Clinical Standards Research Articles

[Expert consensus on clinical application management standards of endoscopic retrograde cholangiopancreatography in children (2024)].

[Expert consensus on clinical application management standards of endoscopic retrograde cholangiopancreatography in children (2024)].

Contactless assessment of heart rate in neonates within a clinical environment using imaging photoplethysmography

IntroductionIn neonatology, the accurate determination of vital parameters plays a pivotal role in monitoring critically ill newborns and premature infants, as well as aiding in disease diagnosis. In response to the limitations associated with contact-based measurement methods, substantial efforts have been directed toward developing contactless measurement techniques, particularly over the past decade.MethodsBuilding upon the insights gained from our pilot study, we realized a new investigation to assess the precision of our imaging photoplethysmography-based system within a clinical environment of the neonatal intermediate care unit. We conducted measurements in 20 preterm infants or newborns requiring therapeutic interventions. As a point of reference, we employed a conventional pulse oximeter. To analytically predict measurement artifacts, we analyzed the potential influence of confounding factors, such as motion artifacts, illumination fluctuations (under- and overexposure), and loss of region of interest prior to heart rate evaluation. This reduced the amount of data we evaluated for heart rate to 56.1% of its original volume.ResultsIn artifact-free time segments, the mean difference between the pulse oximetry and the imaging photoplethysmography-based system for 1 s sampling intervals resulted in −0.2 bpm (95% CI −0.8 to 0.4, LOA ± 12.2). For the clinical standard of 8 s averaging time, the mean difference resulted in −0.09 bpm (95% CI −0.7 to 0.6, LOA ± 10.1). These results match the medical standards.DiscussionWhile further research is needed to increase the range of measurable vital parameters and more diverse patient collectives need to be considered in the future, we could demonstrate very high accuracy for non-contact heart rate measurement in newborn infants in the clinical setting, provided artifacts are excluded. In particular, performing a priori signal assessment helps make clinical measurements safer by identifying unreliable readings.

Hypothermic Oxygenated Perfusion Improves Vascular and Contractile Function by Preserving Endothelial Nitric Oxide Production in Cardiac Grafts Obtained With Donation After Circulatory Death.

Cardiac donation after circulatory death is a promising option to increase graft availability. Graft preservation with 30 minutes of hypothermic oxygenated perfusion (HOPE) before normothermic machine perfusion may improve cardiac recovery as compared with cold static storage, the current clinical standard. We investigated the role of preserved nitric oxide synthase activity during HOPE on its beneficial effects. Using a rat model of donation after circulatory death, hearts underwent insitu ischemia (21 minutes), were explanted for a cold storage period (30 minutes), and then reperfused under normothermic conditions (60 minutes) with left ventricular loading. Three cold storage conditions were compared: cold static storage, HOPE, and HOPE with Nω-nitro-L-arginine methyl ester (nitric oxide synthase inhibitor). To evaluate potential confounding effects of high coronary flow during early reperfusion in HOPE hearts, bradykinin was administered to normalize coronary flow to HOPE levels in 2 additional groups (cold static storage and HOPE with Nω-nitro-L-arginine methyl ester). Cardiac recovery was significantly improved in HOPE versus cold static storage hearts, as determined by cardiac output, left ventricular work, contraction and relaxation rates, and coronary flow (P<0.05). Furthermore, HOPE attenuated postreperfusion calcium overload. Strikingly, the addition of Nω-nitro-L-arginine methyl ester during HOPE largely abolished its beneficial effects, even when early reperfusion coronary flow was normalized to HOPE levels. HOPE provides superior preservation of ventricular and vascular function compared with the current clinical standard. Importantly, HOPE's beneficial effects require preservation of nitric oxide synthase activity during the cold storage. Therefore, the application of HOPE before normothermic machine perfusion is a promising approach to optimize graft recovery in donation after circulatory death cardiac grafts.

