High-risk Sources Research Articles

Study on the Correlation between SLC39A8 Gene and Body Constitution-related Phenotypes and Hearing loss: Based on a Mendelian Randomization analysis

IntroductionWe examined the role of hearing functions as potential mediators in relationships between noise exposures and abnormal body constitution-related results. Additionally, we employed Mendelian randomization (MR) to explore the causative connections between hearing problems and bodily composition.Material and methodsGene connections pertaining to phenotypes of hearing loss and body constitution were obtained from publically available summary data collected from adult population genome-wide association studies. Colocalization analysis was utilized to scrutinize the genetic associations pertaining to age-related hearing impairment (ARHI) liability and BMI within the SLC39A8 locus. For a comprehensive examination, we employed bi-directional MR encompassing both the 'forward' direction (from the composition of the body to hearing) and the 'reverse' direction.ResultsA common causative variable (rs13107325) for BMI and ARHI at the SLC39A8 locus was supported by colocalization analysis, which revealed that the two diseases shared the variant at the SLC39A8 gene. The forward analyses showed that body fat percentage (BFP) was significantly linked with the risk of ARHI [OR =0.95 (95% CI:0.93 to 0.98)] and that waist circumference (WC) was favorably associated with sensorineural hearing loss (SNHL) [OR=0.83 (95% CI:0.72 to 0.97)].ConclusionsWe couldn't find any proof to back up a causal relationship between constitution and HL in the reverse MR Analysis. Colocalization analysis recommended that SLC39A8 variant was often the source of high ARHI and BMI risk. In prospective MR, we discovered causal associations between WC and BFP with SNHL and ARHI, respectively. Therefore, our results suggest lipid metabolic abnormalities leading to adverse health outcome may lead to HL.

Evaluation of methods for detection of Campylobacter in raw milk: A multi-country study

Raw milk is considered a high-risk source of Campylobacter due to faecal contamination from healthy cattle and farm environments, thus linking raw milk consumption to global outbreaks. Detection of Campylobacter in raw milk poses challenges due to low contamination levels and antibacterial properties of the milk. Culture-based protocols for Campylobacter detection in milk vary, mainly with regard to pH adjustment and the choice of enrichment broth.This European collaborative study was organised by the EU Reference Laboratory (EURL) for Campylobacter together with eight EU National Reference Laboratories (NRL) for Campylobacter with the purpose to evaluate methods for culture-based detection of Campylobacter in raw cow's milk. The study was divided into two parts, an interlaboratory part and an intralaboratory part, both organised around the same two protocols. The aim of protocol 1 was to evaluate the impact of pH adjustment and storage of the milk on the culturability of Campylobacter over time. Aliquots of the spiked milk were adjusted either to pH 7.0 or pH 7.6 or left unadjusted. The milk was stored up to 48 h at refrigerated temperature and Campylobacter was quantified according to ISO 10272-2 on day 0, 1 and 2. The aim of protocol 2 was to evaluate which enrichment broth, Bolton broth (BB) or Preston broth (PB), showed highest sensitivity in detection of Campylobacter. The spiked milk was enriched in BB and PB as described in ISO 10272-1:2017 or ISO 10272-1:2017/Amd1.2023. In the interlaboratory part, each milk batch was collected locally by each participating NRL/EURL and inoculated with the same Campylobacter strain. In the follow-up intralaboratory part, the EURL-Campylobacter repeated the tests in protocol 1 and 2 but used different Campylobacter strains and strains subjected to thermal stress prior to inoculation.The results show that pH adjustment of raw milk has a negligible impact on culture-based detection of Campylobacter, regardless of strain and level of environmental stress. The composition of milk and properties of the inoculated strain influence culture-based detection of Campylobacter over storage time, and strains subjected to additional stress prior to inoculation in milk are reduced in culturability much faster than the same strains prepared under normal conditions.Finally, the study showed that PB without Campylobacter growth supplement is less effective than BB in detecting Campylobacter in raw milk.

