Culture data may help determine antibiotic administration options for nonoperative complicated appendicitis. Variability exists in treatment strategies, from solely using intravenous therapy, including outpatient parenteral antibiotic treatment (OPAT), to transitioning to oral (PO) antibiotics. We hypothesize that most patients have an oral antibiotic option based on culture results and that there is no increased rate of readmission due to treatment failure with oral antibiotics.

This was a single-center retrospective cohort study reviewing antibiotic treatment of pediatric patients treated with nonoperative management for complicated appendicitis with abscesses percutaneously drained by Interventional Radiology (IR). We compared case-mix demographic variables, choice and route of antibiotic therapy, culture data, and clinical outcomes between those who exclusively received parenteral antibiotics therapy (PAT) and those who were switched to oral therapy (PO).

We identified 54 cases of nonoperative complicated appendicitis who underwent IR abscess drainage from 2014 to 2019. Forty-five [83%] patients completed therapy with PAT and 9 with PO; forty-six of 54 patients (85%) patients had an oral antibiotic(s) option based on sensitivities. Readmissions and complications included 6 (11%) patients. Three (50%) patients were readmitted due to antibiotic treatment failure with worsening of abscess formation, 2 due to PICC (peripherally inserted central catheters) issues, and 1 due to a drug reaction.

Most patients with nonoperative complicated appendicitis can be transitioned to oral antibiotic options based on the culture susceptibility profiles.

To identify institution-specific risk factors for extended-spectrum beta-lactamase (ESBL) bloodstream infections (BSI) to develop and validate a risk assessment scoring tool that can be utilized for hospitalized patients.

Single-center, retrospective, case-control study.

Tertiary teaching hospital.

Hospitalized adult and pediatric patients with E. coli or Klebsiella spp. BSI were stratified based on ESBL production between August 2019 to July 2021. Exclusion criteria included patients < 28 days old, a positive blood culture resulting prior to admission/after discharge or a polymicrobial and/or carbapenem-resistant BSI.

Multivariable logistic regression assessed predictors of ESBL in a derivation cohort. Predictors were applied to a novel validation BSI cohort using area under the receiver-operator characteristics curve (ROC AUC) to assess the reliability of identifying patients likely to harbor ESBL at the time of organism identification.

A total of 238 patients in the derivation cohort met inclusion criteria stratified as ESBL (n = 68) or non-ESBL (n = 170). Multivariable logistic regression demonstrated diabetes, 30-day history of invasive procedure or antibiotic use, and/or history of ESBL as independent predictors of ESBL. After creation of an ESBL risk assessment tool, the results were applied to a validation cohort of 170 patients. This model displayed good calibration and discrimination with a strong predictive power (Hosmer-Lemeshow χ2= 4.66, p = 0.19; ROC AUC = 0.88, 95% CI = 0.7909 – 0.974).

A validated ESBL risk assessment tool reliably identified hospitalized patients likely to harbor ESBL E. coli or Klebsiella spp. BSI upon organism identification.

To investigate the use of rifampicin vials in Australian operating theaters (OT) to determine the method of administration and rationale for use.

Retrospective (2022 and 2023) OT usage data for rifampicin 600 mg vials were analyzed to compare trends in use between Australian hospitals and between jurisdictions. An audit of rifampicin vials used in OT during 2023 was conducted at a large tertiary hospital.

Fifty-nine of 248 hospitals (24%) contributing data to the National Antimicrobial Utilisation Surveillance Program recorded OT use of rifampicin vials during 2022 and 2023. Excluding hospitals with no usage, the median use was 7 vials/annum/per hospital (IQR: 2–32). A wide variation in use was seen between Australian states and territories. An audit of OT use in 2023 at a large tertiary hospital found poor documentation of topical use; in most cases, documentation was in the operation note only, with no documentation on the medication charts, medical notes, or the anesthetic record. Of 33 rifampicin vials used in 2023, documented topical use was identified for 10 individual patients only, 4 of whom had a confirmed Staphylococcus aureus infection (1 methicillin-resistant and 3 methicillin-susceptible).

Off-label, topical use of rifampicin during surgery is not uncommon in some Australian hospitals despite limited evidence of safety or efficacy. Given the potential for resistance, surgical use of rifampicin should be restricted to a named-patient basis, under the guidance of an infectious disease specialist/clinical microbiologist. Documentation of all medication use is recommended for patient safety.

Respiratory virus testing is routinely performed and ways to obtain specimens aside from a nasopharyngeal swab are needed for pandemic preparedness. The main objective is to validate a self-collected oral-nasal swab for the detection of Influenza and respiratory syncytial virus (RSV).