Antimicrobial Resistance Profile of Uropathogenic Escherichia coli Isolated in Garaku, Keffi and Mararaban-Gurku Healthcentres, Nasarawa-West Senatorial District, Nasarawa State, Nigeria

Aims: This Study is aimed at studying the Antimicrobial Resistance profile of Uropathogenic Escherichia coli isolated in Garaku, Keffi and Mararaban-gurku Healthcentres, Nasarawa-West Senatorial District, Nasarawa State, Nigeria. Study Design: is a survey research. Place and Duration of Study: Department of Microbiology, Nasarawa State University, Keffi, between June, 2021 and January,2024. Methodology: 384 urine samples of patients with suspected cases of UTIs were collected and E. coli was isolated and identified using standard microbiological methods. Antimicrobial Susceptibility Testing of the isolates was carried out in accordance with the Clinical and Laboratory Standards Institute (CLSI) method. Results: The occurrence of E. coli was 92(24%). The isolates were generally more resistant to Ampicillin (AMP) with 75.0%.  Streptomycin (S) 70.7% Cefotaxime (CTX) 68.5% but less resistant to Ciprofloxacin (9.8%) followed by Gentamicin 17.4%. The commonest resistance phenotype was AMC-AMP-CAZ-CTX-S-SXT (5.4%). Most of the isolates showed multiple antibiotic resistance (MAR) Index of above 0.2 with the commonest MAR Index at GHK, GHG and MCM-g of 0.7(21.4%), 0.4(28.0%) and 0.3(23.1%) respectively. The antibiotics resistant E. coli isolates were grouped into different categories of antibiotic resistance namely: Non Multiple Drug Resistance (NMDR); Excessive Drug Resistance (XDR); Multiple Drug Resistance (MDR) and Pan Drug Resistance (PDR). The occurrence of classes of antibiotic resistance was of the orderMDR75(81.5%) ˃ NMDR9(9.8%) ˃XDR7(7.6%) &gt; PDR 1(1.1%). Conclusion: with the results from this research, E. coli being non susceptible to many antimicrobials is a clear indication that, prescription of these antimicrobials by physicians and usage by patients must be done with diligence and utmost care and vigorous campaign by stakeholders must be step up to bring to the barest minimum incidences of Antimicrobial resistance.

Radiotherapy combined with anti-PD-1 and TKI for primary cardiac angiosarcoma considering the joint assessment of TLSs and PD-L1: a case report

BackgroundPrimary cardiac angiosarcoma(PCA) has a low incidence rate and poor prognosis. Currently, no unified clinical treatment standards are available.Case presentationWe report the case of a 48-year-old man presenting chest tightness, breathlessness, and dyspnea. Imaging and postoperative histopathologic studies confirmed PCA and that the tumor had invaded the entire right atrium. The patient developed progressive disease (PD) during postoperative radiotherapy. We used immunotherapy combined with targeted therapy based on the results of molecular profile and evaluation of tertiary lymphoid structures (TLSs) and programmed cell death-ligand 1 (PD-L1). After treatment, the metastatic lymph nodes of the patient were reduced to a certain extent, indicating that combination therapy was effective.ConclusionTo the best of our knowledge, this is the first report of radiotherapy combined with anti-PD-1 and tyrosine kinase inhibitors(TKI) for PCA. In addition, this is the first report on immunotherapy for PCA based on new evaluation methods, including TLSs, PD-L1, and genomic profile.

Photonics-powered augmented reality skin electronics for proactive healthcare: multifaceted opportunities.

