bluuebunny/crossref_metadata_2025 huggingface dataset:
188. Plan PDD (patient directed discharge): Oral contingency plans for people who inject drugs (PWID) with Staphylococcus aureus bacteremia (SAB) who leave the hospital prematurely
Authors: Duffield Olivia , Patel Kaya , Schultz Sara K , Spivack Stephanie
Published: November 2023

Background

There has been an increase in infectious complications in PWID and SAB continues to be a serious consequence with treatment options that may not align with patient's agency. High rates of discharges against medical advice and subsequent readmissions contribute to preventable morbidity and mortality plaguing this stigmatized population. Recent research has indicated that oral antibiotic therapy can be non-inferior to IV therapy for SAB infections.

Methods

We queried Epic for admissions with patients with documented opioid use disorder and injection behavior and positive blood cultures from September of 2021 to March of 2022 at our large academic medical center in Philadelphia. We conducted a retrospective chart review of these encounters and collected data regarding their hospital course and treatment.

Results

Over the six-month study period, there were 159 admissions for bacteremia in PWID. Over half (52%) of these patients left the hospital prior to completing IV treatment, 24 (15%) of which still had positive blood cultures at the time of discharge. 90 patients had SAB infection (56.6%). In patients with SAB, only 23 (25.5%) completed a course of IV antibiotics while 52 (57.8%) patients with SAB left the hospital in a PDD and did not complete a course. In addition, there were 6 in-hospital mortalities (6.7%). Of the 52 patients that left the hospital without completing IV antibiotics, 21 (40.4%) were offered an oral antibiotic alternative. For patients who received an oral antibiotic on discharge, only 2 (9.5%) patients were readmitted in 90-days compared to 11 (35.5%) readmissions if oral antibiotics were not received (Figure 1). 19 patients (22.6%) total with SAB were readmitted within 90 days for the same infection or a complication of inadequately treated bacteremia.

Figure 1

Outcomes for PWID with SAB

Conclusion

PWID with SAB experience significant challenges to remaining in a hospital setting for the prescribed duration of intravenous antibiotics. ID physicians should consider including a contingency plan for oral antibiotics should the patient leave the hospital prematurely. Our results show that oral antibiotics are a viable option to prevent 90-day readmission in PWID with SAB.

Disclosures

Sara K. Schultz, MD FACP FIDSA, AbbVie: Advisor/Consultant
189. Outcomes of High-dose Oral Beta-lactam Step-down Therapy Compared to Alternative Oral Therapy for Bacteremic Urinary Tract Infections
Authors: Geyer Abigail , Dumkow Lisa E , VanLangen Kali , Jameson Andrew
Published: November 2023

Background

Pyelonephritis and associated bacteremia are often treated with intravenous antibiotics followed by oral step-down therapy to a fluoroquinolone (FQ) or trimethoprim/sulfamethoxazole (TMP/SMX). Oral beta-lactams were historically utilized less often due to concern for treatment failure. Literature suggests oral beta-lactams are effective, but there are no preferred oral beta-lactam agents or dosing recommendations. This study evaluates outcomes of high-dose oral beta-lactam therapy for Enterobacterales bacteremia due to a urinary tract infection (UTI) compared to alternative therapy.

Methods

A retrospective, multicenter, observational cohort study was conducted evaluating patients admitted from February 1, 2020, to October 1, 2022, with gram-negative bacteremia from a urinary source. Adult patients were included if they received empiric intravenous antibiotic active against the bacteria isolated and transitioned to appropriately dosed oral cephalexin, amoxicillin, TMP/SMX, or FQ (Table 1). Excluded were patients who received less than 72 hours of oral therapy, had a diagnosis of renal abscess or lobar nephronia, and those who expired during admission. The primary outcome compared the composite of recurrent bacteremia or mortality within 30 days of completing oral therapy. Secondary outcomes included recurrent UTI, emergency department (ED) or hospital readmission, and Clostridioides difficile infections within 30 days of treatment completion.

Results

There were 194 patients who met inclusion criteria. The primary outcome occurred in 1/75 (1.3%) patients in the oral beta-lactam group and 2/119 (1.7%) patients in the FQ or TMP/SMX group (p=1.0). Two patients in the FQ or TMP/SMX expired within 30 days and 1 patient in the beta-lactam group had a recurrent bacteremia. There were 16 (21.3%) and 14 (11.8%) patients in the beta-lactam and FQ or TMP/SMX group, respectively, treated for recurrent UTI (p=0.073). Twenty (27%) patients in the beta-lactam group required ED re-evaluation or hospital readmission compared to 30 (25%) patients who received a FQ or TMP/SMX (p=0.74). Zero patients had a Clostridioides difficile infection.

Conclusion

Oral beta-lactams are as effective as oral FQ and TMP/SMX for the treatment of bacteremia from a urinary source.

Disclosures

All Authors: No reported disclosures
195. Comparative Analysis Between Brucellosis Cases With And Without Liver Involvement
Authors: Hammami Fatma , Koubaa Makram , Rekik Khaoula , Chakroun Amal , Smaoui Fatma , Marrakchi Chakib , Ben Jemaa Mounir
Published: November 2023

Background

Brucellosis, a multisystem disease, involve mostly the reticuloendothelial system, but it can also affect any other organ. Liver involvement is often present during the acute phase. We aimed to compare clinical and laboratory features of brucellosis cases with and without liver involvement.

Methods

We conducted a retrospective study including all acute brucellosis cases hospitalized in the infectious diseases department between 1992 and 2022. Liver involvement were defined as a serum alanine transaminase > 40 U/L and/or a serum aspartate aminotransferase > 40 U/L.

