bluuebunny/crossref_metadata_2025_split huggingface dataset:
726. Risk factor analysis for cefepime and piperacillin/tazobactam resistant organisms
Authors: Pham Tho H , Barletta Jeffrey , Huang Vanthida 
Published: November 2023

Abstract

Background
Carbapenems (CAR) are first line therapy for patients with infections caused by multidrug resistant organisms. As the prevalence of antibiotic resistance is increasing, CAR use has become a common choice for empiric therapy. This increase in use is concerning as prior CAR exposure is a risk factor for CAR resistance. Identification of risk factors associated with resistance for other beta-lactam antibiotics could aid in the appropriate use of CAR therapy while minimizing overuse. The objective of this study was to identify risk factors for cefepime (FEP) and piperacillin/tazobactam (PTZ) resistance and which population required CAR as an empiric therapy.

Methods
This is a retrospective cohort conducted at HonorHealth John C Lincoln Medical Center, Phoenix AZ between January 2020 to July 2021. The case patients will be those who had an infection which is resistant to FEP or PTZ, while control patients have infection which is susceptible to FEP or PTZ. Recurrence of infection after receiving appropriate antimicrobial therapy considered as a separate case. Patients who do not have antimicrobial susceptibilities were excluded. Variables were compared between groups. Multivariate analysis using logistic regression was used to control for confounding variables.

Results
Overall, 230 patients met inclusion criteria and were evenly distributed between cohorts. The mean age of the population at baseline was 64 ± 17.4, 111 (48.3%) patients were in an ICU and 103 (44.8%) patients required mechanical ventilation. Clinical variables which were significant in univariate analysis were included in multivariate analyses. Multivariate analyses revealed prior resistance to FEP or PTZ in the past 12 months (OR 8.35, 95% CI [2.28-30.50], p=0.001), transferred from outside facility (OR 3.40, 95% CI [1.80-6.42], p&lt; 0.001), prior ICU admission in the past 90 days (OR 4.40, 95% CI [1.72-11.27], p=0.002), and prior antibiotic use in the past 30 days (OR 2.60, 95% CI [1.33-5.09], p=0.005) were associated with increased risk of FEP- or PTZ-resistant infections.

Conclusion
Patients with prior resistance to FEP and PTZ within the last 12 months can benefit by initiating empiric therapy with CAR due to the increased risk for subsequent FEP- or PTZ-resistant organisms. Further investigation is warranted.

Disclosures
All Authors: No reported disclosures
727. Following WHO priority pathogen list: Carbapenem-Resistant Enterobacterales infections in a hospital in the Dominican Republic
Authors: Hernandez-Landa Ricardo Ernesto , Guzman-Marte Anel E , Rojas-Fermin Rita A 
Published: November 2023

Abstract

Background
Enterobacterales resistant to third generation cephalosporins and carbapenems are included in the WHO priority pathogen list. Evaluating the frequency and carbapenemase production of Carbapenem-Resistant Enterobacterales (CRE) and clinical characteristics of patients in our institution would be a helpful tool in Antimicrobial Stewardship programs.

Methods
A retrospective case-control study was conducted including all CRE patients (42) and a sample of patients with Carbapenem-Susceptible Enterobacterales (CSE), from Jan 2020 to Oct 2022 in a 289-bed tertiary teaching hospital in the Dominican Republic. Demographics, comorbidities, infection source, length of stay (LOS) and antibiotic use were reviewed. Microbiology results were reviewed for resistance rate and carbapenemase production data. Univariable analysis was performed to calculate Odds Ratio (OR), significant correlations were included in multivariable analysis to identify risk factors for CRE infections. P-values ≤ 0.05 were considered statistically significant.

Results
The CRE rate during the 34-month period was 1.5% (45/3022) while 79.5% (36/45) of isolates showed carbapenemase production. The most frequent carbapenemases were KPC 44.4% (20/45) and MBL types 28.9% (13/45); Klebsiella spp. (44.4%) along with Enterobacter cloacae complex (24.24%) were the most frequent CRE genera. Blood cultures represented the most common source of isolation. Potential risks factors identified in a univariate analysis were LOS ≥15 days, COVID-19 in the previous 6 months, bloodstream infections (BSI), mechanical ventilation, indwelling catheter use and ICU stay, while COVID-19, LOS ≥15 days and BSI resulted as risk factors using logistic regression.

