bluuebunny/crossref_metadata_2025 huggingface dataset:
209. Methicillin-Sensitive Staphylococcus aureus (MSSA) Septicemia-Outcomes of Ceftriaxone Compared with Cefazolin and Oxacillin Outpatient Therapy from a Large National Sample
Authors: Hamad Yasir , Nickel Katelin B , Olsen Margaret A , George Ige
Published: December 2021

Background

Ceftriaxone has activity against MSSA and is convenient to use during outpatient parenteral antimicrobial therapy (OPAT). We examined outcomes of MSSA septicemia on patients receiving cefazolin, ceftriaxone or oxacillin OPAT using administrative data.

Methods

A large insurance claims database of privately insured patients (IBM MarketScan) aged 18 – 64 years from 2010 to 2018 was queried for patients with MSSA septicemia discharged from the hospital on cefazolin, ceftriaxone, or oxacillin OPAT. The primary endpoint was 90-day hospital readmission with same infection category as the index admission. Factors with significant association in univariate analysis were incorporated into a multivariable Cox proportional hazards model with sequential exclusion of variables with p > 0.1.

Results

A total of 1,895 patients were included; the median age was 54 years and 62.9% were male. Primary outcome occurred in 366 (19.3 %). Factors associated with readmission in multivariable analysis included older age (61-64 years) (aHR 1.42 [CI 1.02-1.98]), obesity (1.31 [1.04-1.65]), intensive care unit (ICU) stay during index MSSA hospitalization (2.11 [1.68-2.65]), hospitalization in the month prior to index MSSA (1.46 [1.15-1.85]), central line associated bacteremia (1.72 [1.26-2.35]), endocarditis (1.56 [1.19-2.04]) and prosthetic joint infection (1.77 [1.26-2.50]). There was no difference in infection-associated readmission among patients treated with ceftriaxone compared to cefazolin or oxacillin (Figure 1).

Conclusion

Older age, ICU admission, obesity, endocarditis, and prosthetic joint infections were associated with increased risk of hospital readmission with infection following OPAT for MSSA septicemia. Treatment with ceftriaxone was not associated with worse outcomes compared to oxacillin or cefazolin.

Figure 1. Kaplan Meier Survival Analysis for readmission free survival (log-rank P value 0.31)

Disclosures

Margaret A. Olsen, PhD, MPH, Pfizer (Consultant, Research Grant or Support)
210. Outcomes of Kidney Transplant Recipients with Donor Positive Blood Cultures
Authors: Svoronos Petros , Vijayvargiya Prakhar , Vaitla Pradeep , Wynn James j , Beam Elena , Parham Jason , Sohail Muhammad R , Garrigos Zerelda Esquer
Published: December 2021

Background

Based on expert opinion, solid organ transplant recipients from donors with bacteremia are treated with 7-14 days of pre-emptive antibiotic therapy (PAT). However, studies addressing necessity, optimal duration of therapy, and outcomes in kidney transplant recipients (KTR) are lacking.

Methods

We retrospectively reviewed all kidney transplants performed at our institution from 01/01/2015-01/01/2021 to identify those cases where matched deceased donors had positive blood cultures. Bacteremia was defined per CDC criteria. We analyzed rate of infection in the KTR with the same organism identified in the donor blood culture within 30 days of transplantation.

Results

A total of 56 KTRs with donor positive blood cultures were identified. Demographic data are summarized in Table 1. Twenty of 56 cases (35.8%) had bacteremia and 36 (64.2%) had organisms classified as common commensals. The most common organisms in the bacteremia group were Gram-negative bacteria (12/20) and Staphylococcus aureus (6/20). Most common commensals were coagulase-negative staphylococci (26/36) (Table 2). All KTR received preoperative antibiotics at the time of transplantation, primarily cefazolin (15/20), and vast majority received TMP/SMX prophylaxis, for Pneumocystis jirovecii, post-transplant (19/20). PAT was administered in 70% (14/20) cases of bacteremia for a median of 8.5 days (IQR 7-14), while six cases were left untreated (Table 2). In contrast, majority of cases with common commensals were not treated (75%, 27/36). Of the cases treated (9/36), median duration of therapy was 7 days (IQR 5-14). No cases of infection with the same organism identified in the donor blood culture were reported in KTR within 30 days of transplantation.

Conclusion

KTR donors with bacteremia who were treated received a median of 8.5 days of PAT with no instances of breakthrough infection. In contrast, majority of donor blood cultures with organisms classified as common commensals were not treated and did well. Future studies are needed to assess whether perioperative antibiotics coupled with TMP/SMX prophylaxis post-transplantation are sufficient in select cases of transplantation from donors with bacteremia.

Disclosures

All Authors: No reported disclosures
211. Burkholderia Cenocepacia Infections at Sites Other Than the Respiratory Tract, a Large Case Series from a Tertiary Referral Hospital in Lebanon
Authors: Hariri Housam Eddine Al , Kwayess Rola , Hindy Joya-Rita , Youssef Nada , Elbejjani Martine , Kanj Souha S
Published: December 2021

Background

Burkholderia cenocepacia has been described to cause mainly respiratory tract infections. We noticed an increased number of skin and soft tissue infections (SSTIs), bloodstream infections (BSIs) and osteomyelitis over the past years at our medical center.

Methods

This is a retrospective chart review of 44 patients with documented B. cenocepacia infection at sites other than the respiratory tract diagnosed between 2005 and 2020 at the American University of Beirut Medical Center, a tertiary referral hospital for the Middle East region.

