bluuebunny/crossref_metadata_2025_split huggingface dataset:
1809. Treatment Outcomes in Piperacillin-tazobactam Non-susceptible (TZP-NS)/Ceftriaxone Susceptible (CRO-S) Infections
Authors: Dubrovskaya Yanina , Cao John , Siegfried Justin , Decano Arnold , Mazo Dana , Hochman Sarah , Zacharioudakis Ioannis , Solomon Sadie , Papadopoulos John 
Published: December 2022

Abstract

Background
Piperacillin-tazobactam-non-susceptible/ceftriaxone-susceptible (TZP-NS/CRO-S) Escherichia coli (Ec) and Klebsiella pneumoniae (Kp) phenotypes are hypothesized to be due to hyperproduction of TEM-1/2 and SHV-1 penicillinases. Limited available literature evaluating treatment outcomes in patients with TZP-NS/CRO-S infections may lead to unnecessary carbapenem use.

Methods
This was a retrospective study of non-critically ill adults hospitalized between 2013-2021, and treated for at least 48 hours for TZP-NS/CRO-S Ec or Kp infections. Patients with concomitant multi-drug resistant gram-negative infections were excluded. The primary composite endpoint included the need for escalation to intensive care unit (ICU), infection- or treatment-related readmission, mortality, and infection recurrence. Outcomes were compared between groups who received carbapenem (CG) vs carbapenem-sparing agents (CSG) as targeted therapy.

Results
Out of 1062 patients screened, 200 were included, with 51 in the CG and 149 in the CSG. Baseline characteristics, including Charlson Comorbidity Index (6 [IQR 3-10] vs 6 [4-9], p=0.64), were similar between groups, except for more immunocompromised patients in the CG (29% vs 11%, p=0.001). The most common infection sources were urinary (31% vs 57%, p=0.002), bloodstream (BSI) (18% vs 17%, p=0.887) and intra-abdominal (IAI) (20% vs 8%, p=0.023). Eighty-eight percent of the CG received meropenem, while the most common targeted therapy in the CSG was ceftriaxone (58%) followed by cefepime (24%). The primary composite endpoint was numerically higher in the CG (27% vs 17%, p=0.123), with no differences based on infection type (urine 25% vs 18%, p=0.495; BSI 33% vs 16%, p=0.348; IAI 40% vs 33%, p=1). More patients in the CSG were switched to oral therapy (15 [29%] vs 100 [67%], p&lt; 0.001), with numerically 2 days shorter time to oral switch (6 [3-9] vs 4 [3-7] days, p=0.196). Out of those switched to oral therapy, most had a urinary source (8/15 [53%] vs 59/100 [59%]).

Conclusion
Our study did not find better clinical outcomes with carbapenem therapy for TZP-NS/CRO-S infections, thus CS agents may be considered to spare carbapenems in non-critically ill patients. Further studies are warranted to compare these outcomes in the critically ill.

Disclosures
All Authors: No reported disclosures.
1831. Longitudinal Changes in Antimicrobial-resistant Bacterial Bloodstream Infections in the US Military Health System from 2010-2019
Authors: Vostal Alexander C , Grance Melissa , Powers John H , Carson Leigh , Chukwuma Uzo , Lanteri Charlotte , Seliga Nicholas , Poitras Beth , Parmelee Edward , Mende Katrin 
Published: December 2022

Abstract

Background
The epidemiology of antibiotic-resistant pathogens guides antimicrobial therapy for bacterial bloodstream infections (BSI). We describe changes in antimicrobial-resistant BSI pathogens over time within the US Military Health System (MHS), which prospectively captures clinical and microbiological data from both retired and active-duty US Uniformed service members and their beneficiaries.

Methods
The study population included MHS beneficiaries with blood cultures positive for any bacterial pathogens (Jan 2010 – Dec 2019). Microbiological data were obtained from the Navy and Marine Corps Public Health Center and antibiotic resistance was interpreted using CLSI breakpoints corresponding to collection year. Blood contaminants were excluded. Difficult to treat resistance (DTR) was defined in Gram-negative bacteria (GNB) as isolates with in vitro resistance to three classes of antibiotics: carbapenems, extended-spectrum cephalosporins, and fluoroquinolones.

