Resistance patterns and clinical outcomes of Klebsiella pneumoniae and invasive Klebsiella variicola in trauma patients.

Recent reclassification of the Klebsiella genus to include Klebsiella variicola, and its association with bacteremia and mortality, has raised concerns. We examined Klebsiella spp. infections among battlefield trauma patients, including occurrence of invasive K. variicola disease. Klebsiella isolates collected from 51 wounded military personnel (2009-2014) through the Trauma Infectious Disease Outcomes Study were examined using polymerase chain reaction (PCR) and pulsed-field gel electrophoresis. K. variicola isolates were evaluated for hypermucoviscosity phenotype by the string test. Patients were severely injured, largely from blast injuries, and all received antibiotics prior to Klebsiella isolation. Multidrug-resistant Klebsiella isolates were identified in 23 (45%) patients; however, there were no significant differences when patients with and without multidrug-resistant Klebsiella were compared. A total of 237 isolates initially identified as K. pneumoniae were analyzed, with 141 clinical isolates associated with infections (remaining were colonizing isolates collected through surveillance groin swabs). Using PCR sequencing, 221 (93%) isolates were confirmed as K. pneumoniae, 10 (4%) were K. variicola, and 6 (3%) were K. quasipneumoniae. Five K. variicola isolates were associated with infections. Compared to K. pneumoniae, infecting K. variicola isolates were more likely to be from blood (4/5 versus 24/134, p = 0.04), and less likely to be multidrug-resistant (0/5 versus 99/134, p<0.01). No K. variicola isolates demonstrated the hypermucoviscosity phenotype. Although K. variicola isolates were frequently isolated from bloodstream infections, they were less likely to be multidrug-resistant. Further work is needed to facilitate diagnosis of K. variicola and clarify its clinical significance in larger prospective studies.

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.