Results

The nationalities of our patients were Iraqi (40.9%), Lebanese (34.1%), and Syrian (20.5%). Twenty six of the infections (59.1%) were hospital-acquired infections (HAIs). The most common infections were BSIs (17/44, 38.6%), then SSTIs as well as deep seated cysts and abscesses (16/44, 36.4%) and vertebral osteomyelitis (8/44, 18.2%). Half of the vertebral osteomyelitis were located in the lumbar, and 3 in the cervical region; 5 of these cases were native osteomyelitis. Sixteen patients (36.4%) had prior antibiotic intake within 30 days with ceftazidime, carbapenems and quinolones being the most common. All the patients received directed therapy for an average duration of 23.48 (+/- 37.779) days, and for 60 days for those with osteomyelitis. Combination regimens of 2 antibiotics (ceftazidime, quinolones, carbapenems, trimethoprim-sulfamethoxazole (TMP-SMX)) were used in 10 patients, whereas 24 received a single antibiotic. Thirty three patients (75%) were admitted to the hospital, 20 (45.5%) of which had an indwelling catheter and 12 (27.3%) were in the intensive care unit. Thirty two patients (96.9%) were discharged home. Susceptibility testing revealed 84.1%, 54.5%, 63.2%, and 65.9% susceptibility to ceftazidime, tetracycline, TMP-SMX, and carbapenems respectively.

Characteristics of patients

Conclusion

B. cenocepacia BSIs, SSTIs, abscesses, and osteomyelitis were noted to be more common at our medical center as HAIs particularly in Iraqi and Syrian patients, raising the concern that countries at war might be at increased risk for such infections. Our susceptibilities results were consistent with the literature. Although B. cenocepacia is a resistant bacteria, the majority of our patients were successfully treated.

Disclosures

All Authors: No reported disclosures
213. Assessment of Compliance with Order Set and Bundle for Management of Staphylococcus aureus Bacteremia
Authors: Flynn Ryan R , Obritsch Marilee , Lesselyoung Veronica , Strain Joe , Kappes John
Published: December 2021

Background

Staphylococcus aureus (S. aureus) is an aerobic gram-positive coccus that causes a variety of infections. S. aureus bloodstream infections, also known as bacteremias, have significant morbidity and mortality and are difficult to eradicate. A single-center study showed a 9.4% recurrence rate for S. aureus bacteremia, despite adequate treatment. The Infectious Disease Society of America (IDSA) recognizes the seriousness of S. aureus infections, particularly methicillin-resistant S. aureus (MRSA), and has released guidance for treatment of these infections. Guidance for S. aureus bacteremias include identification and removal of the source and early optimization of antibiotics. Serial imaging and laboratory monitoring, including repeat blood cultures, are also necessary to establish the duration of therapy, ensure microbiologic eradication, and reduce the risk of long-term complications. Due to the complexity of S. aureus bacteremia, early involvement of infectious diseases (ID) specialists is strongly recommended.

Methods

This retrospective, single-center study was designed to evaluate the current management of S. aureus bacteremias, including compliance to the elements of the S. aureus order set and bundle. Patients 18 years and older who had a positive blood culture for S. aureus were included in this study. Recurrence of S. aureus infection was assessed at 6 months. Data was analyzed to compare patients with and without ID consults.

Results

Eighty-four patients met inclusion criteria. ID consultation resulted in a higher percentage of patients achieving 100% compliance with the bundle elements compared to patients without ID consults (73% vs 25%, respectively; p=0.009). For further breakdown of compliance see Table 1. No statistical difference was detected in recurrence rates (11% vs 33%, respectively; p=0.18) or mortality (8% vs 25%, respectively; p= 0.17) possibly due to the small sample size.

Table 1. Outcomes

Conclusion

ID specialist involvement for the treatment of S. aureus bacteremia resulted in greater compliance with the S. aureus bacteremia bundle. No statistical difference in recurrence or mortality rates was detected.

Disclosures

All Authors: No reported disclosures
214. Prospective Evaluation of the GenMark Dx ePlex® Blood Culture Identification Gram Negative Panel
Authors: Meeder Jeremy , Moates Derek , Pierce Hannah , Hutchinson Jamie , Cumagun Pia , White Cameron , Lee Rachael A , McCarty Todd P , Leal Sixto M
Published: December 2021

Background

The ePlex BCID Gram-Negative (GN) panel utilizes electrowetting technology to detect the most common causes of GN bacteremia (21 targets) and 6 antimicrobial resistance genes from positive blood culture bottles. Rapid detection of extended spectrum β-lactamases (ESBL; CTX-M), carbapenemases (KPC, NDM, IMP, VIM, OXA 23/48), and highly resistant bacteria such as Stenotrophomonas maltophilia enables early optimization of antimicrobial therapy.

Methods

In this prospective study, we evaluated the performance of the BCID-GN panel compared to traditional standard of care culture and susceptibility testing with organism identification using the BioMerieux Vitek MS Matrix Assisted Laser Desorption Ionization (MALDI) Time of Flight mass spectrometry. Samples submitted for standard of care testing in Biomerieux BacT/Alert resin FA/FN blood culture bottles on the BacT/Alert VIRTUO automated blood culture system with GN bacteria on direct exam (n=108) were included.

Results

All but two GN bacteria identified by MALDI were represented on the BCID-GN Panel (106/108, 98.1%) and most tests (107/108, 99.1%) yielded valid results. Discordant analyses revealed a positive percent agreement (PPA) of 102/105 (97.2%) with 3 false negatives (2 pan-susceptible Enterobacterales, 1 ESBL E.coli) and a negative percent agreement (NPA) of 105/105 (100%). Consistent with alternative resistance mechanisms, only 8/12 (66.7%) of Enterobacterales with resistance to 3rd generation cephalosporins harbored the CTX-M gene. In contrast, 8/8 (100%) of isolates from samples harboring the CTX-M gene were resistant to 3rd generation cephalosporins.

