Initial Antibiotic Choice Research Articles

Microbiological Profile of Periprosthetic Joint Infections: A Retrospective Analysis from North India

With the rise in total joint arthroplasties, prosthetic joint infections (PJIs) have become a significant complication, leading to high morbidity. The causative organisms of PJIs vary by region, and the rates of drug-resistant organisms are growing, thus complicating the initial empiric choice of antibiotics. This retrospective study analyzed records of patients with orthopedic implants and intraoperative tissue samples sent for sonication and culture at a tertiary care hospital in India. The most common organism was Staphylococcus aureus (14 out of 86 bacterial isolates, 16.3%), followed by Pseudomonas aeruginosa (12 out of 86, 13.9%), and both Staphylococcus epidermidis and Klebsiella pneumoniae (11 each out of 86, 12.8%). There was a high prevalence of multidrug-resistant organisms, and 35% of the gram-negative organisms were carbapenem resistant. Our study reveals that in our setting, PJIs are chiefly driven by multidrug resistant gram-negative bacteria.

Antibiotic therapy for skin and soft tissue infections. current algorithms

Antibiotic therapy for infectious lesions of the skin and soft tissues requires a careful approach to ensure the effectiveness of treatment and prevent the development of resistance. The article discusses the basic principles and algorithms of antibacterial treatment for skin and soft tissue infections, taking into account modern clinical recommendations and standards of pharmaco - therapy. The initial choice of antibiotic is of ten based on the t ypical pathogens associated with the infection (most commonly Staphylococcus aureus and Streptococcus pyogenes). If MRSA (methicillin-resistant Staphylococcus aureus) or other resistant microorganisms are suspected, they must be taken into account in the choice of initial therapy. A fter receiving the results of culture studies and determining the sensitivit y of microorganisms, therapy should be adjusted. It is essential to maintain the antibiotic concentration at a level sufficient to eliminate the infection and prevent recurrence. The choice of antibiotic should take into account the side effects and possible interactions with other drugs.

294 Does the Initial Antibiotic Choice Affect the Incidence of Post-Operative Collections in Paediatric Appendicitis?

Abstract Introduction In appendicitis, antibiotics are routinely commenced prior to consideration of operative management. The choice of initial regimen depends on local antimicrobial guidelines. The presence of resistant organisms risks development of post-operative collections. In our tertiary paediatric surgery unit, antimicrobial guidelines were changed in September 2022 to recommend co-amoxiclav instead of cefuroxime/metronidazole. This study compares incidence of post-operative collections before and after the policy change. Method Patients who underwent appendicectomy between September 2021 and October 2023 were identified and contemporaneous data collected. Patients who had initial surgery elsewhere, interval/incidental appendicectomies or penicillin allergy were excluded. Comparison was made between patients receiving cefuroxime/metronidazole (Group 1) or co-amoxiclav (Group 2). Results Over the 26-month period, there were 104 patients in Group 1 (after excluding 47) and 104 in Group 2 (after excluding 46). 4 (3.8%) developed collections in Group 1 versus 13 (12.5%) in Group 2. In Group 1, 2 (50%) were treated with antibiotics alone, 1 (25%) required drain insertion and 1 (25%) had a laparotomy. In Group 2, 7 (54%) were treated with antibiotics alone, 5 (38%) required drain insertion and 1 (8%) had a laparotomy. The relative risk of developing a post-operative collection was 3.3 (p=0.023) in Group 2 versus Group 1. Conclusions The change in antimicrobial policy resulted in a significant increase in post-operative collections in our unit. This provides evidence that a regimen of cefuroxime/metronidazole is more effective at preventing collections and we are liaising with our Microbiology department with a view to amend the guidelines.

Validation of an electronic algorithm to identify appropriate antibiotic use for community-acquired pneumonia in children

Background: Community-acquired pneumonia (CAP) is a common indication for antibiotic use in hospitalized children and is a key target for pediatric antimicrobial stewardship programs (ASPs). Building upon prior work, we developed and refined an electronic algorithm to identify children hospitalized with CAP and to evaluate the appropriateness of initial antibiotic choice and duration. Methods: We performed a cross-sectional study including children 6 months to 17 years hospitalized for CAP between January 1, 2019, and October 31, 2022, at a tertiary-care children’s hospital. CAP was defined electronically as an International Classification of Disease, Tenth Revision (ICD-10) code for pneumonia, a chest radiograph or chest computed tomography scan (CT) performed within 48 hours of admission, and systemic antibiotics administered within the first 48 hours of hospitalization and continued for at least 2 days. We applied the following exclusion criteria: patients transferred from another healthcare setting, those who died within 48 hours of hospitalization, children with complex chronic conditions, and those with intensive care unit stays >48 hours. Criteria for appropriate antibiotic choice and duration were defined based on established guidelines. Two physicians performed independent medical record reviews of 80 randomly selected patients (10% sample) to evaluate the performance of the electronic algorithm in (1) identifying patients treated for clinician-diagnosed CAP and (2) classifying antibiotic choice and duration as appropriate. A third physician resolved discrepancies. The electronic algorithm was compared to this medical record review, which served as the reference standard. Results: Of 80 children identified by the electronic algorithm, 79 (99%) were diagnosed with CAP based on medical record review. Antibiotic use was classified as the appropriate choice in 75 (94%) of 80 cases, and appropriate duration in 16 (20%) of 80 cases. The sensitivity of the electronic algorithm for identifying appropriate initial antibiotic choice was 94%; specificity could not be calculated because no events of inappropriate antibiotic choice were identified based on chart review. The sensitivity and specificity for determining appropriate duration were 88% and 97%, respectively (Table 1).Conclusions: The electronic algorithm accurately identified children hospitalized with CAP and demonstrated acceptable performance for identifying appropriate antibiotic choice and duration. Use of this electronic algorithm may improve the efficiency of stewardship activities and could facilitate alignment with updated accreditation standards. Future studies validating this algorithm at other centers are needed.Disclosures: None