Spatial distribution and risk assessment of heavy metal pollution from enterprises in China

Heavy metal pollution (HMP) directly affects the safety of agricultural products, thereby impacting human health. Industrial emissions, as the main source of soil HMP in China, require in-depth research on their pollution risks. Based on national heavy metal (HM) enterprise data, this paper analyzes the spatial distribution characteristics of key enterprises involved in the HMP across the country. It constructs the risk assessment index system of enterprise HMP based on the “source-pathway-receptor” (SPR) process of the HMP, evaluates and partitions the risk of the HMP from enterprises nationwide. The results show that: (1) Enterprises and pollutant discharge outlets are mainly distributed in the eastern and southeastern coastal regions. Jiangxi, Yunnan, Guangdong, and Hunan Province are the main distribution regions of smelting enterprises, with the most types of HM pollutants. The hazard of pollution sources shows a spatial distribution pattern of higher risk in the southwest and north, and lower risk in the central region. Counties with high-risk pollution sources are mainly distributed in Yunnan, Hunan, Guangdong, Inner Mongolia, and Jiangxi Province. (2) The hazard of pollutant transmission pathways shows a spatial distribution pattern of higher risk in the southeast and lower risk in the central region. About 31.5 % of counties are at extremely high risk, mainly distributed in the southeastern coastal regions of Guangdong, Jiangsu, Zhejiang, Jiangxi, Shandong, and Fujian Province. (3) The vulnerability of the receptors shows significant clustering characteristics in the northeast and central regions. About 3.3 % of counties have a receptor vulnerability level of “extremely high,” mainly distributed in Inner Mongolia, Jilin, Heilongjiang, Liaoning Province in the northeast, as well as Hubei and Jiangsu Province. (4) About 1.55 % of counties nationwide have a comprehensive risk level of the HMP classified as “extremely high,” mainly distributed in Guangdong Province and Inner Mongolia. Additionally, some counties in Yunnan, Hunan, Jiangsu, Jiangxi, and Zhejiang Province have a risk of exceeding pollution standards, requiring further preventive measures to reduce pollution risks in the future. This paper can provide a scientific basis for the prevention and control (P&C) of the HMP in China.

Antimicrobial resistance and genotypic attributes of virulence among Vibrio spp. isolated from Japanese retail seafood

Bacterial diseases caused by Vibrio spp. are a significant impediment to the aquaculture industry owing to difficult-to-treat infections and mortality in farmed animals, affecting socioeconomic development. This study aimed to evaluate the role of Japanese retail seafood in the production of antimicrobial-resistant Vibrio spp. and pathogenic factors. One hundred seafood samples purchased from various retail supermarkets in Hiroshima, Japan, were examined using microbiological, phenotypic, and molecular techniques. One hundred and twenty-eight Vibrio isolates belonging to more than 11 species were identified and characterized. Among the 100 samples, 26 (26 %) tested positive for Vibrio spp. with antimicrobial resistance, while 44 (44 %) were positive for those carrying virulence determinants. Out of 128 isolates, V. alginolyticus was predominant (38 %), followed by V. parahaemolyticus (29 %), V. neocaledonicus (7.0 %), V. cholerae (6.3 %), among others. For virulence gene assessment, only six of the 10 virulence attributes, tlh (34.4 %), VPI (29.7 %), ompW (7.0 %), toxR (5.5 %), hlyA (3.9 %), and ompU (3.1 %), were detected in the isolates. tcpA, ctxA, ctxB, and tdh are absent. Eight V. cholerae isolates of international origin were VPI-positive, seven of which harbored the toxR regulon and other virulence genes. The blaTEM resistance gene was identified in V. alginolyticus (22 isolates). All 46 antimicrobial resistance gene-harboring isolates were phenotypically susceptible to cephalosporins, aztreonam, meropenem, tetracycline, chloramphenicol, and ciprofloxacin. Ampicillin resistance was the highest (91.3 %), followed by colistin (30.4 %) and fosfomycin (15.2 %). The multiple-antibiotic resistance index ranged from 0.2 to 0.47, suggesting that some isolates originate from high-risk contamination sources. Our results shed light on the incidence of potentially pathogenic Vibrio spp. and highlighted the importance of continuous monitoring to improve food safety in the seafood supply chain. These findings will be useful for developing microbiological risk assessments for retail seafood management.