Rapid technological advancements have created opportunities for new solutions in various industries, including healthcare. One exciting new direction in this field of innovation is the combination of skin-based technologies and augmented reality (AR). These dermatological devices allow for the continuous and non-invasive measurement of vital signs and biomarkers, enabling the real-time diagnosis of anomalies, which have applications in telemedicine, oncology, dermatology, and early diagnostics. Despite its many potential benefits, there is a substantial information vacuum regarding using flexible photonics in conjunction with augmented reality for medical purposes. This review explores the current state of dermal augmented reality and flexible optics in skin-conforming sensing platforms by examining the obstacles faced thus far, including technical hurdles, demanding clinical validation standards, and problems with user acceptance. Our main areas of interest are skills, chiroptical properties, and health platform applications, such as optogenetic pixels, spectroscopic imagers, and optical biosensors. My skin-enhanced spherical dichroism and powerful spherically polarized light enable thorough physical inspection with these augmented reality devices: diabetic tracking, skin cancer diagnosis, and cardiovascular illness: preventative medicine, namely blood pressure screening. We demonstrate how to accomplish early prevention using case studies and emergency detection. Finally, it addresses real-world obstacles that hinder fully realizing these materials' extraordinary potential in advancing proactive and preventative personalized medicine, including technical constraints, clinical validation gaps, and barriers to widespread adoption.

Learning from conect4children: A Collaborative Approach towards Standardisation of Disease-Specific Paediatric Research Data

The conect4children (c4c) initiative was established to facilitate the development of new drugs and other therapies for paediatric patients. It is widely recognised that there are not enough medicines tested for all relevant ages of the paediatric population. To overcome this, it is imperative that clinical data from different sources are interoperable and can be pooled for larger post hoc studies. c4c has collaborated with the Clinical Data Interchange Standards Consortium (CDISC) to develop cross-cutting data resources that build on existing CDISC standards in an effort to standardise paediatric data. The natural next step was an extension to disease-specific data items. c4c brought together several existing initiatives and resources relevant to disease-specific data and analysed their use for standardising disease-specific data in clinical trials. Several case studies that combined disease-specific data from multiple trials have demonstrated the need for disease-specific data standardisation. We identified three relevant initiatives. These include European Reference Networks, European Joint Programme on Rare Diseases, and Pistoia Alliance. Other resources reviewed were National Cancer Institute Enterprise Vocabulary Services, CDISC standards, pharmaceutical company-specific data dictionaries, Human Phenotype Ontology, Phenopackets, Unified Registry for Inherited Metabolic Disorders, Orphacodes, Rare Disease Cures Accelerator-Data and Analytics Platform (RDCA-DAP), and Observational Medical Outcomes Partnership. The collaborative partners associated with these resources were also reviewed briefly. A plan of action focussed on collaboration was generated for standardising disease-specific paediatric clinical trial data. A paediatric data standards multistakeholder and multi-project user group was established to guide the remaining actions—FAIRification of metadata, a Phenopackets pilot with RDCA-DAP, applying Orphacodes to case report forms of clinical trials, introducing CDISC standards into European Reference Networks, testing of the CDISC Pediatric User Guide using data from the mentioned resources and organisation of further workshops and educational materials.

BACTERIOLOGICAL PROFILE OF CLINICALLY SUSPECTED SEPTICEMIA AMONG NEONATES AND THE ANTIBIOTIC SUSCEPTIBILITY PATTERN OF THEIR ISOLATES: A CROSS-SECTIONAL STUDY IN A TERTIARY CARE HOSPITAL OF JHARKHAND

Objectives: Neonatal septicemia is a generalized bacterial infection that occurs during the first 4 weeks of life and is one of the four primary causes of neonatal mortality and morbidity in India. This study aims to determine the bacteriological profile and antibiotic sensitivity patterns of isolates from blood cultures of suspected septicemic neonates in a tertiary care hospital. Methods: Two hundred and twenty-eight blood samples were collected and processed from patients in accordance with standard protocol. The antibiotic susceptibility of the isolates was determined by the disk diffusion method according to Clinical and Laboratory Standards Institute recommendations. Results: Blood culture results were positive in 44.7% of the patients. Late-onset sepsis was present in 53.92%, and early-onset sepsis was observed in 46.08% of the cases. The best overall sensitivity among Gram-negative isolates was to Amikacin, followed by Gentamycin and Meropenem. Gram-positive isolates had sensitivity to Chloramphenicol, tetracycline, Linezolid, Tetracycline, Vancomycin, and Piperacillin. Conclusion: The most common causes of newborn sepsis in this study were Gram-negative organisms (Klebsiella pneumoniae, Escherichia coli, and Citrobacter freundii) and Gram-positive organisms (Staphylococcus aureus), the majority of which are antibiotic-resistant.

