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Background Recent work has argued that genus Klebsiella is best divided into 3 clades: K. pneumoniae (Kp) , K. quasipneumoniae (Kq), and K. variicola (Kv). Kv has drawn attention from reports of higher mortality and virulence. We evaluated a previously defined group of military trauma patients with Klebsiella infections for the presence of Kv, described clinical and isolate characteristics, and compared Kv and Kp groups. Methods All initial and serial (≥7 days from prior isolate) infecting Kp isolates (identified by clinical laboratories without the ability to speciate Kq and Kv) were collected from the Trauma Infectious Disease Outcomes Study (6/09–12/14). Additionally, a previously defined group of colonizing isolates linked to the infecting isolates and a selection of random colonizers were included from groin swabs. DNA extraction and PCR targeting Kv per published methods was performed. Antimicrobial susceptibilities were determined using the BD Phoenix Automated Microbiology System and CLSI criteria. Multidrug resistance was defined as either resistance to ≥3 classes of aminoglycosides, β-lactams, carbapenems and/or fluoroquinolones or production of ESBL or KPC. Results Of 237 archived Kp isolates (from 122 patients), 10 (4%) were identified as Kv by PCR (from 8 [7%] patients). The Kv sources were 4 from blood (40%), 1 intra-abdominal (10%) and 5 from groin (50%). Six (3%) isolates were identified as Kq (4 from groin and 2 from respiratory specimens). The Kv and Kp patients were all males, with a median age of 25 (IQR 21–46) and 23 (IQR 21–28), length of hospital stay of 24 days (IQR: 5–106) and 53 days (IQR 36–74), and Injury Severity Score of 21 (IQR: 10–50) and 38 (IQR: 30–45), respectively. There were no deaths in the Kv group compared with 4 with Kp. Infecting Kv isolates were more likely to be from blood compared with Kp (80% vs. 17%, P = 0.04). No infecting Kv isolates were multidrug-resistant compared with 70% of infecting Kp isolates (P < 0.01). Conclusion Kv represented 4% of the previously identified Kp isolates in this population. Patient characteristics were similar in both groups. While Kv was less resistant than Kp, it was more likely to be associated with invasive disease in this group. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]

Background Biocides play an integral role in infection control. Paralleling concern about rising incidence of multidrug-resistant (MDR) organisms is a concern for resistance to biocides. In small studies, several genes involved in the production of efflux pump proteins have been identified as markers of biocide resistance in Klebsiella spp. namely cepA , qacA , qacE , qac∆E , and acrA. This study aimed to analyze the Klebsiella spp. isolates of a previously defined military trauma group with a high incidence of MDR organisms for the presence of these genes and their correlation with other resistance. Methods All infecting K. pneumoniae, K. variicola , and K. quasipneumoniae isolates archived by the Trauma Infectious Disease Outcomes Study (June 2009–December 2014) were selected. Additionally, all colonizing isolates linked with infecting isolates were included; the remainder to total 50 MDR and 46 non-MDR colonizing isolates were chosen randomly. Antimicrobial identification and susceptibilities were determined by CLSI criteria using the BD Phoenix Automated Microbiology System. PCR according to published methods for cepA , qacA , qacE , qac∆E , and acrA was accomplished in duplicate. MDR was defined as either resistance to ≥3 classes of aminoglycosides, β-lactams, carbapenems and/or fluoroquinolones or production of an ESBL or KPC. Results A total of 237 isolates (221 K. pneumoniae , 10 K. variicola , 6 K. quasipneumoniae) met inclusion criteria, of which 149 (63%) were MDR. All isolates had been exposed to antimicrobials prior to isolation. Of all isolates, 234 (98%) carried cepA : 218 (98%) K. pneumoniae carried cepA, 10 (100%) K. variicola carried cepA, and 6 (100%) of K. quasipneumoniae carried cepA. In addition, 148 (62%) isolates with cepA were MDR. One (10%) K. variicola isolate carried qacE along with cepA. This isolate was the only MDR K. variicola. None of the isolates carried qacA, qac∆E, or acrA. Conclusion We confirmed the near universal presence of the cepA biocide resistance gene in Klebsiella spp. isolated from trauma patients in Iraq and Afghanistan. In the largest evaluation of biocide resistance genes in Klebsiella spp. to our knowledge, the presence of qacA , qacE , qac∆E , and acrA was less common than has been reported elsewhere. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]