Spatial distribution of available phosphorus in surface road and trackway surface materials on a sheep farm in Ireland

Farm roadway runoff is a high-risk source of pollution when connectivity with waters occurs. Nutrients in this runoff are dominated by fresh animal deposits, but recent dairy and beef farm studies showed that available phosphorus (P) accumulates in roadway surface material and can be lost in runoff. A current knowledge gap is to examine available P concentrations in unsealed roadway and trackway (non-maintained) network of a lowland sheep farm. The present study focused on a 45 ha farm stocked with 544 sheep in south-east Ireland. Ten locations were sampled along with the adjacent fields for available P (i.e., Morgan’s P) and ancillary parameters (e.g., pH, total P and heavy metals) in December 2022. The first sampling location was on an aggregate roadway and the other nine were on trackways representing an older aggregate roadway network used by the flock but now covered with soil and grass. Results showed a distinct difference in surface material pH between roadway and trackway locations. Trackways had a pH that mimicked adjacent fields around the agronomic optimum for grassland of ∼6.2. All sampling locations had elevated available P concentrations, ranging from 26.3 to 111.0 mg L−1 (mean 62.8 mg L−1), similar to the spatial distribution for dairy farms but above those found at beef farms previously studied. The highest available P concentrations were found in roadway and trackway sections adjacent to the farmyard. Other elevated sampling areas were on trackways (87.3 or 97.7 mg P L−1) away from the farmyard where sheep are funnelled to pasture, stop to seek shade, urinate and defecate but do not graze. By contrast the average available P concentration for the surrounding fields was 8.4 mg L−1 with a range of 2.7–15.9 mg L−1. Two sampling areas combine to create a critical source area where a high available P source becomes visibly mobilised as runoff during rainfall, discharges into an open drainage ditch, which is then connected to a local stream. Breaking the pathway before runoff enters the open ditch could be a cheap and effective way of mitigating nutrient losses at these two locations.

Automated cooling tower detection through deep learning for Legionnaires’ disease outbreak investigations: a model development and validation study

Cooling towers containing Legionella spp are a high-risk source of Legionnaires' disease outbreaks. Manually locating cooling towers from aerial imagery during outbreak investigations requires expertise, is labour intensive, and can be prone to errors. We aimed to train a deep learning computer vision model to automatically detect cooling towers that are aerially visible. Between Jan 1 and 31, 2021, we extracted satellite view images of Philadelphia (PN, USA) and New York state (NY, USA) from Google Maps and annotated cooling towers to create training datasets. We augmented training data with synthetic data and model-assisted labelling of additional cities. Using 2051 images containing 7292 cooling towers, we trained a two-stage model using YOLOv5, a model that detects objects in images, and EfficientNet-b5, a model that classifies images. We assessed the primary outcomes of sensitivity and positive predictive value (PPV) of the model against manual labelling on test datasets of 548 images, including from two cities not seen in training (Boston [MA, USA] and Athens [GA, USA]). We compared the search speed of the model with that of manual searching by four epidemiologists. The model identified visible cooling towers with 95·1% sensitivity (95% CI 94·0-96·1) and a PPV of 90·1% (95% CI 90·0-90·2) in New York City and Philadelphia. In Boston, sensitivity was 91·6% (89·2-93·7) and PPV was 80·8% (80·5-81·2). In Athens, sensitivity was 86·9% (75·8-94·2) and PPV was 85·5% (84·2-86·7). For an area of New York City encompassing 45 blocks (0·26 square miles), the model searched more than 600 times faster (7·6 s; 351 potential cooling towers identified) than did human investigators (mean 83·75 min [SD 29·5]; mean 310·8 cooling towers [42·2]). The model could be used to accelerate investigation and source control during outbreaks of Legionnaires' disease through the identification of cooling towers from aerial imagery, potentially preventing additional disease spread. The model has already been used by public health teams for outbreak investigations and to initialise cooling tower registries, which are considered best practice for preventing and responding to outbreaks of Legionnaires' disease. None.

A comprehensive, predictive mortality score for patients with bloodstream infections (PROBAC): a prospective, multicentre cohort study.

Bloodstream infections (BSI) are an important cause of mortality, although they show heterogeneity depending on patients and aetiological factors. Comprehensive and specific mortality scores for BSI are scarce. The objective of this study was to develop a mortality predictive score in BSI based on a multicentre prospective cohort. A prospective cohort including consecutive adults with bacteraemia recruited between October 2016 and March 2017 in 26 Spanish hospitals was randomly divided into a derivation cohort (DC) and a validation cohort (VC). The outcome was all-cause 30-day mortality. Predictors were assessed the day of blood culture growth. A logistic regression model and score were developed in the DC for mortality predictors; the model was applied to the VC. Overall, 4102 patients formed the DC and 2009 the VC. Mortality was 11.8% in the DC and 12.34% in the CV; the patients and aetiological features were similar for both cohorts. The mortality predictors selected in the final multivariate model in the DC were age, cancer, liver cirrhosis, fatal McCabe underlying condition, polymicrobial bacteraemia, high-risk aetiologies, high-risk source of infection, recent use of broad-spectrum antibiotics, stupor or coma, mean blood pressure <70 mmHg and PaO2/FiO2 ≤ 300 or equivalent. Mortality in the DC was <2% for ≤2 points, 6%-14% for 3-7 points, 26%-45% for 8-12 points and ≥60% for ≥13 points. The predictive score had areas under the receiving operating curves of 0.81 (95% CI 0.79-0.83) in the DC and 0.80 (0.78-0.83) in the VC. A 30 day mortality predictive score in BSI with good discrimination ability was developed and internally validated.

