bluuebunny/crossref_metadata_2025_split huggingface dataset:
111. Influenza and Pneumococcal vaccination rate in a cohort of adults with chronic comorbid conditions in Colombia.
Authors: Serrano-Mayorga Cristian C , Ibáñez-Prada Elsa D D , Fuentes Yuli V , Lozada Julian , Bustos Ingrid G G , Mendez Lina , Crispin Ana M , Reyes Luis Felipe F 
Published: December 2022

Abstract

Background
Lower respiratory tract infections (LRTI) are the leading cause of mortality and morbidity worldwide. Elderly and patients with comorbid conditions are at higher risk of developing LRTI and systemic complications. Therefore, the Centers for Disease Control and Prevention (CDC) and the United States National Center for Immunization and Respiratory Diseases (US-NCIRD) recommend that patients older than 19 be vaccinated for influenza annually. Patients older than 65 or with comorbid conditions (of any age) should be vaccinated for the pneumococcal vaccine. Low-middle-income countries like Colombia do not have strong policies for adults to get vaccinated. According to CDC recommendations, this study aims to determine the vaccination rate in a Colombian cohort. Figure 1.
Panel A illustrates patients’ distribution of influenza vaccine in the cohort, while Panel B shows the distribution of pneumococcal vaccine

Methods
This is the description of a prospective cohort of patients with chronic comorbid conditions between 2020-and 2022 in Bogotá, Colombia. We compared the number of patients vaccinated against Influenza and S. pneumoniae, according to CDC recommendations, to determine the adherence to international guidelines.

Results
The cohort was composed of 810 patients. The median [IQR] age was 63 [53-62] and the most common comorbidities were 52.2% [423/810] arterial hypertension, 21.7% [176/810] coronary disease, 19.0% [154/810] congestive heart failure, and 17.4% [141/810] chronic kidney disease. According to CDC recommendations, 808 patients should have been vaccinated against influenza (Figure 1A), but only 31.7% [256/808] were immunized last year. Also, 17.8% [144/810] of the whole cohort were 65 years old and should have received the quadrivalent flu shot. Moreover, 86.4% [700/810] patients meet the criteria for pneumococcal vaccination (Figure 1B), but only 11.9% [83/700] received at least one shot.

Conclusion
Vaccination rates in our cohort of adult patients with chronic comorbidities were meager. Therefore, these patients are at higher risk of developing LRTI complications. More robust vaccination programs for adults are required in Colombia.

Disclosures
All Authors: No reported disclosures.
129. LiaX, a Member of the LiaFSR System, is Essential for Cell Envelope Adaptation System in Enterococcus faecium
Authors: Cecilia Tran Truc , Panesso Diana , Zhao Audrey , khan Ayesha , Axell-House Dierdre B , Shamoo Yousif , Arias Cesar A 
Published: December 2022

Abstract

Background
Daptomycin (DAP) is an important antibiotic for enterococci. Our previous studies identified LiaX as a surface-exposed protein that is a mediator of cell envelope homeostasis in Enterococcus faecalis (Efs) upon exposure to DAP via activation of the LiaFSR system. LiaX encodes for a soluble protein with an N-terminal of α-helices, and a C-terminus which is β-pleated sheets. Its role in E. faecium, a species of clinical relevance, remains unknown. In this work, we aim to elucidate the function of LiaX of E. faecium (Efm).

Methods
We used the commensal strain of Efm TX1330RF (DAP minimum inhibitory concentration [MIC] 3 μg/ml), its ΔliaR derivative (TX1330RFΔliaR [DAP MIC 0.125 μg/ml]) and targeted the liaX gene for mutagenesis. Using the PheS* counterselection system, we aimed to create a truncation or in-frame deletion of liaX. Mutants were characterized by determination of DAP MIC and visualization of anionic phospholipid domains by 10-N-nonyl-acridine orange (NAO). The nisin-controlled expression vector, pMSP3535, was used to express LiaX from Efm (LiaXTX1330RF) in Efs host OG1RFΔliaX, which lacks liaX. Expression of LiaX of Efs (LiaXOG1RF) was used as a control.

Results
In the presence of liaR, we were unable to create truncation or in-frame deletion of liaX after many attempts. In Efm TX1330RFΔliaR, we successfully created an in-frame deletion of liaX, TX1330RFΔliaRliaX (DAP MIC 0.125 μg/ml). NAO staining of all strains of TX1330RF, TX1330RFΔliaR and its ΔliaX mutant showed localization of anionic phospholipid domains at septa of the cells. Interestingly, multiple attempts to complement liaR in TX1330RFΔliaRliaX were also futile. NAO staining of Efs OG1RFΔliaX demonstrated that anionic phospholipid microdomains redistributed away from septa. Expression of LiaXOG1RF in Efs OG1RFΔliaX successfully restored microdomains to septal and polar regions of Efs while expression of LiaXTX1330RF did not show any significant difference in the fluorescence staining compared to its parental host (Efs OG1RFΔliaX).