Results

We encountered 105 cases, among which 46 had liver involvement (43.8%). A male predominance was noted among cases with (69.6%) and without (61%) liver involvement, with no significant difference (p=0.363). Vomiting (19.6% vs 5.1% ; p=0.021), nausea (28.3% vs 3.4% ; p< 0.001) and loss of appetite (34.8% vs 10.2% ; p=0.002) were significantly more frequent among cases with liver involvement. Fever (89.1% vs 89.8% ; p=1), arthralgia (52.2% vs 61% ; p=0.364) and myalgia (37% vs 33.9% ; p=0.745) were noted among cases with and without liver involvement. Blood culture positivity was significantly more frequent among cases with liver involvement (43.5% vs 5.1% ; p< 0.001). An elevated C-reactive protein level (85.7% vs 28.8% ; p=0.002), an accelerated erythrocyte sedimentation rate (76.1% vs 54.2% ; p=0.021) and thrombocytopenia (39.1% vs 13.6% ; p=0.003) were significantly more frequent among cases with liver involvement. Anemia (39.1% vs 25.4% ; p=0.133) and leukopenia (21.7% vs 22% ; p=0.971) were noted among cases with and without liver involvement, with no significant difference.

Conclusion

Acute brucellosis cases with liver involvement were characterised by frequent vomiting, nausea and loss of appetite as clinical symptoms, besides elevated inflamatory markers and frequent thrombocytopenia, which might be explained by the involvement of the reticuloendothelial system.

Disclosures

All Authors: No reported disclosures
197. Evaluation of Risk Factors and Outcomes Associated with Daptomycin-nonsusceptible Staphylococcus aureus Bacteremia
Authors: Hanna Zachary W , Alangaden George J , Zervos Marcus , Suleyman Geehan
Published: November 2023

Background

Staphylococcus aureus (SA) is a major cause of hospital-associated infections in the US with high morbidity and mortality. With SA developing resistance to many first-line antibiotics, daptomycin (DAP) has become a critical agent for SA therapy. However, increasing use of DAP has resulted in emergence of DAP-nonsusceptible (DNS) SA strains. We aim to elucidate risk factors associated with DNS SA and compare outcomes between patients with DAP-susceptible (DS) and DNS SA bacteremia (SAB).

Methods

Retrospective cohort analysis was performed on patients with DNS (cases) and DS (controls) SAB admitted to Henry Ford Health between 9/2005 and 3/2023. Patients with persistent ( >7 days of positive blood cultures) DS SAB were used as controls. Demographic, risk factors, clinical characteristics, and outcomes were evaluated. Primary outcomes were 30-day relapse or progression, readmission and mortality; secondary endpoint was 90-day mortality.

Results

A total of 122 patients included 59 (48%) cases and 63 (52%) controls. The majority were male (56.6%) with median age of 59. The study population had a high burden of comorbidities as outlined in the Table; central venous catheter use was significantly more common among cases (p=0.049). History of MRSA infection (p< 0.001) and prior hospitalization (p< 0.001) within 1-year, and antibiotic (p=0.017) use, particularly vancomycin (p=0.011), within 90 days were associated with DNS SA. Primary source of infection and infectious complications were not significantly different among cases and controls. There was no significant difference in outcomes between the two groups. Although not statistically significant, 90-mortality was higher in the DNS group (p=0.075).

Conclusion

Our study highlights risk factors for DNS SA, including recent vancomycin use, and prior hospitalization and MRSA infection within 1 year. While there was no significant difference in outcomes between DNS and DS SAB, overall mortality was high. These findings highlight the need for continued surveillance of DNS SA and careful consideration of risk factors when selecting antimicrobial agents for complicated SA infections. Further studies are needed to identify potential mechanisms of vancomycin cross-resistance in DNS SA.

Disclosures

Marcus Zervos, MD, Contrafect: Advisor/Consultant|GSK: Grant/Research Support|Johnson and Johnson: Grant/Research Support|Pfizer: Grant/Research Support
198. Comparison of Standard versus Extended Treatment Duration for Gram-negative Bloodstream Infections with Obstructing Nephrolithiasis or Urolithiasis
Authors: Harpenau Tara L , Clemens Adam C , Brown Douglas A
Published: November 2023

Background

There is minimal data regarding optimal duration of therapy in gram-negative bloodstream infections (GN-BSI) with obstructing nephrolithiasis/urolithiasis. Prescribing practices often include standard antibiotic duration (fixed duration with an antibiotic free period prior to stone management) or extended duration (continuous antibiotics until definitive stone management). This study compares outcomes between standard versus extended antibiotic durations in patients with GN-BSI with obstructing nephrolithiasis/urolithiasis.

Methods

This IRB approved retrospective cohort study screened patients treated between 1/1/2016 and 1/1/2022. The standard duration group had an antibiotic free period of ≥ 7 days before definitive stone management and the extended duration group had continuous antibiotics without an antibiotic free period ≥ 7 days before definitive stone management. The primary outcome was infection recurrence before definitive stone management. Select secondary outcomes included revisit to care, antimicrobial resistance, and mortality. Continuous data utilized a t-test or Mann-Whitney U test and categorical data utilized either Chi-square or Fisher’s exact test.

Results

After screening 405 encounters, there were 39 standard and 29 extended group patients. Median antibiotic duration was 16 (15,19) vs. 19 (16,23) days, p = 0.06 and time to definitive stone management was 52 (34,71) vs. 22 (15,25.5) days, p< 0.01 in the standard and extended group respectively. Infection recurrence was no different in the two groups, 5% (n=2) vs. 0%, p=0.5. Revisit to care was significantly higher in the standard group 28% (n=11) vs. 3% (n=1), p< 0.01, with the most common patient complaint of “concern for infection.”