Conclusion

Detection of 1 S. maltophilia, 1 Acinetobacter baumannii expressing OXA 23/48, and 8 Enterobacterales expressing CTX-M represent opportunities for early optimization of antimicrobial therapy in 10/108 (9.3%) of samples. The BCID-GN Panel provides rapid accurate detection of resistant gram negative bacteria enabling high quality data driven optimization of antimicrobial therapy.

Disclosures

Todd P. McCarty, MD, Cidara (Grant/Research Support)GenMark (Grant/Research Support, Other Financial or Material Support, Honoraria for Research Presentation)T2 Biosystems (Consultant) Sixto M. Leal, Jr., MD, PhD, Abnova (Grant/Research Support)AltImmune (Grant/Research Support)Amplyx Pharmaceuticals (Grant/Research Support)Astellas Pharmaceuticals (Grant/Research Support)CNINE Dx (Grant/Research Support)GenMark Diagnostics (Grant/Research Support, Other Financial or Material Support, Honoraria- Research Presentation)IHMA (Grant/Research Support)IMMY Dx (Grant/Research Support)JMI/Sentry (Grant/Research Support)mFluiDx Dx (Grant/Research Support)SpeeDx Dx (Grant/Research Support)Tetraphase Pharmaceuticals (Grant/Research Support)
215. Candida glabrata (CG) Bloodstream Infections (BSIs) Are Characterized by Genetically Diverse Populations of Strain Variants Recovered from Positive Blood Cultures (BCs)
Authors: Hassan Badrane , Cheng Shaoji , Liu Guojun , Clancy Cornelius J , Nguyen Minh-Hong
Published: December 2021

Background

The long-standing paradigm is that almost all BSIs stem from a single, clonal organism (“single-organism” hypothesis). We hypothesized that CG-positive BCs were comprised of genetically diverse strain variants.

Methods

Five to ten CG colonies were isolated from positive BC bottles from ten distinct patients (pts) for a total of 94 clones, which underwent NextGen short-read sequencing (Illumina). Variants were analyzed using SNPeff, and a phylogeny was constructed with Maximum Likelihood method.

Results

BCs harbored a diverse population of CG strains that were unique to each pt [Fig. 1]. All strains were genetically distinct, differing by unique SNPs and insertions-deletions (indels) [Fig. 2-3]. SNPs were ~8-fold more common than indels. Individual genomes from the same time point in the same pt exhibited consistent magnitude of variations relative to reference genome; however, variations were unique, pointing to significant genomic variability that could be both intra- and interclonal. The number of variant sites for within-pt pairwise clone comparisons ranged from 1924-8500. There were 124,145 variant sites when all clones are compared. Roughly half of all SNPs were identical in different samples from a given pt; the remainder were present/absent in at least one sample per pt. Long-read WGS revealed strains with structural variants in each pt, including chromosomal recombinations and gene duplications that were not evident by short-read WGS. A genomic phylogeny construction showed that 94 clones spanned 3 distinct clades that were distinct from the reference strain. Finally, comparison of non-synonymous mutations among intra-pt clones showed overwhelming overrepresentation of adhesin and adhesin-like genes, pointing to possible importance in host adaptation.

Venn diagram of core genome SNPs of 5 Candida glabrata recovered from blood cultures of patient C.

Conclusion

Preliminary analyses revealed genetically diverse populations of C. glabrata in BCs of individuals with BSIs. We are studying phenotypic diversity of strain variants, and the clinical implications of genetically diverse Candida BSIs.

Disclosures

Cornelius J. Clancy, MD, Merck (Grant/Research Support) Minh-Hong Nguyen, MD, Merck (Grant/Research Support)
218. A 5-Year Retrospective Study of Actinomyces Odontolyticus Bacteraemia
Authors: Ali Maisa , Razok Almurtada , Ziglam Hisham
Published: December 2021

Background

Actinomyces species are Gram positive anaerobic, non-sporulating, non-acid fast, non-motile, irregularly staining bacterium. It is associated with a wide range of infections including; dental caries, abscesses, intraabdominal and bloodstream infections. A. odontolyticus normally a commensal organism found in the mouth, was first isolated from dental caries in 1958. The incidence of Actinomyces odontolyticus bacteremia is less common.

Methods

We are reporting 15 cases of isolated A. odontolyticus blood stream infection at HMC, State of Qatar from 1/1/2016 to 1/11/2020. We aim to describe their clinical characteristic, risk factors and treatment outcome.

Results

Our patients with bacteraemia fall into one of two groups. The first group consists of paediatric patients with unremarkable co-morbidities. The second group includes older adults, often with co-morbidities that pre-dispose to infection, such as diabetes mellitus or hypertension. Fever was the main presenting sign and symptom in 12 patients (80%). Nine of the patients were females (60%). 13 patients (86%) received antibiotics. Maximum duration of antibiotics was 60 days and minimum duration was three days. The infectious disease team was consulted for six patients (40%). One patient died while the other 14 recovered uneventfully with a case fatality rate of 6.6%.