Fine Modeling and Mechanical Analysis of Human Lumbar Spine

This paper has created a skeletal model of the human lumbar spine and proved its effectiveness. Simulated scenarios when the human body is moving, including forward bending, backward extension, left bending, and left rotation. Compare range of motion, vertebral displacement, annulus fibrosus displacement, endplate displacement, nucleus pulposus displacement, annulus fibrosus stress, endplate stress, nucleus pulposus stress, and cortical bone stress. The model of this study was based on anatomical principles for detailed drawing of the human lumbar spine. ROMs under different physiological motions including flexion, extension, and lateral bending with 300N preload and 3.75N·m moment were measured under the normal finite element model. The degrees of flexion of L1-S1 were 17.204°. The degrees of extension of L1-S1 were 13.959°. The degrees of lateral bending of L1-S1 were 10.326°, axial rotation were 6. 466°. The maximum stress for intervertebral disc flexion is 1.4285MPa. The maximum stress of the extension intervertebral disc is 1.1296MPa. The maximum stress of the intervertebral disc with lateral bending is 1.7589MPa. The maximum stress of the axial rotating intervertebral disc is 1. 1698MPa. After comparing with classical literature, the model of this study meets clinical research standards and may be a good choice for clinical surgical analysis.

Uncommon pathogen misidentification of Herbaspirillum huttiense as Burkholderia cepacia in bacteremia: a case report.

Herbaspirillum huttiense is an opportunistic pathogen associated with rare cases of bacteremia. In this case report, H huttiense was isolated from blood samples collected from an intravenous catheter (incubated for 20.8 hours) and a peripheral vein (incubated for 14.16 hours) of a lung adenocarcinoma patient. Positive blood culture bottles were subjected to smear preparation, and Gram staining and microscopic examination revealed the presence of gram-negative rods in both aerobic bottles. We used the VITEK MS automatic microbial mass spectrometry system, VITEK 2 Compact automatic microbial analysis system, and high-throughput nucleic acid sequencing for accurate identification of the isolate. It is noteworthy that although the VITEK 2 Compact identified the isolate as Burkholderia cepacia, confirmation through VITEK MS mass spectrometry and 16S ribosomal DNA (rDNA) sequencing identified it as H huttiense. Subsequently, antimicrobial susceptibility testing was performed using the broth microdilution method, following the guidelines for nonfermenting gram-negative bacilli provided by the Clinical and Laboratory Standards Institute. This case highlights the possibility of misidentification of H huttiense as B cepacia by VITEK 2 Compact in certain situations, emphasizing the importance of considering uncommon pathogens, such as H huttiense, in the context of bacteremia in cancer patients.

Antimicrobial Resistance Patterns of Urine Culture in Tertiary Care Teaching Hospital Islamabad, Pakistan