Conclusion

This study found no difference in infection recurrence between standard and extended antibiotic treatment strategies but was underpowered. A higher rate of revisit to care in patients who received standard courses of antibiotics is concerning and may also be influenced by a prolonged time to definitive stone management. Further data is necessary to determine the optimal antibiotic treatment strategy and optimal time of definitive stone management after GN-BSI with obstructing stones.

Disclosures

All Authors: No reported disclosures
210. Evaluating the Costs of Escherichia coli Bloodstream Infections: A Population-Based Cohort Study
Authors: King Teagan , Somayaji Ranjani , Leal Jenine , Black Jason , Gregson Dan , Conly John , Rennert-May Elissa
Published: November 2023

Background

Escherichia coli (E. coli) is a frequent cause of blood stream infection (BSI) with associated morbidity and mortality. We evaluated the costs of susceptible and resistant E. coli BSI in children and adults. There is a paucity of studies examining E. coli BSI using micro-costing data within North America.

Methods

Population-based cohort of all blood cultures from 2011 to 2018 in Calgary, Canada, linked to micro- and gross costing data using administrative databases. Compared no BSI to any E. coli infection, classified as resistant to any antimicrobial agent or susceptible, over 90 days. Propensity score matching was done 4:1 by age, sex, and comorbidities. The primary outcome was mean costs, using multivariable linear regression models in R version 4.1.0. Secondary outcomes were length of stay (LOS), readmissions and 90-day all-cause mortality. Comparative analyses were reported using odds ratios (OR) and 95% CIs.

Results

A total of 37,482 children and 89,673 adults were included: 225 susceptible and 21 resistant BSI in children, and 3,870 and 711, in adults. Mean and standard deviation (SD) costs of an E. coli BSI including ED visits and hospitalizations for 90 days in children were $99,214 ($152,809) for susceptible, and $94,628 ($113,281) for resistant infections, and $36,104 ($74,274), and $57,162 ($176,019) in adults. The greatest cost difference in adults was resistant E. coli BSI compared to no BSI ($24,265, 95% CI $11,308-37,223, p< 0.001), with higher odds of readmission (OR 1.54, 95% CI 1.26-1.88, p< 0.001) and increased LOS (4.17 days, 95% CI 1.04-7.30, p=0.009). In children, cost differences were greatest for susceptible infections compared to no BSI ($45,186, 95% CI 27,965-62,406, p< 0.001), with the longest initial hospitalization (17.1 days, 95% CI 10.3-23.9, p< 0.001), and higher readmissions at 90 days (OR 1.65, 95% CI 1.17-2.31, p=0.004). E. coli BSI did not impact mortality for children or adults compared to those with no BSI.

Conclusion

E. coli BSI is associated with substantial morbidity, mortality, and costs. Total cost differences were highest among adults with resistant, and children with susceptible infections compared to no BSI. Further research into cost-effectiveness of BSI diagnosis, treatment and prevention is warranted.

Disclosures

Ranjani Somayaji, M.D, CF Foundation: Grant/Research Support|CIHR: Grant/Research Support|Oncovir: Data and Safety Monitoring Board Fees|Vertex Pharmaceuticals: Advisor/Consultant|Vertex Pharmaceuticals: Grant/Research Support|Vertex Pharmaceuticals: Honoraria Dan Gregson, MD, BioMerieux Canada: Advisor/Consultant
212. Effectiveness of Empirical Piperacillin/tazobactam Compared to Cefepime for Bloodstream Infection Caused by Gram-Negative Bacilli
Authors: Ho Lee Young , Yang Jinyoung , Ko Jae-Hoon , Young Cho Sun , Huh Heejae , Yong Lee Nam , Kang Cheol-In , Ryeon Chung Doo , Ran Peck Kyong , Song Jae-Hoon , Huh Kyungmin
Published: November 2023

Background

Piperacillin/tazobactam (PTZ) and cefepime (CFP) are commonly used antibiotics for healthcare-associated infections and immunocompromised patients. However, few studies have compared the clinical effectiveness of these two antibiotics. Thus, we compared the effectiveness of empirical PTZ and CFP in patients with monomicrobial blood-stream infection (BSI) caused by gram-negative bacilli.

Methods

We conducted a retrospective cohort study of consecutive, non-duplicate monomicrobial BSIs caused by 1 of 4 taxa (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Acinetobacter species) identified from a nationwide, prospective surveillance (Korean Antimicrobial Resistance Surveillance Network [KARS-Net]). Patients who were treated with PTZ or CFP as the only active empirical antibiotic were included. The primary outcome was all-cause, in-hospital 30-day mortality. Logistic regression with backward selection was used to adjust for imbalance in baseline characteristics.

Results

A total of 120 cases were included, among which 87 (72.5%) were treated with PTZ and 33 (27.5%) with CFP. Underlying renal disease was more common in the PTZ group whereas malignancy, septic shock, and neutropenia were more common in the CFP group. (Table 1). All-cause 30-day in-hospital mortality was comparable between the two groups (16.1% vs 12.1%, p=0.777; table 2), as well as attributable mortality. However, the early clinical response at 72 hr was significantly more common in the patients treated with CFP (25.3% vs 57.6%, p=0.001)

The choice of empirical antibiotics was not significantly associated with mortality in a multivariable logistic regression model (Table 3). Older age (≥65 years; adjusted OR. 16.24; 95% CI, 2.21-119.60), lower ECOG (aOR, 2.91 per 1 point, 95% CI, 1.35-6.25), high PITT score (aOR, 1.68; 95% CI, 1.17-6.25) and chronic liver disease (aOR, 39.70; 95% CI, 2.56-615.13) were significant independent risk factors for 30-day in-hospital mortality.