Reported cases of Actinomyces odontolyticus bacteraemia in Hamad Medical Corporation between 1/1/2016 to 1/11/2020

Minimal inhibitory concentrations (MICs) of selected antibiotics against A. odontolyticus, including interpretations and breakpoints, as reported by the AMRHAI reference unit, PHE Colindale

Conclusion

Clinicians of all specialties need to be aware of the rising number of reports of Actinomyces species bacteraemia due to widespread availability of molecular identification techniques, including MALTI-TOF. 3 Furthermore, more studies are needed to determine guidelines for treating these resilient microbes

Disclosures

All Authors: No reported disclosures
219. Outcomes with Low- vs. High-bioavailability Oral Antibiotics in Treatment of Uncomplicated Gram-Negative Bacteremia
Authors: Cubillos Ashley L , Chandler Elisabeth , Murphy Ian P , Castro Robert
Published: December 2021

Background

High-bioavailability (HIGH-BIO) oral agents (i.e. trimethoprim-sulfamethoxazole, fluoroquinolones) are increasingly utilized for definitive treatment of uncomplicated gram-negative (UGN) bloodstream infections (BSI). Literature supports use of HIGH-BIO agents as step-down therapy, but few studies have assessed use of low-bioavailability (LOW-BIO) agents (i.e. beta-lactams). Increased recurrence of BSI has been associated with LOW-BIO agents; suboptimal dosing of beta-lactam agents may have impacted outcomes. Trials have not assessed whether high-dose beta-lactams (HD-BL) improve clinical outcomes over low-dose beta-lactams (LD-BL) for UGN BSI.

Methods

This retrospective cohort study conducted between December 2016 and December 2020 included adults with UGN BSI administered oral step-down therapy for at least 1/3rd the total antibiotic duration. The primary outcome was incidence of treatment failure of HIGH-BIO compared to LOW-BIO agents within 90 days of completing oral therapy. Treatment failure was a composite of all-cause mortality, recurrent BSI, reinfection of the primary site, or transition to IV antibiotics after initiating oral therapy. Secondary outcomes were incidence of treatment failure of HIGH-BIO compared to HD-BL agents, and of HD-BL compared to LD-BL agents.

Results

Of 225 patients, 67 (29.8%) received a HIGH-BIO and 158 (70.2%) a LOW-BIO agent; of those in the LOW-BIO arm 126 (79.7%) received a HD-BL. The most common source of BSI was urinary (202 [89.8%]); transition to oral therapy occurred after a mean of 5 ± 2.39 days. No difference in treatment failure was observed (8 [11.9%] HIGH-BIO vs. 25 [15.8%] LOW-BIO, P = 0.45). A numerically higher number of patients in the LOW-BIO arm had recurrent BSI (4 [2.5%] LOW-BIO vs. 0 [0%] HIGH-BIO, P = 0.18). No difference in treatment failure was observed between HIGH-BIO and HD-BL agents (8 [11.9%] vs. 20 [15.9%], P = 0.46), or HD-BL and LD-BL agents (20 [15.9%] vs. 5 [15.6%], P = 0.97).

Conclusion

No difference in treatment failure was observed between groups; further study is needed due to failure to reach statistical power. A numerical trend towards increased recurrence of BSI was observed with LOW-BIO agents. Beta-lactams may be reasonable for step-down therapy of UGN BSI if HIGH-BIO agents are contraindicated.

Disclosures

All Authors: No reported disclosures
220. The Treatment of Enterococcus Blood Stream Infections in Patients Receiving Extracorporeal Membrane Oxygenation
Authors: Marcus Joseph E , Sobieszcyk Michal , Barsoumian Alice E
Published: December 2021

Background

Background: Extracorporeal membrane oxygenation (ECMO) is a growing modality of life support that is subject to a high rate of nosocomial infections. There is a paucity of data to guide treatment for infections on ECMO, which can lead to vastly different practice patterns at different centers. This case series describes the outcomes of patients with Enterococcus bacteremia at a single center.

Methods

A retrospective chart review was performed on all patients who received ECMO support at a tertiary academic medical center with ECMO capabilities between October 2012 and May 2020 with positive blood cultures for Enterococcus species.

Results

A total of 10 patients had Enterococcus bacteremia during the study period with E. faecalis (n=7, 70%) more commonly than E. faecium (n=3, 30%). Infections occurred more often in men (n=6, 60%) than women (n=4, 40%) with median age 36 (IQR: 31-42). Infections occured late in the hospitalization (median: 33 days (IQR: 26-59)) and after several weeks on the ECMO circuit (median: 24 days (22-52)). Infections were often polymicrobial (n=5, 50%). There were no cases of infective endocarditis. Infections were treated with 7-14 days of therapy with ampicillin being the most common antibiotic prescribed (n=5, 50%). Four (40%) patients were decannulated before completion of therapy. No patients had cannulas removed due to bacteremia. There were no cases of recurrence. Mortality was 20% in this cohort.

Clinical Characteristics of Patients with Enterococcus Bacteremia

Conclusion

Enterococcus is a common cause of blood stream infections in patients with prolonged courses on ECMO circuit. In this cohort of patients, Enterococcus did not cause any metastatic infections and was generally treated with 7-14 days of antibiotics without recurrence, despite many patients remaining on ECMO for extended periods after clearance. As ECMO use continues to expand, there will need to be more data on treatment outcomes of infections to establish best practices.

Disclosures

All Authors: No reported disclosures
221. Evaluation of Rates of Culture Positive Blood Stream Pathogens Prior to and During the SARS-CoV-2 Pandemic: A Multicenter Evaluation
Authors: Puzniak Laura A , Bauer Karri A , Yu Kalvin , Moise Pamela , Gupta Vikas
Published: December 2021

Background

Bacterial co-infections or super-infections are well-characterized complications of viral infections, further increasing morbidity and mortality of global viral pandemics. We evaluated trends in the incidence of culture positive gram-negative (GN), gram-positive (GP), and fungal/yeast pathogens from a blood source in hospitalized patients at US hospitals before and during the SARS-CoV-2 pandemic.

Table: Incidence and rate of blood pathogens in the pre and post SARS-CoV-2 period.

Gray indicates significantly lower rate compared to pre-pandemic time period, black indicates significantly higher rates compared to pre-pandemic.