Background: Urine cultures are performed in laboratories to identify any bacteria or other microorganisms present in urine samples. The purpose of this study was to investigate the microorganisms growing resistant to antibiotics in the urine culture and their antibiotics susceptibility testing. Methods: For this investigation, the Microbiology Department's hospital management information systems records provided the culture and sensitivity data of the uropathogens found in urine samples. Urine samples collected midstream were prepared for microscopy and culture, and the organisms were identified using globally accepted methods. The Kirby-Bauer disk diffusion method was used to determine antibiotic susceptibility in accordance with hospital clinical and laboratory standards as well as international protocols. In this investigation, the information and data were assessed using descriptive statistics. Results: A total number of 207 urine culture data were extracted from the hospital management information system records of which, 116 samples showed positive bacterial growth. Candida had positive growth in 16.4%. Out of positive samples gender-wise, females were in the majority 66.4% and males were 33.6%. Escherichia coli bacteria frequently isolated in positive samples 58/116 (50%), whereas, Enterococcus spp were positive in 17 patients out of 116 (14.7 %). Gram-negative rods were positive in 16 patients out of 116 (13.8%), Klebsiella spp were positive in 4 patients out of 116(3.4%) and Pseudomonas aeruginosa were least positive in only 2 patients out of 116 positive samples (1.7 %).    Conclusion: In our study according to gender distribution female frequency was higher than males. Escherichia coli bacteria were the most common isolate in positive samples, whereas, Enterococcus spp were observed. Vancomycin was most sensitive in all urine cultures against all organisms and Erythromycin was most resistant in urine culture. Antimicrobial resistance is a serious subject on national and international levels that needs continued surveillance and resolute management.

How New Regulation of Laboratory-Developed Antimicrobial Susceptibility Tests Will Affect Infectious Diseases Clinical Practice.

Antimicrobial resistance (AMR) affects 2.8 million Americans annually. AMR is identified through antimicrobial susceptibility testing (AST), but current and proposed regulatory policies from the United States Food and Drug Administration (FDA) jeopardize the future availability of AST for many microorganisms. Devices that perform AST must be cleared by the FDA using their susceptibility test interpretive criteria, also known as breakpoints. The FDA list of breakpoints is relatively short. Today, laboratories supplement FDA breakpoints using breakpoints published by the Clinical and Laboratory Standards Institute, using legacy devices and laboratory-developed tests (LDTs). FDA proposes to regulate LDTs, and with no FDA breakpoints for many drug-bug combinations, the risk is loss of AST for key clinical indications and stifling innovation in technology development. Effective solutions require collaboration between manufacturers, infectious diseases clinicians, pharmacists, laboratories, and the FDA.

PmWebSpec: An Application to Create and Manage CDISC-Compliant Pharmacometric Analysis Dataset Specifications

A well-documented pharmacometric (PMx) analysis dataset specification ensures consistency in derivations of the variables, naming conventions, traceability to the source data, and reproducibility of the analysis dataset. Lack of standards in creating the dataset specification can lead to poor quality analysis datasets, negatively impacting the quality of the PMx analysis. Standardization of the dataset specification within an individual organization helps address some of these inconsistencies. The recent introduction of the Clinical Data Interchange Standards Consortium (CDISC) Analysis Data Model (ADaM) Population Pharmacokinetic (popPK) Implementation Guide (IG) further promotes industry-wide standards by providing guidelines for the basic data structure of popPK analysis datasets. However, manual implementation of the standards can be labor intensive and error-prone. Hence, there is still a need to automate the implementation of these standards. In this paper, we present PmWebSpec, an easily deployable web-based application to facilitate the creation and management of CDISC-compliant PMx analysis dataset specifications. We describe the application of this tool through examples and highlight its key features including pre-populated dataset specifications, built-in checks to enforce standards, and generation of an electronic Common Technical Document (eCTD)-compliant data definition file. The application increases efficiency, quality and semi-automates PMx analysis dataset, and specification creation and has been well accepted by pharmacometricians and programmers internally. The success of this application suggests its potential for broader usage across the PMx community.Graphical

Analysis of Serum Free Thyroxine Concentrations in Healthy Term Neonates Underlines Need for Local and Laboratory-Specific Reference Interval: A Systematic Review and Meta-Analysis of Individual Participant Data.