Conclusion

In patients with BSI caused by gram-negative bacilli, empirical use of either PTZ or CFP was associated with comparable clinical outcomes.

Disclosures

All Authors: No reported disclosures
213. Do Patients with Candidemia Need an Ophthalmology Exam?
Authors: Lehman Alice , Tessier Katelyn , Sattarova Victoria , Rocio Montezuma Sandra , Kline Susan E , Edwin Erayil Serin
Published: November 2023

Background

Candidemia can lead to hematogenous seeding of the eye resulting in chorioretinitis or endophthalmitis. IDSA recommends a screening dilated retinal examination for patients with candidemia, whilst American Academy of Ophthalmology (AAO) recently declared this a low value practice. Using an inter-disciplinary team, we evaluated ophthalmology examination for patients with candidemia.

Methods

We performed a retrospective study of patients with candidemia at an academic medical center and affiliated hospitals between January 2011 – June 2022. Electronic medical records were reviewed for demographics and baseline characteristics. The primary outcome was chorioretinitis and/or endophthalmitis. The study was adjudicated by independent review from infectious disease and ophthalmology providers.

Results

We included 308 patients with a blood culture positive for candida species. 149 patients (48%) received an ophthalmologic exam, of which 55% (82) were asymptomatic. Abnormal ocular findings concerning for presumed ocular candida complications were found in 12 patients (8%, 12/149), of which 4 had alternative diagnoses to candida choriorentinits or endophthalmitis. All of the remaining 8 patients (5%, 8/149) had presumed candida chorioretinitis with no cases of candida endophthalmitis and this led to a change in management in 88% (7/8) of patients (Table 1). Of the 8 patients, 3 patients were asymptomatic, making the number needed to screen 28 to detect presumed candida chorioretinitis amongst asymptomatic patients. We did not identify statistically significant risk factors for development of abnormal ocular findings (Table 2).

Table 1

Clinical diagnosis and management of patients with candida chorioretinitis and/or endophthalmitis

Table 2

Clinical features of patients with and without ocular candidiasis

Conclusion

IDSA and AAO recommend ophthalmologic examination in symptomatic and intubated patients with candidemia. We found a 5% incidence of presumed ocular candidiasis in patients with candidemia. Given the limitations of our study, we could not conclude for or against screening in asymptomatic patients as this did not lead to a significant change in patient outcomes. Inter-disciplinary decisions involving ophthalmology and infectious diseases can help inform best practices for screening in asymptomatic patients. Future studies should evaluate ocular photography and teleophthalmology as screening strategies.

Disclosures

All Authors: No reported disclosures
230. Risk factors for bacteremia in patients receiving extracorporeal membrane oxygenation (ECMO) during the COVID-19 pandemic
Authors: Hendrix Curtis , Radcliffe Christopher , Tantawy Hossam , Roberts Scott C
Published: November 2023

Background

Patients receiving extracorporeal membrane oxygenation (ECMO) are at high risk for bacteremia which can cause substantial morbidity and mortality. We sought to evaluate risk factors for bacteremia in patients receiving ECMO during the COVID-19 pandemic to better characterize those most at risk and areas for prevention.

Methods

A retrospective case control study evaluating patients receiving ECMO support at Yale New Haven Hospital from April 2020 – September 2021 was performed. Cases of patients who developed bacteremia were matched 1:2 to control patients on ECMO who had blood cultures drawn but who did not develop bacteremia. There were no set criteria for drawing the blood cultures; when to draw blood cultures were per provider’s discretion. Only the first set of blood cultures drawn were analyzed.

Results

60 patients received ECMO support and had blood cultures drawn, 20 (33.3%) with bacteremia matched to 40 (66.7%) without bacteremia. Independent risk factors for bacteremia included being diagnosed with COVID-19 (70.0% vs 40.0%, p = 0.028), days on ECMO until culture (13.4 vs 6.2 days, p = 0.005), days on mechanical ventilation until culture (17.5 vs 7.7 days, p = 0.002), corticosteroid use (75.0% vs 40.0%, p = 0.011), ECMO type (80.0% veno-venous [VV] and 20.0% veno-arterial vs 37.5% veno-venous and 62.5% veno-arterial, p = 0.002), proning (60.0% vs 22.5%, p = 0.004), and preceding antibiotic days during the admission (16.1 days vs 9.3 days, p = 0.025). There was no difference in any evaluated infectious metric (white blood cell count, daily maximum temperature, procalcitonin, CRP, d-dimer, ferritin, fibrinogen, LDH) on the day of blood culture in those with compared to those without bacteremia.

Conclusion

Patients receiving ECMO support who developed bacteremia were more likely to be on VV-ECMO, proned, receive corticosteroids, and be on mechanical ventilation for longer periods of time, all factors associated with severe COVID-19. Additional risk factors included more days on ECMO and prior antibiotic use. No laboratory metric was predictive of bacteremia, highlighting the challenges in accurately predicting bacteremia in the ECMO patient population.

Disclosures

All Authors: No reported disclosures
232. Malnutrition is Associated with Poor Outcomes in Patients Hospitalized with Staphylococcus aureus Bacteremia
Authors: Saad Baraa , Saleh Nourhan , Alkhader Aseel , Garg Nikita , Reynoso David
Published: November 2023

Background

Staphylococcus aureus bacteremia (SAB) is one of the most common and clinically significant bacterial infections worldwide. Malnutrition has been linked to poor outcomes in various infectious and non-infectious diseases. The objective of this study is to investigate the impact of malnutrition on the outcomes among adult patients hospitalized with SAB.