Conclusion
Our findings suggest that LiaX has divergent functions as a mediator of cell envelope homeostasis in enterococci and may be essential in the Efm redponse to DAP. Efforts to elucidate its role in DAP resistance in Efm are ongoing.

Disclosures
Cesar A. Arias, MD, PhD, Entasis Phramceuticals: Grant/Research Support|MeMed Diagnostics: Grant/Research Support|Merck: Grant/Research Support.
132. Carbapenem-resistant Enterobacteriaceae colonization in a Neonatal Intensive Care Unit in Bogotá, Colombia: Characterization and clinical outcomes
Authors: Londono-Ruiz Juan Pablo , Alvarez-olmos Martha Isabel , Medina-ramos Diana Carolina , Troncoso-Moreno Gloria Amparo , de la Hoz-Valle Jose Antonio 
Published: December 2022

Abstract

Background
Carbapenem-resistant Enterobacteriaceae (CRE) infections is a global public health problem, especially among vulnerable populations. Studies exploring these outcomes in neonates colonized with CRE are scarce. The aim is to explore differences in clinical outcomes between CRE-colonized versus CRE-non-colonized neonates.

Methods
A retrospective, observational, and longitudinal cohort study was performed for surveillance of CRE colonization in the neonates admitted between 2018-2021 to NICU in Bogotá, Colombia.

Results
From 462 clinical records, 21 (4,5%) were CRE colonized neonates. We found a difference in median gestational age to birth (34 weeks in CRE-colonized vs 37 weeks in non-CRE colonized p 0,018), any previous antibiotic therapy (71% vs 25% p 0,005), carbapenem use before admission (19% vs 1,6% p 0,01), CRE isolation in any sterile fluid during sepsis episodes (14% vs 0% p 0,004), use of empiric carbapenem therapy in sepsis episodes (42% vs 6,3% p 0,0003), empiric therapy for CRE infection (28% vs 6,3% p 0,01), and hospital length of stay (22 vs 11 days p 0,007). We did not find difference in sepsis episodes (66% vs 39% p 0,058) and mortality (4,8% vs 7,9%) among both groups.

Conclusion
Gestational age, prior use of any antibiotic or carbapenems, CRE isolation in sterile fluid during sepsis episodes, and higher length of stay were more frequently identified among CRE-colonized neonates versus CRE non-colonized neonates.

Disclosures
All Authors: No reported disclosures.
134. Characterization of circulating clinical multi-drug resistant and methicillin resistant Staphylococcus aureus isolates in Peru
Authors: Rojas Jesús D , Canal Enrique A , Bernal Manuela M , Lizewski Rhonda A , Rios Paul A 
Published: December 2022

Abstract

Background
Multi-drug resistant and methicillin resistant Staphylococcus aureus (MDR-SA and MRSA, respectively) constitute a significant threat to hospitalized patients. Surveillance for antibiotic resistance is needed in settings where over-the-counter antibiotic use is widespread to identify increasing antibiotic resistance that limits treatment options of nosocomial infections.

Methods
We performed phenotypic and genotypic characterizations of MDR-SA prospectively obtained from hospitals in Lima, Peru between 2015 - 2018. We collected 3103 bacterial isolates from clinical specimens. Bacterial samples were identified by conventional microbiology and BD Phoenix, and antimicrobial susceptibility testing (AST) was performed by disc diffusion, E-test and BD Phoenix. Additionally, multiplex PCR detected mecA, femA, and lukS in MDR-SA isolates. We selected 80 S. aureus isolates that were resistant to ≥ 3 antimicrobial classes and/or resistant to oxacillin or cefoxitin for genomic characterization using an Illumina NextSeq 500 sequencer.

Results
Testing identified 232/3103 isolates as S. aureus, and 80/232 (34%) isolates were MDR-SA, resistant to up to nine different antimicrobial classes. We observed high proportions of resistance to aminopenicillins 80/80 (100%), macrolides 71/80 (89%), lincomycins 69/80 (86%), quinolones 66/80 (83%), aminoglycosides 38/46 (82%). Notably, 75/80 (94%) isolates were MRSA. Interestingly, AST revealed that 81% had inducible resistance to clindamycin. In contrast, all isolates were susceptible to vancomycin, linezolid, and daptomycin. Multiplex PCR revealed that 5% of isolates carried the lukS gene and the mecA gene. 76 % of the isolates carried a bifunctional aminoglycoside modifying enzyme and a aminoglycoside O-nucleotidyltransferase enzymes that confer resistance to aminoglycosides. We detected the ermA gene in 79% of the isolates. In silico multilocus sequence typing (MLST) assigned the sequence type 5 to 91.2% MRSA isolates with multiple high related clusters observed, indicating the possibility of nosocomial dissemination and possible outbreak events.