Background: Initial evaluation of the hypothalamus-pituitary-thyroid axis is done by measuring serum free thyroxine (fT4) and thyrotropin concentrations. For correct interpretation of these measurements, reliable age-specific reference intervals (RIs) are fundamental. Since neonatal fT4 RIs conforming to the Clinical and Laboratory Standards Institute guidelines are not available for all assays, we set out to create literature-based uniform age-specific neonatal fT4 RIs that may be used for every assay. Methods: For meta-analysis of individual participant fT4 concentrations, we systematically searched MEDLINE and Embase (search date December 6, 2023; PROSPERO registration CRD42016041871). We searched for studies reporting fT4 concentrations in healthy term newborns aged 2-27 days, born to mothers without thyroid disease in iodine-sufficient regions. Authors were invited to supply data. Due to standardization differences between assays, data could not be combined for meta-analysis directly, and we attempted to normalize the data using two distinct methods. Results: We obtained 4206 fT4 concentrations from 20 studies that used 13 different assays from 6 manufacturers. First, we set out to normalize fT4 data using the mean and standard deviation of (assay-specific) adult RIs. fT4 concentrations were transformed into Z-scores, assuming a normal distribution. Using a linear mixed-effects model (LMM), we still found a significant difference between fT4 concentration across studies (p < 0.001), after this normalization. As a second approach, we normalized the fT4 concentrations using data from a method/assay comparison study. We used the relationship between the Cobas assay and the other assays as a reference point to convert all values to Cobas values. However, this method also failed to produce consistent results, with significant differences between the normalized data (LMM p < 0.001). Conclusions: We conclude that our attempts at normalizing fT4 assay results were unsuccessful. Confounders related to our unsuccessful analysis may be assay related and/or biological. These findings have significant implications for patient care, since relying on RIs from literature may result in erroneous interpretation of results. Therefore, we strongly recommend to establish local RIs for accurate interpretation of serum fT4 concentrations in neonates.

Evaluation of three protocols for direct susceptibility testing for Gram-negative rods from flagged positive blood culture bottles.

Bloodstream infections are associated with high mortality that can be reduced by targeted antibiotic therapy in the early stages of infection. Direct antibiotic susceptibility testing (AST) from flagged positive blood cultures may facilitate the administration of early effective antimicrobials much before the routine AST. Clinical and Laboratory Standards Institute-recommended direct AST can be performed with a limited number of antibiotic disks only. On the other hand, using an automated system for direct AST will not only allow effective laboratory workflow with reduced turnaround time but also provide the minimum inhibitory concentration values of tested antibiotics. However, using expensive automated systems for direct AST may not be feasible for resource-limited laboratories. Therefore, in this study, we aimed to evaluate the CLSI-recommended method and two other direct AST protocols (one with an automated system and the other with disk diffusion) for Gram-negative rods from flagged positive blood cultures.

3.0T magnetic resonance imaging-based hip bone models for femoroacetabular impingement syndrome are equivalent to computed tomography-based models.

This study aimed to compare three-dimensional (3D) proximal femoral and acetabular surface models generated from 3.0T magnetic resonance imaging (MRI) to the clinical gold standard of computed tomography (CT). Ten intact fresh-frozen cadaveric hips underwent CT and 3.0T MRI scans. The CT- and MRI-based segmented models were superimposed using a validated 3D-3D registration volume-merge method to compare them. The least surface-to-surface distance between the models was calculated by a point-to-surface calculation algorithm using a custom-written program. The variables of interest were the signed and absolute surface-to-surface distance between the paired bone models. One-sample t-tests were performed using a signed and absolute test value of 0.16 mm and 0.37 mm, respectively, based on a previous study that validated 1.5T MRI bone models by comparison with CT bone models. For the femur, the average signed and absolute surface-to-surface distance was 0.18 ± 0.09 mm and 0.30 ± 0.06 mm, respectively. There was no difference in the signed surface-to-surface distance and the 0.16 mm test value (t = 0.650, p = 0.532). However, the absolute surface-to-surface difference was less than the 0.37 mm test value (t = -4.025, p = 0.003). For the acetabulum, the average signed and absolute surface-to-surface distance was -0.06 ± 0.06 mm and 0.26 ± 0.04 mm, respectively. The signed (t = -12.569, p < 0.001) and absolute (t = -8.688, p < 0.001) surface-to-surface difference were less than the 0.16 mm and 0.37 mm test values, respectively. Our data shows that 3.0T MRI bone models are more similar to CT bone models than previously validated 1.5T MRI bone models. This is likely due to the higher resolution of the 3T data.