Results
The 15 most frequent bacterial pathogens, representing 15,358 BSI episodes from 12,749 individuals, were subcategorized in four groups based on shared BSI clinical features. Lactose-fermenting GNB (LFGNB) were most common, accounting for 42% of BSI pathogens, following by Streptococcus/Enterococcus spp. (33%), Staphylococcus aureus (20%), and non-lactose fermenting GNB (NLGNB, 5.5%). The rate of LFGNB BSI increased from 7.57 per 100,000 beneficiaries in 2010 to 8.42 in 2019 (peak of 8.83 in 2016), resulting in an increase of 11.3% during the study period (Figure). Rates of BSI attributed to Streptococcus/Enterococcus spp., S. aureus, and NLGNB decreased 26%, 29%, and 45%, respectively, over the study period. The average annual rates of methicillin-resistant S. aureus, vancomycin-resistant Enterococcus spp., and DTR GNB BSI were 1.30, 0.25, and 0.05 per 100,000 beneficiaries, respectively. Over the study period, these rates decreased 58.3%, 72.4% and 24.2%, respectively.

Conclusion
LFGNB BSI numerically increased over time while NLGNB BSI (e.g., Pseudomonas aeruginosa and Acinetobacter spp.) decreased. The burden of DTR GNB BSI also decreased, indicating that first-line antibiotics remain clinically available for most patients with BSI.

Disclosures
John H. Powers, III, MD, Arrevus: Advisor/Consultant|Eicos: Advisor/Consultant|Evofem: Advisor/Consultant|Eyecheck: Advisor/Consultant|Gilead: Advisor/Consultant|GlaxoSmithKline: Advisor/Consultant|OPKO: Advisor/Consultant|Resolve: Advisor/Consultant|Romark: Advisor/Consultant|SpineBioPharma: Advisor/Consultant|UTIlity: Advisor/Consultant|Vir: Advisor/Consultant.
1852. Recurrent Bacteremia after Endoscopic Injection of N-butyl-2-cyanoacrylate for Gastric Variceal Bleeding
Authors: Kim Hee Yeon , Kim Chang Wook , Kim Yang Ree , Lee Hyo-Jin 
Published: December 2022

Abstract

Background
Gastric variceal bleeding is associated with a high mortality rate, and sclerotherapy using N-butyl-2-cyanoacrylate is the treatment of choice. The risk of recurrent bacteremia after N-butyl-2-cyanoacrylate injection has rarely been reported. We aimed to evaluate the frequency of this complication in a real-world setting.

Methods
We analyzed retrospective data from a single-center cohort of patients with liver cirrhosis who underwent N-butyl-2-cyanoacrylate injection for the treatment of bleeding gastric varices from January 2010 to March 2021. Recurrent bacteremia was defined as repeated bacteremia caused by the same microorganism after the resolution of the first event occurring at least two weeks from the date of the final positive blood culture of the first event.

Results
A total of 232 patients receiving 338 sessions of N-butyl-2-cyanoacrylate injection were enrolled. All patients received antibiotics prophylaxis; third-generation cephalosporins were used. The average age of patients was 59.5 ± 12.2 years and the mean Model for End-Stage Liver Disease (MELD) score was 14.8 ± 7.3. Of the patients following cyanoacrylate injection, 62 patients developed primary bacteremia at a median of 294 (range, 3−3710) days from N-butyl-2-cyanoacrylate injection. Nine out of 62 patients developed recurrent bacteremia following sclerotherapy with N-butyl-2-cyanoacrylate. The identified organisms were: Extended-Spectrum ß-Lactamase (ESBL)-producing Escherichia coli (3), ESBL-producing Klebsiella pneumoniae (2), non-ESBL-producing Klebsiella pneumoniae (2), Pseudomonas aeruginosa (1), and Methicillin-resistant Staphylococcus aureus (1). The median number of episodes of recurrent bacteremia per patient was 3 (range, 2−8) during the median 972 (range, 78−1997) days of follow-up. Four of these nine recurrent bacteremia patients died.

Conclusion
Recurrent bacteremia occurred in 3.9% of cirrhotic patients following cyanoacrylate injection for the treatment of gastric variceal bleeding. Foreign-body-type infection of the polymerized N-butyl-2-cyanoacrylate should be suspected in patients who had received previous endoscopic treatment with N-2-butyl-cyanoacrylate and fails to disclose another source of infection.