Methods

A cohort study was conducted using the Nationwide Inpatient Sample (2016-2019). Adult hospitalizations with Methicillin-Sensitive or -Resistant Staphylococcus aureus bacteremia were identified and stratified by the presence of malnutrition using ICD-10 codes. The primary outcome was in-hospital mortality. Secondary outcomes included ICU admissions, septic shock, mechanical ventilation, length of stay (LOS), and hospital charges. Multivariate regression analysis adjusted for confounding factors.

Results

Of 518,840 SAB patients, 14.10% had malnutrition. Malnourished patients showed higher rates of mortality, septic shock, mechanical ventilation, mean LOS, and hospital charges. Multivariate analysis revealed malnutrition as an independent predictor of worse outcomes. Adjusted odds ratios were 1.60 for mortality (P< 0.001), 1.69 for septic shock (P< 0.001), and 1.75 for mechanical ventilation (P< 0.001). Adjusted mean LOS and total charges increased by 6.14 days and $87,885 for malnourished SAB patients. Outcomes were similar for MSSA and MRSA.

Conclusion

Our study highlights the significant impact of malnutrition on outcome among patients hospitalized with SAB. We found that malnourished individuals with SAB had higher rates of mortality, septic shock, mechanical ventilation, prolonged hospital stays and increased financial burden. These results emphasize the critical need to address and recognize malnutrition as a significant risk factor in the management of SAB. Further research and interventions targeting the issue of malnutrition in SAB patients are needed to enhance outcomes, decrease associated mortality and morbidity, and reduce healthcare cost.

Disclosures

All Authors: No reported disclosures
243. A Laboratory Intervention to Enhance Recognition of Bacteremia in Patients with Staphylococcus aureus Bacteriuria
Authors: Vaillant James J , Chesdachai Supavit , Comba Isin Y , Tabaja Hussam , Yetmar Zachary A , Abu Saleh Omar M
Published: November 2023

Background

Staphylococcus aureus bacteriuria (SABU) represents 0.2–4% of all positive urine cultures. While asymptomatic colonization or infection of the urinary tract is possible, hematogenous seeding from S. aureus bacteremia (SAB) represents a potentially life-threatening condition. The rate of concomitant SAB is estimated to be 6.9–17.2% among those with SABU, and these patients are at higher risk of in-hospital mortality, infective endocarditis, embolic events, and vertebral osteomyelitis. Detection of SABU represents an opportunity for early detection and intervention in SAB.

Methods

We conducted a retrospective analysis of clinical and microbiological characteristics of adult patients with SABU as our pre-intervention baseline. We then implemented a comment with the urine culture result in the electronic medical record (EMR) advising providers about the possibility of concomitant bacteremia. We conducted an interim analysis of early post-intervention data.

Figure 1: Study Workflow

Figure 1: Study workflow depicting case recruitment and blood culture results.

Figure 2: Intervention Flag

Figure 2: Example of intervention comment displayed with the urine culture result in the EMR.

Results

250 adult patients developed SABU from January 1, 2021, to January 31, 2023. Of these, 87 (34.8%) had urinary tract symptoms, and 91 (36.4%) had a chronic indwelling urinary catheter. 74 (29.6%) patients had blood cultures collected within 7 days of positive urine culture. The presence of urinary symptoms or indwelling catheter was not associated with blood culture collection. Only 22 patients (8.8%) had SAB with SABU. One patient was diagnosed with SAB 20 days after detection of SABU with infective endocarditis and disseminated infection, representing a delay in diagnosis.

Following implementation of the intervention, an additional 86 patients with SABU had the result comment displayed in the EMR. Blood cultures were collected in 19 (22.1%) patients, and 2 (2.3%) were positive for S. aureus. There were no significant differences in rates of blood culture collection or SAB after implementation of the EMR result comment.

Conclusion

Our results show a similar rate of SABU associated SAB to that previously reported in the literature. Delayed diagnosis of SAB in SABU is uncommon but does occur rarely with significant morbidity. The addition of a result comment is a simple and cost-effective intervention; however, evaluation of its efficacy is presently limited by a short follow-up duration.

Disclosures

All Authors: No reported disclosures
265. Common Organisms of Parotid abscess in Cambodian Children
Authors: Farrilend Prak
Published: November 2023

Background

Our aim is to determine the most common pathogens to cause parotid abscess and some epidemiology on children under 15 years of age who were admitted at Angkor Hospital for Children and consider where the children lived in order to aid critical thinking for quick diagnosis and proper treatment

Methods

Our study is retrospective study chart review of all the children who had parotid abscess that was confirmed during surgery. The 42 patients were all under 15 years of age and lived in Cambodia. The duration of the study was 5 years, from 01-Jan-2017 to 01-Jan-2022

Results

Of the 42 patients with parotid abscess, the most common pathogen found was Burkholderia Pseudomallei in 76% (32 of cases), of which 60% (19 cases) affected the right side and 40% affected the left side (13 cases) and we less commonly saw bilaterally. Staphylococcus aureus was the second most common cause and found in 24% (9 cases) of which 77% (7 cases) were on left side and only 23% (2 cases) on the right side. Cheek swelling was a chief complaint in 99% of cases and fever was a presenting feature in 90% of cases. They are from multiple different provinces in Cambodia that lie around the Tonle Sap River, primarily Siem Reap 77% (33), then Kampong Thom 9.5% (4), Battambang 5% (2), Phnom Penh 2.3% (1), and Banteay Meanchey 2.3% (1).

Conclusion

The most common cause of parotid abscess in children under 15 years of age in our study was Burkholderia Pseudomallei which is Gram negative rod shape, and mostly involved the right side and was not seen in bilaterally. The other pathogen is Staphylococcus Aureus which more commonly effected the left side. The children all live in provinces surrounding the Tonle Sap River region.

