Vancomycin-resistant Enterococci Research Articles

Antibacterial, Antibiofilm, and Antioxidant Activities of Aqueous Crude Gymnema inodorum Leaf Extract against Vancomycin-Resistant Enterococcus faecium.

Vancomycin-resistant Enterococcus faecium (VREF) causes nosocomial infections with high mortality and morbidity rates. This study aimed to evaluate the antibacterial and antibiofilm activities of aqueous crude Gymnema inodorum leaf extract (GIE) against the VREF ATCC 700221 strain. The antimicrobial activity of GIE against VREF was performed using disk diffusion and broth microdilution. The antibiofilm activities were evaluated using the crystal violet staining assay. The antioxidant potential was evaluated. Preliminary screening of the antimicrobial activity of 50 and 100 µg/disk of GIE against VREF revealed inhibition zones of 8.33 ± 0.58 mm and 8.67 ± 0.29 mm, respectively. Additionally, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against VREF were 125 and ≥ 250 mg/mL, respectively. SEM analysis showed that treatment with GIE caused morphological changes, including incomplete cell division, damaged cell walls, and cell content leakage, suggesting a disruption of bacterial cells. GIE also inhibited and eradicated biofilms formed by VREF. The extract exhibited antioxidant activities in the DPPH and ABTS assays. While GIE shows potential as an antibacterial and antibiofilm agent, further studies are necessary to fully understand the underlying mechanisms and optimize its use for therapeutic applications.

Impact of terminal cleaning in rooms previously occupied by patients with healthcare-associated infections.

Healthcare associated infections (HAIs) are costly but preventable. A limited understanding of the effects of environmental cleaning on the riskiest HAI associated pathogens is a current challenge in HAI prevention. This project aimed to quantify the effects of terminal hospital cleaning practices on HAI pathogens via environmental sampling in three hospitals located throughout the United States. Surfaces were swabbed from 36 occupied patient rooms with a laboratory-confirmed, hospital- or community-acquired infection of at least one of the four pathogens of interest (i.e., Acinetobacter baumannii (A. baumannii), methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterococcus faecalis/faecium (VRE), and Clostridioides difficile (C. difficile)). Six nonporous, high touch surfaces (i.e., chair handrail, bed handrail, nurse call button, desk surface, bathroom counter near the sink, and a grab bar near the toilet) were sampled in each room for Adenosine Triphosphate (ATP) and the four pathogens of interest before and after terminal cleaning. The four pathogens of interest were detected on surfaces before and after terminal cleaning, but their levels were generally reduced. Overall, C. difficile was confirmed on the desk (n = 2), while MRSA (n = 24) and VRE (n = 25) were confirmed on all surface types before terminal cleaning. After cleaning, only MRSA (n = 6) on bed handrail, chair handrail, and nurse call button and VRE (n = 5) on bathroom sink, bed handrail, nurse call button, toilet grab bar, and C. difficile (n = 1) were confirmed. At 2 of the 3 hospitals, pathogens were generally reduced by >99% during terminal cleaning. One hospital showed that VRE increased after terminal cleaning, MRSA was reduced by 73% on the nurse call button, and VRE was reduced by only 50% on the bathroom sink. ATP detections did not correlate with any pathogen concentration. This study highlights the importance of terminal cleaning and indicates room for improvement in cleaning practices to reduce surface contamination throughout hospital rooms.

Clonal expansion of Tn1546-like transposon-carrying vancomycin-resistant Enterococcus faecium, a nationwide study in Taiwan, 2004-2018

ObjectivesThe prevalence of vancomycin-resistant Enterococcus faecium (VREfm) has increased significantly in Taiwan. We investigated the molecular epidemiology of clinical VREfm isolates to increase our understanding on their spread and changes in population structure over a 14-year span. MethodsA total of 1113 E. faecium isolates were collected biennially from 2004 to 2018 in Taiwan. MICs were determined by broth microdilution. Whole-genome sequencing (WGS) was performed on 229 VREfm isolates to characterize their genetic environment of vancomycin resistance and wgMLST was used to investigate their clonal relationship. ResultsAmong the 229 isolates, ST17 and ST78 predominated, especially during the later years, and their prevalences increased from 14.6% (7/48) and 25.0% (12/48) in 2004–2010 to 47.5% (87/181) and 29.8% (54/181) in 2012–2018, respectively. Four types of vanA-carrying Tn1546 variants were detected, with type 1 and type 2 predominated. Type 1 Tn1546 contained an addition of IS1251, while type 2 resembled type 1 but had an addition of IS1678. wgMLST revealed several distinct clusters of ST17 and ST78 isolates, with type 1 Tn1546-harbouring ST17-Cluster 16 being the largest and most widespread clones throughout the study years. Type 2 Tn1546-carrying ST78 became a predominant clone (Cluster 21) after 2012. Isolates within these clusters are highly similar despite being from different hospitals, regions, and study year. ConclusionThe increase of VREfm in Taiwan was attributed to horizontal transfer of vanA-carrying Tn1546 variants between different STs and spread of persistent clones. This study highlights the importance of integrating WGS into surveillance to combat antimicrobial resistance.