Disclosures
All Authors: No reported disclosures.
1857. Risk factors for recurrent bacteremia in children undergoing chemotherapy or hematopoietic stem cell transplantation
Authors: Kim Ye Ji , Kang Hyun Mi , Kim Seong Koo , Lee Jae Wook , Chung Nack-Gyun , Cho Bin 
Published: December 2022

Abstract

Background
Sepsis is a complication frequently encountered in children with underlying malignancies, especially due to a majority of patients having indwelling venous catheters. Indications for catheter removal among children with central-line associated blood stream infection (CLABSI) should follow the recommendations for adults, however, difficulties in vascular access often leads to attempting treatment without catheter removal. Therefore, the primary aim of this study was to find risk factors for recurrent sepsis in children undergoing chemotherapy of HSCT and examine whether more aggressive catheter removal after CLABSI in children is necessary.

Methods
In the Pediatric Bone Marrow Transplant Center of Seoul St. Mary’s Hospital, positive blood cultures were prospectively monitored to control and prevent outbreaks. The date of culture, culture results, symptoms presented, category of blood stream infections (by the CDC/NHSN surveillance definition (2021) of Bloodstream infections), and central-line associated blood stream infection (CLABSI) events were monitored.

Results
During September 2016 to February 2021, a total 280 cases of laboratory confirmed bloodstream infections (LCBI) or Mucosal Barrier Injury LCBI (MBI-LCBI) were diagnosed in children &lt; 18 years old with underlying malignancies. Of these, 52.9% (n=148) were male, and the mean age was 9.7 (SD±6.1) years old. CLABSI was diagnosed in 51.8% (n=145), and the most common pathogens cultured were S. mitis/oralis (24.0%, n=67), E. coli (15.4%, n=43), and coagulase negative Staphylococci (CNS) (10.4%, n=29). Recurrent sepsis occured in 17.1% (n=48), and 9.6% (n=27) had two indwelling catheters . Multivariable analysis showed that factors associated with recurrent blood stream infections were as follows: duration of indwelling catheter (OR, 1.002; 95% CI, 1.001-1.004; P&lt; 0.001) and no removal of central lines after previous episode (OR, 51.143; 95% CI, 6.6-395.0; P&lt; 0.001).

Conclusion
Permanent central lines should be removed as soon as possible, and more aggressive approach in permanent catheter removal after LCBSIs in children is necessary to reduce recurrent infections.

Disclosures
All Authors: No reported disclosures.
1858. Sequential Time to Positivity as a Prognostic Indicator in Staphylococcus aureus bacteremia
Authors: Comba Isin Y , Go John R , Palraj Raj , Abu Saleh Omar M 
Published: December 2022

Abstract

Background
The role of sequential blood culture time to positivity (TTP) as a surrogate marker for bacterial load and as a prognostic indicator in S. aureus bacteremia (SAB) is not well established in the literature.

Methods
We performed a single healthcare system, multi-site, retrospective review of adult patients with positive blood culture for S. aureus between January 2019 and December 2019. Sequential TTP was defined as the TTP of the first subsequent blood cultures obtained from patients with SAB for at least 24 hours. We adapted the previously described TTP ratio of &lt; 1.5 as the cut-off for study groups. Infective endocarditis (IE) was defined according to modified Duke’s criteria. High-grade bacteremia was defined as the growth of the organism in two or more sets of blood cultures or growth in &gt;50% of all bottles collected. Descriptive, comparative statistics and survival analysis were performed using Python 3 and IBM SPSS Statistics for Windows, Version 27.0. Armonk, NY: IBM Corp.

Results
A total of 602 patients with SAB were identified, and 186 patients who met the study criteria were included. Sixty-nine patients (37%) were female, and the mean age was 63.6 years. Patients with initial TTP &lt; 12 hours had higher 30-day and 90-day mortality than those with initial TTP ≥ 12 hours. Patients with TTP ratio of &gt; 1.5 had higher rates of cardiac prosthetic device (30 [26.1%] vs. 9 [12.7%], p = .03) and high-grade bacteremia (106 [92.2%] vs. 56 [78.9%], p = .01). In univariate analysis, history of myocardial infarction, cardiac prosthetic device, and findings of high-grade bacteremia and native valve vegetation in echocardiogram were significant predictors for a TTP ratio of &lt; 1.5. In multivariate analysis, native valve vegetation (OR 2.4; 95% CI 1.2-4.84), and high-grade bacteremia (OR, 0.3; 95% CI, 0.13- 0.77) were independent predictors (Table 1 and 2). No differences in 30- day or 90-day survival based on the TTP ratio were seen (Figure 1). Figure 1.Kaplan-Meier (KM) curves and log rank test results based on time to positivity (TTP) of initial blood cultures and TTP ratio of sequential to initial blood culture
The X-axis represents the days elapsed from the initial blood culture collection. Number of patients at risk and events are given below the x-axis for each group. 30-day and 90-day survival rates were significantly lower in patients with initial TTP of &lt; 12 hours compared with those with ≥ 12 hours. There were no statistically significant differences in survival based on TTP ratio.

