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The World Health Organization developed the Tricycle surveillance programme to obtain a global picture of antimicrobial resistance, especially in countries with limited surveillance capacity. The programme was developed within a One Health perspective. Tricycle provides a framework for applying a standardized technical protocol to determining the prevalence of extended-spectrum [beta]-lactamase (ESBL)-producing Escherichia coli in three sectors: the human, animal and environment sectors. Regular use of the protocol would enable information to be obtained on time trends and on inter- and intraregional variations, thereby generating dynamic data on antibacterial resistance for decision-makers. To date, 19 countries have begun implementing the Tricycle protocol, while other countries will start implementation in the coming years. The Network for Enhancing Tricycle ESBL Surveillance Efficiency (NETESE) was established to support countries implementing the Tricycle protocol. Currently, NETESE includes representatives from 15 institutions in eight low- or middle-income countries at different stages of Tricycle protocol implementation, and from four European countries involved in devising the protocol. This paper describes the Tricycle protocol, reports the initial experiences of NETESE participants with its implementation and discusses future challenges and opportunities. L'Organisation mondiale de la Sante a developpe le programme de surveillance Tricycle afin d'avoir une vue globale de la resistance aux antimicrobiens, en particulier dans les pays oU les capacites de surveillance sont limitees. Ce programme a ete mis au point selon l'approche <>. Tricycle etablit le cadre d'application d'un protocole technique standardise qui vise a mesurer la prevalence de souches d'Escherichia coli productrices de [beta]-lactamase a spectre etendu (BLSE) dans trois secteurs: humain, animal et environnemental. Lusage regulier du protocole permettrait d'obtenir des informations sur l'evolution dans le temps et les variations inter- et intraregionales, ce qui genererait des donnees dynamiques sur la resistance aux antimicrobiens pour les decideurs. A ce jour, 19 pays se sont lances dans la mise en place du protocole Tricycle, tandis que d'autres prevoient de le faire dans les annees a venir. Le reseau NETESE (Network for Enhancing Tricycle ESBL Surveillance Efficiency) a ete cree pour les aider a appliquer ce protocole. Actuellement, le reseau NETESE reunit des representants de 15 institutions dans huit pays a revenu faible ou intermediaire a differents stades de mise en oeuvre du protocole Tricycle, ainsi que quatre pays europeens impliques dans sa conception. Le present document decrit le protocole Tricycle, partage les premieres experiences des participants au reseau NETESE en matiere de deploiement, et aborde les futurs defis et opportunites qui y sont lies. La Organizacion Mundial de la Salud desarrollo el programa de vigilancia Tricycle para obtener un panorama global de la resistencia a los antimicrobianos, especialmente en paises con una capacidad de vigilancia limitada. El programa se creo desde la perspectiva One Health. Tricycle proporciona un marco que permite aplicar un protocolo tecnico estandarizado con el fin de determinar la prevalencia de Escherichia coli productora de [beta]-lactamasa de espectro extendido (ESBL) en tres sectores: el humano, el animal y el medio ambiente. El uso habitual del protocolo permitiria obtener informacion sobre las tendencias temporales y las variaciones inter e intrarregionales, generando asi datos dinamicos sobre la resistencia a los antibacterianos que resultarian utiles para los responsables de la toma de decisiones. Hasta la fecha, 19 paises han comenzado a implementar el protocolo Tricycle, mientras que otros paises comenzaran a aplicarlo en los proximos anos. La red NETESE (Network for Enhancing Tricycle ESBL Surveillance Efficiency), se creo para apoyar a los paises que implementan el protocolo Tricycle. Actualmente, NETESE esta formada por representantes de 15 instituciones de ocho paises con ingresos medios o bajos, que se encuentran en diferentes etapas de implementacion del protocolo Tricycle. Tambien incluye a representantes de cuatro paises europeos que intervienen en el diseno del protocolo. El presente documento describe el protocolo Tricycle, recoge las primeras experiencias de los participantes de NETESE durante la implementacion de dicho protocolo, y aborda tanto los retos como las oportunidades futuras. [phrase omitted], Introduction To provide a picture of antimicrobial resistance in humans, animals and the environment in all countries, especially those with limited surveillance capacity, the World Health Organization (WHO) Advisory Group [...]

