Listeria monocytogenes in Stone Fruits Linked to a Multistate Outbreak: Enumeration of Cells and Whole-Genome Sequencing.

In 2014, the identification of stone fruits contaminated with Listeria monocytogenes led to the subsequent identification of a multistate outbreak. Simultaneous detection and enumeration of L. monocytogenes were performed on 105 fruits, each weighing 127 to 145 g, collected from 7 contaminated lots. The results showed that 53.3% of the fruits yielded L. monocytogenes (lower limit of detection, 5 CFU/fruit), and the levels ranged from 5 to 2,850 CFU/fruit, with a geometric mean of 11.3 CFU/fruit (0.1 CFU/g of fruit). Two serotypes, IVb-v1 and 1/2b, were identified by a combination of PCR- and antiserum-based serotyping among isolates from fruits and their packing environment; certain fruits contained a mixture of both serotypes. Single nucleotide polymorphism (SNP)-based whole-genome sequencing (WGS) analysis clustered isolates from two case-patients with the serotype IVb-v1 isolates and distinguished outbreak-associated isolates from pulsed-field gel electrophoresis (PFGE)-matched, but epidemiologically unrelated, clinical isolates. The outbreak-associated isolates differed by up to 42 SNPs. All but one serotype 1/2b isolate formed another WGS cluster and differed by up to 17 SNPs. Fully closed genomes of isolates from the stone fruits were used as references to maximize the resolution and to increase our confidence in prophage analysis. Putative prophages were conserved among isolates of each WGS cluster. All serotype IVb-v1 isolates belonged to singleton sequence type 382 (ST382); all but one serotype 1/2b isolate belonged to clonal complex 5. IMPORTANCE: WGS proved to be an excellent tool to assist in the epidemiologic investigation of listeriosis outbreaks. The comparison at the genome level contributed to our understanding of the genetic diversity and variations among isolates involved in an outbreak or isolates associated with food and environmental samples from one facility. Fully closed genomes increased our confidence in the identification and comparison of accessory genomes. The diversity among the outbreak-associated isolates and the inclusion of PFGE-matched, but epidemiologically unrelated, isolates demonstrate the high resolution of WGS. The prevalence and enumeration data could contribute to our further understanding of the risk associated with Listeria monocytogenes contamination, especially among high-risk populations.

Volume determination of irregularly-shaped quasi-spherical nanoparticles.

Nanoparticles (NPs) are widely used in diverse application areas, such as medicine, engineering, and cosmetics. The size (or volume) of NPs is one of the most important parameters for their successful application. It is relatively straightforward to determine the volume of regular NPs such as spheres and cubes from a one-dimensional or two-dimensional measurement. However, due to the three-dimensional nature of NPs, it is challenging to determine the proper physical size of many types of regularly and irregularly-shaped quasi-spherical NPs at high-throughput using a single tool. Here, we present a relatively simple method that determines a better volume estimate of NPs by combining measurements from their top-down projection areas and peak heights using two tools. The proposed method is significantly faster and more economical than the electron tomography method. We demonstrate the improved accuracy of the combined method over scanning electron microscopy (SEM) or atomic force microscopy (AFM) alone by using modeling, simulations, and measurements. This study also exposes the existence of inherent measurement biases for both SEM and AFM, which usually produce larger measured diameters with SEM than with AFM. However, in some cases SEM measured diameters appear to have less error compared to AFM measured diameters, especially for widely used IS-NPs such as of gold, and silver. The method provides a much needed, proper high-throughput volumetric measurement method useful for many applications. Graphical Abstract The combined method for volume determination of irregularly-shaped quasi-spherical nanoparticles.

Safety and effectiveness assessment of the surpass evolve (SEASE): a post-market international multicenter study.