Conclusion
Even though our CRE rates can still be considered low, the incidence of CRE infections has risen since the COVID-19 pandemic. Patients with BSI, LOS ≥15 days and those who have had COVID-19 in the previous 6 months have the highest risk for CRE infections. Since carbapenemase production, mainly KPC and MBL types, complicates patient management and outcome, we emphasize the need of tests that allow us to rapidly detect and identify the type of carbapenemase produced or the presence of simultaneous production.

Disclosures
All Authors: No reported disclosures
730. Emerging patterns of multidrug resistance Gram negative bacterial infections and its clinical outcome at a tertiary medical center
Authors: Shetty Shriya C , Shenoy Shilpa , Asha Pai K B , Sudhindra Rao M , Ankeeta Menona J , Shetty Avinash K , Veena Shetty A 
Published: November 2023

Abstract

Background
Antimicrobial resistance (AMR) is a complex threat to global health security and universal health coverage. The continued escalation of AMR among Gram-negative bacteria (GNB) is a major concern due to the endemic presence of MDR and extremely drug-resistant (XDR) pathogens.In this regard, the present study aimed to asses the magnitude of MDR, its risk factors, and mortality in MDR/XDR - GNB.

Methods
GNB isolates were retrieved from patients, identified and assessed for antibiotic resistance pattern using VITEK® 2 compact system. The extended spectrum β-lactamase (ESBL) production in 100 GNB isolates was determined by double disk synergy test and genes confirmed by PCR in retrospective cohort study (2011-2012). The carbapenemase production in 100 isolates was confirmed by modified carbapenem inactivation method in prospective cross-sectional study (2021-2022). The metallo β-lactamase (MBLs) were screened by combined disk test and carbapenemase genes detected by multiplex-PCR. Minimum inhibitory concentration (MIC) of colistin was determined by Broth Micro dilution method and clonal relatedness was evaluated by Multilocus sequence typing (MLST).

Results
In retrospective study, all cases confirmed ESBL with high incidence of antibiotic
resistance in cephalosporins,chloramphenicol and ciprofloxacin. All isolates were susceptible to carbapenem. bla TEM and bla CTX-M were prevalent ESBL genes, with 7 % mortality. In prospective study, isolates were positive for carbapenemase with XDR pattern and 47% of mortality. 90% isolates were MBLs positive and 30% had at least two carbapenemase genes, the combination of bla OXA-48 and bla NDM-1 was highly prevalent. Colistin resistance was observed in 20% and 30% isolates with 8 and 4 µg/ml MICs, respectively. Further, multiplex-PCR confirmed the mcr genes and clonal relatedness was determined.

Conclusion
The high prevalence rate of MDR-GNB from producing ESBLs (2011-12) to carbapenemase (2021-2022) was observed. Our results emphasize on antibiotic stewardship policies and regular surveillance programmes for monitoring AMR and screening of drug resistance genes. MLST, molecular surveillance, is valuable tool for rapid epidemiological investigation with precision in determining clonal relatedness

Disclosures
All Authors: No reported disclosures
732. Increase in the Proportion of Hospitalizations in the Setting of Methicillin-Susceptible vs. Resistant Staphylococcus aureus in New York City (NYC)
Authors: Bromberg Maria , Huang Chaorui C , Doucette John T , Altman Deena 
Published: November 2023

Abstract

Background
Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible SA (MSSA) infections are a public health threat; MSSA is a growing problem requiring targeted attention. Socioeconomically disadvantaged patients face disparate outcomes. We analyzed SA infection trends in NYC.

Methods
Hospitalization data for NYC residents were obtained from the NY SPARCS database for 2009-19. Trends in hospitalization rate by resistance (MSSA vs MRSA), clinical syndrome (bacteremia (BAC), pneumonia (PNA), all other infections (OTH)) and setting (community-associated (CA) vs healthcare-associated (HA)) were assessed with Poisson regression. Associations between baseline variables and death were assessed with multivariable logistic regression. CA SA cases were defined as those: 1) with no prior hospitalization in the past year; 2) with a SA diagnosis present on admission; 3) not admitted for complications from a surgery; 4) with no comorbid chronic conditions.