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1523-1739.2008.01018.x Byline: INNOCENT B. RWEGO (*s.), GILBERT ISABIRYE-BASUTA (*), THOMAS R. GILLESPIE ([dagger][double dagger]), TONY L. GOLDBERG (*[dagger][double dagger]) Keywords: disease ecology; ecosystem health; Escherichia coli; primates; zoonoses Abstract: Abstract: Habitat overlap can increase the risks of anthroponotic and zoonotic pathogen transmission between humans, livestock, and wild apes. We collected Escherichia coli bacteria from humans, livestock, and mountain gorillas (Gorilla gorilla beringei) in Bwindi Impenetrable National Park, Uganda, from May to August 2005 to examine whether habitat overlap influences rates and patterns of pathogen transmission between humans and apes and whether livestock might facilitate transmission. We genotyped 496 E. coli isolates with repetitive extragenic palindromic polymerase chain reaction fingerprinting and measured susceptibility to 11 antibiotics with the disc-diffusion method. We conducted population genetic analyses to examine genetic differences among populations of bacteria from different hosts and locations. Gorilla populations that overlapped in their use of habitat at high rates with people and livestock harbored E. coli that were genetically similar to E. coli from those people and livestock, whereas E. coli from gorillas that did not overlap in their use of habitats with people and livestock were more distantly related to human or livestock bacteria. Thirty-five percent of isolates from humans, 27% of isolates from livestock, and 17% of isolates from gorillas were clinically resistant to at least one antibiotic used by local people, and the proportion of individual gorillas harboring resistant isolates declined across populations in proportion to decreasing degrees of habitat overlap with humans. These patterns of genetic similarity and antibiotic resistance among E. coli from populations of apes, humans, and livestock indicate that habitat overlap between species affects the dynamics of gastrointestinal bacterial transmission, perhaps through domestic animal intermediates and the physical environment. Limiting such transmission would benefit human and domestic animal health and ape conservation. Abstract (Spanish): Transmision de Bacterias Gastrointestinales entre Humanos, Gorilas de Montana y Ganado en el Parque Nacional Bwindi Impenetrable, Uganda Resumen: El traslape de habitats puede incrementar los riesgos de transmision de patogenos antroponotica y zoonotica entre humanos, ganado y simios silvestres. Recolectamos bacterias Escherichia coli de humanos, ganado y gorilas de montana (Gorilla gorilla beringei) en el Parque Nacional Bwindi Impenetrable, Uganda, de mayo a agosto 2005 para examinar si el traslape de habitat influye en las tasas y patrones de transmision de patogenos entre humanos y simios y si el ganado facilita esa transmision. Determinamos el genotipo de 496 aislados de E. coli con marcaje de reaccion en cadena de polimerasa palindromica extragenica (rep-PCR) y medimos la susceptibilidad a 11 antibioticos con el metodo de difusion de disco. Realizamos analisis de genetica poblacional para examinar las diferencias geneticas entre poblaciones de bacterias de huespedes y localidades diferentes. Las poblaciones de gorilas con alto grado de traslape en el uso de habitat con humanos y ganado presentaron E. coli geneticamente similar a E. coli de humanos y ganado, mientras que E. coli de gorilas sin traslape en el uso habitat con humanos y ganado tuvo relacion lejana con las bacterias de humanos y ganado. Treinta y cinco porciento de los aislados de humanos, 27% de los aislados de ganado y 17% de los aislados de gorilas fueron clinicamente resistentes a por lo menos un antibiotico utilizado por habitantes locales, y la proporcion de gorilas individuales con presencia de aislados resistentes declino en las poblaciones proporcionalmente con la disminucion en el grado de traslape con humanos. Estos de patrones de similitud genetica y resistencia a antibioticos entre E. coli de poblaciones de simios, humanos y ganado indican que el traslape de habitat entre especies afecta la dinamica de transmision de bacterias gastrointestinales, probablemente a traves de animales domesticos intermediarios y el ambiente fisico. La limitacion de esa transmision beneficiaria a la salud de humanos y animales domesticos y a la conservacion de simios. Author Affiliation: (*)Makerere University, Department of Zoology, P.O. Box 7062, Kampala, Uganda ([dagger])Department of Pathobiology, College of Veterinary Medicine, University of Illinois, 2001 South Lincoln Avenue, Urbana, IL 61802, U.S.A. ([double dagger])Department of Anthropology, University of Illinois, Urbana, IL 61801, U.S.A. Article History: Paper submitted October 15, 2007; revised manuscript accepted March 10, 2008. Article note: (s.) email rwegovet@yahoo.co.uk