121 Impacting Clinical Research Nurses’ Intent to Stay Through Mentoring

OBJECTIVES/GOALS: Clinical Issue/ Practice Problem: A high turnover rate for research nurses was identified between 2017-2022 in the clinical research center at an urban Midwest academic health center. Inexperienced staff and high turnover are barriers to maintaining high-quality research integrity, efficacy, and safety for research projects and participants. METHODS/STUDY POPULATION: Project Implementation: A formal mentorship program was developed based on a curriculum from the International Association of Clinical Research Nursing Scope and Standards of Practice. The six-week project was implemented for research nurses with less than 2 years of experience. Mentees were paired with senior research nurses and met one-on-one weekly. Mentees completed the Anticipated Turnover Scale (ATS) survey in week 1 and week 6. All program participants completed a final evaluation survey. RESULTS/ANTICIPATED RESULTS: Outcomes: There was a one-point average reduction in pre- and post-ATS survey scores. This result supports the theory that mentees were less likely to leave their research role after a formal mentorship program. Qualitative results from the final evaluation survey demonstrate the program had a positive impact and benefits for both the mentees and the mentors. DISCUSSION/SIGNIFICANCE: Clinical Implications: By decreasing turnover rates, a highly competent and knowledgeable research nursing staff is attained to ensure appropriate nursing action and safety profiles for novel therapies.

Comparison of broth microdilution and E-test for susceptibility of MRSA to vancomycin

Introduction: Healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) developed soon after the introduction of methicillin. These bacteria have shown resistance to multiple drugs and therefore vancomycin became the antibiotic of choice for treatment of MRSA infections. Vancomycin is a bactericidal antibiotic that acts by inhibiting bacterial cell wall synthesis. This study aimed to compare broth microdilution (BMD) and E-test in determining vancomycin minimum inhibitory concentration (MIC) against MRSA.Methods: A total of 30 clinical isolates of MRSA were acquired from Colombo South Teaching Hospital, Sri Lanka. These MRSA strains were identified by cefoxitin disk diffusion and the vancomycin MIC was determined through BMD and E-test. The Kruskal-Wallis test was applied to test if the samples originated from the same distribution with post hoc determination of the correlation between methods using the Mann-Whitney U test.Results: All 30 MRSA isolates were 100% vancomycin susceptible (≤2 μg/mL) irrespective of methodology, according to the Clinical and Laboratory Standards Institute (CLSI) established breakpoints. However, the E-test MIC values were 1 to 2 dilutions higher than those of BMD. A statistically significant difference between vancomycin MICs of BMD and E-test (p = &lt;0.00001) was calculated which indicated a difference in accuracy.Conclusion: Due to cost, convenience, and the ability to detect vancomycin intermediate Staphylococcus aureus (VISA), exploring the possibility of using E-test as an alternative to BMD is worthwhile.