Conclusion
Antibiotic pressure on the resistance patterns of S. aureus is evident in the high levels of resistance seen in these clinical isolates.

Disclosures
All Authors: No reported disclosures.
156. Using Whole Genome Sequencing to Genetically Profile and Analyze Escherichia coli Isolates with Varying Resistance to β-Lactam/β-lactamase Inhibitor Combinations
Authors: Marc Gohel , Amiji Hatim , Strope Benjamin , Sahasrabhojane Pranoti V , Greenberg David E , Shropshire William , Shelburne Samuel A 
Published: December 2022

Abstract

Background
Whole-genome sequencing has gained interest for assessing antimicrobial resistance (AMR). However, multiple studies have shown a poor correlation between the β-lactam/β-lactamase inhibitor (BL/BLI) phenotype and β-lactamase gene presence/absence. In a recent publication, we found that amplification of β-lactamase encoding genes potentially contribute to BL/BLI resistance and here we explore if gene amplifications allow for better BL/BLI genotype/phenotype correlations.

Methods
We selected 109 E. coli bacteremia isolates and performed ETests (bioMerieux, Inc) to determine AST profiles using the following BL/BLI antibiotics: ampicillin/sulbactam (SAM), amoxicillin/clavulanic acid (AMC), and piperacillin/tazobactam (TZP). CLSI M100 guidelines (2018) were used to stratify isolates into 4 groups: SAM/AMC/TZP susceptible (Group 1), SAM resistant only (Group 2), SAM/AMC resistant (Group 3), and SAM/AMC/TZP resistant (Group 4). Short-read whole genome sequencing was performed on these isolates and analyzed by identifying AMR genes, establishing multi-locus sequence type (MLST), estimating copy number variants (CNV), and investigating blaTEM-1 promoter regions in relation to phenotype. A t-Distributed Stochastic Neighbor Embedding (t-SNE) clustering method and a core-genome, maximum-likelihood phylogeny was generated to group isolates based on AMR gene content and CNV data.

Results
We found 34 different MLST groups with the three most common sequence types ST131 (n=41), ST1193 (n=12), and ST648 (n=6). Group 1 and Group 2 isolates had similar copy number estimates of β-lactamase blaTEM-1 (1.8X and 1.5X respectively) while there was an increase for both Group 3 (3.7X) and Group 4 (8.2X) isolates (Table 1). Additionally, blaOXA-1 was primarily present in Group 4 isolates (63%) with elevated copy numbers (5.2X). We did not observe associations of blaTEM-1 promoter regions with each of the BL/BLI Groups. Our t-SNE analysis shows that Group 1, Group 3, and Group 4 isolates cluster independently.
Core Genome Maximum-likelihood Phylogeny.
Midpoint-rooted core-genome maximum-likelihood phylogeny comparing core elements (MLST) to non core elements (CNV). AMR CNV and presence/absence associate better with BL/BLI phenotypes than do core elements.

Conclusion
There is a clear delineation between fully susceptible and fully resistant BL/BLI E. coli isolates when gene amplification and presence/absence of narrow-spectrum β-lactamases are considered, which should be considered for BL/BLI resistance prediction models.

Disclosures
David E. Greenberg, MD, Shionogi: Grant/Research Support.
157. A Survey of the Mid-South VA Healthcare Network on Ordering Practices and Interpretation of Procalcitonin
Authors: Eason Jane V , Bennett Jessica G , Byrd Jonathan , Callicott William , Thomas-Gosain Neena 
Published: December 2022

Abstract

Background
Procalcitonin (PCT) is an inflammatory biomarker that can be helpful for early detection of certain types of infections and can be a useful tool to decrease unnecessary antibiotic (abx ) exposure. However, its use among clinicians remains variable. The aim of this study was to elucidate current practices at a selection of Veteran’s Administration medical centers.

Methods
The VISN-9 Antimicrobial Stewardship Collaborative distributed a 15-question survey electronically to providers at all five VA medical centers in VISN-9 between 1/15/22 to 3/31/22 to clinicians practicing in the acute care, ICU and ED settings. Information on level of training, primary site as well as current practices and beliefs about PCT were collected. Responses were tabulated as percentages for this cross-sectional study.