Results
The overall rate of hospitalization with SA infection declined by 7.8% from 2009 to 2019. The hospitalization rate for all MSSA infections increased significantly (+21.8% BAC, +65.5% PNA, +18.1% OTH MSSA; p &lt; 0.001 all groups) (F1). The rate of MRSA PNA increased significantly (+11%; p &lt; 0.001) but MRSA BAC and OTH MRSA hospitalizations significantly declined (-25% and -30.4%, respectively; p &lt; 0.001) (F1). CA cases declined as a proportion of all SA hospitalizations, from 18.4% in 2009 to 12.4% in 2019 (F2).
Age, living in a high-poverty area (HPA), and Medicaid or Medicare insurance were significantly associated with higher odds of in-hospital death for CA cases. Non-Hispanic Black and Hispanic Black patients had lower odds of death for HA but not CA cases; the effect of living in a HPA appeared to attenuate the association between race/ethnicity and death. A logistic regression model with demographic predictors (age, sex, race/ethnicity, HPA, insurance, and borough) was discriminative in predicting in-hospital death for CA cases (area under the curve: 0.87).
Crude Hospitalization Rates
Crude Hospitalization Rates by Pathogen (MSSA, MRSA, and Unspecified SA infection) and Clinical Syndrome (Pneumonia, Bacteremia, and all other infections)

Total counts of hospitalizations by resistance (methicillin-resistant, methicillin-susceptionble, or unknown) and setting (hospital-associated or community-associated)

Conclusion
While hospitalization with SA is declining overall, the relative burden of MSSA has increased compared to MRSA. Further studies and interventions are needed to understand this and baseline risk factors for SA mortality in vulnerable populations.

Mandatory disclaimer for publications using NYS Department of Health data and/or produced under auspices of NYC Department of Health and Mental Hygeine

Disclosures
All Authors: No reported disclosures
733. The attributable mortality, length of stay, and healthcare costs of methicillin-resistant Staphylococcus aureus infections in Singapore
Authors: Cai Yiying , Philip Edwin , Arora Shalvi , Sim Jean X Y , Whiteley Sean , Chow Weien , Tiang Daniel , Neo Siow Leng , Hong Wei Wei , Venkatachalam Indumathi , Graves Nicholas 
Published: November 2023

Abstract

Background
Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are known to compromise patient outcomes and increase healthcare costs. Previous evidence on the prolongation of length of stay due to MRSA infections in Singapore is limited by methodology, including time-dependent bias. We used a multistate model to estimate the expected attributable mortality, length of stay, and healthcare costs of MRSA infections in Singapore.

Methods
We conducted a retrospective case-cohort study in patients admitted to a Singapore tertiary hospital from 2018 – 2022. Patients with MRSA infections were matched to those without infections in a 1: 3 ratio, by age and admitting specialty. We used a multistate model to derive excess length of stay (Fig 1). Attributable cost of MRSA infections from the healthcare perspective (in 2023 Singapore dollar) was estimated by multiplying excess length of stay with the monetary value of a bed-day and MRSA incidence. Cox regression with adjustment of confounders was used to derive hazard ratios (HR) for mortality estimates.

Results
We matched 752 patients with MRSA infections to 2,256 patients without MRSA infections. The most common MRSA infections were skin and soft tissue infections (44.5%) and bacteraemia (18.9%). From the multistate model, the excess length of stay of a MRSA infection was 3.02 days (95% CI, 1.90 – 4.13 days). This translated to an excess healthcare cost of $594,128 (95% CI, $375,111– $813,144) per 100,000 admissions. MRSA skin and soft tissue infections had the longest length of excess stay (3.98 days; 95% CI, 2.50 – 5.46 days) and contributed most to health-care costs ($348,788 per 100,000 admissions; 95% CI, $219,099 – $478,476). After adjusting for potential confounders, the mortality risk of all MRSA infections compared to patients without infection was 1.40 (95% CI, 0.94 – 2.08). Among the different infection types, pneumonia (HR, 4.28; 95% CI, 1.25 – 14.57) and bacteraemia (HR, 2.60; 95% CI, 1.33 – 5.08) had the high mortality risk compared to patients without infection.