Diagnostic test validation of a self-collected oral nasal swab as compared to a provider-collected nasopharyngeal swab.

Emergency Department at Michael Garron Hospital.

Consecutive individuals who presented to the Emergency Department with a suspected viral upper respiratory tract infection were included if they self-collected an oral-nasal swab. Individuals testing positive for Influenza or RSV along with randomly selected participants who tested negative were eligible for inclusion.

All participants had the paired oral-nasal swab tested using a multiplex respiratory virus polymerase chain reaction for the three respiratory pathogens and compared to the nasopharyngeal swab.

48 individuals tested positive for Influenza, severe acute respiratory coronavirus virus 2 (SARS-CoV-2) or RSV along with 80 who tested negative. 110 were symptomatic with the median time from symptom onset to testing of 1 day (interquartile range 2–5 days). Using the clinical nasopharyngeal swab as the reference standard, the sensitivity was 0.75 (95% CI, 0.43–0.95) and specificity was 0.99 (95% CI, 0.93–1.00) for RSV, sensitivity is 0.67 (95% CI, 0.49–0.81) and specificity is 0.96 (95% CI, 0.89–0.99) for Influenza.

Multiplex testing with a self-collected oral-nasal swab for Influenza and RSV is not an acceptable substitute for a healthcare provider collected nasopharyngeal swab primarily due to suboptimal Influenza test characteristics.

Optimizing antibiotic prescribing for urinary tract infections (UTI) represents an opportunity for ambulatory antibiotic stewardship programs (ASPs). A pre-populated order panel for UTI was implemented in the Mayo Clinic Enterprise in May 2022. The order panel provides antibiotic regimens aligning with institutional guidelines according to patient characteristics, presence or absence of complicating features, and antimicrobial allergy status. We assessed impacts of panel use on prescribing practices for cystitis.

This retrospective cohort study of ambulatory encounters with a primary diagnosis of cystitis from May 16, 2022, to May 15, 2023, compared encounters in which the order panel was utilized to encounters managed without the panel. The primary outcome was concordance with institutional guidelines, including drug selection, dose/frequency, and duration. Secondary outcomes included rate of repeat healthcare contact for UTI within 14 days and total duration of therapy.

793 randomly selected patient encounters (397 panel and 396 non-panel) were included. Prescribing was guideline adherent in 79.3% and 64.9% (P < 0.001) of panel and non-panel encounters, respectively. There were more 3- and 5-day treatment courses in the panel cohort; however, inappropriate duration of therapy was the most common reason for non-concordance in both cohorts. There was no significant difference between groups in repeat 14-day healthcare contact for UTI (13.4% panel vs 11.1% no panel, P = 0.34).

Use of a pre-populated ambulatory order panel for the treatment of cystitis was associated with greater concordance with institutional guidelines, without adversely impacting repeat healthcare contact for UTI.

To compare outcomes of patients treated with low-dose (LD) versus high-dose (HD) trimethoprim-sulfamethoxazole (TMP-SMX) for Stenotrophomonas maltophilia pneumonia.

Retrospective cohort study.

Large academic tertiary-care center.

Hospitalized adult patients who received at least 8 mg/kg/day of TMP-SMX for at least 96 hours for treatment of S. maltophilia pneumonia between October 2012 and September 2022. Patients were included if they were diagnosed with pneumonia based on clinical and radiographic findings at the time of initiation of antibiotics.

The primary outcome was clinical success at the end of therapy among patients treated with LD (8–12 mg/kg/day) versus HD (>12 mg/kg/day) TMP-SMX. Secondary outcomes included microbiological success, all-cause and infection-related inpatient mortality, infection recurrence, development of TMP-SMX resistance, and incidence of acute kidney injury (AKI) and hyperkalemia.

95 patients were included (LD, n = 20 versus HD, n = 75). There was no difference in the primary outcome of clinical success at the end of therapy between groups (LD 57% versus HD 65%, P = 0.53). Secondary outcomes, including inpatient infection-related mortality (P = 0.56), AKI (P = 0.61), and hyperkalemia (P = 0.34) also did not differ significantly between the LD and HD groups.

No differences in clinical success or adverse events were observed in patients with S. maltophilia pneumonia treated with either LD or HD TMP-SMX.

A multidisciplinary beta-lactam allergy management program was implemented at our community medical center to facilitate allergy documentation, conduct penicillin skin testing (PST), and decrease non-beta-lactam (NBL) use. This study measures PST-associated antibiotic use and financial outcomes.

