Whole apples have not been previously implicated in outbreaks of foodborne bacterial illness. We investigated a nationwide listeriosis outbreak associated with caramel apples. We defined an ...outbreak-associated case as an infection with one or both of two outbreak strains of Listeria monocytogenes highly related by whole-genome multilocus sequence typing (wgMLST) from 1 October 2014 to 1 February 2015. Single-interviewer open-ended interviews identified the source. Outbreak-associated cases were compared with non-outbreak-associated cases and traceback and environmental investigations were performed. We identified 35 outbreak-associated cases in 12 states; 34 (97%) were hospitalized and seven (20%) died. Outbreak-associated ill persons were more likely to have eaten commercially produced, prepackaged caramel apples (odds ratio 326·7, 95% confidence interval 32·2–3314). Environmental samples from the grower's packing facility and distribution-chain whole apples yielded isolates highly related to outbreak isolates by wgMLST. This outbreak highlights the importance of minimizing produce contamination with L. monocytogenes. Investigators should perform single-interviewer open-ended interviews when a food is not readily identified.
The ozonation of compounds in water is a complex process. The mechanisms are very complicated, the parameters are many, but the possibilities of developing cost-effective treatment schemes for ...drinking water and waste water are large. Most books available today concentrate on either drinking water or waste water treatment, seldom dealing with both or explaining the essential differences. And only rare exceptions deal with the how-to of ozone experiments. This practical guide fills the gap. It contains the cumulative knowledge on experimental design, execution, interpretation and application. Drawing on experience gained from hours spent on laboratory research with drinking and waste waters, literature study, intensive discussion with leading experts, perplexed reflection and deep thought, the book offers practical help to avoid common pitfalls and unnecessary work. This book is aimed at professionals in industry and research currently using ozonation who want to optimize their system, as well as students beginning work with ozonation. It contains just enough information for beginners to start with, but goes rapidly to the detailed information that advanced readers need.
Foodborne non-typhoidal salmonellosis causes approximately 1 million illnesses annually in the USA. In April 2015, we investigated a multistate outbreak of 65 Salmonella Paratyphi B variant L(+) ...tartrate(+) infections associated with frozen raw tuna imported from Indonesia, which was consumed raw in sushi. Forty-six (92%) of 50 case-patients interviewed ate sushi during the week before illness onset, and 44 (98%) of 45 who specified ate sushi containing raw tuna. Two outbreak strains were isolated from the samples of frozen raw tuna. Traceback identified a single importer as a common source of tuna consumed by case-patients; this importer issued three voluntary recalls of tuna sourced from one Indonesian processor. Four Salmonella Weltevreden infections were also linked to this outbreak. Whole-genome sequencing was useful in establishing a link between Salmonella isolated from ill people and tuna. This outbreak highlights the continuing foodborne illness risk associated with raw seafood consumption, the importance of processing seafood in a manner that minimises contamination with pathogenic microorganisms and the continuing need to ensure imported foods are safe to eat. People at higher risk for foodborne illness should not consume undercooked animal products, such as raw seafood.
Listeria monocytogenes is a foodborne pathogen that can cause bacteraemia, meningitis, and complications during pregnancy. In July 2012, molecular subtyping identified indistinguishable L. ...monocytogenes isolates from six patients and two samples of different cut and repackaged cheeses. A multistate outbreak investigation was initiated. Initial analyses identified an association between eating soft cheese and outbreak-related illness (odds ratio 17·3, 95% confidence interval 2·0–825·7) but no common brand. Cheese inventory data from locations where patients bought cheese and an additional location where repackaged cheese yielded the outbreak strain were compared to identify cheeses for microbiological sampling. Intact packages of imported ricotta salata yielded the outbreak strain. Fourteen jurisdictions reported 22 cases from March–October 2012, including four deaths and a fetal loss. Six patients ultimately reported eating ricotta salata; another reported eating cheese likely cut with equipment also used for contaminated ricotta salata, and nine more reported eating other cheeses that might also have been cross-contaminated. An FDA import alert and US and international recalls followed. Epidemiology-directed microbiological testing of suspect cheeses helped identify the outbreak source. Cross-contamination of cheese highlights the importance of using validated disinfectant protocols and routine cleaning and sanitizing after cutting each block or wheel.