Methods: This was a multi-center, retrospective cohort analysis of all hospitalized patients from 267 US acute care facilities with >1-day inpatient admission between 7/1/19-5/19/21 (BD Insights Research Database [Becton, Dickinson and Company, Franklin Lakes, NJ]). SARS-CoV-2 infection was identified by a positive PCR during or ≤7 days prior to hospitalization. All admissions with a non-contaminant culture positive GN, GP, and fungal/yeast pathogen from a blood source were evaluated prior to and during the SARS-CoV-2 pandemic as rates per 1,000 admissions (p< .05 for significance).

Results

There were 2,001,793 admissions in the pre-SARS-CoV-2 period (7/2019-2/2020) and 2,875,219 admissions during the SARS-CoV-2 pandemic. Incidence of GN/GP blood stream pathogens was significantly higher prior to the SARS-CoV-2 pandemic than during the pandemic. Higher rates of blood stream pathogens occurred in those who were tested for SARS-CoV-2, but all non-tested patients had significantly lower rates than pre-pandemic. Rates of Candida spp., Enterococcus spp., Serratia marcescens, and Enterobacter cloacae were higher in SARS-CoV-2 positive patients compared to pre-pandemic patients. Compared to the prior pandemic period, the incidence of B. fragilis, Streptococcus, Enterococcus and Candida were higher among those tested for SARS-CoV-2 but were negative.

Conclusion

In general, rates of positive blood cultures for bacterial pathogens were either lower or similar during the SARS-CoV-2 period compared to the pre-SARS-CoV-2 pandemic period. The patients that were tested for SARS-CoV-2 but were positive who had higher rates of infection than prior may indicate the similarity in viral and bacterial clinical presentation. Further evaluation of higher rates of Enterococcus and Candida in the pandemic period are warranted.

Disclosures

Laura A. Puzniak, PhD, Merck & Co., Inc. (Employee) Karri A. Bauer, PharmD, Merck & Co., Inc. (Employee, Shareholder) Kalvin Yu, MD, BD (Employee) Pamela Moise, PharmD, Merck (Employee) Vikas Gupta, PharmD, BCPS, Becton, Dickinson and Company (Employee, Shareholder)
223. The Value of Neutrophil to Lymphocyte Count Ratio for Predicting the Clinical Outcomes of Patients with Carbapenem-resistant Klebsiella pneumonia Blood Stream Infection
Authors: Wu Heng
Published: December 2021

Background

The neutrophil to lymphocyte count ratio (NLR) has been recognized as a useful marker of inflammation. But, the prognostic function of NLR in patients with Carbapenem-resistant Klebsiella pneumonia (CRKP) blood stream infection is still largely unknown. The aim of this study was to explore the relationship between postoperative NLR and mortality in those patients.

Methods

We performed a retrospective study based on the database from Computerized Patient Record System in Sir Run Run Shaw Hospital from 1/1/2017 to 31/10/2020. Logistic analysis was performed to assess the associations between NLR and 28-day mortality. Multivariate analyses were used to control for confounders.

Results

A total of 134 CRKP blood stream infection inpatients were included in this study, including 54 fatal cases and 80 survival cases on the 28-day after the onset of CRKP BSI, the overall 28-day mortality rate of patients with a CRKP BSI episode was 40.3% (54/134). We conducted a multivariate analysis on these 134 patients and found that APACHE II score on the 4th day (OR 1.379 95% CI 1.065- 1.785, p = 0.015), NLR on the 4th day (OR 1.134 95% CI 1.054- 1.221, p = 0.001) were significant risk factors for the 28-day mortality of CRKP BSI patients

Conclusion

Elevated NLR was significantly associated with increased 28-day mortality as well as APACHE II score on the 4th day after first positive culture.NLR is promising to be a readily available and independent prognostic biomarker for patients with CRKP blood stream infection.

Disclosures

All Authors: No reported disclosures
224. Evaluating the Epidemiology of Bloodstream Infections: A Population-Based Study
Authors: Niazi Elaha , Mponponsuo Kwadwo , Somayaji Ranjani , Rennert-May Elissa , Conly John , Gregson Dan , Leal Jenine
Published: December 2021

Background

Bloodstream infections (BSI) are a major cause of morbidity, mortality, and health care costs worldwide. Population-based studies are key to assess BSI epidemiology over time while minimizing selection bias but remain limited. Therefore, we aimed to assess the incidence of BSI in a large Canadian health region in a contemporary period. We hypothesized that there would be significant age and sex-based differences including over time.

Methods

We conducted a retrospective cohort study from 2011 through 2018 using a population-based microbiology database to determine the annual age- and sex-specific BSI testing and case rates with the census as the population reference. BSI was defined as a positive blood culture for a pathogen. Episodes > 30 days apart were included for analysis. Incidence rate ratios (IRR) for testing and case rates including by sex were calculated to assess changes over time. All analyses were run at a two-sided α of 0.05 and were conducted with R 4.0.4.

Results

A total of 154,147 distinct individuals (49.9% male) were analyzed and 22,869 (14.8%) had a BSI at the first encounter in the study period. Overall BSI testing incidence ranged from 1529 to 1707 per 100,000 person-years and case incidence ranged from 180 to 292 per 100,000 person-years. Testing and case incidence for BSI was greatest in the 0-4 and 75+ years age groups (p < 0.01). Males compared to females had greater testing and case incidence rates in young and old age groups, but females had greater rates in the 15-44 years groups (p < 0.01). Overall IRR for cases comparing 2018 to 2011 was 0.62 (95% CI 0.59-0.65) reflecting a significant decrease over time. Testing also decreased over the study period with an IRR of 0.90 (95% CI 0.88-0.91). Testing and case IRRs were not significantly different stratified by sex.

