bluuebunny/crossref_metadata_2025_split huggingface dataset:
203. Evaluating the Impact of Extended-Infusion Beta-Lactam Therapy on Clinical Outcomes and the Subsequent Emergence of Resistance in Adults with Gram-Negative Bloodstream Infections
Authors: Karaba Sara M , Hyoung Lee Jae , Fiawoo Suiyini , Cosgrove Sara E , Tamma Pranita 
Published: November 2023

Abstract

Background
Data are conflicting regarding the impact of extended-infusion beta-lactam (EI-BL) therapy on patient outcomes. We investigated the impact of EI-BL therapy on clinical outcomes and subsequent emergence of resistance in adults with Gram-negative bloodstream infections (GN-BSI) admitted to 24 US hospitals in 2019.

Methods
Patients who received ≥ 3 days of EI-BL (i.e., ≥ 3-hour infusion) were compared to patients who received the same agents as ≤ 1-hour standard infusions (SI-BL). The EI-BL group underwent 3:1 nearest neighbor propensity score matching without replacement with the SI-BL group based on: Pitt bacteremia score ≥ 4, Charlson comorbidity index ≥ 5, severe immunocompromise, ICU status, source control, active empiric therapy, urinary source, and the 3 most common species. Multivariable regression was applied to the matched cohort to investigate mortality, recurrent infection with the same species, subsequent emergence of resistance (i.e., ≥ 4-fold increase in MIC of the β-lactam used to treat the index BSI), and treatment-related adverse events (AEs), all censored at day 90.

Results
There were 352 and 4,509 patients in the EI-BL and SI-BL groups, respectively. Excellent balance was achieved across all variables in the 3:1 matched cohort. The odds of mortality at day 90 were lower in the EI-BL vs SI-BL group (aOR=0.71, 95% CI 0.52-0.97, p=0.033). When stratified to evaluate the mortality benefit in those with and without severe illness or elevated MICs, a significant mortality benefit was only identified in patients with severe illness and/or elevated MICs. No differences were observed in recurrent infection. There was an increased odds of catheter complications (aOR=3.14, 95% 1.66-5.96, p&lt; 0.001) and early antibiotic discontinuation because of AEs (aOR=3.66, 95% CI 1.68-7.95, p=0.001) in the EI-BL group. Emergence of resistance was similar in the EI-BL and SI-BL groups at 2.9% vs 7.2%, respectively (p=0.351).

Conclusion
The benefits of EI-BL therapy need to be balanced with associated AEs. EI-BL therapy should be prioritized in the severely ill or those infected with non-susceptible organisms. The subsequent emergence of resistance warrants investigation in a larger cohort.

Disclosures
Sara M. Karaba, MD, PhD, MHS, Entasis: Advisor/Consultant Sara E. Cosgrove, MD, MS, Debiopharm: Advisor/Consultant|Duke Clinical Research Institute: Advisor/Consultant
207. The increased frequency and clinical characteristics of Streptococcus agalactiae serotype VIII from blood isolates at two tertiary care hospital in South Korea over 14 years
Authors: Ji kim Min , Ji Sehyun , Lee Ahrang , Kim Sarah , Jung Lee Yoon , Sung Jeong Hae , un Shin Sung , Jin Kim Uh , Kang Seung-Ji , Park Kyung-Hwa , Jung Sook-In , Eun Kim Seong 
Published: November 2023

Abstract

Background
Invasive group B Streptococcus (GBS) infections are increasing among non-pregnant adults with underlying diseases. Previous studies have shown that the proportion of GBS serotype of pregnant women were differed from geographic regions. However, studies on the serotype of invasive GBS infection in non-pregnant adults are sparse. This study aimed to evaluate epidemiology and clinical characteristics of strains caused GBS bloodstream infection according to serotypes.

Methods
S. agalactiae blood isolates were collected between March 2007 and December 2021, and their clinical data were obtained from two tertiary hospital of South Korea. Species identification was performed using MALDI-TOF MS and serotyping test was performed using commercial latex particle agglutination kit. Antimicrobial susceptibility tests are conducted using automated equipment.