We investigated a large multistate outbreak that occurred in the United States in 2015-2016. Epidemiologic, laboratory, and traceback studies were conducted to determine the source of the infections. ...We identified 907 case-patients from 40 states with illness onset dates ranging from July 3, 2015 to March 2, 2016. Sixty-three percent of case-patients reported consuming cucumbers in the week before illness onset. Ten illness sub-clusters linked to events or purchase locations were identified. All sub-clusters investigated received cucumbers from a single distributor which were sourced from a single grower in Mexico. Seventy-five cucumber samples were collected, 19 of which yielded the outbreak strain. Whole genome sequencing performed on 154 clinical isolates and 19 cucumber samples indicated that the sequenced isolates were closely related genetically to one another. This was the largest US foodborne disease outbreak in the last ten years and the third largest in the past 20 years. This was at least the fifth multistate outbreak caused by contaminated cucumbers since 2010. The outbreak is noteworthy because a recall was issued only 17 days after the outbreak was identified, which allowed for the removal of the contaminated cucumbers still available in commerce, unlike previous cucumber associated outbreaks. The rapid identification and response of multiple public health agencies resulted in preventing this from becoming an even larger outbreak.
Norovirus is the leading cause of foodborne disease in the United States. During October 2011-January 2013, we conducted surveillance for norovirus infection in Minnesota among callers to a ...complaint-based foodborne illness hotline who reported diarrhea or vomiting. Of 241 complainants tested, 127 (52.7%) were positive for norovirus.
Synopsis
Incorporation of sunscreens into lipid carriers with an increased sun protection factor (SPF) has not yet been fully accomplished. In the present paper, the effectiveness of a sunscreen ...mixture, incorporated into the novel topical delivery systems, i.e. solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), used as ultraviolet (UV) protector enhancers with a distinctly higher loading capacity has been developed and evaluated. SLN and NLC were produced by hot high pressure homogenization technique in lab scale production. Size distribution and storage stability of formulations were investigated by laser diffractometry and photon correlation spectroscopy. Nanoparticles were characterized by their melting and recrystallization behaviour recorded by differential scanning calorimetry. Lipid nanoparticles produced with a solid matrix (SLN and NLC) were established as a UV protection system. The loading capacities for molecular sunscreens reported before now were in the range of 10–15%. It was possible to load NLC with up to 70% with molecular sunscreen, which is appropriate to obtain high SPFs with this novel UV protection system. The developed formulations provide a beneficial alternative to conventional sunscreen formulations. The UV protective efficacy of the lipid particles varied with the nature of lipid and UV wavelength.
Résumé
L'incorporation des protections solaires dans des porteurs de lipide avec un facteur accru de protection du soleil n'a pas été encore entièrement accomplie. Dans le papier de recherches il a été développée et évalué l'efficacité d'un mélange de protection solaire incorporé aux systèmes topiques, c.‐à‐d. les nanoparticule lipidique solide (SLN) et porteurs lipidique nano‐structurés (NLC), utilisés en tant que renforceurs de protection ultra‐violets (UV) et possédant une capacité nettement plus élevée de chargement. SLN et NLC ont été produits par une technique d'homogénéisation à haute pression chaude, en production d’échelle de laboratoire. La grandeur de distribution et la stabilité de stockage des formulations ont étéétudiées par difractometrie laser (LD) et spectroscopie de corrélation fotonique (PCS). Les nanoparticules ont été caractérisées par leurs comportement de fusion et de recristallisation, et enregistrées par calorimétrie à balayage différentiel (DSC). Des nanoparticules lipidique produites avec une matrice solide (SLN et NLC) ont étéétablis comme système de protection UV. Les capacités de chargement, pour les protections solaires moléculaires rapportées avant, étaient maintenant dans la gamme de 10–15%. Il a été possible de charger les NLC avec jusqu’à 70% de protection solaire moléculaire, ce qui est appropriée pour obtenir les facteurs élevés de protection solaire (SPF) avec ce système de protection UV. Les formulations développées fournissent une alternative salutaire aux formulations de protection solaire conventionelles. L'efficacité de la protection UV des particules de lipide a changé avec la nature du lipide et la longueur d'onde des UV.