This study aims to develop, characterize, and evaluate the best statin-loaded Collagen Silver nanoparticle-coated polycaprolactone nanofibers by electrospinning technique. The characterization and evaluation results reveal that nanofibers had shown an aligned Collagen Silver nanoparticle-coated polycaprolactone nanofibers distribution of fibers and aliment of collagen and silver nanoparticle coating material on the surface of the nanofibers. Furthermore, the electrospun nanofibers have shown no interaction between the drug and collagen and PCL polymeric material and have demonstrated controlled drug release for 360 h and significant degradation for 60 days of the study. In vitro, among the nanofiber treatment groups and the control groups, Pravastatin Collagen Silver nanoparticle-coated polycaprolactone nanofibers have shown cell proliferation and migration of NHDF cells and blood vessel development in the CAM assay and potential anti-bacterial activity against S. aureus and E. coli. In vivo, the Pravastatin Collagen Silver nanoparticle-coated polycaprolactone nanofibers have demonstrated improved wound recovery, reepithelization, fibroblast cell proliferation, angiogenesis, and ECM remodeling and enhanced VEGF-sprouting in the excised tissues of streptozotocin-induced diabetic rats for 7, 14, and 21 days of the study. Therefore, the developed Pravastatin Collagen Silver nanoparticle-coated polycaprolactone nanofibers could be a promising wound-dressing platform for effectively treating and managing diabetic wounds. Highlights * Nanofiber wound dressings provide numerous structural features in biomaterials. * Polycaprolactone can release the repurposed statin molecules into the wound site in a controlled manner. * In diabetic wounds, ECM tissue remodeling stimulates repair and vessel growth. * Pravastatin has been demonstrated to improve angiogenesis and ECM secretion for wound healing in diabetic conditions. KEYWORDS diabetic wounds, electrospinning, hypoxic microenvironment, nanofibers, pro-angiogenesis, re-epithelization, wound dressing, 1 | INTRODUCTION The most prevalent cause of death in diabetic individuals is diabetic wounds. Unfortunately, the bulk of the treatment options in the market do not entirely address how [...]

Previous studies have shown that a majority of vendors at farmers markets reuse cardboard cartons to store and transport produce to and from farmers markets, rendering the cartons a potential source of microbial contamination. This study investigated the ability of foodborne pathogens to persist on cardboard cartons over 44 days. Briefly, a mixture of Listeria monocytogenes, Salmonella spp., and E. coli O157:H7 were inoculated onto cardboard coupons and pathogen viability was quantified for up to 44 days. The results demonstrated that while E. coli O157:H7 survived for no longer than 2 days, L. monocytogenes and Salmonella spp. were recovered up to 32 and 44 days, respectively. These results highlight key challenges associated with reusing cardboard containers and the potential of microbial contamination transfer onto produce. The results of this study emphasize the need for science-based food safety training for vendors and managers at farmers markets to ensure that only containers that can be easily cleaned and sanitized are used to transport and store produce., Introduction According to the U.S. Department of Agriculture (USDA), the number of farmers markets in the U.S. has grown rapidly over the past two decades from 1,755 in 1994 to [...]

Living systems can generate an enormous range of cellular functions, from mechanical infrastructure and signalling networks to enzymatic catalysis and information storage, using a notably limited set of chemical functional groups. This observation is especially notable when compared to the breadth of functional groups used as the basis for similar functions in synthetically derived small molecules and materials. The relatively small cross-section between biological and synthetic reactivity space forms the foundation for the development of bioorthogonal chemistry, in which the absence of a pair of reactive functional groups within the cell allows for a selective in situ reaction.sup.1-4. However, biologically 'rare' functional groups, such as the fluoro.sup.5, chloro.sup.6,7, bromo.sup.7,8, phosphonate.sup.9, enediyne.sup.10,11, cyano.sup.12, diazo.sup.13, alkene.sup.14 and alkyne.sup.15-17 groups, continue to be discovered in natural products made by plants, fungi and microorganisms, which offers a potential route to genetically encode the endogenous biosynthesis of bioorthogonal reagents within living organisms. In particular, the terminal alkyne has found broad utility via the Cu(i)-catalysed azide-alkyne cycloaddition 'click' reaction.sup.18. Here we report the discovery and characterization of a unique pathway to produce a terminal alkyne-containing amino acid in the bacterium Streptomyces cattleya. We found that l-lysine undergoes an unexpected reaction sequence that includes halogenation, oxidative C-C bond cleavage and triple bond formation through a putative allene intermediate. This pathway offers the potential for de novo cellular production of halo-, alkene- and alkyne-labelled proteins and natural products from glucose for a variety of downstream applications. Microbial generation of a terminal-alkyne-containing amino acid can be encoded into E. coli and provides the potential for in vivo generation of proteins and natural products for click chemistry., Author(s): J. A. Marchand [sup.1] , M. E. Neugebauer [sup.1] , M. C. Ing [sup.2] , C.-I. Lin [sup.3] , J. G. Pelton [sup.4] , M. C. Y. Chang [sup.2] [...]