Conclusion
Patients with MRSA pneumonia and bacteraemia had highest mortality risk. MRSA skin and soft tissue infections were associated with the highest healthcare costs. Coordinated efforts to reduce these infections may save lives and free valuable resources.

Disclosures
Sean Whiteley, BSc (IT), Axomem: Board Member|Axomem: Fees received for service and software licenses
737. Timing, Microbiology, Antibiotic Use, and Financial Impact of Left Ventricular Assist Device Infections: A Prospective Case-Control Approach
Authors: Ficinski Matthew , Glassman Shannon , Wojciechowski Katrina J , West Jennifer , Feitell Scott , Lesho Emil P 
Published: November 2023

Abstract

Background
Left-ventricular assist devices (LVAD) are increasingly used to treat advanced heart failure, and infection is a leading complication. Although the main registries such as INTERMACS publish annual quality reports, recently they have called for more details regarding antibiotic exposure and microbiology, which are not typically included in those reports.

Infection Timing and Antibiotic Usage

Methods
All patients who receive an LVAD are prospectively monitored by a team of heart failure and infectious diseases specialists until death or they permanently leave the catchment area. All patients from program inception (11-01-18) were included. A cut-off date of 12-3-22 was used to allow for at least of 6-month follow-up period from the last insertion. Internationally standardized infection definitions, a case-control approach, and T and Chi Squared tests were used.

Results
46 of 73 patients developed an LVAD-associated or specific infection. Of those, 57%, 28%, and 13% were driveline, bacteremia, or surgical site infections, respectively. No baseline patient characteristic, including immune status, BMI, co-morbidity, guideline congruent perioperative prophylaxis, or device trauma was associated with infection (Table 1). 48% of infections occurred &lt; 90 days, but there was no association with surgeon, surgical team, or operating room. The mean time to infection was 260 days (IQR 374). The mean days of antibiotic therapy ranged from 21 days for SSI to 37 days for driveline infection (Table 2). Staphylococcus aureus and Streptococcus species, and vancomycin and cefazolin were the predominant organisms and antibiotics used, respectively. The mean lengths of stay and costs were similar between infected and uninfected patients, but infected patients required 3x the number of re-admissions and 2x number of hospital days (Table 1).

Conclusion
Most infections occurred after 90 days, with 34% occurring ≥ 1 year after discharge, suggesting a potential role of community or socioeconomic factors. Other confounders that occurred during this study included COVID-19- related issues, staffing shortages, and shortages of chlorhexidine containing skin preparations and other supplies. 59% of patients with an initial infection had recurrent infections. Going forward, we aim to provide similar details for each subsequent infection.

Disclosures
Katrina J. Wojciechowski, MS, PA-C, Abbott: Honoraria Scott Feitell, DO, FACC, FHFSA, Abbott Laboratories: Advisor/Consultant|Abbott Laboratories: Honoraria
738. Spatiotemporal Patterns of Antimicrobial Resistance of Outpatient Staphylococcus aureus Isolates in the United States, 2010-2019
Authors: Smith Matthew , Carrel Margaret , Shi Qianyi , Hasegawa Shinya , Clore Gosia , Tang Austin , Perencevich Eli N , Goto Michihiko 
Published: November 2023

Abstract

Background
Oral non-beta-lactam antibiotics are commonly used for empiric therapy of Staphylococcus aureus infections, especially in outpatient settings. However, little is known about geographic heterogeneity in the prevalence and temporal trends of antibiotic resistance among different regions in the US. We aimed to characterize the spatiotemporal patterns of drug-resistance prevalence of S. aureus using the nationwide surveillance data from the Veterans Health Administration (VHA) system.

Methods
Utilizing a dataset of 383,514 S. aureus isolates obtained in outpatient settings in the VHA from 2010-2019, we explored the spatiotemporal variation of S aureus resistance to clindamycin, tetracyclines, trimethoprim-sulfamethoxazole, and macrolides, stratified by methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA), and subdivided by regions of the United States (Northeast, Midwest, South, and West).