For the regional of their living were from different province and place in that we found from the surrounding the Tonle Sap River, Siem reap 77% (33), Kampong Thom 9.5% (4), Phnom Penh2.3% (1), Battambang 5% (2), Banteay Meanchey 2.3% (1).

Disclosures

All Authors: No reported disclosures
280. A cross-sectional pilot study on the relationship of gut microbiota pattern to immunogenicity of influenza vaccine in lupus patients
Authors: Kiewsanuan Nathathai , Ngamjanyaporn Pintip , Pisitkun Prapaporn , Payungporn Sunchai , Sawaswong Vorthon , Chanchaem Prangwalai , Maiuthed Arnatchai , Rotjanapan Porpon
Published: November 2023

Background

Immunosuppressive therapy, the nature of the autoimmune disease, and different gut microbiome patterns may affect influenza vaccination responses of lupus patients. Thus far, the gut microbiome patterns in this population in response to influenza vaccination have yet to be studied extensively. So, this study aims to evaluate the gut microbiome pattern associated with influenza vaccination response and assess the associated factors that may affect different gut microbiome patterns among lupus patients.

The bar plot shows relative abundances of gut microbiome at the phylum level in lupus patients and healthy controls.

Methods

The cross-sectional pilot study was conducted at Ramathibodi Hospital during 2021-2022. This study is a substudy of another cohort study investigating influenza vaccination response to different dosing regimens, randomly into the high-dose (HD) and standard-dose (SD) quadrivalent influenza vaccination. The patient’s demographics and other relevant information were retrieved. Fecal samples were collected at enrollment for microbiota study. Immunogenicity to vaccination was determined via seroprotection and seroconversion rates.

Results

A total of 62 participants were enrolled. Most patients were female (93.55%). The median (IQR) ages among SD and HD groups were 35.5 (28-42.5) and 34 (25-43) (P=0.878) years old. 18 (29.03%) were taking high-level immunosuppressive treatment (HI) received SD, and 18 (29.03%) were taking low-level immunosuppressive treatment (LI) received SD. There was no significant difference in gut microbiota patterns among all patient groups. Firmicutes were the most abundant phylum, and Bacteroides were the most abundant genera in all patient groups. The alpha diversity was more prominent in the seroconversion groups but no statistical differences (P=0.260 in Shannon indexes). Multivariate logistic regression analysis revealed the LI group (AOR: 7.39, 95% CI 1.11 to 49.36; P=0.039), presence of Bacteroides (AOR 1.16, 95% CI 1.01 to 1.33; P=0.031) were associated with seroconversion of influenza vaccine.

Conclusion

The gut microbiota patterns of lupus patients were not different from healthy controls nor vaccination response. Therefore, the immunosuppressive therapy did not affect the gut microbiota patterns in lupus patients, and an HD of influenza vaccine may not be necessary.

Disclosures

All Authors: No reported disclosures
285. The Pediatric Urinary Microbiome: A Comparison of infants under 12 months with and without Urinary Tract Infection in South Korea
Authors: Hyen Lee Ji , Won Lee Jung
Published: November 2023

Background

The microbiome of the urinary tract plays a significant role in maintaining health through its impact on bladder homeostasis. Urobiota helps maintain the urothelial integrity and prevents urinary tract infection (UTI), regulating neurotransmission and promoting local immune function. However, the number of studies on the pediatric population, especially those in the infant age group in Asia, is limited.

Methods

We prospectively analyzed the urine microbiome of 15 Infants under 12 months between Jan. 2022 and Dec. 2022, grouped as UTI and control groups. UTI group was defined with fever (body temperature ≥38°C), pyuria (≥5 WBC/ high power field), significant bacteriuria (positive urine culture with pure growth 50,000 colony forming unit (CFU)/mL in catheterized urine culture) and control group was recruited from healthy infants who came to our hospital for vaccination but were uninfected. The urine samples underwent DNA extraction and 16S ribosomal RNA gene sequencing, urinalysis and urine culture. The Shannon diversity, the relative abundances of genus and species level, was analyzed with a Mann-Whitney U test and Kruskal-Wallis test.

Results

The number of subjects was fifty and the mean age of the pediatric subjects was 6.2 months old. Ten of the subjects were in the control group (the ratio of male to female was 5:5), and five of the subjects in the UTI group (the ratio of male to female was 2:3). Most common genus are streptococcus, bacteroids, prevotella, citrobacter, and bifidobacterium in control group, while UTI group are frequently dominated by the genus Escherichia coli, streptoccus, bacteroids, prevotella, and bifidobacterium. There was no difference in genus lactobacillus between the two groups. In the analysis of the Shannon diversity, those with UTIs had significantly decreased diversity compared to the control group (P =0.037).

The top 20 genus in pediatric urine specimens

The comparison of Shannon diversity of control group and pediatric Urinary tract infection group in South Korea

Conclusion

A urinary microbiome was identified in infants under 12 months and we observed the differences in microbiome diversity and composition. The pediatric urinary microbiome has just begun to be explored, and further research and investigation must be conducted into about different ethic and demographic pediatric population characteristics.

Disclosures

All Authors: No reported disclosures
286. The Effect of Fecal Microbiota Transplantation on Decolonization of Multidrug-resistant Organisms in the gut
Authors: Soon Lee Seung , Tae Suk Ki , eun Yong Dong
Published: November 2023

Background

Gut colonization of multidrug-resistant organisms (MDROs), such as carbapenemase-producing Enterobacteriaceae (CPE) and vancomycin-resistant Enterococci (VRE), precedes clinical infections. It increases the risk of patient-to-patient transmission of MDROs as well as clinical infections such as bacteremia. Therefore, decolonization of MDROs in the gut by restoring colonization resistance through fecal microbiota transplantation (FMT) could be an effective infection control strategy for MDROs.