Pathogenic bacteria such as Escherichia coli assemble surface structures termed pili, or fimbriae, to mediate binding to host-cell receptors.sup.1. Type 1 pili are assembled via the conserved chaperone-usher pathway.sup.2-5. The outer-membrane usher FimD recruits pilus subunits bound by the chaperone FimC via the periplasmic N-terminal domain of the usher. Subunit translocation through the [beta]-barrel channel of the usher occurs at the two C-terminal domains (which we label CTD1 and CTD2) of this protein. How the chaperone-subunit complex bound to the N-terminal domain is handed over to the C-terminal domains, as well as the timing of subunit polymerization into the growing pilus, have previously been unclear. Here we use cryo-electron microscopy to capture a pilus assembly intermediate (FimD-FimC-FimF-FimG-FimH) in a conformation in which FimD is in the process of handing over the chaperone-bound end of the growing pilus to the C-terminal domains. In this structure, FimF has already polymerized with FimG, and the N-terminal domain of FimD swings over to bind CTD2; the N-terminal domain maintains contact with FimC-FimF, while at the same time permitting access to the C-terminal domains. FimD has an intrinsically disordered N-terminal tail that precedes the N-terminal domain. This N-terminal tail folds into a helical motif upon recruiting the FimC-subunit complex, but reorganizes into a loop to bind CTD2 during handover. Because both the N-terminal and C-terminal domains of FimD are bound to the end of the growing pilus, the structure further suggests a mechanism for stabilizing the assembly intermediate to prevent the pilus fibre diffusing away during the incorporation of thousands of subunits.The structure of a pilus assembly intermediate reveals the timing of subunit polymerization and how chaperone-subunit complexes are transferred from N-terminal to C-terminal domains of the usher in the formation of bacterial pili., Author(s): Minge Du [sup.1] , Zuanning Yuan [sup.1] , Hongjun Yu [sup.1] , Nadine Henderson [sup.2] [sup.3] , Samema Sarowar [sup.4] , Gongpu Zhao [sup.5] , Glenn T. Werneburg [sup.2] [...]

Adaptation of organisms to environmental niches is a hallmark of evolution. One prevalent example is that of thermal adaptation, in which two descendants evolve at different temperature extremes.sup.1,2. Underlying the physiological differences between such organisms are changes in enzymes that catalyse essential reactions.sup.3, with orthologues from each organism undergoing adaptive mutations that preserve similar catalytic rates at their respective physiological temperatures.sup.4,5. The sequence changes responsible for these adaptive differences, however, are often at surface-exposed sites distant from the substrate-binding site, leaving the active site of the enzyme structurally unperturbed.sup.6,7. How such changes are allosterically propagated to the active site, to modulate activity, is not known. Here we show that entropy-tuning changes can be engineered into distal sites of Escherichia coli adenylate kinase, allowing us to quantitatively assess the role of dynamics in determining affinity, turnover and the role in driving adaptation. The results not only reveal a dynamics-based allosteric tuning mechanism, but also uncover a spatial separation of the control of key enzymatic parameters. Fluctuations in one mobile domain (the LID) control substrate affinity, whereas dynamic attenuation in the other domain (the AMP-binding domain) affects rate-limiting conformational changes that govern enzyme turnover. Dynamics-based regulation may thus represent an elegant, widespread and previously unrealized evolutionary adaptation mechanism that fine-tunes biological function without altering the ground state structure. Furthermore, because rigid-body conformational changes in both domains were thought to be rate limiting for turnover.sup.8,9, these adaptation studies reveal a new model for understanding the relationship between dynamics and turnover in adenylate kinase.By engineering entropy-tuning changes into distal sites of a bacterial adenylate kinase, an allosteric tuning mechanism based on protein dynamics is revealed., Author(s): Harry G. Saavedra [sup.1] [sup.2] , James O. Wrabl [sup.1] [sup.2] , Jeremy A. Anderson [sup.1] [sup.2] , Jing Li [sup.1] [sup.2] , Vincent J. Hilser [sup.1] [sup.2] Author [...]

Jiyun Li, Zhenwang Bi, Shizhen Ma, Baoli Chen, Chang Cai, Junjia He, Stefan Schwarz, Chengtao Sun, Yuqing Zhou, Jia Yin, Anette Hulth, Yongqiang Wang, Zhangqi Shen, Shaolin Wang, Congming Wu, [...]