Results
A total of 130 patients with GBS bacteremia were identified and among them 125 isolates were serotypeable. The median age were 66 years and 46% were male. Serotype VIII was most dominant (31.5%) and Ib, III, Ia, V were as follows (20.8%, 13.8%, 12.3%, 11.5% retrospectively). The proportion of serotype VIII increased from 27.3% to 53.3% from 2015 to 2021. Most common source of GBS bloodstream infection were primary bacteremia (34.4%), followed by bone and joint infections (16.8%) and skin and soft tissue infections (13.6%). Cardiovascular disease (79.2%) was most frequently reported in GBS bacteremia patients, followed by malignancy (44.6%) and diabetes mellitus (40%). The 30-day mortality rate was 12.3% and there was no difference in 30-day mortality according to serotypes (log rank test P=0.39). In logistic regression analysis, high SOFA score was significantly associated with 30-day mortality (odd ratio 1.28, 95% C.I. 1.28-2.53, P&lt; 0.01). All isolated GBS were susceptible to penicillin and resistances were identified against clindamycin, erythromycin and levofloxacin as 30%, 26.9%, 24.6% of the isolates, respectively.

Conclusion
We found the most common capsular serotype was VIII (31.5%) in Korea and the proportion of type VIII increasing over time. It is necessary to consider GBS vaccine in adults with underlying disease and its composition for serotype VIII according to epidemiologic characteristics.

Disclosures
All Authors: No reported disclosures
208. Clinical Characteristics and Risk Factors for Septic Shock in Patients with Pyometra: A Retrospective Multicenter Cohort Study
Authors: Jang Sukbin , Jeon Minji , Jun Mun Seok , Kim Si-Ho 
Published: November 2023

Abstract

Background
Pyometra is a disease of pus collection in the uterine cavity. The clinical characteristics and etiology of pyometra have not been well-described. In this study, we investigated the clinical characteristics, epidemiology, outcomes, and risk factors of septic shock in patients with pyometra.

Methods
The study population was selected from adult patients (≥ 18 years old) diagnosed with the International Classification of Diseases 10th code for inflammatory disease of the uterus (N71) in four academic hospitals between 2010 and 2021. Only patients with definitive pus collection in the uterus confirmed by imaging tests were included. Intra-or post-partum infection and surgical site infection were excluded. The primary endpoint was all-cause 28-day mortality, and the secondary endpoint was a 1-year recurrence. Clinical characteristics and outcomes were compared among patients with or without septic shock.

Results
Among 406 patients diagnosed with the N71 code, 193 patients were classified as pyometra. 28-day all-cause mortality was 5.0%, and the 1-year recurrence rate was 6.1%. The median patient age was 74.5 years. The most common symptom was abdominal pain (48.7%) and vaginal discharge (48.2%). The most common pathogens isolated from culture were Escherichia coli (39.9%), Streptococcus spp.(16.6%), and Klebsiella pneumoniae(16.0%) and isolated from polymerase chain reaction (PCR) were Mycoplasma spp., and Ureaplasma spp. Patients with septic shock were older and have a shorter interval between symptom onset (or discovery) and diagnosis. These patients had larger pyometra diameters, more frequent uterine perforation, more dementia, and were more frequently referred from long-term care facilities. The 28-survival rate was lower in patients with septic shock (72.8%) than without septic shock (98.7%, P &lt; 0.001)

Conclusion
Our study suggested pyometra is a unique gynecological infectious syndrome in post-menopausal women. The most common pathogen was similar to pathogens causing urinary tract infections. Risk factors with septic shock suggested that decreased cognitive functions could delay early diagnosis of pyometra, and lead to more septic shock and higher mortality.

Disclosures
All Authors: No reported disclosures
209. Validation of a New Risk Stratification System-Based Management for Methicillin-Resistant Staphylococcus aureus Bacteremia: Analysis of a Multicenter Prospective Study
Authors: Kim Taeeun , Lee Sang-Rok , Yeon Park Seong , Mi Moon Song , Jung Jiwon , Jae Kim Min , Sung Heungsup , Kim Mi-Na , Kim Sung-Han , Choi Sang-Ho , Lee Sang-Oh , Soo Kim Yang , Hee Song Eun , Pil Chong Yong 
Published: November 2023

Abstract

Background
Distinguishing between complicated and uncomplicated Staphylococcus aureus bacteremia (SAB) is therapeutically essential. However, this distinction has limitations in reflecting the various manifestation of SAB. In the light of this, Koujizer et al. proposed a new risk stratification system for metastatic infection in SAB, which involves a stepwise approach to diagnosis and treatment. We tested this risk stratification system in methicillin-resistant SAB (MRSAB) patients.