Fitness costs of Tn1546-type transposons harboring the vanA operon by plasmid type and structural diversity in Enterococcus faecium

BackgroundThis study analyzed the genetic traits and fitness costs of vancomycin-resistant Enterococcus faecium (VREfm) blood isolates carrying Tn1546-type transposons harboring the vanA operon.MethodsAll E. faecium blood isolates were collected from eight general hospitals in South Korea during one-year study period. Antimicrobial susceptibility testing and vanA and vanB PCR were performed. Growth rates of E. faecium isolates were determined. The vanA-positive isolates were subjected to whole genome sequencing and conjugation experiments.ResultsAmong 308 E. faecium isolates, 132 (42.9%) were positive for vanA. All Tn1546-type transposons harboring the vanA operon located on the plasmids, but on the chromosome in seven isolates. The plasmids harboring the vanA operon were grouped into four types; two types of circular, nonconjugative plasmids (Type A, n = 50; Type B, n = 46), and two types of putative linear, conjugative plasmids (Type C, n = 16; Type D, n = 5). Growth rates of vanA-positive E. faecium isolates were significantly lower than those of vanA-negative isolates (P < 0.001), and reduction in growth rate under vancomycin pressure was significantly larger in isolates harboring putative linear plasmids than in those harboring circular plasmids (P = 0.020).ConclusionsThe possession of vanA operon was costly to bacterial hosts in antimicrobial-free environment, which provide evidence for the importance of reducing vancomycin pressure for prevention of VREfm dissemination. Fitness burden to bacterial hosts was varied by type and size of the vanA operon-harboring plasmid.

Impact of multidrug resistance on outcomes in hematologic cancer patients with bacterial bloodstream infections

Despite the improved outcomes in patients with hematological malignancies, infections caused by multidrug-resistant organisms (MDROs) pose a new threat to these patients. We retrospectively reviewed the patients with hematological cancer and bacterial bloodstream infections (BSIs) at a tertiary hospital between 2003 and 2022 to assess the impact of MDROs on outcomes. Among 328 BSIs, 81 (24.7%) were caused by MDROs. MDRO rates increased from 10.3% (2003–2007) to 39.7% (2018–2022) (P < 0.001). The 30-day mortality rate was 25.0%, which was significantly higher in MDRO-infected patients than in non-MDRO-infected patients (48.1 vs. 17.4%; P < 0.001). The observed trend was more pronounced in patients with newly diagnosed diseases and relapsed/refractory disease but less prominent in patients in complete remission. Among MDROs, carbapenem-resistant Gram-negative bacteria exhibited the highest mortality, followed by vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus, and extended-spectrum β-lactamase-producing Enterobacteriaceae. Multivariate analysis identified independent risk factors for 30-day mortality as age ≥ 65 years, newly diagnosed disease, relapsed/refractory disease, MDROs, polymicrobial infection, CRP ≥ 20 mg/L, and inappropriate initial antibiotic therapy. In conclusion, MDROs contribute to adverse outcomes in patients with hematological cancer and bacterial BSIs, with effects varying based on the underlying disease status and causative pathogens. Appropriate initial antibiotic therapy may improve patient outcomes.

High Serum S100A12 as a Diagnostic and Prognostic Biomarker for Severity, Multidrug-Resistant Bacteria Superinfection and Herpes Simplex Virus Reactivation in COVID-19.

Neutrophils are critical immune cells in severe coronavirus disease 2019 (COVID-19). S100 calcium-binding protein A12 (S100A12) is highly expressed in neutrophils during acute inflammation. The aim of this study was to evaluate serum S100A12 levels as a diagnostic and prognostic tool in COVID-19. Serum samples of patients with moderate and severe COVID-19 were collected during 2020 to 2024. Enzyme-linked immunosorbent assay was used to measure serum S100A12 levels in 63 patients with moderate COVID-19, 60 patients with severe disease and 33 healthy controls. Serum S100A12 levels were elevated in moderate COVID-19 compared to controls and were even higher in severe cases. In moderate disease, serum S100A12 levels positively correlated with immune cell counts. While C-reactive protein and procalcitonin are established inflammation markers, they did not correlate with serum S100A12 levels in either patient cohort. Patients with severe COVID-19 and vancomycin-resistant enterococcus (VRE) infection had increased S100A12 levels. Elevated S100A12 levels were also observed in patients with herpes simplex reactivation. Fungal superinfections did not alter S100A12 levels. These data show that serum S100A12 increases in moderate and severe COVID-19 and is further elevated by VRE bloodstream infection and herpes simplex reactivation. Therefore, S100A12 may serve as a novel biomarker for severe COVID-19 and an early diagnostic indicator for bacterial and viral infections.