Background Primary care antimicrobial stewardship interventions can improve antimicrobial prescribing, but there is less evidence that they reduce rates of resistant infection. This study examined changes in broad-spectrum antimicrobial prescribing in the community and resistance in people admitted to hospital with community-associated coliform bacteraemia associated with a primary care stewardship intervention. Methods and findings Segmented regression analysis of data on all patients registered with a general practitioner in the National Health Service (NHS) Tayside region in the east of Scotland, UK, from 1 January 2005 to 31 December 2015 was performed, examining associations between a primary care antimicrobial stewardship intervention in 2009 and primary care prescribing of fluoroquinolones, cephalosporins, and co-amoxiclav and resistance to the same three antimicrobials/classes among community-associated coliform bacteraemia. Prescribing outcomes were the rate per 1,000 population prescribed each antimicrobial/class per quarter. Resistance outcomes were proportion of community-associated (first 2 days of hospital admission) coliform (Escherichia coli, Proteus spp., or Klebsiella spp.) bacteraemia among adult (18+ years) patients resistant to each antimicrobial/class. 11.4% of 3,442,205 oral antimicrobial prescriptions dispensed in primary care over the study period were for targeted antimicrobials. There were large, statistically significant reductions in prescribing at 1 year postintervention that were larger by 3 years postintervention when the relative reduction was -68.8% (95% CI -76.3 to -62.1) and the absolute reduction -6.3 (-7.6 to -5.2) people exposed per 1,000 population per quarter for fluoroquinolones; relative -74.0% (-80.3 to -67.9) and absolute reduction -6.1 (-7.2 to -5.2) for cephalosporins; and relative -62.3% (-66.9 to -58.1) and absolute reduction -6.8 (-7.7 to -6.0) for co-amoxiclav, all compared to their prior trends. There were 2,143 eligible bacteraemia episodes involving 2,004 patients over the study period (mean age 73.7 [SD 14.8] years; 51.4% women). There was no increase in community-associated coliform bacteraemia admissions associated with reduced community broad-spectrum antimicrobial use. Resistance to targeted antimicrobials reduced by 3.5 years postintervention compared to prior trends, but this was not statistically significant for co-amoxiclav. Relative and absolute changes were -34.7% (95% CI -52.3 to -10.6) and -63.5 (-131.8 to -12.8) resistant bacteraemia per 1,000 bacteraemia per quarter for fluoroquinolones; -48.3% (-62.7 to -32.3) and -153.1 (-255.7 to -77.0) for cephalosporins; and -17.8% (-47.1 to 20.8) and -63.6 (-206.4 to 42.4) for co-amoxiclav, respectively. Overall, there was reversal of a previously rising rate of fluoroquinolone resistance and flattening of previously rising rates of cephalosporin and co-amoxiclav resistance. The limitations of this study include that associations are not definitive evidence of causation and that potential effects of underlying secular trends in the postintervention period and/or of other interventions occurring simultaneously cannot be definitively excluded. Conclusions In this population-based study in Scotland, compared to prior trends, there were very large reductions in community broad-spectrum antimicrobial use associated with the stewardship intervention. In contrast, changes in resistance among coliform bacteraemia were more modest. Prevention of resistance through judicious use of new antimicrobials may be more effective than trying to reverse resistance that has become established., Author(s): Virginia Hernandez-Santiago 1, Peter G. Davey 2, Dilip Nathwani 3, Charis A. Marwick 2,*, Bruce Guthrie 4 Introduction Increasing antimicrobial resistance (AMR) is a major global public health threat [...]

The RNA-guided CRISPR-associated (Cas) proteins Cas9 and Cas12a provide adaptive immunity against invading nucleic acids, and function as powerful tools for genome editing in a wide range of organisms. Here we reveal the underlying mechanisms of a third, fundamentally distinct RNA-guided genome-editing platform named CRISPR-CasX, which uses unique structures for programmable double-stranded DNA binding and cleavage. Biochemical and in vivo data demonstrate that CasX is active for Escherichia coli and human genome modification. Eight cryo-electron microscopy structures of CasX in different states of assembly with its guide RNA and double-stranded DNA substrates reveal an extensive RNA scaffold and a domain required for DNA unwinding. These data demonstrate how CasX activity arose through convergent evolution to establish an enzyme family that is functionally separate from both Cas9 and Cas12a.CRISPR-CasX represents a distinct RNA-guided platform that is functionally separate from Cas9 and Cas12a and is active for bacterial and human genome modification., Author(s): Jun-Jie Liu [sup.1] [sup.2] [sup.3] , Natalia Orlova [sup.2] , Benjamin L. Oakes [sup.4] , Enbo Ma [sup.1] , Hannah B. Spinner [sup.4] , Katherine L. M. Baney [sup.4] [...]