Change in Gustilo-Anderson classification at time of surgery does not increase risk for surgical site infection in patients with open fractures: A secondary analysis of a multicenter, prospective randomized controlled trial.

Open fractures represent a major source of morbidity. Surgical site infections (SSIs) after open fractures are associated with a high rate of reoperations and hospitalizations, which are associated with a lower health-related quality of life. Early antibiotic delivery, typically chosen through an assessment of the size and contamination of the wound, has been shown to be an effective technique to reduce the risk of SSI in open fractures. The Gustilo-Anderson classification (GAC) was devised as a grading system of open fractures after a complete operative debridement of the wound had been undertaken but is commonly used preoperatively to help with the choice of initial antibiotics. Incorrect preoperative GAC, leading to less aggressive initial management, may influence the risk of SSI after open fracture. The objectives of this study were to determine (1) how often the GAC changed from the initial to definitive grading, (2) the injury and patient characteristics associated with increases and decreases of the GAC, and (3) whether a change in GAC was associated with an increased risk of SSI. Using data from the FLOW trial, a large multicenter randomized study, we used descriptive statistics to quantify how frequently the GAC changed from the initial to definitive grading. We used regression models to determine which injury and patient characteristics were associated with increases and decreases in GAC and whether a change in GAC was associated with SSI. Of the 2420 participants included, 305 participants had their preoperative GAC change (12.6%). The factors associated with upgrading the GAC (from preoperative score to the definitive assessment) included fracture sites other than the tibia, bone loss at presentation, width of wound, length of wound, and skin loss at presentation. However, initial misclassification of type III fractures as type II fractures was not associated with an increased risk of SSI (P = 0.14). When treating patients with open fracture wounds, surgeons should consider that 12% of all injuries may initially be misclassified when using the GAC, particularly fractures that have bone loss at presentation or those located in sites different than the tibia. However, even in misclassified fractures, it did not seem to increase the risk of SSI.

Impact of Appropriate Antibiotics within One Hour and Patients' Outcome: A Study and Review

Background: Rapid initiation of antibiotic treatment is considered crucial in patients with severe infections such as septic shock & bacterial meningitis. The initiation of treatment with inappropriate antimicrobial agents (in relation to the subsequently demonstrated sensitivity of the pathogen) as the initial empiric therapy may be the single most common cause of prolonged delays in the introduction of effective therapy. Only in 5% of cases were antibiotics administered within 1 hr of the decision making, in 47% of cases it took 1–2 hrs. Only in 33% of cases antibiotics were prescribed within one hour of decision making. In 95% of cases antibiotics were administered within one hour of prescription. Sepsis is the main cause of death in patients treated in intensive care units (ICU). Current sepsis guidelines recommend administration of antibiotics within one hour of ED triage. However, the quality of supporting evidence is moderate & studied have shown mixed results regarding the association between antibiotics administration timing & outcome in septic shock. Objective:The aim of this study was to assess whether timing of administration of appropriate antibiotics within one hour of admission to the ICU impact patient outcomes. Method: Timing of ICU admission noted from the patient’s ICU nursing chart when the first vital parameters are noted by the nurse. Timing of administration of 1st dose of antibiotic and antibiotic that is administered within the first one hour of admission is noted from ICU nursing chart (in minutes from the timing of ICU admission). Appropriateness of antibiotic is assessed from the microbiology culture and sensitivity result. Outcome measures is noted from the ICU database. Data is then recorded systemically in the data collection form and finally entered in the excel sheet for analysis. All the data is then analysed by statistician by appropriate statistical tests. Result: A total of 53 patients, including 63.2% in the sepsis group and 53.4% in the septic shock group received antibiotics within the first hour. 87.5 % patients who received antibiotic within one hour of admission were discharged compared to 81.0% patients who received first dose of antibiotic beyond one hour of admission. The commonest gram-negative organisms were E. coli and Klebsiella in both groups. The commonest antibiotic administered was Meropenem in both groups. All patients who received appropriate antibiotic were discharged compared with only 69.2% patients discharged whose antibiotic choice was inappropriate. Mortality was 30.8% in the group whose initial antibiotic choice was inappropriate while no patients died in the group where the patient received appropriate empirical therapy. Conclusion: In my study it is demonstrated that gram-negative bacteria remain the major pathogen in sepsis as has been demonstrated in most ICUs in India. When appropriateness as well as timing of administration were compared simultaneously, all patients who received appropriate antibiotic within one hour or more than one hour survived to discharge. However, if antibiotic choice was inappropriate, 25% patients died even if they received the antibiotics within one hour and if the first dose was delayed beyond the first hour, the mortality further increased to 40%. There was no significant difference in the mean of ICU length of stay and mean hospital length of stay of patients based on appropriateness of empirical antibiotic therapy.

