bluuebunny/crossref_metadata_2025_split huggingface dataset:
207. Ineffective Initial Antibiotics for Enteric Bacteremia: Does Every Hour Count with Rapid Diagnostics and Stewardship Intervention?
Authors: Box Maggie , Bagsic Samantha , Saiki Shaina 
Published: December 2021

Abstract

Background
It has been a long-standing practice to administer broad-spectrum antibiotics early for sepsis as each hour delay is associated with increase in mortality. With increasing rates of antibiotic resistance fueled by unnecessary use of antibiotics, it is delicate to balance the benefits vs consequences of empiric carbapenem therapy. With rapid molecular blood culture diagnostics available, identification of extended-spectrum beta-lactamase (ESBL) producing bacteremia can occur within hours and therapy optimized with active stewardship intervention. With rapid diagnostics, does each hour of ineffective antibiotic therapy really count?

Methods
This multicenter, retrospective, cohort study compared adult inpatients with E. coli bacteremia from a urinary source who received initial effective (EA) vs ineffective antibiotics (IA). The primary outcome was clinical treatment success at day 4. Secondary endpoints included length of stay (LOS), infection-related mortality, incidence of C. difficile infection (CDI), and subgroup analysis of outcomes by ESBL (CTX-M type) vs non-ESBL. Associations with endpoints were assessed using Fisher’s Exact tests using R v. 4.0.3.

Results
Clinical treatment success at day 4 was higher in the EA (n = 488) vs IA (n = 119) groups (93.7% vs 86.6%, p = 0.01) and median LOS was shorter (5 [IQR 4-6] vs 5 [IQR 5-7] days, p &lt; 0.01). There were no differences in infection-related mortality (3.1% vs 3.4%, p = 0.8), 30-day mortality (2.5% vs 2.5%, p &gt; 0.9), or incidence of CDI (1.8% vs 0%, p = 0.3) in the EA vs IA groups, respectively. For patients on IA &lt; 24 h vs &gt; 24 h, there was no difference in clinical improvement at day 4 (86.7% vs 90.5%, p &gt; 0.9) nor 30-day mortality (2.4% vs 4.8%, p = 0.4). Clinical treatment success at day 4 was higher among non-CTX-M (n = 476) vs CTX-M (n = 131) patients (93.9% vs 86.3%, p = 0.01) even among those that received initial EA (94.5% vs 83.3%, p = 0.02). Median LOS was also shorter in CTX-M vs non CTX-M (5 [IQR 4-6] vs 5 [IQR 4-8] days, p &lt; 0.01).

Conclusion
There was no mortality difference among patients receiving initial EA vs IA for E. coli bacteremia with rapid molecular blood culture diagnostics with active stewardship. Therapy for patients on IE is rapidly corrected and stewardship programs can use this intervention to promote judicious use of carbapenems.

Disclosures
All Authors: No reported disclosures
208. Comparison of Bloodstream Infections in Hospitalized Patients Before and During the COVID-19 Surge in a Community Hospital in the South Bronx: An Observational Study
Authors: Afzal Afsheen , Gomez Edgar , Guttierrez Victor Perez , Mon Aye Myat , Sarmiento Carolina Moreira , Khalid Amna , Polishchuk svetlana , Al-Khateeb Mohannad Al-Khateeb , Yankulova Boyana , Yusuf Mubarak , De Castro Yinelka Silverio , Pillai Anjana , Venugopal Usha , Feinstein Addi , LaFortune Alexander , Sittler Daniel , Hennessey Karen , Menon Vidya 
Published: December 2021

Abstract

Background
There is a paucity of data of bloodstream infections (BSI) before and during the COVID-19 pandemic. The aim of our study was to compare the incidence and characteristics of blood stream infections (BSI) in hospitalized patients before and during the surge of COVID-19 pandemic in a community hospital in South Bronx.

Methods
This is a retrospective observational comparative study of adult hospitalized patients with BSI admitted before (Jan 1-Feb 28, 2020) and during COVID-19 surge (Mar 1- May 1,2020). The incidence of BSI, patient demographics, clinical and microbiological characteristics of infections including treatment and outcomes were compared.

Results
Of the 155 patients with BSI, 64 were before COVID and 91 were during the COVID surge (Table 1). Incidence of BSI was 5.84 before COVID and 6.57 during surge (p = 0.004). Majority of patients during COVID period had ARDS (39.6%), required mechanical ventilation (57%), inotropic support (46.2%), therapeutic anticoagulation (24.2%), proning (22%), rectal tube (28.6%), Tocilizumab (9.9%), and steroids (30.8%) in comparison to pre-COVID (Table 2). Days of antibiotic therapy prior to BSI was 5 days before COVID and 7 during COVID. Mortality was higher among patients with BSI admitted during COVID surge (41.8% vs. 14.1% p &lt; 0.0001). Of 185 BSI events, 71 were Pre-COVID and 114 during surge. Primary BSI were predominant (72%) before COVID contrary to secondary BSI (46%) (CLABSI) during COVID. Time from admission to positive culture was 2.5 days during COVID compared to 0.9 pre-COVID. Majority of BSI during COVID period were monomicrobial (93%) and hospital acquired (50%) (p=0.001). Enterococcus (20.2%), E.coli (13.2%), and MSSA (12.3%) were predominant microbes causing BSI during COVID vs. MRSA (15.5%), Streptococci (15.5%), and S. pneumoniae (14.1%) before COVID (Figure 1). In multivariate logistic regression, Enterococcal coinfection was associated with COVID positivity (OR 2.685, p = 0.038), mechanical ventilation (OR 8.739, p = 0.002), and presence of COPD/Asthma (OR 2.823, p = 0.035).

Comparison of Microorganisms Isolated in the BSI

X-axis represents the total number of BSI events whereas the number at the end of each bar represents the percentage

Conclusion
Higher incidence of secondary BSI (CLABSI) due to Enterococcus spp. was observed during the surge of COVID-19 infection in the South Bronx. Breakdown of infection control measures during the COVID-19 pandemic could have been contributory.

Disclosures
All Authors: No reported disclosures
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

Abstract

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 &gt; 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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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