Results
99 providers completed the survey with two centers comprising 83% of responses. 44% of respondents were attendings.
The Figures illustrate some interesting variability in the use of PCT. Figure 1 reveals more than half of residents but less than a quarter of attendings ordered PCT on admission for patients with suspected infection. Figure 2 shows similar use of PCT by attendings and residents to initiate abx, however, residents used PCT much more than attendings to justify continuation of abx, and residents used PCT somewhat more than attendings to de-escalate abx. Only one clinician ordered PCT daily. Figure 3, ordering practices by disease state, shows similar trends between the two groups.
44% of all respondents felt somewhat comfortable whereas 22% felt somewhat uncomfortable interpreting PCT results. Some of the interesting comments from respondents included: “PCT is “ordered too often and indiscriminately”; “I never know what to do with it”; and “I usually allow my patients to complete their abx courses rather than discontinuing abx earlier”.

Conclusion
Using PCT to help guide abx use can help minimize unnecessary abx exposure which may help to stem the increase in antimicrobial resistance. This survey indicates that many clinicians are unsure of when to use PCT, how often to order it, and whether it is a reliable enough tool on which to base treatment decisions. Further education will be necessary to help inform best practices.

Disclosures
All Authors: No reported disclosures.
181. Impact of Rapid Diagnostic Technology on Patients with Candidemia
Authors: Funderburk Patrick , Carr Amy L , Hayes Jillian E 
Published: December 2022

Abstract

Background
Candida spp. are the fourth most common cause of bloodstream infections (BSI) in the United States and have an associated mortality rate of 19-40.5%. Mortality rates are further impacted by delay in time to adequate antifungal therapy, historically due to delayed time to identification on culture. The utilization of rapid diagnostic technology (RDT) has been effective in timely identification of bacterial pathogens causing BSI, but RDT for fungal organisms has demonstrated mixed results. At AdventHealth Central Florida Division South (CFD-S), pharmacists provide 24-hour coverage for real-time notification of all positive blood culture results. The objective of this study was to evaluate the clinical impact of the GenMark ePlex Blood Culture Identification Panels (BCID) fungal pathogen (FP) panel paired with 24/7, pharmacist-driven response in patients with candidemia.

Methods
This multi-site, pre/post, retrospective chart review included adult patients admitted to CFD-S with at least one positive blood culture with Candida spp. from June 2019 through May 2020 (pre-RDT), and August 2020 through July 2021 (post-RDT). Patients receiving systemic antifungal prophylaxis, with known candidiasis at time of index RDT result, or who discharged prior to culture positivity were excluded. The primary outcome was time to effective antifungal therapy in patients with candidemia.

Results
A total of 200 patients were included in the study (100 pre-RDT and 100 post-RDT). Overall, patients had a median age of 61 years and 50% were male. Patient characteristics are summarized in Table 1; median APACHEII score differed by three points (13.5 vs. 16.5). Time to effective therapy was similar between groups (39.8 vs. 38.5 hours, p=0.217). There was no difference in secondary outcomes (Table 2) other than ICU length of stay (2.5 vs. 6.0 days, p=0.033) and all-cause in-hospital mortality (15% vs. 30%, p=0.011).

Conclusion
Pharmacist-driven, real-time response to RDT did not significantly impact time to effective antifungal therapy in patients with candidemia. Higher rate of in-hospital mortality was likely a reflection of increased severity of illness in the post-RDT group.

Disclosures
Amy L. Carr, PharmD, BCIDP, Shionogi: Advisory Board.
186. Klebsiella aerogenes: Are there implications to taxonomic accuracy?
Authors: Herrera Lauren Nicholas , Brown Matthew L , Edwards William S , Leal Sixto M , Stripling Joshua , Lee Rachael A 
Published: December 2022

Abstract

Background
With advances in genomics, microbiologists can accurately rename existing bacteria which may cause confusion among clinicians familiar with prior names. Limited investigation is available on the clinical impact of these name changes. University of Alabama at Birmingham Hospital microbiology updated Klebsiella aerogenes in the electronic medical record (EMR) to "Klebsiella (Enterobacter) aerogenes" to reflect change in nomenclature. Therapy selection differs between Klebsiella pneumoniae and Enterobacter spp. due to differences in Ambler Class C (AmpC) beta-lactamase production. Our Antimicrobial Stewardship Program previously implemented selective and cascaded susceptibility reporting for E. aerogenes to guide antibiotic selection which remained after nomenclature change. The goal of this study is to determine if the change led to inappropriate antibiotic use.