Impact of Appropriate Antibiotics within One Hour and Patients' Outcome: A Study and Review

Background: Rapid initiation of antibiotic treatment is considered crucial in patients with severe infections such as septic shock & bacterial meningitis. The initiation of treatment with inappropriate antimicrobial agents (in relation to the subsequently demonstrated sensitivity of the pathogen) as the initial empiric therapy may be the single most common cause of prolonged delays in the introduction of effective therapy. Only in 5% of cases were antibiotics administered within 1 hr of the decision making, in 47% of cases it took 1-2 hrs. Only in 33% of cases antibiotics were prescribed within one hour of decision making. In 95% of cases antibiotics were administered within one hour of prescription. Sepsis is the main cause of death in patients treated in intensive care units (ICU). Current sepsis guidelines recommend administration of antibiotics within one hour of ED triage. However, the quality of supporting evidence is moderate & studied have shown mixed results regarding the association between antibiotics administration timing & outcome in septic shock. Objective: The aim of this study was to assess whether timing of administration of appropriate antibiotics within one hour of admission to the ICU impact patient outcomes. Method: Timing of ICU admission noted from the patient’s ICU nursing chart when the first vital parameters are noted by the nurse. Timing of administration of 1st dose of antibiotic and antibiotic that is administered within the first one hour of admission is noted from ICU nursing chart (in minutes from the timing of ICU admission). Appropriateness of antibiotic is assessed from the microbiology culture and sensitivity result. Outcome measures is noted from the ICU database. Data is then recorded systemically in the data collection form and finally entered in the excel sheet for analysis. All the data is then analysed by statistician by appropriate statistical tests. Result: A total of 53 patients, including 63.2% in the sepsis group and 53.4% in the septic shock group received antibiotics within the first hour. 87.5 % patients who received antibiotic within one hour of admission were discharged compared to 81.0% patients who received first dose of antibiotic beyond one hour of admission. The commonest gram-negative organisms were E. coli and Klebsiella in both groups. The commonest antibiotic administered was Meropenem in both groups. All patients who received appropriate antibiotic were discharged compared with only 69.2% patients discharged whose antibiotic choice was inappropriate. Mortality was 30.8% in the group whose initial antibiotic choice was inappropriate while no patients died in the group where the patient received appropriate empirical therapy. Conclusion: In my study it is demonstrated that gram-negative bacteria remain the major pathogen in sepsis as has been demonstrated in most ICUs in India. When appropriateness as well as timing of administration were compared simultaneously, all patients who received appropriate antibiotic within one hour or more than one hour survived to discharge. However, if antibiotic choice was inappropriate, 25% patients died even if they received the antibiotics within one hour and if the first dose was delayed beyond the first hour, the mortality further increased to 40%. There was no significant difference in the mean of ICU length of stay and mean hospital length of stay of patients based on appropriateness of empirical antibiotic therapy.

Urinary tract infection in children: A narrative review of clinical practice guidelines.

Urinary tract infection (UTI) has been a major burden on the community and the health-care systems all over the globe. It is the most common cause of bacterial infection in the pediatric age group, with an annual incidence of 3%. The aim of this study is to review and summarize all available guidelines on the diagnosis and management of children with UTI. This is a narrative review of the management of children with a UTI. All biomedical databases were searched, and any guidelines published from 2000 to 2022 were retrieved, reviewed, and evaluated to be included in the summary statements. The sections of the articles were formulated according to the availability of information in the included guidelines. UTI diagnoses are based on positive urine culture from a specimen of urine obtained through catheterization or suprapubic aspiration, and diagnoses cannot be established on the bases of urine collected from a bag. The criteria for diagnosing UTI are based on the presence of at least 50,000 colony-forming units per milliliter of a uropathogen. Upon confirmation of UTI, the clinician should instruct parents to seek rapid medical assessment (ideally within 48 h) of future febrile disease to ensure that frequent infections can be detected and treated immediately. The choice of therapy depends on several factors, including the age of the child, underlying medical problems, the severity of the disease, the ability to tolerate oral medications, and most importantly local patterns of uropathogens resistance. Initial antibiotic choice of treatment should be according to the sensitivity results or known pathogens patterns with comparable efficacy of oral and parenteral route, for 7 days to 14 days duration. Renal and bladder ultrasonography is the investigation of choice for febrile UTI, and voiding cystourethrography should not be performed routinely unless indicated. This review summarizes all the recommendations related to UTIs in the pediatric population. Due to the lack of appropriate data, further high-quality studies are required to improve the level and strength of recommendations in the future.