Objective To assess the burden posed by foodborne diseases in Japan using methods developed by the World Health Organization's Foodborne Disease Burden Epidemiology Reference Group (FERG). Methods Expert consultation and statistics on food poisoning during 2011 were used to identify three common causes of foodborne disease in Japan: Campylobacter and Salmonella species and enterohaemorrhagic Escherichiacoli (EHEC). We conducted systematic reviews of English and Japanese literature on the complications caused by these pathogens, by searching Embase, the Japan medical society abstract database and Medline. We estimated the annual incidence of acute gastroenteritis from reported surveillance data, based on estimated probabilities that an affected person would visit a physician and have gastroenteritis confirmed. We then calculated disability- adjusted life-years (DALYs) lost in 2011, using the incidence estimates along with disability weights derived from published studies. Findings In 2011, foodborne disease caused by Campylobacter species, Salmonella species and EHEC led to an estimated loss of 6099, 3145 and 463 DALYs in Japan, respectively. These estimated burdens are based on the pyramid reconstruction method; are largely due to morbidity rather than mortality; and are much higher than those indicated by routine surveillance data. Conclusion Routine surveillance data may indicate foodborne disease burdens that are much lower than the true values. Most of the burden posed by foodborne disease in Japan comes from secondary complications. The tools developed by FERG appear useful in estimating disease burdens and setting priorities in the field of food safety. Objectif Evaluer la charge des maladies d'origine alimentaire au Japon, a l'aide de methodes developpees par le Groupe de travail de reference de l'OMS sur l'epidemiologie des maladies d'origine alimentaire (FERG). Methodes Des avis d'experts et des statistiques sur les intoxications alimentaires pour l'annee 2011 ont ete utilises pour identifier les trois principales causes des maladies d'origine alimentaire au Japon: a savoir les especes Campylobacter, Salmonella et Escherichia coli enterohemorragique (ECEH). Nous avons procede a des revues systematiques de la litterature anglaise et japonaise sur les complications causees par ces agents pathogenes, en faisant des recherches dans Embase (base de donnees bibliographiques de la societe medicale du Japon) et Medline. Nous avons evalue l'incidence annuelle de la gastroenterite aigue a partir des donnees de surveillance disponibles, sur la base des probabilites estimees qu'une personne affectee ira consulter un medecin et sera diagnostiquee comme souffrant de gastro-enterite. Nous avons ensuite calcule les AVCI (annees de vie corrigees du facteur incapacite) perdues en 2011, en utilisant les evaluations d'incidence ainsi que les coefficients de ponderation de l'incapacite tires des etudes publiees. Resultats En 2011, au Japon, les maladies d'origine alimentaire causees par les especes Campylobacter, Salmonella et ECEH ont respectivement entraine une perte estimee a 6099, 3 145 et 463 AVCI. Ces charges estimees sont fondees sur la methode de reconstruction de la pyramide de surveillance. Elles sont largement liees a la morbidite--plutot qua la mortalite--et sont tres superieures a celles indiquees par les donnees de surveillance de routine. Conclusion Il est possible que les donnees de surveillance de routine refletent des chiffres largement inferieurs a la realite. La charge des maladies d'origine alimentaire au Japon est principalement liee a leurs complications secondaires. Les outils developpes par le FERG semblent etre utiles pour evaluer les charges des maladies et definir les priorites en matiere de securite sanitaire des aliments. Objetivo Evaluar la carga que plantean las enfermedades de transmision alimentaria en Japon mediante la utilizacion de metodos desarrollados por el Grupo de Referencia sobre Epidemiologia de la Carga de Enfermedades de Transmision Alimentaria (FERG) de la Organizacion Mundial de la Salud. Metodos Se utilizaron consultas de expertos y estadisticas en intoxicacion alimentaria durante 2011 para identificar tres causas comunes en las enfermedades de transmision alimentaria en Japon: las bacterias Campylobacter, Salmonella y E. coli enterohemorragica (EHEC). Se llevaron a cabo revisiones sistematicas de bibliografia inglesa y japonesa sobre las complicaciones causadas por estos patogenos buscando en Em base, la base de datos de la sociedad medica japonesa, y Medline. Se estimo la incidencia anual de gastroenteritis aguda de los datos de vigilancia Informados, en base a probabilidades estimadas de que una persona afectada acudiria a un medico y se le confirmaria la gastroenteritis. Entonces se calcularon los anos de vida ajustados en funcion de la discapacidad (AVAD) perdidos en 2011, utilizando los calculos de incidencia junto con los pesos de la discapacidad derivados de estudios publicados. Resultados En 2011, las enfermedades de transmision alimentaria causadas por las haneuas Campylobacter. Salmonella y EHEC condujeron a una perdida de 6.099, 3.145 y 363 AVAD, respectivamente. Estas cargas estimadas estan basadas en el metodo de reconstruccion de la piramide de vigilancia, se deben en gran parte a la morbilidad mas que a la mortalidad y son mucho mas altas que aquellas indicadas por los datos obtenidos a partir de la vigilancia rutinaria. Conclusion Los datos de la vigilancia rutinaria pueden indicar que las cargas de enfermedades de transmision alimentaria son mucho mas bajas que los valores reales. La mayoria de la carga que plantean las enfermedades de transmision alimentaria en Japon proviene de complicaciones secundarias. Las herramientas desarrolladas por el FERG parecen utiles a la hora de estimar las cargas de enfermedades y de configurar prioridades en el area de la seguridad alimentaria., Introduction There have been few attempts to provide comprehensive, consistent and comparable estimates of the burden of acute foodborne diseases. (1) In 2006, however, the World Health Organization (WHO) set [...]