Potential high-risk release sources of thallium and arsenic from surrounding rocks of a typical thallium and arsenic mining area in southwest China

Abundant naturally and anthropogenically exposed surrounding rocks (NESRs and AESRs) in mining areas may pose persistent threats as sources of potentially toxic elements (PTEs), but this has been historically overlooked, especially for thallium (Tl) and arsenic (As). Here, the release risks of Tl and As from both NESRs and AESRs in a typical TlAs sulfide mining area were investigated. In a single leaching process, AESRs released 10.4 % of total Tl (157 μg L−1) and 32.5 % of total As (4089 μg L−1), 2–3 orders of magnitude higher than NESRs. Prolonged multiple leaching tests revealed notable and long-term risks of release of Tl and As from AESRs, associated with oxidation and dissolution of iron/sulfur-bearing minerals. Substantial release of PTEs was linked to the transformation/degradation of the -OH functional group and extensive dissolution of secondary sulfate minerals in AESRs. Ultrafiltration and STEM-EDS indicate that 18.4 % of water-extracted As released from AESRs existed as natural nanoparticles consisting of iron/sulfur-bearing minerals. This study highlights the high risks of Tl and As release from anthropogenically exposed surrounding rocks and the importance of nanoparticles in PTE transport, and provides insights into the control of PTEs in mining areas.

Long-Term Clinical Implications of High-Risk Cardiac Computed Tomography Findings in Patients With Acute Ischemic Stroke.

Cardiac computed tomography (CT) acquired during the initial acute stroke imaging protocol (acute cardiac CT) is increasingly used to screen for cardioembolism, but information on the long-term clinical implications of its findings is lacking. We performed a prospective, single-center cohort study in which consecutive patients with ischemic stroke underwent ECG-gated acute cardiac CT and were followed up for 2 years. The primary outcome was functional outcome assessed using the modified Rankin Scale. Secondary outcomes were death and occurrence of major adverse cardiovascular events (composite of recurrent ischemic stroke, myocardial infarction, and cardiovascular death). We compared patients with and without a high-risk structural source of embolism on acute cardiac CT. Of 452 included patients, 55 (12.2%) had a high-risk source of embolism, predominantly cardiac thrombi (38 patients) and signs of endocarditis (8 patients). Follow-up at 2 years was complete for 430 (95.1%) patients. Patients with a high-risk source of embolism had a worse functional outcome (median modified Rankin Scale, 6 [IQR, 2-6] versus 2 [IQR, 1-5]; adjusted common odds ratio, 2.92 [95% CI, 1.62-5.25]), increased mortality rate (52.7% versus 23.7%; adjusted hazard ratio [HR], 3.28 [95% CI, 1.94-5.52]), and major adverse cardiovascular events (38.9% versus 17.5%; adjusted HR, 3.20 [95% CI, 1.80-5.69]). A high-risk source of embolism was not associated with recurrent ischemic stroke (11.1% versus 9.6%; adjusted HR, 1.30 [95% CI, 0.49-3.44]). Structural high-risk sources of embolism on acute cardiac CT in patients with ischemic stroke were associated with poor long-term functional outcome and occurrence of major adverse cardiovascular events but not with recurrent stroke.

Constructing ZnTe Spherical Quantum Well for Efficient Light Emission.