Bacterial infections in hospitalized cancer patients. The role of drug-resistant pathogens

Aim. To present data on the structure of bacterial pathogens causing infectionsin cancer patients atthe N.N. Blokhin National Research Center of Oncology and analyze them in comparison with data of domestic and foreign literary sources.Materials and methods. The data of 11,853 microorganisms isolated from patients hospitalized in the N.N. Blokhin National Research Center of Oncology in 2023 were analyzed.Results. Bacteria accounted for 90.0 % of all isolated microorganisms and only 10.0 % were fungal pathogens. Despite the fact that gram-negative pathogens have given way to gram-positive pathogens in absolute numbers, gram-negative microorganisms (60.7 %) still prevail in “clinically significant” biomaterials (blood, spinal fluid, urine, wound discharge, BAL, etc.), primarily Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii and others. With the exception of Escherichia coli, a high percentage of carbapenem-resistant strains is noted for other pathogens: Klebsiella pneumoniae – 34 %, Pseudomonas aeruginosa – 50 %, Acinetobacter baumannii – 69 %. Real-time polymerase chain reaction revealed the leading carbapenemases: in Klebsiella pneumoniae strains – KPC or OXA-48 carbapenemases were detected in 55 % of cases, and NDM metallo-β-lactamasesin 45 %; in Pseudomonas aeruginosa strains – VIM metalloβ-lactamases were registered in 29 % of cases. Among gram-positive microorganisms, the most problematic is vancomycinresistant Enterococcus faecium. It accounts for 45 % of all E. faecium strains.Conclusion. Along with modern diagnostics and infection control measures, knowledge of the leading microbiota in a particular clinic will prevent the spread of infection and provide timely medical care to patients.

A bacteriocin-based coating strategy to prevent vancomycin-resistant Enterococcus faecium biofilm formation on materials of interest for indwelling medical devices

The ever-increasing use of exogenous materials as indwelling medical devices in modern medicine offers to pathogens new ways to gain access to human body and begin, in some cases, life threatening infections. Biofouling of such materials with bacteria or fungi is a major concern during surgeries, since this is often associated with biofilm formation and difficult to treat, recalcitrant infections. Intense research efforts have therefore developed several strategies to shield the medical devices' surface from colonization by pathogenic microorganisms. Here, we used dopamine as a coupling agent to coat four different materials of medical interest (plastic polyetheretherketone (PEEK), stainless steel, titanium and silicone catheter) with the bacteriocins, enterocin EJ97-short and the thiopeptide micrococcin P1. Water contact angle measurements and x-ray photoelectron spectroscopy were used to verify the effective coating of the materials. The effect of bacteriocins coated on these materials on the biofilm formation by a vancomycin resistant Enterococcus faecium (VRE) strain was studied by biofilm-oriented antimicrobial test (BOAT) and electron scanning microscopy. The in vitro biocompatibility of bacteriocin-modified biomaterials was tested on cultured human cells. The results demonstrated that the binding of the bacteriocins to the implant surfaces is achieved, and the two bacteriocins in combination could inhibit biofilm formation by E. faecium on all four materials. The modified implant showed no cytotoxicity to the human cells tested. Therefore, surface modification with the two bacteriocins may offer a novel and effective way to prevent biofilm formation on a wide range of implant materials.

Timesavers: Clinical Decision Support and Automation of MRSA and VRE Deisolation

Background: Most healthcare facilities in the US apply contact precautions (CP) for patients with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) infection and/or colonization. Most individuals with MRSA or VRE colonization will clear over time; however, frontline clinicians rarely evaluate for discontinuation of CP, resulting in increased burden on infection preventionists (IPs). Automation of time- and test-based evaluation using clinical decision support systems (CDSS) embedded in electronic health records (EHR) may increase evaluation and discontinuation of CP when appropriate, while preserving IP resources. Methods: This quality improvement initiative was implemented at Mass General Brigham (MGB), an integrated healthcare system, where patients with MRSA or VRE infection/colonization are identified in the EHR with a corresponding “infection status” and CP applied. Following MGB policy (Figure 1), CDSS features included: 1) automated time-based resolution from 2/15/2023-11/13/2023 and 2) automated ordering of screening assays for patients eligible for test-based evaluation from 6/20/2023-11/14/2023 (Figure 2). Counts of CP discontinuation and automated ordering were performed. IPs at one MGB facility performing manual review of patients self-recorded the time spent evaluating for CP discontinuation. Using these time reports, the average time to complete these tasks and the projected time savings were calculated over the implementation period. Results: Four IPs recorded the time to review patients for CP discontinuation, including reviewing recent antimicrobial administration, microbiology results, ordering screening test(s), and contacting the primary team. Twenty-five patient encounters were timed with a mean of 4.7 minutes documented per encounter. Over a 9-month period after initiation of the automated time-based resolution, the monthly mean number of patients with CP for MRSA and VRE which were automatically discontinued was 247 and 100, respectively. Projected IP time savings over the same 9-month period for MRSA and VRE were 174.1 and 70.5 hours, respectively. Over a 5-month period after initiation of automated ordering of MRSA polymerase chain reaction (PCR)/culture, as well as VRE culture for test-based evaluation, the monthly mean number of MRSA culture, MRSA PCR, and VRE culture automatically ordered for patients on CP for MRSA and VRE were 176, 24, and 145, respectively. Projected IP time savings over the same 5-month period for MRSA and VRE were 78.3 and 56.8 hours, respectively.Conclusion: Healthcare systems that enhance their EHR with CDSS to automate CP evaluations may improve frontline clinician workflow, patient flow and bed capacity, while optimizing use of IP resources.