Conclusion
In patients with SAB, a second TTP to first TPP ratio of &gt; 1.5 was associated with higher rates of presence of the cardiac prosthetic device and high-grade bacteremia. Initial TTP &lt; 12 hours was associated with lower survival; however sequential TTP ratio didn’t predict mortality.

Disclosures
All Authors: No reported disclosures.
1861. The Spectrum and Clinical Significance of Actinomyces Blood Stream Infection
Authors: Ali Maisa , Razok Almurtada , Al Maslamani Muna A , Hadi Hamad Abdel 
Published: December 2022

Abstract

Background
Actinomyces species are Gram-positive anaerobic branching bacilli which are commensal of oropharynx, urogenital and gastrointestinal tracts that is associated with infrequent chronic granulomatous diseases including cervicofacial, intrabdominal and genital infections. Actinomyces Blood Stream Infections (BSIs) are usually rare but becoming more frequent with advanced modern diagnostic techniques. The presented study aims to evaluate the spectrum and clinical relevance of Actinomyces BSI at Hamad Medical Corporation (HMC), Qatar.

Methods
A retrospective observational study was conducted for all reported Actinomyces species BSI at HMC between January 2016 to November 2020. Isolates were identified using modern automated BD PhoenixTM and MALDI-TOF microbiological methods.

Results
Over the five years study period, 37 episodes of Actinomyces BSIs were recorded the majority of which identified as Actinomyces odontolyticus (40.5 %, 15/37). The mean age was 32 years (range 1 month – 81 years), 62.2 % were females (23/37), 64.8 % had chronic medical conditions while 78.4 % developed fever as presenting illness. Out of the total cases, cultures were considered significant in only 48.6 % of cases (18/37), in which primary source of infection was oropharyngeal (10) followed by genitourinary (4), gastrointestinal (2) and 2 infected diabetic foot. However, 86.5 % (32/37) received antimicrobial therapy mainly as βlactam antibiotics or cephalosporins ranging between 3 days to 6 months.
Antimicrobial therapy was given for a short duration in 87.5% (28/32) of cases for less than 14 days with no long-term complications while only four cases received prolonged therapy. The remaining Five patients did not receive any antibiotics as the cultures were considered contaminants by the primary provider.

Conclusion
Actinomyces species blood stream infection is becoming more frequent with advanced diagnostic techniques affecting all age groups. Females and patients with chronic comorbidities are more commonly affected while A. odontolyticus is the predominant isolated species. Almost half of the cases were not clinically relevant, but most cases received short courses of antimicrobial therapy with no long-term complications.

Disclosures
All Authors: No reported disclosures.
1864. Trends in Staphylococcus aureus Bacteremia Rates among U.S. Acute Care Hospitals, January 2017- June 2021
Authors: Rose Ashley , Hatfield Kelly M , Reddy Sujan , Wolford Hannah , McCarthy Natalie L , Olubajo Babatunde , Jernigan John A , Baggs James , See Isaac 
Published: December 2022

Abstract

Background
Previous estimates of methicillin-resistant and -sensitive Staphylococcus aureus (MRSA, MSSA) bacteremia rates in hospitalized patients showed decreases in hospital-onset (HO) MRSA, no changes in community-onset (CO) MRSA and HO MSSA, and slight increases in CO MSSA rates from 2012–2017; more recent trends have not been well characterized.

Methods
We calculated monthly S. aureus bacteremia rates using microbiology data from hospitals reporting antibiotic susceptibility results in the Premier Healthcare Database from January 2017- June 2021. S. aureus blood isolates resistant to methicillin, oxacillin, or cefoxitin were categorized as MRSA. Positive blood cultures collected on or before hospital day 3 were categorized as CO; those collected on day 4 or later were categorized as HO. Annual rate differences were assessed using generalized estimating equation models with a negative binomial distribution adjusting for hospital bed size, teaching status, urban/rural designation, discharge month, census division, distributions of patient age, sex and race and hospital-level clustering.