Methods
We retrospectively analyzed data of a 3-year multicenter, prospective cohort of hospitalized patients with MRSAB. We classified the patients into three risk groups: low, indeterminate, and high, based on the new system and compared between-group management and outcomes, as well as microbiologic features.

Results
The demographic and baseline characteristics of patients are shown in Table 1. The most frequent source of MRSAB was central venous catheter-related infection (25.5%), followed by unknown origin (15.3%) and pneumonia (11.1%). Echocardiography was performed in 248 cases (65.3%). Of 380 patients with MRSAB, 6.3% were classified as low-, 7.6% as indeterminate-, and 86.1% as high-risk for metastatic infection (Figure 1). No metastatic infection occurred in the low-, 6.9% in the indeterminate-, and 17.7% in the high-risk groups (P=0.03) (Figure 2A). After an in-depth diagnostic work-up, patients were finally diagnosed as ‘without metastatic infection (6.3%)’, ‘with metastatic infection (15.8%)’, and ‘uncertain metastatic infection (77.9%)’. 30-day mortality increased markedly as the severity of diagnosis shifted from ‘without metastatic infection’ to ‘uncertain’ and ‘with metastatic infection’ (P=0.07) (Figure 2B). In multivariable analysis, independent factors associated with metastatic complications were suspicion of endocarditis in transthoracic echocardiography, clinical signs of metastatic infection, Pitt bacteremia score ≥4, and persistent bacteremia.

Figure 1.
Flowchart of risk stratification and final diagnosis
Figure 2.
Outcomes of metastatic infection and 30-day mortality. A, metastatic infection according to the risk stratification, B, 30-day mortality according to the final diagnosis

Conclusion
The new risk stratification system provides good discrimination in predicting metastatic complications, making it a reliable tool for guiding work-up and management of MRSAB. However, minimizing the number of ‘uncertain metastatic infection’ cases remains an area for improvement.

Disclosures
All Authors: No reported disclosures
211. Disease burden of bacteremia with extended-spectrum beta-lactamase-producing or carbapenem-resistant Enterobacteriaceae in Korea
Authors: Mi Lee Chan , Lee Shinwon , Beom Park Wan , Gyun Choe Pyoeng , Kim Chung-Jong , Kim Bongyoung , Mi Moon Song , Gyung Kwak Yee , Kim Yeon-Sook , Keun Kim Young , Jin Sohn Yu , Park Kyung-Hwa , Eun Kim Seong , Suk Kim Eu , Bin Kim Hong , Ahn Jeonghoon , Song Kyoung-Ho 
Published: November 2023

Abstract

Background
Despite the importance of multidrug-resistant organisms (MDRO) bacteremia, especially extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) or carbapenem-resistant Enterobacteriaceae (CRE), the disease burden of those has not been investigated in detail. Thus, we tried to evaluate the clinical outcomes and estimate the socioeconomic burden of those MDROs bacteremia at a nationwide level in the Republic of Korea.

Methods
We retrospectively searched for all cases of ESBL-E or CRE bacteremia, as well as matched control patients, in ten hospitals representing regions across the country over a six-month period. Patients with ESBL-E or CRE bacteremia were classified as the R group, while matched controls with antibiotic-susceptible bacteremia or those without infection were classified as the S and N groups, respectively. Patients’ clinical data, including demographic data, underlying medical conditions, and microbiologic data were collected. We estimated economic burden by considering medical expenses, loss of productivity, and total costs.

Results
We identified a total of 795 patients, including 265 cases with ESBL-E or CRE bacteremia, and their matched controls after propensity-score matching. The mean total length of stay for ESBL-E and CRE matching in the R group were 7.8 days and 18.3 days longer compared to the S group, and 12.2 days and 14.5 days longer compared to the N group. The 90-day mortality rates for ESBL-E and CRE matching in the R, S, and N groups were 12.1%, 5.6%, 3.4%, and 24.0%, 12.0%, 0.0%, respectively. The total costs of the R, S, and N groups showed significant differences in both ESBL-E and CRE matching ($11,151 vs. $8,712 vs. $6,063, P = 0.004; $40,464 vs. $8,748 vs. $7,279, P = 0.024).

Conclusion
The mortality rates of ESBL-E or CRE bacteremia were found to be tremendously high. Furthermore, the economic burden imposed by ESBL-E or CRE bacteremia, compared to controls without infection, were approximately two and five times higher, respectively. These findings suggest that ESBL-E and CRE bacteremia impose a significant clinical and economic burden, and adequate efforts to control these resistant bacteremia might be necessary to reduce this burden.
This Study is sponsored by Pfizer Pharmaceuticals Korea Ltd.