Analysis of molecular epidemiological characteristics and antimicrobial susceptibility of vancomycin-resistant and linezolid-resistant Enterococcus in China

BackgroundThis study investigates the distribution and characteristics of linezolid and vancomycin susceptibilities among Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) and explores the underlying resistance mechanisms.MethodsA total of 2842 Enterococcus clinical isolates from patients were retrospectively collected, and their clinical data were further analyzed. The minimum inhibitory concentrations (MICs) of vancomycin and linezolid were validated by broth dilution method. The resistance genes optrA, cfr, vanA, vanB and vanM were investigated using polymerase chain reaction (PCR). Housekeeping genes and resistance genes were obtianed through whole-genome sequencing (WGS).ResultsOf the 2842 Enterococcus isolates, 88.5% (2516) originated from urine, with E. faecium accounted for 60.1% of these. The vanA gene was identified in 27/28 vancomycin resistant Enterococcus (VRE) isolates, 4 of which carried both vanA and vanM genes. The remaining strain was vanM positive. The optrA gene was identified in all E. faecalis isolates among linezolid resistant Enterococcus (LRE). E. faecium showed a higher multiple antibiotic resistance index (MAR index) compared to E. faecalis. The multi-locus sequence typing (MLST) showed the sequence type of E. faecium mainly belongs to clonal complex (CC) 17, nearly E. faecalis isolates analyzed were differentiated into 7 characteristics of sequence types (STs), among which ST16 of CC16 were the major lineage.ConclusionUrine was the primary source of VRE and LRE isolates in this study. E. faecium showed higher levels of resistance compared to E. faecalis. OptrA gene was detected in 91.6% of LRE, which could explain linezolid resistance, and van genes were detected in all vancomycin resistant Enterococcus strains, while vanA was a key resistance mechanism in VRE identified in this study.

Empowering Patient Hand Hygiene and Reducing Infection in the Oncology Population

Background: Significant focus has been placed on healthcare worker hand hygiene, but little attention is has been assigned to the role of patient hand hygiene (HH) in reducing hospital acquired infections. Therefore, in this quality improvement study, we examined the impact of providing patients with hand hygiene products around mealtime on increasing patient HH adherence and on reducing acquisition of nosocomial antibiotic resistant organisms. Methods: Patients on two inpatient leukemia units at a tertiary oncologic center were provided with a single use pre-packaged alcohol wipe on their meal trays prior to every meal (three times daily). Additionally, an information card explaining to patients how and when to use the alcohol wipe was provided on the meal trays three times a week. Both the wipe and instructions were designed with input from patient representatives at the hospital. Two oncologic control units were selected where no specific intervention for patient hand hygiene was conducted. Patient hand hygiene adherence on the control and intervention units were measured through once monthly patient interviews conducted after meals where patients were asked to recall whether they washed their hands prior to eating (using any product). Vancomycin Resistant Enterococcus (VRE) incidence was compared on the intervention and control units during the 7 months prior and 7 months following initiating the intervention. Results: During the seven-month intervention period, more than 15 000 wipes were dispensed to patients on the intervention units. Through interview, 91% of 87 patients on the intervention units reported cleaning their hands before eating a meal using any cleaning product compared to 72% of 68 patients on the control units (X2 = 9.32, p = 0.002). Furthermore, on the intervention units, 30 (38%) patients endorsed using the provided hand hygiene product. During intervention period, the combined incidence rate of VRE the intervention units was 1.85 case/1000 patient-days compared to 5.35 cases/1000 patient-days during the 7 months prior to intervention (t = 3.24, p=0.007)(Figure 1). Conclusions: This patient-centered quality improvement intervention increased patient hand hygiene and potentially reduced VRE incidence in a vulnerable oncologic population. This practical intervention that incorporated the patient perspective provided accessible hand hygiene products with simple instruction and reminders required minimal participation of unit staff. Further application of the intervention in non-oncologic populations is needed to further establish the relationship between patient hand hygiene and the acquisition of nosocomial infections.