1789. Current Antibiotic Prescription Practices in Hospitalized Patients with Acute Myeloid Leukemia (AML) and Febrile Neutropenia of Unknown Origin (FN-FUO): Data from a Large Tertiary Community Hospital

Abstract Background Optimal duration of empiric antibiotic therapy in hospitalized patients with febrile neutropenia of unknown origin (FN-FUO) remains controversial. Emerging evidence suggests that early discontinuation of antibiotics at 48-72 hours of apyrexia is safe regardless of neutrophil count. However, in the U.S., the adoption of this and other antibiotic use practices in these patients remains unstandardized and understudied, particularly in community hospitals. In this pilot study, we sought to evaluate current antibiotic prescription practices in our large community hospital in admitted patients with AML and FN-FUO. Methods We conducted a retrospective cohort study from January 1st, 2020 to December 16th, 2021. All patients admitted with a diagnosis of AML and febrile neutropenia (FN) were screened and those with FN-FUO, defined as no microbiological growth on blood, respiratory or urine cultures at 48 hours of first fever were included. Data on initial antibiotic choices, use of vancomycin and its congruence with IDSA guidelines, mean days of therapy (DOT), mean days of “excess” therapy (DOET), defined by days of antibiotics after >72 hours of apyrexia and total DOET were obtained by medical record review and descriptive analysis was performed. Results A total of 65 patients with FN were screened. After screening, 27 patients met criteria for inclusion and data from their hospital stay was obtained (Table 1). Cefepime was the preferred choice of initial intravenous β-lactam in 85% of cases and piperacillin-tazobactam was used in the remainder of cases. Vancomycin was used initially in 55% of cases out of which its use was considered to be incongruent with IDSA guidelines in 25% of cases. The most common reason for IDSA incongruent use of vancomycin was lack of documentation for its use. Mean DOT was 10 and mean DOET was 3 (Table 2). In total, we identified 87 excess days of antibiotic therapy in this cohort. Conclusion Little is known about antibiotic prescription practices in high risk FN-FUO patients in community hospitals. Our findings highlight potential concrete antibiotic stewardship targets and shortening this knowledge gap may help guide the development of interventions that have been previously shown to improve clinical outcomes in this overall underrepresented population. Disclosures All Authors: No reported disclosures.

Effect of Gram Stain–Guided Initial Antibiotic Therapy on Clinical Response in Patients With Ventilator-Associated Pneumonia

Gram staining should provide immediate information for detecting causative pathogens. However, the effect of Gram staining on restricting the initial antibiotic choice has not been investigated in intensive care units (ICUs). To compare the clinical response to Gram stain-guided restrictive antibiotic therapy vs guideline-based broad-spectrum antibiotic treatment in patients with ventilator-associated pneumonia (VAP). This multicenter, open-label, noninferiority randomized clinical trial (Gram Stain-Guided Antibiotics Choice for VAP) was conducted in the ICUs of 12 tertiary referral hospitals in Japan from April 1, 2018, through May 31, 2020. Patients aged 15 years or older with a VAP diagnosis and a modified Clinical Pulmonary Infection Score of 5 or higher were included. The primary analysis was based on the per-protocol analysis population. Patients were randomized to Gram stain-guided antibiotic therapy or guideline-based antibiotic therapy (based on the 2016 Infectious Disease Society of America and American Thoracic Society clinical practice guidelines for VAP). The primary outcome was the clinical response rate; clinical response was defined as completion of antibiotic therapy within 14 days, improvement or lack of progression of baseline radiographic findings, resolution of signs and symptoms of pneumonia, and lack of antibiotic agent readministration, with a noninferiority margin of 20%. Secondary outcomes were the proportions of antipseudomonal agents and anti-methicillin-resistant Staphylococcus aureus (MRSA) agents as initial antibiotic therapies; 28-day mortality, ICU-free days, ventilator-free days; and adverse events. In total, 206 patients (median [IQR] age, 69 [54-78] years; 141 men [68.4%]) were randomized to the Gram stain-guided group (n = 103) or guideline-based group (n = 103). Clinical response occurred in 79 patients (76.7%) in the Gram stain-guided group and 74 patients (71.8%) in the guideline-based group (risk difference, 0.05; 95% CI, -0.07 to 0.17; P < .001 for noninferiority). Reduced use of antipseudomonal agents (30.1%; 95% CI, 21.5%-39.9%; P < .001) and anti-MRSA agents (38.8%; 95% CI, 29.4%-48.9%; P < .001) was observed in the Gram stain-guided group vs guideline-based group. The 28-day cumulative incidence of mortality was 13.6% (n = 14) in the Gram stain-guided group vs 17.5% (n = 18) in the guideline-based group (P = .39). Escalation of antibiotics according to culture results was performed in 7 patients (6.8%) in the Gram stain-guided group and 1 patient (1.0%) in the guideline-based group (P = .03). There were no significant differences between the groups in ICU-free days, ventilator-free days, and adverse events. Results of this trial showed that Gram stain-guided treatment was noninferior to guideline-based treatment and significantly reduced the use of broad-spectrum antibiotics in patients with VAP. Gram staining can potentially ameliorate the multidrug-resistant organisms in the critical care setting. ClinicalTrials.gov Identifier: NCT03506113.

