{'fraction_non_alphanumeric': 0.04234625168337573, 'fraction_numerical': 0.02109830914260063, 'mean_word_length': 5.396172248803828, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
2266. Management of Ertapenem-Resistant, Meropenem-Susceptible Enterobacteriaceae

Abstract Background Carbapenemases are the most frequent mechanism of carbapenem resistance in Enterobacteriaceae. However, alternative mechanisms such as loss of porin channels or up-regulation of efflux pumps can cause intermediate- to high-level resistance to ertapenem (ERTA) and possibly reduced susceptibilities to meropenem (MERO) leading to discordant phenotypic profiles. Clinical implications of discordant carbapenem susceptibilities and optimal therapy options are yet unknown. We sought to describe our experience with carbapenem-discordant Enterobacteriaceae (CDE). Methods Descriptive study of hospitalized adult patients with a CDE positive culture from December 1/16 - December 1/18. Discordance was defined as Enterobacteriaceae with an ERTA-resistant and MERO-susceptible phenotype. Primary objective was to describe antibiotic use patterns for CDE infections. Secondary outcomes included infectious diseases (ID) involvement and clinical outcomes. Clinical failure was defined as a composite of in-hospital mortality, switch of definitive therapy due to clinical worsening, re-hospitalization within 30 days for re-infection, or failure to achieve blood culture clearance for ≥7 days. Results A total of 55 patients with CDE were identified. Most common organisms were Enterobacter cloacae complex (72%) and Klebsiella pneumoniae (9%). Of 21 isolates tested, 1 (4.8%) was positive for a carbapenemase. Mean age of patients was 61 ± 16 years, 51% were admitted to a medicine service, and 18% were immunocompromised. ID was involved in 82% of CDE cases. Most common sites were urine (33%), wound/tissue (27%), and respiratory (18%). 43/55 (78%) patients were treated – 17/43 (40%) with MERO, 14/43 (33%) with fluoroquinolones. Ceftazidime/avibactam and tigecycline were used in 4 (9%) patients each. Combination therapy was used in 8 (19%) patients, most commonly with MERO or tigecycline. Clinical failure occurred in 21/43 (49%) patients – 8/43 (19%) were receiving MERO-based therapy, 13/43 (30%) were receiving a non-MERO-based therapy. Conclusion Discordance between ERTA and MERO susceptibility was more common in Enterobacter spp. Majority of isolates tested negative for a carbapenemase. MERO and fluoroquinolones were the most frequently used antibiotics for treatment of CDE infections. Disclosures All authors: No reported disclosures.


An Evaluation of Empiric Treatment Patterns for Adult Patients with Community-Onset (CO) "Low-Risk" (LR) Complicated Intra-Abdominal Infections (cIAI) Across US Hospitals
Thomas Lodise, PharmD, PhD 1 ; Sergey Izmailyan, BS 2 ; Melanie Olesky, PhD 2 ; Kenneth Lawrence, PharmD 2 ; Larry Tsai, MD 2 ; 1 Albany College of Pharmacy and Health Sciences, Albany, New York; 2 Tetraphase Pharmaceuticals, Watertown, Massachusetts Saturday, October 5, 2019: 12:15 PM Background. Current cIAI guidelines recommend that broad-spectrum antibiotics (abs) like anti-pseudomonal β-lactams should be reserved for "high-risk" CO cIAI patients. Fluoroquinolone (FQ) use is also discouraged in geographic areas with a high incidence of FQ-resistance. Compliance with these recommendations are unclear as there are limited data on empiric treatment (tx) patterns for adult patients with cIAI across US hospitals. This study sought to evaluate empiric tx patterns for patients with CO LR cIAI and assess compliance with cIAI guideline recommendations.

Methods.
A retrospective multi-center study using data from the Premier Research Database (October 2015-December 2017) was performed. Inclusion criteria: age ≥ 18 years; hospitalized; primary cIAI diagnosis and a cIAI surgical procedure or a secondary cIAI diagnosis and cIAI surgical procedure within 5 days of admission; and received an ab within first 4 hospital days. For patients with multiple cIAI admissions, only the first cIAI was considered. Apt was classified as high-risk (HR) if they met any one of the following criteria: sepsis, severe sepsis, septic shock; ≥3 components of sepsis; or ≥2 two physiologic risk factors (age ≥ 70 years, malignancy, kidney dysfunction, hepatic dysfunction, hypoalbuminemia, and significant cardiovascular compromise). Empiric tx was abs received during the first 4 hospital days. Incidence of empiric tx regimen including one of the following abs was determined among LR patients: piperacillin/tazobactam (TZP), meropenem (MER), cefepime (CFP), and FQ.
Conclusion. Overuse of non-guideline concordant broad-spectrum abs was commonplace among CO cIAI patients classified as LR. These findings can serve as the basis for an antimicrobial stewardship initiative in hospitals aspiring to reduce the use of broad-spectrum antibiotics.
Disclosures. All authors: No reported disclosures.

Background.
Burkholderia cepacia complex (Burkholderia cenocepacia and Burkholderia multivorans) (BCC) are uncommon, yet serious often drug-resistant pathogens of immunocompromised patients, especially in lung transplants; pre-operative infection/colonization is seen as a contraindication to transplant. Optimal treatment for these difficult infections is not known. We examined impact of single vs. combination therapy on patient outcomes.
Methods. All cases of BCC positive pulmonary or blood cultures at The Ohio State University Wexner Medical Center between January 1, 2012 and June 30, 2018 were analyzed. No cystic fibrosis patients were included. All combinations thereof were evaluated. The primary outcomes were 30 all-cause mortality and 30-day infection-related mortality. Secondary outcomes included sterilization of cultures, isolation of a non-susceptible isolate within 30 days of therapy, hospital and intensive care unit (ICU) length of stay, and adverse drug effects (ADE) of therapy including: hyperkalemia, acute kidney injury (AKI), transaminitis, and QTc prolongation.
Results. There were 90 unique patients who grew BCC (22 patients with 92 positive blood cultures; 54 patients with 87 positive pulmonary cultures). Four patients had mixed pulmonary and blood cultures. Ten patients died prior to having treatment for their cultures and were not evaluated. Overall, there were 85 evaluable infection events.
Conclusion. Overall mortality trends improved with combination therapy in blood culture patients and with monotherapy patients in pulmonary cultures. These findings are influenced by the limited number of patients available, and the medical co-morbidities of these patients. In lung patients there were significantly fewer ADE associated with monotherapy as opposed to combination therapy.
Disclosures. All authors: No reported disclosures.