Disclosures
All Authors: No reported disclosures
216. A Comparison of Multidrug-Resistant Gram-negative Bacteremia in Cancer and Non-Cancer Patients
Authors: Haris Khan Muhammad , Munshi Ruhul , Wangjam Tamna , Bhuiyan Mohammad Alfrad Nobel , Self Michelle , Alam Mohammad , Malek Alexandre E 
Published: November 2023

Abstract

Background
Multidrug-resistant gram-negative bacteremia (MDR-GNB) is a growing threat worldwide as it is associated with increased morbidity and mortality. We sought to describe the clinical features of MDR-GNB and outcomes in cancer and non-cancer Pts.

Methods
We performed a retrospective study of adult patients with MDR-GNB at the Ochsner LSU Health Shreveport between January 2018 and July 2022. We collected patients' demographics, medical comorbidities, cancer diagnosis, causative bacteria (MDROs), source of bacteremia, antibiotics therapy, and clinical outcomes.

Results
We identified 112 Pts with MDR-GNB. Pts were divided into 2 groups: cancer group (n=33, 29%) and non-cancer group (n=79, 71%). In the cancer group, the majority of Pts had solid tumors (n=20, 61%) vs liquid tumors (n=13, 39%). Mean age was 69 y in cancer compared to 57 y in the non-cancer group. Enterobacteriaceae were isolated in 28 cancer Pts (85%) including ESBL E. coli in 20 Pts (61%), Klebsiella s.p (CRE/ESBL) in 5 Pts (15%), and ESBL P. mirabilis in 3 Pts (9%). Pseudomonas aeruginosa CRO in 3 Pts (9%) and A. baumannii in 2 Pts (6%). In non-cancer Pts, Enterobacteriaceae were isolated in 65 Pts (82%) including ESBL E. coli in 40 Pts (51%), Klebsiella s.p (CRE/ESBL) in 18 Pts (23%) and ESBL P. mirabilis in 6 Pts (8%). P. aeruginosa CRO found in 6 Pts (8%) and A. baumannii in 8 Pts (10%). The sources of bacteremia in cancer group were UTI in 14 Pts (42.4%), osteoarticular infection (OAI) in 5 Pts (15%), pneumonia in 3 Pts (9%), CLABSI in 2 Pts (6%), endovascular in 1 Pt (3%) and unknown in 8 Pts (24%), whereas in non-cancer group, UTI was reported in 40 Pts (68%), pneumonia in 9 (27%), OAI in 1 (1.3%), endocarditis in 1 Pt (1.3%), and unknown in 20 Pts (25.3%). Mean duration of targeted antibiotics was 9 days in cancer vs 13.3 days in non-cancer group (p-value=0.4). Mean length of hospital stay was comparable, 34 d in cancer vs 31 d in non-cancer(p-value= 0.87). 9 Pts were admitted to ICU in cancer group (27%) vs 39 Pts (49%). Mortality rate was 39% in cancer (8 pts went to hospice) vs 16.4% in non-cancer.

Conclusion
Our data showed that the common source of MDR-GNB remains urinary tract infection in both groups and the bacterial epidemiology is comparable between the two groups. Further studies are warranted to assess the impact of resistant organisms on cancer Pts.

Disclosures
All Authors: No reported disclosures
217. Eosinophil count recovery as a predictor of bloodstream clearance in Staphylococcus aureus bacteremia
Authors: McHugh Jack W , Khodadadi Ryan B , Yetmar Zach , Halvorsen Andrew , Abu Saleh Omar M 
Published: November 2023

Abstract

Background
Eosinopenia has previously been studied as a predictor of bacteremia and sepsis, and has been identified as a marker of increased mortality in critically ill patients. To date, one study has examined changes in eosinophil count during bacterial infection, noting quicker normalization of eosinophil count versus traditional markers of inflammation, whereas no studies have examined eosinophil count recovery as a predictor of blood stream clearance.