Review Article : Treatment of Bacterial Meningitis at Educational Al Hussein Hospital and Review of Antibiotics from Global Sources

The outcome of bacterial meningitis critically depends on the rapid initiation of bactericidal antibiotic therapy and adequate management of septic shock. In the main laboratory at Educational Al Hussein Hospital. antibiotics have been used to have bacteriocidal effect on bacteria and the review of empirical and specialized antibiotics for meningitis from global sources. In bacterial meningitis, the choice of an optimum initial empirical antibiotic depends on the resistance patterns. who demonstrate the use of cephalosporin groups, penicillins wth amoxicillin, according to the age groups and the amount of dose , also treatment (specific antibiotic) according to the bacterial species that causes meningitis and explains the duration. If you do not respond to this treatment, there is an alternative, this method is specialized in the elimination of meningitis.

Performance and Impact on Initial Antibiotic Choice of Direct Identification of Pathogens from Pediatric Blood Culture Bottles Using an In-House MALDI-TOF MS Protocol.

ABSTRACTThe performance and early therapeutic impact of direct identification by matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-TOF; DIMT) on pediatric blood culture bottles using in-house-developed methods to obtain microbial pellets for spectrometric analysis have seldom been studied. During a 2-year period (June 2018 to May 2020), DIMT was performed on broths from positive pediatric blood culture bottles using an in-house-developed method. Organism identifications with a score of ≥1.6 were notified to treating clinicians. Therapeutic modifications that occurred after the communication of DIMT were reviewed through the electronic medical records. DIMT was performed on 530 pediatric positive blood culture bottles. Among 505 monomicrobial bottles, identifications from 298 (97.7%) deemed as bloodstream infections (BSI) and 189 (94.5%) as contaminations had DIMT notified to clinicians. All identifications were correct except for one Streptococcus mitis incorrectly reported as Streptococcus pneumoniae. Therapy modifications resulting from DIMT occurred in 27 (8.3%) patients with BSI. Deescalation from effective or ineffective broad-spectrum regimens occurred mainly in Enterococcus faecalis bacteremia, whereas appropriate escalation from an ineffective regimen with narrower spectrum occurred mainly in bacteremia caused by AmpC-β-lactamase-producing Enterobacterales. Escalation therapy was instituted significantly faster than deescalation therapy (median time, 0.75 versus 10.5 h [P = 0.01]). DIMT also enabled clinicians to confirm contamination in nearly one-half of patients with contaminated blood cultures. Our DIMT method applied to positive pediatric blood culture bottles demonstrated reliable performance for the rapid identification of pathogens. Our DIMT approach allowed therapeutic optimization in BSI, especially involving microorganisms with intrinsic antibiotic resistance, and was helpful in the early identification of likely contaminants.IMPORTANCE We demonstrate the performance and early impact on the antimicrobial management of bloodstream infections of an inexpensive, in-house preparation method for direct identification of bloodstream pathogens in pediatric blood culture bottles by matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry.

Poor clinical outcomes associated with suboptimal antibiotic treatment among older long-term care facility residents with urinary tract infection: a retrospective cohort study

BackgroundAntibiotic use is associated with several antibiotic-related harms in vulnerable, older long-term care (LTC) residents. Suboptimal antibiotic use may also be associated with harms but has not yet been investigated. The aim of this work was to compare rates of poor clinical outcomes among LTC residents with UTI receiving suboptimal versus optimal antibiotic treatment.MethodsWe conducted a retrospective cohort study among residents with an incident urinary tract infection (UTI) treated in Veterans Affairs LTC units (2013–2018). Potentially suboptimal antibiotic treatment was defined as use of a suboptimal initial antibiotic drug choice, dose frequency, and/or excessive treatment duration. The primary outcome was time to a composite measure of poor clinical outcome, defined as UTI recurrence, acute care hospitalization/emergency department visit, adverse drug event, Clostridioides difficile infection (CDI), or death within 30 days of antibiotic discontinuation. Shared frailty Cox proportional hazard regression models were used to compare the time-to-event between suboptimal and optimal treatment.ResultsAmong 19,701 LTC residents with an incident UTI, 64.6% received potentially suboptimal antibiotic treatment and 35.4% experienced a poor clinical outcome. In adjusted analyses, potentially suboptimal antibiotic treatment was associated with a small increased hazard of poor clinical outcome (aHR 1.06, 95% CI 1.01–1.11) as compared with optimal treatment, driven by an increased hazard of CDI (aHR 1.94, 95% CI 1.54–2.44).ConclusionIn this national cohort study, suboptimal antibiotic treatment was associated with a 6% increased risk of the composite measure of poor clinical outcomes, in particular, a 94% increased risk of CDI. Beyond the decision to use antibiotics, clinicians should also consider the potential harms of suboptimal treatment choices with regards to drug type, dose frequency, and duration used.