Background Deep soft-tissue infections (DSTIs) are a common complication of combat-related extremity trauma. We present an epidemiologic assessment of combat-related DSTIs among wounded military personnel. Methods Wounded personnel were included in the analysis if they sustained an open combat-related extremity wound (2009–2014), were admitted to a participating US military hospital, had a DSTI as the first confirmed extremity wound infection (within 30 days post-injury), started antibiotics ±3 days of DSTI diagnosis, and received ≥5 days of directed antibiotic treatment. Results Among 1961 combat casualties with open extremity wounds, 259 had a DSTI diagnosis with 173 (67%) having only 1 index DSTI and 86 (33%) having >1 index DSTI diagnosed on the same day. Nearly all patients (95%) were injured via a blast mechanism. Patients with >1 index DSTI were more severely injured (median injury severity score: 35 vs. 33; P = 0.009) and required large volume blood transfusions within 24 hours of injury (median units: 23 vs. 17; P < 0.001). Initial empiric antibiotic treatment largely involved carbapenem and vancomycin (77% and 72% of patients, respectively). For diagnosis timing, 130 (50%) patients had an early DSTI diagnosis (≤7 days post-injury), while the remaining 129 (50%) patients had a delayed diagnosis (>7 days post-injury). Patients with early DSTI diagnoses more often had >1 index DSTI (47% vs. 19% with delayed DSTI; P < 0.001). Polymicrobial DSTIs were common (73% of early DSTIs; 58% of delayed DSTIs) with Enterococcus spp. most frequently identified (56% of early DSTIs; 31% of delayed DSTIs) as well as Enterobacter spp. Escherichia coli , Pseudomonas aeruginosa , and Acinetobacter spp. Moreover, 26% and 39% of early and delayed DSTIs had multidrug-resistant Gram-negative bacteria. Receipt of >20 units of blood within 24 hours of injury and having >1 index DSTI were independently associated with an early DSTI diagnosis (odds ratio [OR]: 3.21; 95% CI: 1.47–7.02 and OR: 2.98; 95% CI: 1.63–5.42, respectively). Conclusion Multiple index DSTIs and massive blood transfusion requirement are associated with early infection onset post-injury. Awareness of wound microbiology findings relative to DSTI onset provides guidance on empiric antimicrobial therapy. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]

We present extremity wound microbiology data from 250 combat casualties (2009–2012). Confirmed extremity wound infections (EWIs) were based on clinical and laboratory findings. Suspected EWIs had isolation of organisms from wound cultures with associated signs/symptoms not meeting clinical diagnostic criteria. Colonized wounds had organisms isolated without any infection suspicion. A total of 335 confirmed EWIs (131 monomicrobial and 204 polymicrobial) were assessed. Gram-negative bacteria were predominant (57% and 86% of monomicrobial and polymicrobial infections, respectively). In polymicrobial infections, 61% grew only bacteria, while 30% isolated bacteria and mold. Multidrug resistance was observed in 32% of isolates from first monomicrobial EWIs ±3 days of diagnosis, while it was 44% of isolates from polymicrobial EWIs. Approximately 96% and 52% of the suspected and colonized wounds, respectively, shared ≥1 organism in common with the confirmed EWI on the same patient. Understanding of combat-related EWIs can lead to improvements in combat casualty care. • Sixty-one percent of 335 confirmed extremity wound infections were polymicrobial. • Gram-negative bacteria predominant among combat-related extremity wound infections. • Enterococcus spp. most frequent organism isolated from polymicrobial infections. [ABSTRACT FROM AUTHOR]