BACKGROUND: Flow diverters are the first-line treatment for specific intracranial aneurysms (iA). Surpass Evolve (SE) is a new-generation 64-wire flow diverter with a high braid angle. Current literature on the SE is limited. We aimed to report the first international real-world experience evaluating the safety and effectiveness of the SE. METHODS: The Safety and Effectiveness Assessment of the Surpass Evolve (SEASE) was a multicenter retrospective international post-marketing cohort study including consecutive patients treated with SE for iAs between 2020 and 2022. Demographic, clinical, and angiographic data were collected. Primary effectiveness was independent core lab adjudicated complete occlusion rates (Raymond-Roy Class 1) at last follow-up. Primary safety were major ischemic/hemorrhagic events and mortality. RESULTS: In total, 305 patients with 332 aneurysms underwent SE implantation. The patients had a median age of 59 [50-67] years, and 256 (83.9%) were female. The baseline modified Rankin scale score was 0-2 in 291 patients (96.7%). Most aneurysms were unruptured (285, 93.4%) and saccular (309, 93.1%). Previous treatment was present in 76 (22.9%) patients. The median aneurysm size was 5.1 [3.4-9.0] mm, and the median neck width was 3.6 [2.7-5.1] mm. Most aneurysms were in the internal carotid artery C6 ophthalmic segment (126, 38.0%), followed by the communicating segment (58, 17.5%). At median 10.2 [6.4-12.9] months follow-up, 233 (73.0%) aneurysms achieved complete occlusion. After adjusting for confounders, complete occlusion remained consistent. Major stroke and procedure-related mortality were reported in 6 (2%) and 2 (0.7%) cases, respectively. CONCLUSION: These results demonstrate that SE has a consistently high effectiveness and favorable safety for the treatment of iAs.

Benefits of nature-based walking for breast cancer survivors.

INTRODUCTION: Physical activity (PA) promotes significant physical and psychosocial benefits for breast cancer survivors. While evidence exists regarding recommendations for the frequency, duration and intensity of exercise that optimise PA benefits for cancer survivors, the role of the environment in achieving optimal outcomes has yet to be determined. This paper presents a protocol for a clinical trial to evaluate the feasibility of a 3-month nature-based walking programme for breast cancer survivors. Secondary outcomes assessed include the impact of the intervention on fitness, quality of life outcomes, and biomarkers of ageing and inflammation. METHODS AND ANALYSIS: The trial is a 12-week single-arm pilot study. Twenty female breast cancer survivors will engage in a supervised moderate intensity walking intervention in small groups in a nature reserve for 50 minutes three times per week. Data will be collected at baseline and end of study, and include assessment of inflammatory cytokines and anti-inflammatory myokines (TNF-α, IL-1ß, IL-6, CRP, TGF-ß, IL-10, IL-13), as well as ageing (DNA methylation, ageing genes) biomarkers; surveys (Patient-Reported Outcomes Measurement Information System-29, Functional Assessment of Cancer Therapy-General, Post-Traumatic Growth Inventory); and fitness assessments (6 min Walk Test, Grip-Strength, One Repetition-Maximum Leg Press). Participants will also complete weekly surveys assessing social support and participate in an exit interview. This is an important first step for future research on the influence of exercise environment on cancer survivor PA outcomes. ETHICS AND DISSEMINATION: This study was approved by the Cedars Sinai Medical Center Institutional Review Board (IIT2020-20). Findings will be disseminated through academic manuscripts, conferences, and community presentations. TRIAL REGISTRATION NUMBER: NCT04896580.

Molecular Subtyping of Shiga Toxin-Producing Escherichia coli Using a Commercial Repetitive Sequence-Based PCR Assay.

PCR-based typing methods, such as repetitive sequence-based PCR (rep-PCR), may facilitate the identification of Shiga toxin-producing Escherichia coli (STEC) by serving as screening methods to reduce the number of isolates to be processed for further confirmation. In this study, we used a commercial rep-PCR typing system to generate DNA fingerprint profiles for STEC O157 (n = 60) and non-O157 (n = 91) isolates from human, food, and animal samples and then compared the results with those obtained from pulsed-field gel electrophoresis (PFGE). Fifteen serogroups were analyzed using the Kullback Leibler or extended Jaccard statistical method, and the unweighted pair group method of averages algorithm was used to create dendrograms. Among the 151 STEC isolates tested, all were typeable by rep-PCR. Among the non-O157 isolates, rep-PCR clustered 79 (88.8%) of 89 isolates according to serogroup status, with peak differences ranging from 1 (96.4% similarity) to 12 (58.7% similarity). The genetic relatedness of the non-O157 serogroups mirrored the branching of distinct clonal groups elucidated by other investigators. Although the discriminatory power of rep-PCR (Simpson's index of diversity [SID] = 0.954) for the O157 isolates was less than that of PFGE (SID = 0.993), rep-PCR was able to identify 29 pattern types, suggesting that this method can be used for strain typing, although not to the same level as PFGE. Similar results were obtained from analysis of the non-O157 isolates. With rep-PCR, we assigned non-O157 isolates to 46 pattern types with a SID of 0.977. By PFGE, non-O157 STEC strains were divided into 77 pattern types with a SID of 0.996. Together, these results indicate the ability of the rep-PCR typing system to distinguish between and within O157 and non-O157 STEC groups. Rapid PCR-based typing methods could be invaluable tools for use in outbreak investigations by excluding unrelated STEC isolates within 24 h.