Knowledge, Attitude and Practice of Family Physicians on Antimicrobial Therapy for Acute Respiratory Tract Infections - A Study from Istanbul, Turkey

Aim: We aimed to investigate the knowledge, attitude, practice of family physicians regarding an-timicrobial therapy in acute respiratory tract infections. Methods: After receiving the ethics committee approval, the data were collected by online questionnaire from a phone application with 304 physicians. Questions about socio-demographic features and knowledge, attitude, and practices on antibiotics use were asked. Using SPSS, we did the statistical analyses with appropriate procedures. Results: Among the participants, 127 (41.8%) were specialists, and 177 (58.2%) were gen-eral practitioners. The specialists gave correct answers about tonsillopharyngitis and bron-chiolitis significantly more often than the general practitioners did. The antibiotic choices for acute otitis media were not in compliance with the guidelines of the Centers for Disease Control, and between the groups, there was no significant difference in terms of initial antibiotic choice. The self-reported antibiotic prescription rate was 25%. In 10%, the most common perceived reason for inappropriate antibiotic prescription was pressure from patients. Conclusion: There remains considerable misuse of antibiotics by primary care physicians for acute respiratory tract infections. Education of physicians and patients regarding acute respiratory tract infections may be needed to lower the rate of inappropriate antibiotic pre-scriptions. Keywords: public health practice, practice patterns, primary healthcare

89. Construction of an Electronic Algorithm to Efficiently Target Antimicrobial Stewardship Efforts for Adults Hospitalized with Community-acquired Pneumonia

BackgroundAlthough antibiotic stewardship programs (ASPs) have had success in curtailing inappropriate antibiotic use, they remain time- and labor-intensive. To expand the reach of ASPs, approaches to more efficiently target ASP efforts are urgently needed. We developed and validated an electronic algorithm to identify inappropriate antibiotic use in patients hospitalized with community-acquired pneumonia (CAP).MethodsWithin the Hospital of the University of Pennsylvania (HUP) and Penn Presbyterian Medical Center (PPMC), we used ICD-10 diagnostic codes to identify inpatient patient encounters for pneumonia between 3/15/17 – 3/14/18 for which patients received a systemic antibiotic in the first 48 hours of hospitalization. Exclusion criteria included transfer from another facility, intensive care unit admission or death in first 48 hours, immunocompromising condition, or specific comorbidities. We randomly selected 300 subjects (150-HUP, 150-PPMC). Inappropriateness of antibiotic use based on chart review served as the basis for assessment of the electronic algorithm which was constructed using only data in the electronic health record (EHR). Criteria for appropriate prescribing, choice of antibiotic, and duration of therapy were based on established hospital and IDSA guidelines.ResultsOf 300 subjects, median age was 60, 53% were female, and median hospital stay was 4.25 days. Of the 300 subjects, 237 (79%) were admitted to general medicine, hospitalist, family medicine, or geriatrics services. On chart review, 295 (98%) subjects were correctly diagnosed with CAP. Of these subjects, the choice of initial antibiotic(s) was appropriate in 263 (89%). Of these 263 subjects, 222 (84%) had an appropriate duration of therapy. Test characteristics of the EHR algorithm (compared to chart review) are noted in the Table.ConclusionAn electronic algorithm for identifying inappropriate prescribing, antibiotic choice, and duration is highly accurate for patients hospitalized for CAP. This algorithm could be used to efficiently target ASP initiatives. The impact of interventions based on this algorithm should be tested in future studies.Test Characteristics of Electronic Algorithm for Inappropriate Prescribing, Agent, and Duration Disclosures All Authors: No reported disclosures

151. An Electronic Algorithm to Better Target Antimicrobial Stewardship Program (ASP) Efforts for Children Hospitalized with Community-Acquired Pneumonia (CAP)