Cohort study.

Non-teaching, urban, community medical center within a multi-hospital health system.

Adult inpatients who underwent PST and received antibiotic therapy during a 5-year period at our facility.

Demographics, allergies, laboratory results, PST outcome, and antimicrobial regimens were assessed. Actual NBL days of therapy (DOT) were collected from the electronic medical record. NBL DOT that patients would have received without PST were modeled by forecasting the original regimen to end of inpatient treatment. Difference between actual and forecasted DOT was deemed DOT avoided (DOT-A) for each consecutively enrolled patient. The financial analysis evaluated cumulative NBL cost avoided. PST outcomes and average time from antibiotic initiation to PST were assessed.

The study included 600 patients who underwent PST an average of 3.7 days into treatment. The most common indication was acute bacterial skin and skin structure infections (23.9%). PST results were negative in 98% of patients. NBL DOT-A was 944.8/1000DT (8.8 DOT-A per intervention) accounting for an estimated cost savings of $206,500 ($344.10 per intervention), driven primarily by aztreonam avoidance.

This study highlights significant avoidance of NBL DOT in one of the largest identified cohort of inpatients undergoing PST. Associated cost avoidance contributes to the sustainability and longevity of the allergy management program.

Surgical site infection (SSI) following orthopedic surgery is a complication associated with morbidity and economic burden. Transmission of airborne bacteria that settle into surgical wounds constitutes a risk factor for SSIs. However, monitoring microbial contamination inside operating rooms with conventional methods is resource and time-consuming.

This study aimed to assess correlation between a biofluorescent particle counter (BFPC) and conventional air sampling, to enable real-time monitoring of airborne contamination. Additionally, the study aimed to analyze correlation between particles near the surgical site and particles 1 meter away, to evaluate the feasibility of distance-based measurements.

Correlation analysis was conducted to compare colony-forming units (CFU) collected using a Sartorius MD8 air sampler with biofluorescent viable particles detected by BioTrak 9510-BD, both positioned near the surgical site. Additionally, correlation between particle counts measured by AeroTrak 6510, positioned 1 meter away, and total particle counts measured by the BioTrak near the surgical site was evaluated. Sampling took place in two operating rooms: one with turbulent mixed airflow (TMA) and one with unidirectional airflow (UDAF).

Negligible to low correlation between biofluorescent particles and CFU was observed, both in UDAF (n = 100) and TMA (n = 22). However, strong correlation was found between BFPC and particle counter measurements of total numbers of particles (Rp = 0.634–0.769, P < .001).

While BFPCs offer real-time monitoring of airborne contamination, their predictive ability for CFU levels remains uncertain. Yet, the strong correlation between particles in the surgical site and particles measured 1 meter away suggests feasibility to conduct future studies with larger cohorts.

Artificial intelligence (AI) has the potential to enhance clinical decision-making, including in infectious diseases. By improving antimicrobial resistance prediction and optimizing antibiotic prescriptions, these technologies may support treatment strategies and address critical gaps in healthcare. This study evaluates the effectiveness of AI in guiding appropriate antibiotic prescriptions for infectious diseases through a systematic literature review.

We conducted a systematic review of studies evaluating AI (machine learning or large language models) used for guidance on prescribing appropriate antibiotics in infectious disease cases. Searches were performed in PubMed, CINAHL, Embase, Scopus, Web of Science, and Google Scholar for articles published up to October 25, 2024. Inclusion criteria focused on studies assessing the performance of AI in clinical practice, with outcomes related to antimicrobial management and decision-making.

Seventeen studies used machine learning as part of clinical decision support systems (CDSS). They improved prediction of antimicrobial resistance and optimized antimicrobial use. Six studies focused on large language models to guide antimicrobial therapy; they had higher prescribing error rates, patient safety risks, and needed precise prompts to ensure accurate responses.

AI, particularly machine learning integrated into CDSS, holds promise in enhancing clinical decision-making and improving antimicrobial management. However, large language models currently lack the reliability required for complex clinical applications. The indispensable role of infectious disease specialists remains critical for ensuring accurate, personalized, and safe treatment strategies. Rigorous validation and regular updates are essential before the successful integration of AI into clinical practice.

Antipseudomonal antibiotics are commonly prescribed for diabetic foot infections (DFI) at our institution despite a low local prevalence of Pseudomonas aeruginosa. A multidisciplinary team implemented a DFI electronic health record (EHR)-embedded treatment algorithm and order set.