Efficacy of Empiric Contact Precautions for Patients from High Risk Facilities

Background: Infection prevention surveillance revealed that patients admitted from two specific long term care facilities comprised the majority of multi-drug resistant organisms (MDRO) and scabies cases at our institution. Current practices include performing active surveillance for Candida auris and methicillin-resistant Staphylococcus aureus (MRSA) for specific high-risk patients, as surveillance for all MDROs and scabies is impractical. We therefore sought to create an admission screening process to efficiently identify patients from high-risk facilities (HRFs) and place them in pre-emptive contact precautions upon admission. Methods: Patients admitted from HRFs were identified on admission as part of the initial nursing assessment. For any positive responses, nursing received a Best Practice Advisory to place the patient in contact precautions and patient placement received an alert that the patient would require a private room. Infection Preventionists reviewed a report of all patients who screened positive and added a “High Risk Facility” banner to the chart. This banner remained for the duration of hospitalization and for every subsequent readmission and outpatient visit. We reviewed the electronic medical records of all patients with a HRF banner placed from March 8, 2023 to September 15, 2023 and abstracted data regarding the presence of scabies or any of the following MDROs before and after placement of the banner: C. auris, carbapenem-resistant enterobacterales (CRE), MRSA, vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Acinetobacter, and MDR Pseudomonas. Results: Of the 93 patients who had a HRF banner added during the study period, 31 (33.33%) were already known to have MDRO colonization at the time of admission to our facility. Thirty-three of the remaining 62 patients (53.22%) without known MDRO colonization were subsequently found to have MDRO colonization/infection or scabies infestation that may have required contact precautions during their index admission or a subsequent admission. This included 14 patients with C. auris, 2 with CRE, 3 with MDR Pseudomonas, 12 with MRSA, 12 with carbapenem-resistant Acinetobacter, and 2 with VRE. Patients were admitted for a median of 9 days before their diagnosis, and 36 of the 93 patients (38.71%) were re-admitted to our hospital during the study period. Conclusion: We found that empiric contact precautions based solely on exposure to specific HRFs facilitated earlier isolation by a median of 9 days. This approach should be considered in acute care hospitals with a high proportion of admissions from HRFs, especially when active and passive surveillance for MDROs is limited.

Application of a Model Using Prior Healthcare Information to Predict Multidrug-Resistant Organism (MDRO) Carriage

Background: Early identification of patients colonized with MDROs can help healthcare facilities improve infection control and treatment. We evaluated whether a model previously validated to predict carbapenem-resistant Enterobacterales (CRE) carriage on hospital admission (area under the curve [AUC]=0.86, Lin et al. OFID 2019) would generalize to predict a patient’s likelihood of CRE and non-CRE MDRO colonization at the time of medical intensive care unit (MICU) admission. Methods: We analyzed data collected previously in a retrospective observational cohort study of patients admitted to Rush University Medical Center’s MICU from 1/2017-1/2018 and screened within the first two days for rectal MDRO colonization. Organisms of interest included CRE, carbapenem-resistant Pseudomonas aeruginosa (CRPA), vancomycin-resistant enterococci (VRE), and third-generation cephalosporin-resistant Enterobacterales (3GCR-E). Methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization at admission was determined by routine clinical screening. Each patient’s first MICU admission during the study period was linked to Illinois’ hospital discharge database and assigned a CRE colonization risk probability using the existing model. Model covariates were age, and during the prior 365 days, number of short-term acute care hospitalizations (STACH) and mean STACH length of stay, number of long-term acute care hospitalizations (LTACH) and mean LTACH length of stay, prior hospital admission with an ICD-10 diagnosis code indicating bacterial infection, and current admission to LTACH. Predictive value of the model was evaluated by receiver operating characteristic (ROC) curves. Results: We analyzed 1237 MICU admissions. MDRO admission prevalence is shown in the Table. The model performed well to predict carriage of healthcare-associated MDROs, including CRE, CRPA, composite CR-MDROs (CRE &amp; CRPA), and VRE. However, the model performed poorly for MDROs with known community reservoirs, including 3GCR-E and MRSA (Table). In general, MDRO admission prevalence increased in parallel with predicted CRE colonization risk (Figure). The number needed to screen (NNS) to detect one healthcare-associated MDRO carrier was inversely related to the CRE colonization risk score. For example, NNS in the total cohort compared to those with CRE risk score of &gt;0.5% was: CRE 111 vs 32 patients, CRPA 333 vs 42 patients, composite CR-MDRO 83 vs 18 patients, and VRE 12 vs 4 patients. However, higher CRE risk score cutoff was inversely related to screening sensitivity. Conclusion: A prediction model using prior healthcare exposure information successfully discriminated patients likely to harbor healthcare-associated MDROs upon MICU admission. Prediction scores generated by a public-health accessible database could be used to target screening/isolation or enact protective measures for high-risk patients.