ZnTe colloidal semiconductor nanocrystals (NCs) have shown promise for light-emitting diodes (LEDs) and displays, because they are free from toxic heavy metals (Cd). However, so far, their low photoluminescence (PL) efficiency (∼30%) has hindered their applications. Herein, we devised a novel structure of ZnTe NCs with the configuration of ZnSe (core)/ZnTe (spherical quantum well, SQW)/ZnSe (shell). The inner layer ZnTe was grown at the surface of ZnSe core with avoiding using highly active and high-risk Zn sources. Due to the formation of coherently strained heterostructure which reduced the lattice mismatch, and the thermodynamic growth of ZnTe, the surface or interface defects were suppressed. A high PL efficiency of >60% was obtained for the green light-emitting ZnSe/ZnTe/ZnSe SQWs after ZnS outer layer passivation, which is the highest value for colloidal ZnTe-based NCs. This work paves the way for the development of novel semiconductor NCs for luminescent and display applications.

Occurrence of Salmonella spp. in animal patients and the hospital environment at a veterinary academic hospital in South Africa.

Nosocomial infections caused by Salmonella spp. are common in veterinary facilities. The early identification of high-risk patients and sources of infection is important for mitigating the spread of infections to animal patients and humans. This study investigated the occurrence of Salmonella spp. among patients at a veterinary academic hospital in South Africa. In addition, this study describes the environmental factors that contribute to the spread of Salmonella spp. in the veterinary facility. This study used a dataset of Salmonella-positive animals and environmental samples submitted to the bacteriology laboratory between 2012 and 2019. The occurrence of Salmonella isolates at the veterinary hospital was described based on source, month, season, year, and location. Proportions and 95% confidence intervals were calculated for each variable. A total of 715 Salmonella isolates were recorded, of which 67.6% (483/715) came from animals and the remainder (32.4%, 232/715) came from environmental samples. The highest proportion (29.2%) of Salmonella isolates was recorded in 2016 and most isolates were reported in November (17.4%). The winter season had the lowest (14.6%) proportion of isolates reported compared to spring (31.3%), summer (27.8%), and autumn (26.4%). Salmonella Typhimurium (20.0%) was the most frequently reported serotype among the samples tested, followed by Salmonella Anatum (11.2%). Among the positive animal cases, most (86.3%) came from equine clinics. Most reported isolates differed based on animal species with S. Typhimurium being common in equines and S. Anatum in bovines. In this study, S. Typhimurium emerged as the predominant strain in animal and environmental samples. Equines were the most affected animals; however, Salmonella serotypes were also detected in the production animals. Environmental contamination was also a major source of Salmonella species in this study. To reduce the risk of transmission, strict infection prevention and control measures (biosecurity) must be implemented.

Different “nongrain” activities affect the accumulation of heavy metals and their source-oriented health risks on cultivated lands

“Nongrain” production on cultivated land is one of the primary environmental issues in China. Different “nongrain” activities may introduce different pollution sources to the local environment, leading to variations in heavy metal contents in soil, which can profoundly impact national food security. In this study, three typical “nongrain” regions (Nanxun (NX), Xiaoshan (XS) and Lin'an (LA)) with intensive aquaculture, tea planting and flower (seedling) growth on cultivated land around the Hangzhou metropolitan area were selected to address the spatial heterogeneity of accumulation levels, sources and source-oriented health risks of heavy metals in soil. The results showed that Hg was the main pollutant in NX and XS, while Cd and As were the major contaminants in LA. Aquiculture and sericultural industries (37.43%), natural sources (23.59%) and industrial activities (38.99%) were the major sources in NX; atmospheric deposition (37.73%), flower and seedling planting (23.49%) and metal-related industries (35.16%) were the major sources in XS; and atmospheric deposition (28.06%), excessive application of fertilizers and pesticides during tea planting (43.47%) and natural sources (28.47%) were the major sources in LA. The major risk population, area, exposure route and hazardous elements were children, LA, ingestion and As and Cr, respectively. From the perspective of source-based health risk assessment, in addition to natural sources that are difficult to intervene in, industrial activities, especially leather and wood process industries, metal-related industries and excessive fertilizer and pesticide application during tea planting contributed the most to the total health risk, which explained 67%, 41% and 42%, respectively, of the total risk in NX, XS and LA. High health risks are present in sources with heavy loadings of hazardous heavy metals (As and Cr); thus, to protect human health, the corresponding high-risk anthropogenic pollution sources in different “nongrain” areas need to be controlled.

Assessment of health risks associated with prediction of vegetable inorganic arsenic concentrations given different soil properties.