Incidence rates (per 100,000 person-years) of BSI testing and cases by sex from 2011 through 2018 in a Canadian health region

Conclusion

In our large population-based study of BSI, we identified that BSI remain frequent and the youngest and oldest age groups as well as males in these age groups have the greatest BSI incidence rates which may reflect both biological sex and gender-based differences. Encouragingly, BSI incidence rates have decreased over time at a greater increment relative to testing rates. Future studies of BSI should focus on pathogen and outcome-based evaluations.

Disclosures

All Authors: No reported disclosures
225. Risk Factors for Mortality in Stenotrophomonas Bacteremia: A Retrospective Study
Authors: Huang Glen , Davis Matthew R , Allyn Paul R
Published: December 2021

Background

Stenotrophomonas is a gram-negative organism typically associated with nosocomial infections. It is an emerging multi-drug resistant pathogen associated with significant morbidity and mortality in hospitalized patients. Optimal therapy is unknown. In this study, we evaluated the impact of treatment agent, dosing regimen, and patient characteristics on 30-day mortality for Stenotrophomonas bacteremia in our hospital system.

Methods

Retrospective chart review from April 2013 to September 2019 at Ronald Reagan and Santa Monica UCLA Medical Centers in Los Angeles, California. Adult patients who were hospitalized and received active therapy for Stenotrophomonas bacteremia were included in the study. Chi-square or Fischer test was used for categorical variables, Student’s t-test or Mann-Whitney U test was used for continuous variables.

Results

Sixty-nine patients were included in the study. The median age was 53 and 31 patients (44.9%) were female. Central line associated infections were the most common source of infection (79.7%, n = 55). Two patients (3%) had a relapse of infection. The overall 30-day mortality was 30.4% (n=21). The patients who did not survive to 30 days tended to have a higher Pitt bacteremia score, a longer length of stay, and were more likely to have used other antibiotics in the 30 days prior to culture collection. Trimethoprim-sulfamethoxazole (TMP-SMX) was the most common antibiotic used for treatment (n = 45, 65.2%). Of the patients who were treated with TMP-SMX, 19 were treated with high-dose (defined as 15 mg/kg or equivalent) and 26 had an alternative dosage after adjusting for renal function. There was no difference in 30-day mortality in the TMP-SMX high dose vs alternative dose (42.1% vs 30.8%, p = 0.53).

Conclusion

Stenotrophomonas bacteremia was associated with high mortality. High-dose TMP-SMX did not impact survival in our study; however, this may be due to small sample size. More research is needed to determine optimal therapy.

Disclosures

All Authors: No reported disclosures
226. Multidrug Resistant Polymicrobial Gram-negative Bacteremia in Hematologic Cancer Patients with Febrile Neutropenia at the Uganda Cancer Institute
Authors: Lubwama Margaret , Bwanga Freddie , Kateete David , Adams Scott , Namubiru Betty , Nabiryo Barbara , Orem Jackson , Phipps Warren
Published: December 2021

Background

Bloodstream infections (BSI) are associated with significant mortality in hematologic cancer patients with febrile neutropenia. Poor clinical outcomes are associated with presence of multidrug resistant (MDR) organisms and polymicrobial infections. We sought to determine antimicrobial resistance and outcomes of polymicrobial bloodstream infections in hematologic cancer patients with febrile neutropenic episodes (FNEs) at the Uganda Cancer Institute.

Methods

Blood drawn from participants during an FNE (fever ≥ 37.5°C and neutrophil count ≤ 1000 cells/µL) was cultured in the BACTEC 9120 blood culture system. Bacteria from positive cultures were identified biochemically. Antimicrobial susceptibility testing was performed with the disc diffusion method. Participants were followed for 30 days from first FNE onset for death from any cause. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95%).

Results

Six hundred and twenty-nine participants were followed for FNE. Two hundred and twenty-eight FNEs in 159 participants were observed. Of 181 FNEs with blood cultures completed, 65 (36%) had pathogenic organism isolated. A total of 74 Gram negative and 18 Gram positive bacteria were isolated. Forty-eight (74%) FNEs had monomicrobial (MBSI) and 17 (26%) had polymicrobial (PBSI) bloodstream infections. Gram negative - Gram negative (10 out of 17, 59%) was the most frequent PBSI combination (Fig 1). Up to 75% (12 out of 16) of Gram-negative PBSI were MDR. The most common organism isolated was E. coli (38% of isolates). Participants with PBSI had higher early mortality rates at 7 days compared to MBSI and negative cultures (44%, 22%, and 16% for PBSI, MBSI, and negative respectively; HR (95% CI): 3.63 (1.49, 8.86) for PBSI v. negative/MBSI cultures). Similarly, PBSI was associated with higher mortality within 30 days of FNE onset (63%, 52%, and 38% for PBSI, MBSI, and negative respectively; HR (95% CI): 2.17 (1.09, 4.32) for PBSI v. negative/MBSI) (Fig 2).

Figure 1. Bar graph showing combinations for polymicrobial bloodstream infections (PBSI). GNGN: Gram-negative – Gram-negative; GNGP: Gram-negative – Gram-positive; GNO: Gram-negative – Other (fungi); GPGP: Gram-positive – Gram-positive

Figure 2. Kaplan-Meier failure curves of participants with negative cultures, monomicrobial infections and polymicrobial infections

Conclusion

PBSI episodes were more likely to be multidrug resistant and are associated with higher mortality. Empirical therapy for patients with PBSI should consider multidrug resistant Gram-negative bacteria

Disclosures

All Authors: No reported disclosures
231. Retrospective Comparison of Intravenous Therapy, Oral Therapy, and Lipoglycopeptides for the Treatment of Osteomyelitis
Authors: Stumphauzer Alex , Moenster Ryan P , Linneman Travis W
Published: December 2021

Background

The use of oral (PO) antibiotics and lipoglycopeptides are challenging the previous standard of osteomyelitis (OM) treatment, but there is currently a paucity of comparative data between these approaches.