Background The impacts of climate change on surface water, waterborne disease, and human health remain a growing area of concern, particularly in Africa, where diarrheal disease is one of the most important health threats to children under 5 years of age. Little is known about the role of surface water and annual flood dynamics (flood pulse) on waterborne disease and human health nor about the expected impact of climate change on surface-water-dependent populations. Methods and findings Using the Chobe River in northern Botswana, a flood pulse river-floodplain system, we applied multimodel inference approaches assessing the influence of river height, water quality (bimonthly counts of Escherichia coli and total suspended solids [TSS], 2011-2017), and meteorological variability on weekly diarrheal case reports among children under 5 presenting to health facilities (n = 10 health facilities, January 2007-June 2017). We assessed diarrheal cases by clinical characteristics and season across age groups using monthly outpatient data (January 1998-June 2017). A strong seasonal pattern was identified, with 2 outbreaks occurring regularly in the wet and dry seasons. The timing of outbreaks diverged from that at the level of the country, where surface water is largely absent. Across age groups, the number of diarrheal cases was greater, on average, during the dry season. Demographic and clinical characteristics varied by season, underscoring the importance of environmental drivers. In the wet season, rainfall (8-week lag) had a significant influence on under-5 diarrhea, with a 10-mm increase in rainfall associated with an estimated 6.5% rise in the number of cases. Rainfall, minimum temperature, and river height were predictive of E. coli concentration, and increases in E. coli in the river were positively associated with diarrheal cases. In the dry season, river height (1-week lag) and maximum temperature (1- and 4-week lag) were significantly associated with diarrheal cases. During this period, a 1-meter drop in river height corresponded to an estimated 16.7% and 16.1% increase in reported diarrhea with a 1- and 4-week lag, respectively. In this region, as floodwaters receded from the surrounding floodplains, TSS levels increased and were positively associated with diarrheal cases (0- and 3-week lag). Populations living in this region utilized improved water sources, suggesting that hydrological variability and rapid water quality shifts in surface waters may compromise water treatment processes. Limitations include the potential influence of health beliefs and health seeking behaviors on data obtained through passive surveillance. Conclusions In flood pulse river-floodplain systems, hydrology and water quality dynamics can be highly variable, potentially impacting conventional water treatment facilities and the production of safe drinking water. In Southern Africa, climate change is predicted to intensify hydrological variability and the frequency of extreme weather events, amplifying the public health threat of waterborne disease in surface-water-dependent populations. Water sector development should be prioritized with urgency, incorporating technologies that are robust to local environmental conditions and expected climate-driven impacts. In populations with high HIV burdens, expansion of diarrheal disease surveillance and intervention strategies may also be needed. As annual flood pulse processes are predominantly influenced by climate controls in distant regions, country-level data may be inadequate to refine predictions of climate-health interactions in these systems., Author(s): Kathleen A. Alexander 1,2,*, Alexandra K. Heaney 3, Jeffrey Shaman 3 Introduction Across land types, the flow of water (ground water, surface water, and rainfall) has been demonstrated to [...]

The regular arrangements of [beta]-strands around a central axis in [beta]-barrels and of [alpha]-helices in coiled coils contrast with the irregular tertiary structures of most globular proteins, and have fascinated structural biologists since they were first discovered. Simple parametric models have been used to design a wide range of [alpha]-helical coiled-coil structures, but to date there has been no success with [beta]-barrels. Here we show that accurate de novo design of [beta]-barrels requires considerable symmetry-breaking to achieve continuous hydrogen-bond connectivity and eliminate backbone strain. We then build ensembles of [beta]-barrel backbone models with cavity shapes that match the fluorogenic compound DFHBI, and use a hierarchical grid-based search method to simultaneously optimize the rigid-body placement of DFHBI in these cavities and the identities of the surrounding amino acids to achieve high shape and chemical complementarity. The designs have high structural accuracy and bind and fluorescently activate DFHBI in vitro and in Escherichia coli, yeast and mammalian cells. This de novo design of small-molecule binding activity, using backbones custom-built to bind the ligand, should enable the design of increasingly sophisticated ligand-binding proteins, sensors and catalysts that are not limited by the backbone geometries available in known protein structures.The elucidation of general principles for designing [beta]-barrels enables the de novo creation of fluorescent proteins., Author(s): Jiayi Dou [sup.1] [sup.2] , Anastassia A. Vorobieva [sup.1] [sup.2] , William Sheffler [sup.1] [sup.2] , Lindsey A. Doyle [sup.3] , Hahnbeom Park [sup.1] [sup.2] , Matthew J. Bick [...]