Inorganic arsenic (iAs) is a carcinogen. Vegetables such as water spinach (Ipomoea aquatica Forssk.) and amaranth (Amaranthus mangostanus L.) are recognized as high-risk sources of iAs exposure because they can accumulate significant amounts of iAs and are widely consumed. To ensure safe cultivation conditions, this study aimed to establish prediction models for iAs concentration in the edible parts of water spinach and amaranth based on soil properties. Subsequently, health risk assessments associated with iAs exposure through the consumption of these vegetables were conducted using prediction models. Soil samples were collected from agricultural fields in Taiwan and used in the pot experiments. Pearson correlation and partial correlation analyses were used to explore the relationship between soil properties, including total As, clay, organic matter, iron oxides and available phosphates, and iAs concentration in edible parts of water spinach and amaranth. Prediction models based on soil properties were developed by stepwise multiple linear regression. Health risk assessments were conducted using the Monte Carlo algorithm. The results indicate that total As and organic matter contents in soil were major predictors of iAs concentration in water spinach, whereas those in amaranth were total As and clay contents. Therefore, higher health risks for consuming water spinach and amaranth are associated with higher levels of organic matter and clay contents in soil, respectively, and these are crucial factors to consider to ensure food safety. This study suggested that As-elevated soils enriched with organic matter and clay contents should be avoided when growing water spinach and amaranth, respectively.

Quantifying the Contribution of Soil Heavy Metals to Ecological and Health Risk Sources

Quantifying the risk of soil heavy metal sources can identify the main pollution sources. It can provide a scientific basis for reducing the ecological and human health risks of soil heavy metals. Taking the shallow soil in a Pb-Zn mine watershed in northern Guangxi as a research object， ecological and human health risk assessments were conducted using potential ecological risk assessment （RI） and human health risk assessment （HRA）， and the source apportionment of soil heavy metals was completed using the absolute principal component-multiple linear regression receptor （APCS-MLR） model and random forest （RF） model. Then， a combined risk assessment model， consisting of RI， HRA， and APCS-MLR， was used to quantify the risk of soil heavy metal sources. The results showed that the contents of Pb， Zn， Cu， and Cd exceeded the environmental screening values for agricultural land with mean values of 342.77， 693.34， 61.27， and 3.08 mg·kg-1， respectively， and there was a certain degree of contamination. Pb， Cr， and As were the main health risk impact factors， with higher health risks for children than for adults. Three sources were identified： mining activities （Source Ⅰ）， soil parent material sources and original formation （Source Ⅱ）， and unknown sources. Pb， Zn， Cu， and Cd were mainly derived from Source Ⅰ， and Cr and As were controlled by unknown sources and Source Ⅱ. The source risk assessment results of soil heavy metals indicated that the potential ecological risk and non-carcinogenic risk were mainly from Source Ⅰ and Source Ⅱ， and carcinogenic risk was mainly from unknown sources. The unknown sources had a high proportion in source apportionment and risk assessment， and should be further researched to provide scientific basis for soil heavy metal control. The combined risk assessment model based on source analysis， focusing on the risk characteristics of different sources， can accurately identify high-risk pollution sources. It is a more reasonable and reliable risk assessment method.

Abstract WP283: Association of High-Risk Cardioembolic Sources on Cardiac CT With Acute Ischemic Stroke: A Case-Control Study

Background: Cardiac CT is increasingly used to detect a source of cardioembolism in stroke patients. We assessed the association between sources of embolism on cardiac CT, which were predefined as high-risk, and acute ischemic stroke. Methods: We analyzed data from Mind the Heart, a prospective, single-center, observational cohort study, and included consecutive patients with a suspected stroke who underwent ECG-gated cardiac CT during the initial stroke imaging protocol. Cases were patients with a final diagnosis of acute ischemic stroke (AIS), established by an adjudication committee. Controls were patients with stroke mimics (SMi). We excluded patients with a transient ischemic attack. Cardiovascular radiologists diagnosed structural high-risk sources of cardioembolism on cardiac CT according to predefined criteria. High-risk sources on cardiac CT were: cardiac thrombi, signs of endocarditis, recent myocardial infarction, prosthetic valve abnormalities, atrial myxomata and signs of rheumatic valvular disease. We used logistic regression, adjusting for age, sex, history of atrial fibrillation, and history of myocardial infarction. Results: Of 607 included patients, 452 had AIS (74%, median age 72, 59% male) and 155 had a SMi (26%, median age 70, 46% male). Diagnoses in the SMi group were: seizures (45/155, 29%) peripheral vestibulopathy (22/155, 14%), functional neurologic symptoms (16/155, 10%), benign headache disorder (8/155, 5%), intoxication (7/155, 5%), and other diagnoses (57/155, 37%). Cardiac CT detected a structural high-risk cardioembolic source in 52/452 AIS patients (12%) and in 5/155 SMi patients (3%, three patients with seizures, one with peripheral vestibulopathy and one with traumatic brain injury, aOR: 4.1, 95%CI 1.7-12.1). Cardiac thrombi were the most commonly observed high-risk sources of embolism and were detected in 38 (8%) AIS patients and in 2 (1%) SMi patients (aOR 7.0, 95%CI 2.1-43.9). Discussion and conclusion: A high-risk source of cardioembolism was detected on cardiac CT four times more often in patients with acute ischemic stroke than in patients with a stroke mimic. These data substantiate the clinical relevance of using acute CT to search for sources of cardioembolism in ischemic stroke patients.