Results
Among 11 million discharges from 356 hospitals, we identified 5,627 HO S. aureus bacteremia events: 2,558 (45%) MRSA and 3,069 (55%) MSSA. In 2017, we observed HO MRSA bacteremia rates of 0.41 and HO MSSA rates of 0.49 per 10,000 patient-days. Compared with 2017, adjusted rates of HO MRSA and MSSA bacteremia were significantly higher in 2019, 2020, and 2021 (Figure 1).
Of 42,587 CO S. aureus bacteremia events, 19,107 (45%) were MRSA and 23,480 (55%) MSSA. CO MRSA bacteremia rates were lowest in 2017 (1.52 per 1,000 discharges), and adjusted rates were significantly higher in all later years (Figure 2); we observed significant regional variability in annual differences (p=0.018). The observed CO MSSA bacteremia rate was 2.03 per 1,000 discharges in 2017, and adjusted rates were significantly higher in 2020 and 2021. Figure 1.Hospital-Onset MRSA and MSSA Bacteremia Incidence Rate Ratios* with 95% confidence intervals, 2017 – 2021**.*Reference year =2017.**2021 includes data during January – June.***Statistically significant at p&lt;0.05.Figure 2.Community-Onset MRSA and MSSA Bacteremia Incidence Rate Ratios* with 95% confidence intervals, 2017 - 2021***Reference year =2017.**2021 includes data during January – June.***Statistically significant at p&lt;0.05.

Conclusion
In contrast with previous trends, recent S. aureus bacteremia rates in this cohort have increased in comparison to 2017. Potential explanations warranting exploration include differences in regional trends and pandemic-associated changes in inpatient risk, severity of illness, length of stay, and hospital utilization

Disclosures
All Authors: No reported disclosures.
1868. Characterization of COVID-19 Symptoms and Outcomes by Variant Period in the North Carolina COVID-19 Community Research Partnership (NC-CCRP)
Authors: DeWitt Michael E , Edelstein Sharon , Tjaden Ashley H , Herrington David M , Schieffelin John , Gibbs Michael A , Weintraub William , Sanders John W 
Published: December 2022

Abstract

Background
We characterize the evolution of symptoms in those with self-reported SARS-CoV-2 infections and the likelihood of seeking treatment or medical care during different waves of the pandemic.

Methods
The NC-CCRP is a longitudinal observational study of 37,820 participants who completed a daily symptom log from April 2020 through February 2022, during which there were 5,167 self-reported COVID-19 infections. Three variant periods were defined as pre-delta, delta, and omicron, based on the predominant variant in North Carolina. Quasi-Poisson and logistic regression models adjusted for demographics and vaccination were used to assess COVID-19 symptoms and their duration and seeking treatment or hospitalization.

Results
Cough was the most reported symptom in all waves and increased from 77% pre-delta to 85% during omicron (p=0.001). Sore throat was more common during self-reported infections during omicron (71%), compared with 62% during delta and 54% pre-delta (p&lt; 0.001). The largest change in proportion reporting a symptom was loss of taste or smell which decreased from 55% during pre-delta to 17% during omicron (p&lt; 0.001). Compared with the pre-delta period, delta (incidence risk reduction, IRR 0.86; 95% CI 0.79-0.93) and omicron (IRR 0.67; 95% CI 0.61-0.73) were associated with lower symptom duration. Participants infected during the delta wave were more likely to seek treatment compared with either pre-delta (odds ratio, OR 1.32 95% CI 1.06-1.64) or omicron (OR 1.42; 95% CI 1.21-1.67). Omicron period infections were associated with a lower likelihood of self-reported hospitalization compared with pre-delta (OR 0.26; 95% CI 0.10-0.59) or delta (OR 0.26; 95% CI 0.11-0.60). Vaccination was associated with a reduced likelihood of hospitalization (OR 0.35; 95% CI 0.18-0.70).
Proportion and Duration of Symptoms by Variant Wave; Unadjusted by Vaccination Status.

Conclusion
Our study indicates evolution in symptom presentation and duration by variant period. The omicron wave was associated with shorter duration and lower severity of illness. Longitudinal tracking of symptomology and severity of a novel pathogen provide insights into the evolution of the pathogen in the community and is vital for public health and clinical response.

Disclosures
All Authors: No reported disclosures.