Case validation of bloodstream infections with an antibiotic-resistant organism

Background: Bloodstream infections (BSIs) are an important cause of morbidity and mortality in severely ill patients, contributing to increased length of hospital stay and higher cost of care. Alberta Health Services Infection Prevention and Control (IPC) conducts inpatient surveillance of new episodes of BSIs with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) or carbapenemase-producing organisms (CPO) in 112 acute care facilities. A case-finding process was undertaken to verify the accuracy of BSI data entry. Methods: All positive MRSA, VRE or CPO blood cultures in 2021 were linked to the Inpatient Discharge Abstract Database (DAD) and the National Ambulatory Care Reporting System (NACRS) to identify new cases during acute care admissions. The results were then compared to surveillance records captured by infection control professionals (ICPs). Cases with unmatched culture date and/or encounter date and cases not identified by ICPs were screened by the study team with final decision made by ICPs. Results were analyzed by ARO and by % increase in number of surveillance records. Results: The laboratory linkage identified 286 new cases. Comparing to surveillance records (n = 248) captured by ICPs, 137 (57.3%) had matching collection dates and encounter dates, 85 (35.6%) had close matches on collection dates and encounter dates, 17 (7.1%) records had either matching collection dates or encounter dates, and 1 (0.4%) record did not have any matches on dates. There were 46 records identified in the laboratory data that were not in the surveillance system and 8 records that were in the surveillance system but not matched to the laboratory data. After review, 22 Surveillance records had data entry errors (1 CPO BSI, 20 MRSA BSI, and 1 VRE BSI), and there were 14 BSI records found to be missing (13 MRSA BSI, 1 VRE BSI). This represents a 6% increase in MRSA BSI and a 3% increase in VRE BSI identified in 2021 and no increase in CPO BSI. Conclusions: A laboratory validation to determine if BSIs with an ARO were missed during routine IPC surveillance identified a small proportion of missed bloodstream infections. The most common reason for the miss was admission through the emergency department with multiple blood cultures collected during a single admission. These results will be shared with the Infection Control program to facilitate correct BSI capture.

From Swiffers to Solutions: The Impact of Environmental Sampling in the Veterinary Medical Center at OSU

Background: In 2018, the Ohio State University College of Veterinary Medicine (OSU CVM) implemented an Antimicrobial Stewardship Program, central to which was the integration of an environmental surveillance (ES) program. The ES focuses on pathogens recognized as urgent threats to public health by the Centers for Disease Control and Prevention. The pathogens currently targeted include carbapenemase-producing Enterobacterales (CPE), Salmonella spp., methicillin-resistant Staphylococcus spp. (MRSs), vancomycin resistant Enterococcus spp., and enrofloxacin resistant Pseudomonas aeruginosa. Identification of these pathogens allows the hospital to be aware of the local environmental microflora which can act as a sentinel for disease in the hospital, potentially causing healthcare associated infections. Therefore, the objective of this program is to identify resistant bacterial pathogens, characterize their resistance profiles, analyze prevalence patterns, and initiate infection control interventions where needed in the OSU VMC. Method: From January 2018 through December 2023, a total of 5449 samples were collected from approximately 86 locations across the OSU VMC encompassing the small animal, equine, and farm animal sections. A majority (64%, n=3561) of samples were collected from the small animal hospital, with the farm animal section contributing 1055 samples and the equine section 899. Areas sampled were frequented by both humans and animals, as well as surfaces exclusively touched by humans. Samples were collected using Swiffers® and processed through selective culture media. Result: Approximately half (52%, n=2890) of the samples collected represented human-touch only surfaces. A total of 3794 bacterial isolates were recovered, with an overall low prevalence for all targeted pathogens. Prevalence of CPE was 2% (n=103), with Enterobacter species being the most common. Recovery of MRSs was 8.5% (n=464) and Salmonella species was 1% (n=47). Conclusion: Through this initiative, the equine division of the OSU VMC collaborated with the antimicrobial stewardship team to enhance their Salmonella fecal and ES practices. In 2019, ES was critical in identifying persistent CPE and extended-spectrum cephalosporin-resistant Enterobacteriaceae in the ICU and surrounding areas of the small animal hospital. Effective measures were taken to halt the spread of ESC among patients and eliminate CPE in the environment. With the discovery of a new CPE in early 2023 in the small animal ICU and nearby areas, the program initiated targeted ES and cleaning and disinfection protocols, to identify contaminated areas and control disease transmission. These efforts have increased patient safety, health, and well-being, demonstrating how ES can be an important tool for infection control and prevention in veterinary settings.

Use of Whole Genome Sequencing for Investigation of Potential Hospital-Acquired Vancomycin Resistant Enterococcus