469 Diverse Role of blaCTX-M and Porins in Mediating Ertapenem Resistance Among Carbapenem Resistant Enterobacterales

OBJECTIVES/GOALS: In this study, we aim to report the role of porins and blaCTX-M β-lactamases among Escherichia coli and Klebsiella pneumoniae, focusing on emerging carbapenem resistant Enterobacterales (CRE) subtypes, including non-carbapenemase producing Enterobacterales (NCPE) and ertapenem-resistant but meropenem-susceptible (ErMs) strains. METHODS/STUDY POPULATION: Whole genome sequencing was conducted on 76 carbapenem-resistant isolates across 5 hospitals in San Antonio, U.S. Among these, NCP isolates accounted for the majority of CRE (41/76). Identification and antimicrobial susceptibility testing (AST) results were collected from the clinical charts. Repeat speciation was determined through whole genome sequencing (WGS) analysis and repeat AST, performed with microdilution or ETEST®. Minimum inhibitory concentrations (MIC) were consistent with Clinical and Laboratory Standards Institute (CLSI M100, ED33). WGS and qPCR were used to characterize the resistome of all clinical CRE subtypes, while western blotting and liquid chromatography with tandem mass spectrometry (LC-MS-MS) were used to determine porin expression and carbapenem hydrolysis, respectively. RESULTS/ANTICIPATED RESULTS: blaCTX-Mwas found to be most prevalent among NCP isolates (p = 0.02). LC-MS/MS analysis of carbapenem hydrolysis revealed that blaCTX-M-mediated carbapenem hydrolysis, indicating the need to reappraise the term, “non-carbapenemase (NCP)®” for quantitatively uncharacterized CRE strains harboring blaCTX-M. Susceptibility results showed that 56% of all NCPE isolates had an ErMs phenotype (NCPE vs. CPE, p &lt; 0.001), with E. coli driving the phenotype (E. coli vs. K. pneumoniae, p &lt; 0.001). ErMs strains carrying blaCTX-M, had 4-fold more copies of blaCTX-M than ceftriaxone-resistant but ertapenem-susceptible isolates (3.7 v. 0.9, p &lt; 0.001). Immunoblot analysis demonstrated the absence of OmpC expression in NCP-ErMs E. coli, with 92% of strains lacking full contig coverage ofompC. DISCUSSION/SIGNIFICANCE: Overall, this work provides evidence of a collaborative effort between blaCTX-M and OmpC in NCP strains that confer resistance to ertapenem but not meropenem. Clinically, CRE subtypes are not readily appreciated, potentially leading to mismanagement of CRE infected patients. A greater focus on optimal treatments for CRE subtypes is needed.

Antibiotic Susceptibility and Biofilm Production among Coagulase Negative Staphylococci Isolated from Clinical Samples at Tertiary Care Hospital.

Coagulase Negative Staphylococci have been widely associated with medical device implant treatment and immune-compromised patients. Despite having increasing interest in Coagulase Negative Staphylococci, few studies from Nepal have reported the association of these organisms with urinary tract infections, conjunctivitis, high vaginal swabs, and cerebrospinal fluid. This study was carried out to determine antibiotic susceptibility pattern and biofilm production among Coagulase Negative Staphylococci isolated from clinical samples at tertiary care hospital. This study was a hospital based cross-sectional study in which 3690 clinical samples were included. Isolation and identification of isolates was done following standard microbiological protocol. Coagulase Negative Staphylococci were identified phenotypically on the basis of gram staining, slide and tube coagulase test and by various sugar fermentation tests. Antibiotic susceptibility test was done following Kirby Bauer disk diffusion method (Clinical and Laboratory Standards Institute 2020). Biofilm production was determined by Tissue Culture Plate technique. A total of 113 isolates of Coagulase Negative Staphylococci were detected. Among them S. epidermidis (45.1%), S. saprophyticus (23.9%), S. haemolyticus (16.8%), S. hominis (5.3%), S. capitis (2.7%), -----S. cohini (1.8%), S. lugdunensis (1.8%) and S. sciuri (2.7%) were identified phenotypically. All isolates were found to be resistant against Ampicillin and 111 (98.2%) were sensitive against Linezolid.23.9% of CoNS were strong biofilm producers, 19.5% moderate and 56.6 % were non/weak biofilm producers. It requires susceptibility test for prescribing antibiotics against Coagulase Negative Staphylococci in hospital and the misuse of antibiotics should be prevented.