Norovirus is the etiology for about 60% of foodborne outbreaks identified in Minnesota. Contamination of food during preparation by food handlers is by far the most common cause of these outbreaks. ...Norovirus outbreaks due to commercially distributed foods are rarely reported in the United States, and only 2 have been previously identified in Minnesota, both due to oysters.
In August 2016, we investigated an outbreak of norovirus gastroenteritis in Minnesota that was linked to consumption of commercially distributed ice cream at multiple venues. Sanitarians from local public health agencies visited the facilities involved for follow-up, and case-control studies were conducted. The outbreak was identified by linking multiple independent illness reports to a centralized foodborne illness complaint system and subsequently confirmed though genotyping of stool specimens.
A total of 15 cases from 4 venues were reported. Raspberry chocolate chip ice cream was statistically associated with illness in 2 analytic studies (6 of 7 cases vs 0 of 7 controls; odds ratio, undefined; P = .005). Norovirus GII.17P17 (GII.17 Kawasaki) strains from case stool specimens matched norovirus found in frozen raspberries imported from China that were used to make the implicated ice cream.
To our knowledge, this is the first norovirus outbreak due to commercially distributed frozen berries identified in the United States. To detect norovirus outbreaks associated with commercially distributed food vehicles, investigators should thoroughly investigate all norovirus outbreaks (including stool testing and genotyping), coordinate complaint and response activities across agencies and jurisdictions, and consider testing food for norovirus when appropriate.
Summary
Salmonella enterica is a global health concern because of its widespread association with foodborne illness. Bayesian models have been developed to attribute the burden of human salmonellosis ...to specific sources with the ultimate objective of prioritizing intervention strategies. Important considerations of source attribution models include the evaluation of the quality of input data, assessment of whether attribution results logically reflect the data trends and identification of patterns within the data that might explain the detailed contribution of different sources to the disease burden. Here, more than 12,000 non‐typhoidal Salmonella isolates from human, bovine, porcine, chicken and turkey sources that originated in Minnesota were analysed. A modified Bayesian source attribution model (available in a dedicated R package), accounting for non‐sampled sources of infection, attributed 4,672 human cases to sources assessed here. Most (60%) cases were attributed to chicken, although there was a spike in cases attributed to a non‐sampled source in the second half of the study period. Molecular epidemiological analysis methods were used to supplement risk modelling, and a visual attribution application was developed to facilitate data exploration and comprehension of the large multiyear data set assessed here. A large amount of within‐source diversity and low similarity between sources was observed, and visual exploration of data provided clues into variations driving the attribution modelling results. Results from this pillared approach provided first attribution estimates for Salmonella in Minnesota and offer an understanding of current data gaps as well as key pathogen population features, such as serotype frequency, similarity and diversity across the sources. Results here will be used to inform policy and management strategies ultimately intended to prevent and control Salmonella infection in the state.
The formation of coils is common in nature when achiral symmetry breaking occurs. Here we describe spectacular examples of single, double and triple coils observed in smectic liquid crystal phases of ...achiral banana-shaped molecules. Such molecules form chiral smectic phases due to two symmetry-breaking instabilities: polar molecular packing, and molecular tilt. The appearance of helical filaments at the isotropic-smectic transition is therefore a direct indication of the achiral symmetry-breaking of the smectic structures. The number of observed left- and right-handed domains is equal, reflecting the achiral nature of the constituent molecules. Our studies indicate that the helical filaments consist of concentric smectic layers. The coiling stabilizes the growth process and suppresses the penetration of molecules from the isotropic phase, leading to moving of the tip with constant speed.
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