Background: Whole genome sequencing (WGS) is a relatively new method for analyzing outbreaks and modes of transmission, particularly for multidrug resistant bacteria. This study sought to investigate clusters of patients with genetically related Vancomycin-Resistant Enterococcus spp. (VRE) bacteremia for shared hospital environmental exposures. Methods: All VRE blood culture isolates from patients from July 1, 2021 to June 30, 2022 underwent Illumina WGS. Core single nucleotide polymorphisms (SNPs) were identified, and multi-locus sequence typing (MLST) was performed across the VRE isolates. Clusters were defined as isolates with 15 or fewer core genome SNPs and were investigated for potential transmission routes. For each cluster, patients were evaluated in the 12 weeks before and after the first VRE isolate for shared hospital environmental exposures (hospital unit, patient rooms, procedural rooms, and radiology suites). Hospital units were comprised of patient rooms located geographically together on the same floor of the hospital. Results: A total of 82 VRE isolates underwent WGS. Thirty-eight (46%) clustered genetically with at least one other isolate. Clusters included 2 to 15 patients per group and represented 10 distinct MLST subgroups (Figure 1). Nine hundred and thirty-nine hospital environmental exposures were identified across the 38 patients. For each cluster, there was a total of 341 (36.3%) shared exposures. Shared environmental exposures occurred in radiology suites (35, 38.5%), patient rooms (32, 35.6%) and procedural rooms (23, 25.6%). Of the patients who shared the same hospital unit, 10 (31.3%) had the same patient room with 7 (70%) of them being in the emergency department (ED). Overall, the ED represented 7 (21.9%) of the shared hospital units. Each cluster had at least one shared hospital environmental exposure found. Conclusions: Use of WGS can help investigate outbreak clusters of resistant organisms such as VRE. In this study, nearly half of all VRE blood isolates were able to be segregated into clusters with at least one other isolate. Although VRE colonization of hospital rooms is well described, patient rooms represented the smallest proportion of shared hospital environmental exposures. This study thus suggests other environmental transmission routes such as radiology suites and procedural rooms warrant closer investigation.

Vancomycin resistance and virulence genes evaluation in Enterococci isolated from pork and wild boar meat

Enterococci are considered valuable sentinel Gram-positive bacteria for monitoring vancomycin antibiotic resistance due to their widespread presence and characteristics. The use of antimicrobials in farming animals has a role in the increasing of Antimicrobial Resistance (AMR) and the anthropogenic transformation of the landscape has forced wildlife into greater contact with humans and their livestock. The transmission of resistant bacteria by their meat products is a significant contributor to AMR development.The present study aimed to assess the prevalence of vancomycin resistant Enterococci spp. In antimicrobial-treated farmed pigs meat and in antimicrobial-free wild boars meat.A total of 341 Enterococci were isolated from 598 pork meat samples (57 %) and 173 Enterococci were isolated from 404 wild boar meat samples (42.8 %). Data found showed that low-resistance was detected more in wild boars meat Enterococci (52.6 %) than in pork meat once (48.4 %). However, the prevalence of resistance genes was at low level (33.9 % in pork meat Enterococci and 4.4 % in wild boar meat ones) and the only gene found was vanC1/C2, related to intrinsic AMR. Normally, Enterococci persist in the normal intestinal flora of animals including humans. However, the presence of resistance genes was frequently linked to the detection of pathogenic genes, mostly gelE in pork meat isolates and asa1 in wild boars meat isolates. Pathogenic bacteria can cause severe infections in human that can become more risky if associated to the presence of AMR. Pathogenic bacteria were characterized and a high presence of E. gallinarum and E. casseliflavus was found.Given the growing interest in wild game meat consumption the monitoring of AMR in these matrices is essential. Further surveillance studies are needed to fully evaluate the emergence and spread of vancomycin-resistant Enterococci (VRE) and pathogenic Enterococci from animal-derived food to humans, including the role of wildlife in this phenomenon. Giving the higher interest in wild animals meat consumption, it is important to better evaluate the spread of AMR phenomenon in the future and intensify hygienic control of wild animals derived food.

Rapid Genomic Characterization of High-Risk, Antibiotic Resistant Pathogens Using Long-Read Sequencing to Identify Nosocomial

Background: Current epidemiological methods have limitations in identifying transmission of bacteria causing healthcare-associated infections (HAIs). Recent whole genome sequencing (WGS) studies found that genetically related strains can cause HAIs without meeting standard epidemiologic definitions, but these results could not provide data in a timely fashion needed for intervention. Given recent advances in Oxford Nanopore Technologies (ONT) sequencing, we sought to establish a validated ONT pipeline capable of providing accurate WGS-based comparisons of clinical pathogens within a short time frame that would allow for infection control interventions. Method: Using electronic medical record data, we identified potential healthcare acquisition of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and carbapenem-resistant gram-negative rods. Bacterial genomic DNA was directly extracted from clinical microbiology lab plates. Sequencing was conducted with the ONT MinION sequencer and R10.4.1 flow cell. MINTyper for single nucleotide polymorphism (SNP) calling and Ridom SeqSphere+ for core genome MLST were used to determine genetic relatedness. The main outcome was time from pathogen identification to completed genetic analysis. Result: The weekly workflow, from genomic DNA extraction to complete data analysis, averaged 2.6 days with a standard deviation of 1.3 days. (range: 1 to 6 days). Starting in August 2023, we have sequenced a total of 177 bacterial isolates from 156 unique patients. Isolates came from blood (38%), tissue/wound/body fluid (24%), urinary tract (20%), respiratory tract (16%), and rectal swab (2%). To date, six genetically related clusters have been identified. Three clusters involved ST117 vancomycin-resistant Enterococcus faecium (VREfm), comprising a total of 13 unique patients distributed as 2, 3, and 8 patients in each group, with pairwise SNP differences of 20, 11, and 14. Patients within the same clusters showed epidemiological links through overlapping admissions and temporally shared ICU stays. Additionally, another cluster consisted of five genetically related ST633 Pseudomonas aeruginosa isolates, with a pairwise SNP difference of 57.5. Each patient in this cluster had potential epidemiological links through overlapping admission times, despite the absence of identified shared spaces. The last two clusters involved Klebsiella pneumoniae and Escherichia coli (two cases each), with pairwise SNP differences of 18 and 9, respectively. In both cases, each patient showed potential epidemiological links through overlapping admission times. Conclusion: Our stand-alone ONT pipeline was able to rapidly and accurately detect genetically related AMR pathogens, aligning closely with epidemiological data. Our approach has the potential to assist in the efficient detection and deployment of preventative measures against healthcare-associated infection transmission.