BackgroundPediatric antibiotic stewardship programs (ASPs) have been successful in decreasing inappropriate antibiotic use. However, they require considerable time and effort. Approaches to increase ASP efficiency are urgently needed. We developed and validated an electronic algorithm to identify inappropriate antibiotic use in children hospitalized with community-acquired pneumonia (CAP).MethodsAt Children’s Hospital of Philadelphia (CHOP), we used ICD-10 diagnostic codes to identify inpatient patient encounters for pneumonia between 3/15/17 – 3/14/18 for which patients received a systemic antibiotic in the first 48 hours of hospitalization. Exclusion criteria included transfer from another facility, intensive care unit admission or death in first 48 hours, immunocompromising condition, or specific comorbidities. We randomly selected 150 subjects. Inappropriate antibiotic use based on chart review served as the basis for assessment of the electronic algorithm which was constructed using only data in the electronic health record (EHR). Criteria for appropriate prescribing, choice of antibiotic, and duration of therapy were based on established CHOP and IDSA/PIDS guidelines.ResultsOf 148 eligible subjects, median age was 3.8, 48% were female, and 129 (86%) were admitted to a general pediatrics service. On chart review, 147 (99%) subjects were correctly diagnosed with CAP. Of these subjects, the choice of initial antibiotic(s) was appropriate in 133 (90%). Of the 147 subjects, 137 (93%) had an appropriate duration of therapy. Test characteristics of the EHR algorithm (compared to chart review) are noted in the Table.ConclusionIn pediatric patients hospitalized with CAP, the electronic algorithm for identifying inappropriate prescribing, antibiotic choice, and duration was highly accurate. This algorithm could have considerable utility in targeting ASP initiatives. The impact of interventions based on this algorithm should be tested in the futureTest Characteristics of Electronic Algorithm for Inappropriate Prescribing, Agent, and Duration Disclosures All Authors: No reported disclosures

1082. Characterization of Ceftriaxone-Resistant Viridans Streptococci Bacteremia Among Patients at a Comprehensive Cancer Center

BackgroundViridans streptococci (VS) are opportunistic oral commensals and a common cause of bacteremia, particularly in neutropenic patients. We sought to investigate the prevalence of ceftriaxone (CTX) resistance in VS blood isolates at our medical center among patients with cancer or treated with hematopoietic cell transplant (HCT), and to describe treatment and clinical course.MethodsIn this retrospective single center cohort study, we identified CTX-resistant (CTX-R) VS isolates among patients between January 2005 – June 2020. VS in blood cultures were identified using a combination of biochemicals and mass spectrometry. Susceptibility testing was performed by Kirby Bauer and E-Test. Demographic data, clinical outcomes, and antimicrobial use, including prophylactic, empiric treatment and definitive therapy choices were assessed through electronic medical record review.ResultsOf unique VS with sensitivities (n=693), 27 (3.9%) patients had confirmed CTX-R VS bacteremia over the 15-year period; the majority were S. mitis (23/27 [85%]). 17 (63%) were cancer center patients, of whom 15/17 (88%) had a known hematologic malignancy, 11 (65%) had undergone HCT, and 15 (88%) were neutropenic (absolute neutrophil count ≤500 cells/microliter). Of CTX-R strains, 15/17 (88%) had concomitant resistance to penicillin, erythromycin (12 [71%]), and levofloxacin (12 [71%]); all were sensitive to vancomycin. Most were on levofloxacin prophylaxis (11/17 [65%]) at the time of diagnosis. Initial empiric antibiotic choices primarily included cefepime, ceftazidime, or meropenem, with 16/17 (94%) receiving concomitant empiric vancomycin; 14/17 (82%) were de-escalated to vancomycin once sensitivities were obtained. 2/17 (12%) patients died within 30 days of CTX-R VS bacteremia. Despite increasing susceptibility testing among VS isolates, there did not appear to be an increase in the percentage of CTX-R over time.ConclusionVS is a common pathogen in neutropenic cancer patients treated with chemo and/or BMT, and multi-drug resistant CTX-R strains are of concern. In the modern era of ambulatory cancer care, prescribers must be cautious using ceftriaxone monotherapy in the absence of susceptibility information, particularly among patients with hematologic malignancies.Disclosures Steven A. Pergam, MD, MPH, Chimerix, Inc (Scientific Research Study Investigator)Global Life Technologies, Inc. (Research Grant or Support)Merck & Co. (Scientific Research Study Investigator)Sanofi-Aventis (Other Financial or Material Support, Participate in clinical trial sponsored by NIAID (U01-AI132004); vaccines for this trial are provided by Sanofi-Aventis)

Measuring Empiric Antibiotic Spectrum Patterns Across Space and Time

Background: Quantitative evaluation of antibiotic spectrum is an important, underutilized metric in measuring antibiotic use (AU) and may assist antimicrobial stewards in identifying targets and strategy for intervention. We evaluated the spectrum of initial antibiotic choices by hospital location, day of the week, and time of day to determine whether these factors may be associated with broad-spectrum antibiotic choices. Methods: We identified all admissions with antibiotic exposure in medical and surgical wards and critical care units in a tertiary academic medical center between July 1, 2014, and July 1, 2019. The antibiotic spectrum index (ASI), proposed by Gerber et al, is a numeric score based on the number of pathogens covered by a particular agent. We defined ASI for initial antibiotic choice as follows: ASI for each unique antibiotic administered within 24 hours of the first antibiotic administration was summed and assigned to the administration time of the first dose. We categorized time into 4 distinct categories: weekday days (Monday–Friday, 7 a.m.–7 p.m.), weekday nights, weekend days, and weekend nights. Weekend time began 7 p.m. Friday and ended 7 a.m. Monday. We constructed heatmaps stratified by hospital location. Mann-Whitney U tests were applied to evaluate differences in the distributions of ASI using weekday days as a reference. Results: Data included 90,455 unique antibiotic admissions with initial antibiotic starts in medical and surgical wards and critical care units. Patterns of ASI for initial antibiotic choice varied between unit locations and time (Figs. 1 and 2). Mean and median ASIs for initial antibiotic choices were higher for medical ward and medical ICUs than for surgical wards and surgical ICUs. Initial antibiotic choices had higher ASIs during overnight hours for all units except the surgical ICU. Notable differences in ASIs were identified between weekday and weekend prescribing for surgical units, whereas medical units demonstrated less extreme differences. Conclusion: We observed a “weekend effect” across hospital units; the most extreme occurred in surgical wards. This observation may be due to differences in patient volume and rounding patterns. For example, hospitalist and critical care units have 7-day schedules, whereas surgical wards are highly influenced by operating room schedules. Antimicrobial stewardship teams may use these data to identify strategies targeting the most opportune time and place to intervene on the spectrum of initial antibiotic choice.Funding: NoneDisclosures: None