This multi-center, quasi-experimental study evaluated adults on antibiotics admitted for DFI to vascular surgery or medical units pre- and post-implementation of an EHR-embedded treatment algorithm and order set. Exclusion criteria: duplicate patients, concomitant infection, transfer from an outside hospital. Primary endpoint: antipseudomonal use among included patients (DOT/1000 DFI days present). Secondary outcomes: empiric antipseudomonal use, length of stay, 30-day readmission, mortality, amputation, and Clostridioides difficile infection. Patient demographics, diagnostics, treatments, and outcomes were evaluated.

Two hundred ten patients were included with 70 patients included in each group. The post-algorithm group had lower antipseudomonal DOT/1000 DFI days present compared to the pre-intervention group (360 vs 503, P < 0.001). The post-order set group had the lowest antipseudomonal use (347 vs 503, P < 0.001). Empiric antipseudomonal use decreased from 85.7% pre-intervention to 72% post-algorithm and 68.5% post-order set. Collectively, 30-day mortality was < 5%. Amputation during and within 30 days of hospitalization was similar in the pre-intervention (48.6%), post-algorithm (30%), and post-order set (41.4%) groups. Methicillin-susceptible Staphylococcus aureus and Streptococcus spp. were most frequently isolated. Wound cultures were not collected in 24.3%, 22.9%, and 40% of the pre-intervention, post-algorithm, and post-order set group.

EHR-embedded clinical decision-making tools reduce antipseudomonal use for DFI treatment without increasing 30-day mortality or amputation.

In our study, we aim to compare the resistance profiles of Acinetobacter baumannii and Pseudomonas aeruginosa isolates from intensive care unit (ICU) patients before and during the COVID-19 pandemic.

The study involved adult patients monitored in the ICUs of a secondary-level hospital from January 2019 to December 2022. Isolates of A. baumannii and P. aeruginosa were obtained from blood, urine, and respiratory samples. Identification and antibiotic susceptibility tests were conducted using the disk diffusion method and the VITEK 2 system.

The average age of the patients was 61.3 ± 21.9 years (range: 18–95), with a majority of 1306 (51.6%) being male. During the pandemic, A. baumannii isolates showed a significant increase in resistance rates for several antibiotics compared to the pre-pandemic period: imipenem (96% vs 35.1%), amikacin (84.1% vs 14.4%), ciprofloxacin (96.9% vs 36.9%), trimethoprim-sulfamethoxazole (66.4% vs 27%), and ceftazidime (96.5% vs 33.3%) (all with P < .001). However, there was no significant change in colistin resistance rates in these isolates (0.9% vs 0%; P = .307). Similarly, Pseudomonas aeruginosa isolates exhibited significant increases in resistance rates during the pandemic compared to the pre-pandemic period: imipenem (51.5% vs 18.8%; P < .001), colistin (4.9% vs 0.6%; P = .009), amikacin (23.5% vs 4.4%; P < .001), ciprofloxacin (53.3% vs 13.8%; P < .001), and ceftazidime (39.2% vs 12.7%; P < .001).

Our results demonstrate a significant increase in antibiotic resistance levels in Acinetobacter and Pseudomonas strains associated with hospital-acquired infections or colonization during the COVID-19 pandemic.

Outbreaks of Pseudomonas aeruginosa infections have been linked to water-related sources. We describe the investigation of a suspected outbreak of five P. aeruginosa infections in pediatric oncology patients in 2021 that triggered a retrospective review and prospective monitoring of additional cases, environmental sampling, and bacterial genomic analysis.

Pediatric oncology center.

Medical records of patients with P. aeruginosa were reviewed and staff were interviewed to identify common exposures. Environmental samples were cultured for P. aeruginosa. Patient and environmental isolates underwent whole genome sequencing and core genome multi-locus sequence typing (cgMLST) and sequences were added to a previously existing library of P. aeruginosa clinical isolates collected in 2017 and onwards to determine strain relatedness.

During 2019–2022, 82 patients with 110 episodes of P. aeruginosa infections were identified and 132 isolates of P. aeruginosa were sequenced. Twenty-three environmental samples were collected, of which two grew P. aeruginosa in culture. CgMLST demonstrated four multi-patient isolate clusters but no genetic relatedness among the isolates from the patients in the suspected outbreak. Two sink-derived isolates from 2021 were genetically related to patient-derived isolates from 2018 and 2017.

Sequencing revealed there is no common source or linkage between the isolates of the suspected P. aeruginosa outbreak in 2021. However, it revealed genetic relatedness of previous patient strains to later strains collected from hospital sinks, suggesting persistent colonization of a reservoir with P. aeruginosa.