Abstract WMP105: Association of Comorbidities, Stroke Etiology, and Polygenic Risk Score in Japanese Ischemic Stroke Patients

Background: Previous trans-ancestry genome-wide association studies (GWAS) of stroke reported 32 stroke risk loci, which were conducted predominantly in populations of European ancestry. The aim of this study was to examine the association of comorbidities, stroke etiology, and polygenic risk score (PRS) for stroke in the Japanese population. Methods: A total of 19702 ischemic stroke patients (n= 12241 male and n= 7261 female, median age 71 years old) were analyzed. We selected 19 significant stroke loci from a set of 32 stroke-related genes to construct the PRS in the Japanese population. The multivariate logistic regression model was conducted to estimate odds ratios (ORs) and 95% confidence intervals (95% CI) for comorbidity and stroke etiology across the PRS. Results: Compared with the lowest quintile PRS, the ORs (95%CIs) of atrial fibrillation/flutter at the top PRS quintile was significantly higher independently from traditional stroke risk factors (ORs, 2.13; 95%CIs 1.69-2.68). This significant association remained through continuous PRS (ORs, 1.59; 95%CIs 1.10-2.31). Other traditional stroke risk factors were not significantly associated with increased PRS. Similarly, we also investigated the association between the PRS and stroke subtype in patients with identified stroke etiology based on the TOAST criteria (n=6608). Continuous PRS was significantly higher in patients with cardioembolism by multivariate logistic analysis (ORs 1.45; 95%CIs 1.14-1.85). Conversely, continuous PRS was significantly lower in patients with small vessel occlusion (ORs 0.85; 95%CIs 0.73-0.98). Conclusion: In Japanese ischemic stroke patients, PRS for stroke was significantly associated with atrial fibrillation/flutter and cardioembolism. Our findings suggest that the importance of a PRS for stroke may be helpful for identifying high-risk sources of cardioembolism including atrial fibrillation in the Japanese population.

Dual resistance to heavy metals and antibiotics of Aeromonas hydrophila isolated from Carassius carassius (Linnaeus, 1758) in Lake Tonga, Algeria

Aeromonas hydrophila, a bacterium with significant virulence potential, is the predominant pathogenic bacteria naturally infecting fish. This study aims to identify the antibiogram and heavy metal resistance pattern of Aeromonas hydrophila obtained from both Carassius carassius fish and their surrounding water environment in Lake Tonga, Algeria. A total of 59 strains of Aeromonas hydrophila were isolated from 168 Carassius carassius samples and 144 waters samples of Lake Tonga. All the strains were tested for resistance to 13 antibiotics and three types of heavy metals (Cobalt, copper and cadmium) using disk diffusion and two-fold agar dilution method, respectively. Clinical macroscopic examination of the fish was also carried out. More than 14% of the examined fishes showed the characteristic clinical signs. Drug screening showed high levels of resistance to β-lactam antibiotics, 100% of the strains were resistant to ampicillin followed by cefalotin (91.53%) and ticarcillin (88.14%). More than 40% of the strains exhibited resistance against gentamicin, amikacin and chloramphenicol. The multiple antibiotic resistance (MAR) indexing of A. hydrophila strains showed that all of them originated from high-risk sources. Among tested heavy metals, bacterial isolates exhibited resistant pattern of Co&gt;Cu &gt;Cd. A positive correlation was observed between antimicrobial resistance and metal tolerance (Odds Ratio&gt;0.1). These resistant profiles could be useful information to avoid unnecessary use of chemical and antimicrobial products in the aquatic environment and to provide a novel approach to manage bacterial infection in fish.

