultimately identified the organism as D. capnocytophagoides. Despite ceftriaxone resistance, he reported feeling well at follow-up with negative surveillance blood cultures. This patient shares several features with the few patients previously identified with D. capnocytophagoides bacteremia, including malignancy, recent neutropenia, and presumed gastrointestinal source. As in the small number of prior reported cases, the organism was difficult to identify leading to delay in diagnosis and treatment. The case demonstrates the importance of critical thinking in the face of contradictory test results. Additionally, based on susceptibility profiles described in prior literature, we suspect doxycycline treated his bacteremia.

Microbiology and clinical characteristics of industrial oil burns.

INTRODUCTION: Infections complicating burns generally transition from Gram-positive to Gram-negatives over the first couple weeks, but this depends on multiple factors. The microbiology of infections complicating crude oil (CO) and hydraulic fracturing (FRAC) burns is unknown. METHODS: We performed a retrospective study of patients with industrial thermal burns hospitalized >2 days with ≥1 day in the ICU between 4/2011-11/2016. Burns were oil-related (ORB; CO or FRAC) or non-oil related (NORB). Epidemiology and microbiology during the first 15 hospital days was compared. RESULTS: 149 patients were included, with 11 FRAC and 24 CO. CO burns were more severely burned than those with FRAC and NORB (p<0.05). Mortality was 17% and 18% for CO and FRAC burns compared to 3% in NORB (p<0.01). More cultures were obtained from ORB than NORB (p<0.05). ORB were associated with Stenotrophomonas maltophilia and FRAC associated with Serratia marcescens and Candida glabrata. Patients with FRAC, CO and NORB had a median of 13, 3.5, and 4 days to first positive culture respectively (p=0.03). CONCLUSION: ORB were associated with more severe burns and unique microbiology. FRAC burns had longer to initial positive culture, potentially suggesting our current methodology is inadequate to diagnose infections associated with FRAC.

Early infectious outcomes after addition of fluoroquinolone or aminoglycoside to posttrauma antibiotic prophylaxis in combat-related open fracture injuries.

BACKGROUND: We examined combat-related open extremity fracture infections as a function of whether posttrauma antimicrobial prophylaxis included expanded Gram-negative (EGN) coverage. METHODS: Military personnel with open extremity fractures sustained in Iraq and Afghanistan (2009-2014) who transferred to participating hospitals in the United States were assessed. The analysis was restricted to patients with a U.S. hospitalization period of ≥7 days. Prophylaxis was classified as narrow (e.g., IV cefazolin, clindamycin, and/or amoxicillin-clavulanate) or EGN, if the prophylactic regimen included fluoroquinolones and/or aminoglycosides. RESULTS: The study population included 1,044 patients, of which 585 (56%) and 459 (44%) received narrow and EGN coverage, respectively (p < 0.001). Skin and soft-tissue infections (SSTIs) were more common among patients who received narrow prophylaxis compared to EGN coverage (28% vs. 22%; p = 0.029), whereas osteomyelitis rates were comparable between regimens (8%). Similar findings were noted when endpoints were measured at 2 and 4 weeks postinjury. There was no significant difference related to length of hospitalization between narrow and EGN regimens (median: 34 and 32 days, respectively) or operating room visits (median: 5 and 4). A higher proportion of EGN coverage patients had Gram-negative organisms isolated that were not susceptible to fluoroquinolones and/or aminoglycosides (49% vs. 40%; p < 0.001). In a Cox proportional model, narrow prophylaxis was independently associated with an increased risk of extremity SSTIs (hazard ratio: 1.41; 95% confidence interval: 1.09-1.83). DISCUSSION: Despite seeing a small benefit with EGN coverage related to a reduction of SSTIs, it does not decrease the risk of osteomyelitis, and there seems to be a cost of increased antibiotic resistance associated with use. Overall, our findings support the current post-combat trauma antibiotic prophylaxis guidelines, which recommend the use of cefazolin or clindamycin with open fractures. LEVEL OF EVIDENCE: Prognostic/Epidemiological, Level II; Therapy, level IV.

Clinical utility of fungal screening assays in adults with severe burns.

BACKGROUND: Fungal wound infection is a leading cause of burn wound infections, and diagnosis is often delayed as it conventionally requires culture and histopathology. Fungal screening assays have sped diagnosis of invasive fungal infections in other populations. Few studies have evaluated the performance of fungal screening assays outside of the hematologic malignancy and hematopoietic stem cell transplant populations. METHODS: We performed a three year retrospective analysis of all fungal screening assays in burn patients in the ICU between 2008 and 2011. The primary goal was to evaluate the correlation between the two available fungal screening assays, (1→3)-ß-d-glucan (BG) and galactomannan (GM) assay, and fungal wound colonization (FWC) and infection (FWI). We also evaluated previously hypothesized causes of false positives and their associations with false positives in the burn population. RESULTS: We identified 53 patients [median 29% total body surface area burned (TBSA), IQR 17-51] with BG or GM serological tests available, of which 15 had a FWI or FWC. FWC/FWI was associated with higher TBSA (p=0.02). BG and GM correlated with TBSA (BG 0.57, p<0.01; GM 0.35, p=0.02), but neither assay was associated with FWI/FWC or species of fungus involved when FWI/FWC was diagnosed. CONCLUSIONS: Positive BG and GM fungal screening assays are not associated with FWI/FWC, or with species of fungus when FWC/FWI is present. BG false positives are common and associated with higher TBSA burns.