Methods

From March 2019 to November 2022, FMT for CPE and VRE decolonization in the gut was conducted at Hallym University Chuncheon Sacred Heart Hospital. Frozen or capsulized stool (MicroBiotix FMT Delivery Microbiota Preparation) from unrelated pre-screened healthy donor was used for each FMT. The rates of and the time to successful decolonization, defined as 3 consecutive negative results from rectal swab culture repeated with 3-day intervals after the initial FMT, were investigated in CPE and VRE rectal colonizers, respectively.

Results

FMT was performed in 60 CPE rectal carriers (KPC=55, KPC & NDM=2, KPC & IMP=1, NDM=1, NDM & OXA=1) and in 15 VRE rectal carriers (E. faecium=14, E. faecalis=1). Among patients with follow-up data after initial FMT, decolonization success rates for CPE and VRE rectal carriers were 44.8% (26/58) and 66.7% (10/15) at 1 month, 77.1% (37/48) and 92.9% (13/14) at 3 months, 95.5% (42/44) and 100% (14/14) at 6 months, respectively. Median and mean times to decolonization after initial FMT were 30 and 43 days in CPE rectal colonizers and 14 and 29 days in VRE rectal colonizers, respectively.

FMT results for decolonization of MDROs in the gut of Chuncheon Sacred Heart Hospital (ClinicalTrials.gov number, NCT04583098)

Conclusion

FMT as a microbiome restoration therapy is an effective method to control CPE and VRE colonization (ClinicalTrials.gov number, NCT04583098).

Disclosures

All Authors: No reported disclosures
291. A Longitudinal Study of The Effect of Fecal Microbiota Transplantation on Klebsiella pneumoniae and its Bacteriophages in a Patient with Long-Term Colonization
Authors: Manuel Joshua , Forsstrom Sarah , Berryhill Brandon A , Burke Kylie , Smith Andrew , Woodworth Michael H , Levin Bruce
Published: November 2023

Background

Live biotherapeutic products such as fecal microbiota transplantation (FMT) show promise as therapies for conditions associated with gut microbiome composition and function, including colonization and recurrent infection with multidrug resistant organisms (MDRO). Although FMTs can reduce colonization with MDROs, much is still unknown about the mechanisms responsible for successful treatment with FMTs. The observation that bacteriophages (phages) are ubiquitous in all microbial communities including FMT doses and are being developed as therapies for MDROs suggests that phages contribute to FMT efficacy. We present results of a case study employing experimental and metagenomic analyses to test the hypothesis that phages contribute to the clinical efficacy of FMTs.

A patient with recurrent urinary tract infections (UTI) with a multidrug resistant Klebsiella pneumoniae was treated with an FMT delivered by retention enema as part of a recent clinical trial (NCT02922816). Metagenomic analyses showed that this patient had baseline K. pneumoniae intestinal domination with relative abundance of 90%. At Day 2 post FMT, the relative abundance of K. pneumoniae was 0.5% and follow-up stool cultures with Klebsiella selective and differential media were negative.

Methods

We competitively aligned reads from the stool metagenomes to the gut phage database using bowtie2 and inStrain. We isolated K. pneumoniae and phages from the donor and patient samples and bacteria susceptibility.

Methods For K. pneumoniae/Phage Isolation and Metagenomic Analysis

Results

We found 76 potential K. pneumoniae phages in the patient before treatment, of which 58 have a breadth of coverage > 0.10. Among these, 39/58 (67%) are known to be temperate and are able to incorporate in the host bacterial genomes as prophages.

Breadth of Coverage of K. pneumoniae Phages in the Patient Prior to FMT

Solid bars represent unknown free phages identified in the sample. Dashed bars represent phages that are known to be temperate found in the patients metagenome.

Conclusion

As resistance to host phages quickly emerges, we postulated that phages in the FMT dose contribute to the elimination of K. pneumoniae in this patient. To test the hypothesis, we follow the changes in relative densities of gut K. pneumoniae phages with metagenomic coverage analyses in longitudinally collected fecal samples post FMT. To further test this hypothesis, we isolated phages and bacteria from the FMT and sequential fecal samples from the patient and tested the susceptibility of the K. pneumoniae to the phages from both the FMT dose and the patient.

Disclosures

All Authors: No reported disclosures
306. Determining natural killer cell responses to JC polyomavirus
Authors: Tan C Sabrina , Ahn Jenny , Chen Sarah , Lee Esther , Gikundiro Eunice , Craemer Melissa , Gressens Simon , Yoder Taylor , Lifton Michelle , Jost Stephanie
Published: November 2023

Background

JC polyomavirus (JCPyV) infects oligodendrocytes and causes progressive multifocal leukoencephalopathy (PML), a potentially fatal complication of monoclonal antibody treatments for cancer and autoimmune diseases, and a rare but often-fatal disease in people living with HIV. There is currently no effective treatment against JCPyV and novel immunotherapies for PML are urgently needed. Natural killer (NK) cells play critical roles in defense against viral infections, yet NK cell responses to JCPyV remain largely unexplored.

Methods

Intracellular cytokine staining (ICS) of NK and T cells stimulated with overlapping peptide pools covering the JCPyV capsid VP1 was performed. A novel flow cytometry-based assay was created to determine NK cell killing efficiency of infected SVG-A cells. Blocking antibodies were used to determine NK cell receptors responsible for immune recognition of JCPyV-infected cells. Single cell cloning was used to expand a homogenous population of NK cells.