962. Impact of Care Bundle Element Compliance on Clinical Outcomes for Pediatric Patients with Staphylococcus aureus Bacteremia

Abstract Background Staphylococcus aureus bacteremia (SAB) is a major cause of morbidity and mortality in children. The Infectious Disease Society of America (IDSA) outlines standards of care for patients with SAB known to positively impact morbidity and mortality, which have been validated in numerous studies within the adult population. However, there is limited data evaluating the clinical impact of compliance with these standards in pediatric patients. The primary objective of this study was to evaluate the impact of compliance with seven key bundle elements for the treatment of SAB in children. Methods This was a retrospective, single-center, cohort study of pediatric patients aged 18 years or younger with SAB admitted to Michigan Medicine from 2019–2022. The seven bundle elements evaluated included timely initiation of antibiotics, appropriate targeted antibiotic therapy, ID consultation, documented culture clearance, an echocardiogram for high-risk patients, source control, and appropriate duration of therapy. To be considered fully compliant, patients had to meet all seven elements. The primary endpoint was a composite endpoint of mortality and 30-day infection-related readmission rates. Results A total of 73 patients were included; 40 (54.8%) met the fully compliant bundle definition, and 33 (45.2%) were partially compliant. Fully compliant patients had a significantly lower incidence of combined mortality and readmission (7.5% vs. 24.2%; p = 0.0466). Lack of appropriate targeted therapy and lack of source control in patients with a removable source were the most common reasons for not meeting full bundle compliance (Table 1). Appropriate duration of therapy was met in 78.8% of patients in the partially compliant group (26/33, p = 0.0026).Table 1.Bundle Element Compliance.Bundle element compliance between the two cohorts (fully bundle compliant vs partially bundle compliant)Table 2.Primary OutcomeCombine primary outcome of 30-day mortality and 30-day infection-related readmission (fully bundle compliant vs partially bundle compliant) Conclusion Adherence to all bundle elements was associated with lower incidences of mortality and readmission. The results of this study will assist in quality improvement interventions at Michigan Medicine. Disclosures All Authors: No reported disclosures

Toxigenic Escherichia coli with high antibiotic resistance index recovered from sands of recreational beaches of Mumbai, India

Mumbai, India's seven-island city, is known for its sandy beaches as a major tourist attraction, but urbanization and industrialization have weakened the environment. Unregulated sewage disposal and untreated effluents off the coast have made the beach environment vulnerable. Therefore, monitoring water and sand quality at beaches should be mandatory. This study was thus designed to determine the microbiological status of selected sandy beaches, viz. Versova, Juhu, and Girgaon. The study found fecal coliforms in the sand, with stx1 and stx2 genes specific for Shiga toxin-producing E. coli pathotypes in 5.5 % of isolates, whereas the presence of eaeA gene specific for enteropathogenic E. coli pathotype was detected in 12.2 % of isolates, and the presence of the LT and ST genes specific for enterotoxigenic E. coli pathotype was detected in 6.6 % of isolates. Multiple antibiotic-resistant indices indicated high-risk contamination sources. The study suggests routine monitoring of pollution levels at coastal cities' beaches.

Research on key risk chain mining method for urban rail transit operations: A new approach to risk management

To ensure the safety of urban rail transit operations and uncover the transmission dynamics of risk sources, a key risk chain mining method for urban rail transit operation is proposed. Firstly, the H-Apriori association rule algorithm is proposed for the characteristics of low frequency but high riskiness of high hazard degree risk sources in urban rail transit operation, which adds a new hazard degree evaluation index to the traditional Apriori algorithm and couples with support degree two-dimensionally to mine the strong association rules among risk sources. Secondly, we construct a weighted risk network with risk sources as network nodes and strong association rules as network edges, and propose a key risk chain mining method for urban rail transit operation based on path search theory to mine key risk chains from the weighted risk network. Finally, using the actual urban rail transit operation data of a city in China as an example, a total of 17 key risk chains are mined, and then 5 key risk sources and 8 key chain break locations are obtained by riskiness and frequency analysis of key risk chains, and control plans are proposed. The research outcomes introduce a novel approach to mining risk chains in urban rail transit operations, shedding light on the propagation mechanisms, triggering probabilities, and degrees of unsafety associated with risk sources. The results not only provide theoretical support but also offer methodological guidance for pinpointing locations of risk chain breaks and refining the control of risk sources.