Methods

This retrospective study included patients diagnosed with OM treated with intravenous (IV) antibiotics, PO antibiotics, or lipoglycopeptides between January 1, 2010 and June 1, 2020. Patients in the PO group could receive no more than 14 days of IV antibiotics prior to the PO course, and inclusion into the lipoglycopeptide group required at least 2 doses of drug to be administered. The primary outcome was occurrence of clinical failure within six months of completion of therapy, which was defined as new antibiotics or unplanned surgical intervention for an infection at the same site. Secondary outcomes included in-hospital length of stay (LOS), amputation within 6 months of therapy completion, and incidence of drug and line-related adverse effects. Previous osteomyelitis at index site, surgical intervention as a part of initial management, presence of Staphylococcus aureus on culture, utilization of outpatient parenteral antibiotic therapy (OPAT) services (IV group only), and concomitant PO therapy (lipoglycopeptide group only) were included in a bivariate analysis and variables with a p-value < 0.2 were included in a multivariate regression model.

Results

The IV group included 257 patients, while the PO and lipoglycopeptide groups included 20 and 15 patients respectively. In the IV group, 89 (35%) of the patients experienced clinical treatment failure compared to 5 (25%) in the PO group and 5 (33%) in the lipoglycopeptide group (p=0.71). Median LOS was significantly shorter in the PO group compared to the IV and LGP groups [1 day (IQR 0-2.5) vs. 7 days (IQR 4-10) and 4 days (IQR 4-9), p=0.003]. No difference between groups was observed for amputation within 6 months or incidence of adverse effects. The only variable included in the multivariate regression model was previous osteomyelitis at index site [OR 1.75, 95% CI (1.07 – 2.87)].

Conclusion

PO and lipoglycopeptide therapy resulted in similar outcomes compared to IV antibiotics. Only previous OM at the same site was identified as an independent risk factor for failure.

Disclosures

Ryan P. Moenster, Pharm.D., FIDSA, AbbVie (Speaker’s Bureau)Melinta (Consultant, Speaker’s Bureau)
232. Safety and Effectiveness of Intravenous to Oral De-escalation Compared to Continued Vancomycin Therapy in Orthopedic Infections
Authors: Gallagher Chanah , Benefield Russell J , Certain Laura
Published: December 2021

Background

The Oral versus Intravenous Antibiotics for Bone and Joint Infection (OVIVA) trial determined oral antibiotics administered during the first six weeks of therapy were non-inferior to parenteral antibiotics. There was no difference in the incidence of serious adverse effects. The objective of this study was to evaluate the safety and effectiveness of de-escalating to oral therapy compared to continuing parenteral vancomycin therapy in patients with orthopedic infections in a real-world setting.

Methods

We conducted a single-center, retrospective cohort study of patients discharged between April 1, 2018 and April 1, 2020 with an orthopedic infection, a prescription for at least four weeks of parenteral vancomycin, and documented follow-up. The primary outcome was incidence of adverse events defined as provider documentation of the event and changes to therapy. The secondary outcome was incidence of 6-month treatment failure defined as repeat surgical intervention or therapy escalation.

Results

One hundred fifty-seven patients were included. Twenty-nine (18.5%) patients were de-escalated to oral therapy. Three (10%) patients in the oral therapy group had an adverse event compared to 35 (27%) in the vancomycin group (p=0.058). Of the 35 patients with an adverse event in the vancomycin group, eight were due to parenteral access-related complications. Treatment failure occurred in three (10%) patients in the oral therapy group compared to 27 (21%) patients in the vancomycin group (p=0.29). Three (10%) patients in the oral therapy group had an unplanned readmission compared to 25 (20%) patients in the vancomycin group (p=0.24).

Baseline Characteristics, Unplanned Readmission Rates, and Incidence of Adverse Events and 6-Month Treatment Failure

Conclusion

Patients de-escalated to oral therapy had fewer adverse events and similar incidences of treatment failure compared to patients maintained on parenteral vancomycin. Switching to oral therapy avoids some adverse events related to parenteral access. Our results in an uncontrolled, real-world setting are consistent with the OVIVA trial. Though limited by sample size, our data indicate switching to oral therapy in patients with an orthopedic infection improves safety outcomes without compromising effectiveness compared to continued parenteral vancomycin therapy.

Disclosures

Russell J. Benefield, PharmD, Paratek Pharmaceuticals (Grant/Research Support)
233. Osteomyelitis of the jaw: A retrospective analysis of clinical, microbiologic characteristics and antimicrobial treatment at a Tertiary Care Medical Center
Authors: Nguyen Thinh , Surpure Sudheer , Echevarria Leonor
Published: December 2021

Background

Osteomyelitis of the jaw is a relatively rare entity in the post antibiotic era. The aim of this study is to describe clinical characteristics, microbiology and antibiotics use (oral vs intravenous) for treatment. We review 5 years of experience at Banner University Medical Center-Phoenix (BUMC-P) of proven cases of OM jaw by clinical, pathological, radiological criteria.

Methods

Retrospective study of cases. From January 2011 to November 2015 ,157 cases of osteomyelitis of the jaw, we excluded cases of radiation therapy or neoplasia to the head and neck region, a history of antiresorptive medication use. A total of 34 patients with diagnosis of osteomyelitis of the jaw were reviewed. All patients met criteria for diagnosis of osteomyelitis and underwent surgical debridement and received antibiotics that included parenteral, orals and combined. We reviewed clinical, microbiology, antibiotic use. A successful outcome was defined as elimination of clinical symptoms, restoration of function and if available radiographic evidence of arrest and resolution of bony necrosis.