Unraveling host-pathogen dynamics in a murine model of septic peritonitis induced by vancomycin-resistant Enterococcus faecium

ABSTRACT Vancomycin-resistant Enterococcus faecium (E. faecium) infection is associated with higher mortality rates. Previous studies have emphasized the importance of innate immune cells and signalling pathways in clearing E. faecium, but a comprehensive analysis of host-pathogen interactions is lacking. Here, we investigated the interplay of host and E. faecium in a murine model of septic peritonitis. Following injection with a sublethal dose, we observed significantly increased murine sepsis score and histological score, decreased weight and bacterial burden, neutrophils and macrophages infiltration, and comprehensive activation of cytokine-mediated signalling pathway. In mice receiving a lethal dose, hypothermia significantly improved survival, reduced bacterial burden, cytokines, and CD86 expression of MHC-II+ recruited macrophages compared to the normothermia group. A mathematical model constructed by observational data from 80 animals, recapitulated the host-pathogen interplay, and further verified the benefits of hypothermia. These findings indicate that E. faecium triggers a severe activation of cytokine-mediated signalling pathway, and hypothermia can improve outcomes by reducing bacterial burden and inflammation.

Comparative Analysis of Healthcare-associated Bloodstream Infections &amp; CLABSI Surveillance in A Singaporean tertiary Hospital

Background: Healthcare-associated central line associated bloodstream infection (HA-CLABSI) surveillance is important for monitoring healthcare-associated infections (HAIs) and evaluating effectiveness of infection prevention (IP) measures. However, implementing it is a laborious and time-consuming approach. Exclusive focus on central lines neglects HAI risk due to peripheral vascular catheters. This study aimed to assess whether HA-CLABSI incidence could be inferred from HA-bloodstream infection (BSI) trends and explore shift to HA-BSI surveillance. Methods: The study was performed in a Singaporean tertiary care hospital. Electronic medical records review was performed to determine whether positive blood cultures met Centers for Disease Control/National Health Safety Network (CDC/NHSN) definitions for HA-CLABSI and HA-BSI. Incident episodes of HA-BSI were included (excluding positive cultures repeated within 14 days). Incident organisms were explored to identify common causative pathogens (excluding same organisms isolated from cultures repeated within 14 days). CLABSI and BSI occurring ≥72hrs after admission were considered healthcare-associated. Patients under oncology or hematology service were considered immunocompromised. Incidence rates (IR) per 10,000 patient-days, patient characteristics and causative pathogens were compared between both indicators. Results: From January 2022 to October 2023, mean IR for HA-CLABSI was 0.63 (n=68) and for HA-BSI was 10.06 (n=1094). Median age of patients with HA-CLABSI was 66 years and HA-BSI was 68 years. HA-CLABSI and HA-BSI were more common in males (60.86% &amp; 58.68%). Median duration between admission to HA-CLABSI was 20 days and to HA-BSI was 12 days. Median duration between central line insertion to HA-CLABSI was 16 days. Of 1094, 631 (57.7%) patients had vascular catheter(s) (i.e., IV cannula, port-a-cath, peripherally-inserted central catheter or central line) inserted at time of HA-BSI diagnosis, of whom 46 (7.3%) patients had CLABSI ±2days from positive blood culture. There was no significant correlation between monthly aggregate data from these indicators (Spearman’s correlation coefficient= 0.36, p-value=0.1). Predominant organisms causing HA-CLABSI and HA-BSI were gram negative bacteria (GNB, 40% &amp; 57.21%), gram positive bacteria (24.71% &amp; 22.23%), and fungi. Common GNB in CLABSI patients were Pseudomonas spp. and Stenotrophomonas maltophilia (8.24%), followed by Serratia marcescens and Klebsiella pneumoniae (5.88%). The frequent GNB in HA-BSI patients were Escherichia coli (15.4%), Klebsiella pneumonia (12.68%), and Pseudomonas spp. (6.69%). Common multi-drug resistant organisms were vancomycin-resistant Enterococcus faecium (10.59% &amp; 3.69%) and methicillin-resistant Staphylococcus aureus (10.59% &amp; 3.07%). Conclusion: HA-BSI did not correlate with HA-CLABSI. HA-BSI reflects heterogenous population outcomes. For utilization as surveillance indicator, further assessment on exclusion criteria is required to improve specificity.