Methods
We conducted a multicenter, retrospective cohort study of adult patients diagnosed with Staphylococcus aureus bacteremia (SAB) between January 2018 and December 2019 at Mayo Clinic campuses. Patients with eosinopenia on the date of the first positive blood culture were selected for further analysis. Eosinopenia was defined as an eosinophil count &lt; 0.03 x10(9)/L. Eosinophil count recovery was defined as the first subsequent date where an eosinophil count ≥0.03 x10(9)/L was recorded. Clearance of SAB was defined as negative blood cultures at 48 hours on two consecutive days, and the date of clearance was defined as the date of first negative blood culture.

Results
A total of 213 cases of SAB were identified where an eosinophil count was obtained on date of first positive blood culture. Of these cases, 132 (62.0%) had eosinopenia at time of diagnosis. Data related to count recovery was available for 90 patients, with associated characteristics for this cohort detailed in Table 1. S. aureus isolates were oxacillin susceptible in 91.1% (82/90) of cases. The median time to clearance of bacteremia was 2.7 days (IQR 1.8-4.7 days), and the median time to eosinophil count recovery was 2.0 days (IQR 2.0-3.0 days). Data related to timing of eosinophil count recovery are presented in Table 2. Resolution of eosinopenia occurred within 48 hours of bloodstream clearance in 79/90 (87.8%) of cases and preceded or occurred within 48 hours of blood culture clearance in 88/90 (97.8%) of cases.

Conclusion
Eosinopenia is a common finding at time of diagnosis of SAB, and recovery of eosinophil count is suggestive of imminent clearance of blood cultures.

Disclosures
All Authors: No reported disclosures
220. Effectiveness of Piperacillin/tazobactam Loading Dose for Extended Infusion Dosing Among Patients with Gram-negative Bacteremia (EZ-LD)
Authors: Patel Savan , Mohayya Sana , Yassin Arsheena , Aboujaoude Emily , Dao Judy , Bhatt Pinki , Kaye Keith S , Abdul Azim Ahmed , Narayanan Navaneeth 
Published: November 2023

Abstract

Background
The rationale for a loading dose (LD) prior to administering extended infusion piperacillin/tazobactam (PTZ) is theoretical and based on pharmacokinetic/pharmacodynamic (PK/PD) principles and simulations. The clinical data to support the use of a LD for extended infusion are limited.

Methods
This is a single-center, retrospective cohort study evaluating adult patients with gram-negative bacteremia who received extended infusion PTZ for at least 48 hours between 2015 and 2022. In December 2019, the study institution developed a policy that automatically ordered a PTZ LD whenever PTZ therapy was prescribed. The study compared patients who received the loading dose to those who did not. Electronic medical records were queried for patient demographic and clinical data. The primary endpoint was 30-day mortality. Key secondary endpoints included clinical cure, time to clinical cure, 14-day mortality, in-hospital mortality, time to mortality, and microbiologic cure. Clinical cure was defined by antibiotic discontinuation or narrowing of antibiotics in the setting of patient survival. Descriptive and inferential statistics were used for all data analyses. Logistic regression modeling was performed to control for confounding.

Results
A total of 102 patients were included in the analysis, with 51 patients in the LD group and 51 patients in the no LD group. Baseline characteristics were similar in both treatment groups with the exception of ICU admission which was higher in the LD group (41% vs. 24%; P = 0.57). The 30-day mortality was 12% (6/51) in the LD group compared to 6% (3/51) in the no LD group (P = 0.49). There were no significant differences in 14-day mortality, in-hospital mortality, clinical cure, and microbiologic cure. After adjusting for potential confounders, there were no significant associations between LD and 30-day mortality (OR, 1.69; 95% CI, 0.36 to 7.96).

Conclusion
We observed no significant association between LD for extended infusion PTZ and clinical outcomes. Larger cohorts with adequately powered sample sizes are needed to validate these findings. Future investigations should evaluate the impact of a LD for extended infusion PTZ on safety and PK/PD outcomes.

Disclosures
Pinki Bhatt, MD, Sanofi: Grant/Research Support Keith S. Kaye, MD, MPH, Abbvie: Advisor/Consultant|Abbvie: Honoraria|Entasis: Advisor/Consultant|Entasis: Honoraria|GSK: Advisor/Consultant|GSK: Honoraria|Merck: Advisor/Consultant|Merck: Honoraria|Shionogi: Advisor/Consultant|Shionogi: Honoraria|VenatoRx: Advisor/Consultant|VenatoRx: Honoraria Navaneeth Narayanan, PharmD, MPH, BCIDP, Astellas: Honoraria|Beckman Coulter: Honoraria|Merck: Grant/Research Support|Shionogi: Grant/Research Support