Results

This retrospective study involved 34 patients. Most common organisms were oropharyngeal flora 22 samples (65%): streptococcus anginosus group. 4 samples grew unusual gram negative bacteria. 10 (29%) samples grew fungal species. Antimicrobial regimen was divided in: intravenous (n=14) (41.2%), oral (n=7) (20.6%) and combination intravenous followed by orals as follows: 13 (38.2 %).The average antibiotic duration was 8.1 + 4.7 weeks. We were able to follow up 30 patients, average follow up was 32.1-44.7 weeks. The overall success rate was (n=24) 80% with uneventful healing and. (n=6) (20%) treatment failure. There was more failure in the oral antibiotics group (n=3).

Conclusion

This study is limited by small numbers. Surgery and cultures should guide treatment of osteomyelitis of the jaw. The use of oral antimicrobial therapy was associated to a higher likelihood of treatment failure. Although rarely linked as a cause of osteomyelitis, the authors think that the cultivation of candida spp should prompt appropriate coverage. More study is required to understand the efficacy of oral antimicrobial therapy in treating osteomyelitis of the jaw.

Disclosures

All Authors: No reported disclosures
234. Dalbavancin versus Outpatient Parenteral Antimicrobial Therapy with Vancomycin for Treatment of Bone and Joint Infections in a Veteran Population
Authors: Gibbons Emily A , Hopkins Teri L , Escobar Manuel R , Yang Linda , Walter Elizabeth , Cadena-Zuluaga Jose
Published: December 2021

Background

Dalbavancin is a long-acting lipoglycopeptide with broad gram-positive activity. A long half-life makes it an attractive treatment option for bone and joint infections (BJI). Previous studies have demonstrated efficacy of dalbavancin in the treatment of BJI. Based on these studies, our institution established a protocol for using dalbavancin as an alternative to IV antibiotics via PICC line.

Methods

Chart review was performed to compare outcomes of patients who were treated with dalbavancin versus vancomycin for BJI from 8/2017 –7/2020. Patients that received two doses of dalbavancin for BJI were compared with patients who received OPAT with vancomycin during the same time period. Patients were excluded if they were bacteremic or received dalbavancin for another indication. Data was collected from the Veterans Health Administration’s Corporate Data Warehouse and retrospective chart review. No statistical analyses were performed due to the descriptive nature of this study.

Results

A total of 59 patients were included; 25 received dalbavancin and 34 received vancomycin. Relevant differences in baseline characteristics included a higher proportion of patients with osteomyelitis (88% vs 74%) and refractory infection (64% vs 44%) in the dalbavancin group. More patients in the dalbavancin group (38% vs 24%) were readmitted for the same infection within one year, required (29% vs 21%) additional surgical intervention, and had increased CRPH on follow-up labs (32% vs 3%). Dalbavancin use likely expedited discharge in at least 5 cases where vancomycin levels were not therapeutic. No significant adverse effects due to dalbavancin were noted, aside from one patient with an increase in serum creatinine. In the vancomycin group, 8 patients changed antibiotics due to adverse effects or difficulty managing levels and 3 patients had ED visits for PICC line care.

Conclusion

Dalbavancin may be a safe PICC-sparing treatment for BJI, particularly in cases where compliance is of concern, or there are logistical or tolerability issues with vancomycin. Our findings do raise concern for worse outcomes with dalbavancin, but the small sample size, difference in baseline characteristics between groups and descriptive nature of the study preclude any conclusions from being drawn.

Disclosures

All Authors: No reported disclosures
237. Evaluating Epidural Abscess Outcomes in a County Hospital with Antibiotic Therapy Alone Compared to Antibiotics and Surgical Intervention
Authors: Lee Moses , Kesbeh Yazeed , Weng Bruce , Sutjita Made
Published: December 2021

Background

Spinal epidural abscess (SEA) remains a rare suppurative infection which bacteria invade the epidural space through contiguous spread or hematogenous dissemination. Diabetes mellitus (DM), IV drug abuse (IVDA), alcohol abuse, degenerative joint disease (DJD) have been shown to confer risk for SEA. Antimicrobial therapy is critical, but literature remains less clear on surgical intervention. Primary aim for study was to evaluated outcomes with SEA when treated with antibiotics alone compared to antibiotics and surgical intervention at our county hospital.

Methods

A retrospective case series assessed patients 18 years or older at our county hospital with SEA consulted by infectious disease from 7/2009 to 7/2018. Data collected included demographics, social history (IVDA, alcohol abuse, homelessness), and microbiology results. Physician review of records determined if outcomes of SEA demonstrated improvement of symptoms compared to no improvement of symptoms.

Results

Of 37 patients, 15 patients were treated with antibiotics alone, 22 with antibiotics plus surgical spinal intervention. Of patients treated with antibiotics alone, 12/15 (80%) had improvement of symptoms and 3/15 (20%) had no improvement of symptoms. Those treated with antibiotics plus surgical intervention, 17/22 (77%) had improvement or resolution of symptoms and 5/22 (23%) had no improvement of symptoms. No statistically difference in outcome was observed between the two groups (p=0.835). The majority of cases were positive for Staphylococcus aureus (21/37, 56.7%). Methicillin-sensitive S. aureus (MSSA) comprised (12/21, 57%) and Methicillin-resistant S. aureus (MRSA) comprised (9/21, 43%).

Conclusion

Our retrospective study demonstrated no differences in outcome observed between patients treated with antibiotics alone compared to those with antibiotics plus surgical spinal intervention. Staphylococcus aureus was the most common organism. Management of patients with SEA currently remains individualized based on clinical condition, comorbidities and clinician judgement given limited literature. Proper sample collection for cultures and immediate intervention, either antibiotics only or antibiotics plus surgical interventions are crucial for better patient outcomes in SEA.

Disclosures

All Authors: No reported disclosures