Results
Over the ten-year study period there was a national decrease in the proportion of S. aureus isolates which were MRSA, from 54% to 39% (Figure 1). Amongst MRSA isolates (Figure 2, panels A-D), we observed stability of clindamycin resistance (from 24.5% to 31.1%), an increase in tetracycline resistance (from 3.9% to 13.1%), an increase in trimethoprim-sulfamethoxazole resistance (from 2.7% to 9.3%), and a decrease in macrolide resistance (from 72% to 60%). For MSSA (Figure 2, panels E-H), we observed relative stability of resistance over time for all four drug classes. Regional analysis (Figure 3) demonstrated that the Northeastern US had slightly higher rates of clindamycin resistance than other regions but lower rates of tetracycline resistance, while the South had notably higher rates of trimethoprim-sulfamethoxazole resistance than other regions, particularly amongst MRSA isolates.
Figure 1
Frequency of S. aureus isolates by year (A), proportion of S. aureus isolates resistant to methicillin (B), and proportion of S. aureus isolates resistant to methicillin by region (C)
Figure 2
Proportion of S aureus isolates resistant to Clindamycin, Tetracyclines, Trimethoprim-Sulfamethoxazole, and Macrolides, stratified by MRSA (panels A-D) and MSSA (panels E-H)
Figure 3
Proportion of S aureus isolates resistant to Clindamycin, Tetracyclines, Trimethoprim-Sulfamethoxazole, and Macrolides, stratified by MRSA (panels A-D) and MSSA (panels E-H), subdivided by region

Conclusion
Even though the prevalence of MRSA is decreasing nationally, there are variable levels of co-resistance to non-beta-lactam antibiotics amongst S. aureus isolates. There was some regional variability in co-resistance amongst MRSA isolates, but less so for MSSA isolates. Further studies are needed to better understand which biological mechanisms mediate these differences.

Disclosures
Michihiko Goto, MD MSCI, Merck & Co.: Grant/Research Support
747. Employer requirements of COVID-19 vaccination reported by healthcare personnel, April 2022
Authors: de Perio Marie , Srivastav Anup , Laney Anthony , Black Carla , Razzaghi Hilda 
Published: November 2023

Abstract

Background
Healthcare personnel (HCP) are at risk for acquiring and transmitting coronavirus disease 2019 (COVID-19) at work. Vaccination against COVID-19 is a primary strategy to prevent transmission in healthcare settings. Our objectives were to describe HCP reporting employer COVID-19 vaccine requirements, identify differences across occupations and settings, and describe policies.

Methods
In a national opt-in internet panel survey of HCP in April 2022 to assess influenza and COVID-19 vaccination coverage, respondents were also asked about employer vaccination requirements. We weighted responses to the U.S. HCP population by age, sex, race, ethnicity, work setting, and U.S. census region. We assessed differences using two-tailed t tests with significance set at p&lt; 0.05. We used multivariable logistic regression to identify factors associated with reporting employer requirements.

Results
Of 3,618 responding HCP, 60.0% reported employer requirements for the COVID-19 primary series. Of those, 95.5% reported completing the primary series vs. 81.9% without requirements (p&lt; 0.001). In addition, 24.0% of HCP reported employer requirements for a booster dose. Of those eligible, 90.8% reported receiving a booster vs. 60.2% without a requirement (p&lt; 0.001). Employer requirements for the primary series varied by occupation [46.1% (assistants/aides) to 77.5% (nurses)] and work setting [40.4% (other clinical settings) to 75.4% (hospitals)]. Of 2,157 HCP reporting a primary series requirement, employer accepted reasons for not being vaccinated included medical (56.8%), religious (50.9%), philosophical (10.0%), all three reasons (16.7%), and no reason (14.9%). Factors independently associated with no reported primary series requirements included working as an assistant/aide, in a non-clinical or other clinical occupation, in ambulatory care, long-term care/home health, or other clinical setting, and in the Midwest and South.

Conclusion
Most HCP in this sample reported employer requirements for the COVID-19 vaccination primary series although requirements were less common for boosters. Differences by healthcare setting exist. Implementing workplace strategies, including vaccine requirements, may lead to higher COVID-19 vaccination coverage.

Disclosures
All Authors: No reported disclosures