Patterns and Predictors of UTI Treatment Practices in Nursing Homes

Background: Suspicion of urinary tract infection (UTI) is the most common justification for prescribing antibiotics in nursing homes. More than half of antibiotic prescriptions for treatment of UTI in nursing homes are either unnecessary or inappropriate. Achieving a better understanding of the factors that underlie UTI treatment decisions is necessary to improve the quality of antibiotic prescribing in nursing homes. An ongoing hybrid type 2 effectiveness-implementation cluster randomized trial of a recently developed nursing home UTI recognition and management tool kit provided us with an opportunity to explore the influence of organizational, clinical, and staff attributes on UTI antibiotic prescribing practices in nursing homes. Methods: Data on antibiotic starts for suspected UTIs were collected in 29 nursing homes over a 9-month period. Antibiotic practices evaluated included total antibiotic starts per 1,000 resident days, % antibiotic starts with treatment duration &gt;7 days, % antibiotic starts in which the initial antibiotic choice was a fluoroquinolone, and % antibiotic starts meeting UTI tool-kit criteria of appropriateness. Prior research and bivariate analyses were used to select clinical and organizational attributes as well as individual nursing staff-level retention rates for inclusion in a stepwise linear regression model for each antibiotic practice outcome. Results: In total, 602 UTI antibiotic events were evaluated. Four associations were identified for antibiotic starts including nursing home urine culture rate, ICP status, nonprofit and part-time LPN retention. Nursing homes with higher full-time LPN retention had a lower rate of antibiotic treatment duration &gt;7 days. Full-time CNAs and part-time LPNs retention and for-profit status was associated with the proportion of fluoroquinolone antibiotic starts. No attributes influenced the proportion of antibiotic starts meeting appropriateness criteria (Fig. 1). Urine culture rates are driving overall nursing home antibiotic prescribing. Conclusions: Urine culture practices was strongly associated with UTI treatment rates in nursing homes. A variety of organizational characteristics were also associated with UTI treatment rates as well as other UTI antibiotic prescribing practices. Some of these associations appear paradoxical but may reflect increasing resident acuity and increased capacity to standardize practices through organizational centralization.Funding: Support for the project provided by the Wisconsin Partnership Program.Disclosures: None

Association of sputum microbiome with clinical outcome of initial antibiotic treatment in hospitalized patients with acute exacerbations of COPD

Identification of risk factors for antibiotic treatment failure is urgently needed in acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Here we investigated the relationship between sputum microbiome and clinical outcome of choice of initial antibiotics during hospitalization of AECOPD patients. Sputum samples of 41 AECOPD patients and 26 healthy controls were collected from Guangzhou Medical University, China. Samples were processed for 16S rRNA gene-based microbiome profiling. Thirty patients recovered with initial antibiotic treatment (antibiotic success or AS), while 11 patients showed poor outcome (antibiotic failure or AF). Substantial differences in microbiome were observed in AF versus AS patients and healthy controls. There was significantly decreased alpha diversity and increased relative abundances of Pseudomonas, Achromobacter, Stenotrophomonas and Ralstonia in AF patients. Conversely, Prevotella, Peptostreptococcus, Leptotrichia and Selenomonas were depleted. The prevalence of Selenomonas was markedly reduced in AF versus AS patients (9.1 % versus 60.0 %, P = 0.004). The AF patients with similar microbiome profiles in general responded well to the same new antibiotics in the adjusted therapy, indicating sputum microbiome may help guide the adjustment of antibiotics. Random forest analysis identified five microbiome operational taxonomic units together with C-reactive protein, procalcitonin and blood neutrophil count showing best predictability for antibiotic treatment outcome (area under curve 0.885). Functional inference revealed an enrichment of microbial genes in xenobiotic metabolism and antimicrobial resistance in AF patients, whereas genes in DNA repair and amino acid metabolism were depleted. Sputum microbiome may determine the clinical outcome of initial antibiotic treatment and be considered in the risk management of antibiotics in AECOPD.