Results

Using ICS, about 40% of healthy donors demonstrated NK cell responses, with CD107a upregulation and robust IFNy production by NK cells extending beyond T cell responses(Fig 1). Next, we showed that co-culture of NK cells and JCPyV-infected SVG-A cells leads to, on average, a 65% reduction of infected cells (Fig2). Expression of ligands for the activating NK cell receptor NKG2D was modulated in JCPyV-infected cells, with overall enhanced expression of ULBP-2. Accordingly, NKG2D blockade resulted in decreased NK cell degranulation. Interestingly, we also identified JCPyV-derived peptides that elicit dominant responses by NK cells and can stabilize HLA-E, the ligand for the inhibitory NKG2A and the activating NKG2C receptors. Blockade of NKG2A enhanced NK cell response to JCPyV-infected targets. Finally, we have isolated and expanded single NK cell clones with potent cytotoxic functions against autologous target cells pulsed with JCPyV-derived peptides (Fig 3) and JCPyV-infected SVG-A cells.Fig 2.Fig. 3

Conclusion

Altogether, these findings suggest NKG2D-mediated activation and the NKG2/HLA-E axis may play key roles in controlling JCPyV replication and targeting these receptors and/or expansion of JCPyV-specific NK cells may be promising NK cell-based immunotherapeutic for PML.

Disclosures

All Authors: No reported disclosures
321. Early Intervention: Readmission Reduction Efforts in OPAT via Early Patient Contact
Authors: Swartwood Michael , Schranz Asher J , Farel Claire E , Mavrogiorgos Nikolaos , Fabricio Julia B , Bowman M C , Oosterwyk Teresa M , Boerneke Renae
Published: November 2023

Background

Outpatient parenteral antimicrobial therapy (OPAT) leverages the expertise of a multidisciplinary Infectious Diseases (ID) team to provide antimicrobial therapy at home in a safe and cost-effective manner. To reduce adverse events (AE) and hospitalizations among patients receiving OPAT, we implemented two initiatives: early care coordination phone calls (CCPC) and short-term ID follow-up appointments after OPAT initiation. The difficulties with hospital discharge are well described. Our efforts were designed to prevent these before they resulted in a hospital readmission.

Methods

In March 2019, we implemented an early CCPC after hospital discharge. The content of these conversations were chosen to identify or reduce potential reasons for readmission. Patients at potentially increased readmission risk were prioritized via specific criteria.

In October 2020, we aimed to shorten the interval between hospital discharge and ID follow-up. Historically, these had taken place at the end of OPAT therapy. By shortening this interval, we hoped to leverage ID expertise to identify potential rehospitalization during OPAT.

Results

For patients completing OPAT therapy in 2021, 82% received a CCPC. While the call content was clinically beneficial in many cases, the readmission rate was static.

For 2020, the median days until ID follow-up was 28 days and decreased to 16 days in 2022. The percentage of visits via telehealth increased from 15% in 2020 to 30% in 2022.

During 2015-2019, the readmission rate during OPAT was 19%. In 2022, UNC OPAT achieved a readmission rate of 14%. This was a 9% readmission rate for reasons unrelated to OPAT and a 5% readmission rate for OPAT-related causes.

The reduction in negative patient outcomes was not limited to readmissions. For patients completing OPAT in 2022, we saw a decrease in the rate of patients experiencing several AE’s.

Conclusion

We piloted two interventions to decrease hospitalizations during OPAT. While early CCPC had qualitative benefits, it did not correlate with a decrease in hospitalizations. Early ID appointments did correlate with a large reduction in on-treatment readmissions. These findings are consistent with numerous studies showing that early ID clinician involvement is linked to favorable outcomes for patients and health systems.

Disclosures

Asher J. Schranz, MD, MPH, WoltersKluwer: Honoraria
324. The Impact of Adding Staff-performed Telephone Call Reminders to Automated Call Reminders in An Infectious Diseases Outpatient Practice
Authors: Deeb Mery , Hadeel Zainah
Published: November 2023

Background

Automated text message service reminders have been shown to increase show-up rates in outpatient practices. Furthermore, automated telephone call service reminders also decrease the no-show rates; however, no-show rates have decreased even further when telephone call reminders were done by health-care personnel. We sought to demonstrate the benefit of telephone call reminders done by clinic staff when added to the automated call reminders on improving show-up rates.

Methods

This was a quality improvement project, which was conducted by performing prospective data collection from our outpatient Infectious Diseases (ID) practice between May 2021 and May 2022. The outpatient ID practice served a 359-bed community hospital. There were two providers in the ID practice. The automated call reminder system was utilized for all patients’ visits. Starting November 2021, our medical assistant performed a telephone call reminder one day prior to the visit. We compared the rates of no-shows between May 2021 to November 2021 to those between November 2021 and May 2022

Results

In a period of 6 months, there were 277 patients scheduled for outpatient visits. The automated call reminders were being utilized routinely. There were 18 patients (7.93%) who did not present to the scheduled appointments. In the following 7 months, after incorporating staff reminder calls, 21 of 321 scheduled patients (6.54%) did not show up to the visits. There was a decrease of 1.39 % in the no-show rate after the staff call implementation (P-value of 1). The No-show rate was different between the two providers. No-show rate decreased from 6.76% to 5.68% for provider A (P-value: 0.8), compared to a decrease from 10.13% to 7.59% for provider B (P-value: 0.6).

Conclusion

When done one day prior to the appointment, staff-performed call reminders did not improve show-up rates when added to the automated call reminders in the Infectious Diseases outpatient practice. Further studies are needed to evaluate the impact of adding staff-performed call reminders at a different interval from the scheduled appointments.

Disclosures

All Authors: No reported disclosures