Methods
We reviewed blood culture data from May 2016-2020 which grew Enterobacter aerogenes or Klebsiella "Enterobacter" aerogenes. We excluded polymicrobial blood cultures, patients aged 18 and under, and patients who died within 48 hours of drawing blood cultures. Appropriate therapy was defined as an antibiotic with reported susceptibility with consideration of AmpC induction for a duration appropriate to clinical syndrome with minimum of 7 days. We recorded patient demographics, nature of therapy, and clinical outcomes. We performed comparative analysis with descriptive statistics to compare the two groups.

Results
There were 38 patients with K. aerogenes bacteremia, 21 patients prior to name change and 17 afterwards. None were ESBL. Cefepime was most often used directed inpatient therapy while oral ciprofloxacin was the most common outpatient regimen with no use of ceftriaxone. Prior to name change, there was one case (4.76%) that did not receive targeted AmpC therapy while there were two afterwards (11.8%), one of which decided by the ID consult team. Table 1
Demographics (Data presented as No. (%)) Table 2
Microbiology and Outcomes (Data presented as No. (%)) Table 3
Antimicrobial Selection. One patient that received 72 hours of appropriate therapy but died prior to completion of therapy. This was labeled labelled as appropriate therapy.

Conclusion
Care must be taken when taxonomic changes of clinically relevant bacteria may potentially affect optimization of antibiotics. As the ID consultants, we must be aware of these name changes and provide up to date recommendations. Cascade reporting and documentation in the EMR may be helpful to reduce morbidity related to changes in nomenclature.

Disclosures
Sixto M. Leal, Jr., MD, PhD, GenMark Dx: Grant/Research Support|GenMark Dx: Honoraria.
198. The correlation of the genetic antibiotic resistance markers to antibiotic susceptibility testing (AST)
Authors: Morrison Caitlin , Pham Janis , Pearson Alicyn , King John , Lapp Noucas Heather S , Shivers Robert , Smith Roger 
Published: December 2022

Abstract

Background
Antibiotic resistant infections are a risk for increased patient mortality due to long time-to-results for current diagnostic methods. Results from a ∼1,500 patient trial demonstrated bacterial blood culture required 51 hours on average for a positive result. Current antibiotic susceptibility testing (AST) requires two additional days for phenotypic results. Studies show delays in effective treatment increases mortality rates by 7.6% every hour. The CDC classifies carbapenem-resistant Enterobacterales (13,000 annual deaths) as urgent threats, and vancomycin-resistant Enterococci and methicillin-resistant S. aureus (∼15,000 annual deaths combined) as serious threats. Identifying resistance markers direct from patient samples may aid clinical decisions, reduce antibiotic use, reduce time to effective therapy, and improve patient outcomes

Methods
200 antibiotic resistant bacterial strains were genotyped for 13 clinically-relevant resistance genes and screened for antibiotic resistance phenotypes. Results identified correlations between resistance markers and phenotypic resistance and potential aid for clinical treatment.

Results
High resistance to vancomycin and piperacillin-tazobactam, first-line antibiotics, were seen in 48 Gram-positive and 69 Gram-negative strains. Presence of Gram-positive markers vanA or vanB correlated to 100% (28/28) vancomycin resistance and 88% (25/28) ampicillin resistance. In 85 sequenced Gram-negative strains, 35 harbored metallo-β-lactamase (blaIMP,blaNDM,blaVIM), 35 contained extended spectrum β-lactamase (blaCTX-M-14,blaCTX-M-15), 21 contained AmpC β-lactamase (blaDHA,blaCMY), and 34 contained carbapenenase (blaKPC,blaOXA48). These markers correlated to 100% resistance to ampicillin, cefazolin, and cefuroxime in all strains.

Conclusion
Together, these data suggest that molecular diagnostics that identify genetic markers may provide clinicians with needed information during a window when therapeutic intervention can improve patient outcomes.

Disclosures
Caitlin Morrison, B.S., T2 Biosystems: Stocks/Bonds Janis Pham, B.S., T2 Biosystems: Stocks/Bonds Alicyn Pearson, PhD, T2 Biosystems: Stocks/Bonds John King, B.S., T2 Biosystems: Stocks/Bonds Heather S. Lapp Noucas, MSc, T2 Biosystems: Stocks/Bonds Robert Shivers, PhD, T2 Biosystems: US20200291488A1|T2 Biosystems: Stocks/Bonds Roger Smith, Ph.D., T2 Biosystems, Inc: US20180188195A1, EP3849938A1,WO2020257691A1, WO2020252084A1|T2 Biosystems, Inc: Stocks/Bonds.