Gram-negative bacteria possess a complex cell envelope that consists of a plasma membrane, a peptidoglycan cell wall and an outer membrane. The envelope is a selective chemical barrier.sup.1 that defines cell shape.sup.2 and allows the cell to sustain large mechanical loads such as turgor pressure.sup.3. It is widely believed that the covalently cross-linked cell wall underpins the mechanical properties of the envelope.sup.4,5. Here we show that the stiffness and strength of Escherichia coli cells are largely due to the outer membrane. Compromising the outer membrane, either chemically or genetically, greatly increased deformation of the cell envelope in response to stretching, bending and indentation forces, and induced increased levels of cell lysis upon mechanical perturbation and during L-form proliferation. Both lipopolysaccharides and proteins contributed to the stiffness of the outer membrane. These findings overturn the prevailing dogma that the cell wall is the dominant mechanical element within Gram-negative bacteria, instead demonstrating that the outer membrane can be stiffer than the cell wall, and that mechanical loads are often balanced between these structures.The outer membrane of Gram-negative bacteria is shown to be at least as stiff as the cell wall, and this property enables it to protect cells from mechanical pertubations., Author(s): Enrique R. Rojas [sup.1] [sup.2] [sup.3] , Gabriel Billings [sup.4] , Pascal D. Odermatt [sup.1] [sup.5] , George K. Auer [sup.6] , Lillian Zhu [sup.1] , Amanda Miguel [sup.1] [...]

The spread of antimicrobial resistance has become a serious public health concern, making once-treatable diseases deadly again and undermining the achievements of modern medicine.sup.1,2. Drug combinations can help to fight multi-drug-resistant bacterial infections, yet they are largely unexplored and rarely used in clinics. Here we profile almost 3,000 dose-resolved combinations of antibiotics, human-targeted drugs and food additives in six strains from three Gram-negative pathogens--Escherichia coli, Salmonella enterica serovar Typhimurium and Pseudomonas aeruginosa--to identify general principles for antibacterial drug combinations and understand their potential. Despite the phylogenetic relatedness of the three species, more than 70% of the drug-drug interactions that we detected are species-specific and 20% display strain specificity, revealing a large potential for narrow-spectrum therapies. Overall, antagonisms are more common than synergies and occur almost exclusively between drugs that target different cellular processes, whereas synergies are more conserved and are enriched in drugs that target the same process. We provide mechanistic insights into this dichotomy and further dissect the interactions of the food additive vanillin. Finally, we demonstrate that several synergies are effective against multi-drug-resistant clinical isolates in vitro and during infections of the larvae of the greater wax moth Galleria mellonella, with one reverting resistance to the last-resort antibiotic colistin.Screening pairwise combinations of antibiotics and other drugs against three bacterial pathogens reveals that antagonistic and synergistic drug-drug interactions are specific to microbial species and strains., Author(s): Ana Rita Brochado [sup.1] , Anja Telzerow [sup.1] , Jacob Bobonis [sup.1] , Manuel Banzhaf [sup.1] [sup.11] , André Mateus [sup.1] , Joel Selkrig [sup.1] , Emily Huth [sup.2] [...]

Bacteria have developed mechanisms to communicate and compete with one another in diverse environments (1). A new form of intercellular communication, contact-dependent growth inhibition (CDI), was discovered recently in Escherichia coli (2). CDI is mediated by the CdiB/CdiA two-partner secretion (TPS) system. CdiB facilitates secretion of the CdiA 'exoprotein' onto the cell surface. An additional small immunity protein (CdiI) protects [CDI.sup.+] cells from autoinhibition (2,3). The mechanisms by which CDI blocks cell growth and by which CdiI counteracts this growth arrest are unknown. Moreover, the existence of CDI activity in other bacteria has not been explored. Here we show that the CDI growth inhibitory activity resides within the carboxy-terminal region of CdiA (CdiA-CT), and that CdiI binds and inactivates cognate CdiA-CT, but not heterologous CdiA-CT. Bioinformatic and experimental analyses show that multiple bacterial species encode functional CDI systems with high sequence variability in the CdiA-CT and CdiI coding regions. CdiA-CT heterogeneity implies that a range of toxic activities are used during CDI. Indeed, CdiA-CTs from uropathogenic E. coliand the plant pathogen Dickeya dadantii have different nuclease activities, each providing a distinct mechanism of growth inhibition. Finally, we show that bacteria lacking the CdiA-CT and CdiI coding regions are unable to compete with isogenic wild-type [CDI.sup.+] cells both in laboratory media and on a eukaryotic host. Taken together, these results suggest that CDI systems constitute an intricate immunity network with an important function in bacterial competition., CDI was discovered in E. coli strain EC93, which inhibits the growth of other E. coli strains on direct cell-to-cell contact (2). Epitope insertion mutagenesis revealed the importance of the [...]

In this study, a full-length cDNA of the acyl-ACP thioesterase, Ah FatA, was cloned from developing seeds of Arachis hypogaea L. by 3'-RACE. Sequence analysis showed that the open reading frame encodes a peptide of 372 amino acids and has 50-70% identity with FatA from other plants. Real-time quantitative PCR analysis revealed that Ah FatA was expressed in all tissues of A. hypogaea L., but most strongly in the immature seeds harvested at 60 days after pegging. Heterologous expression of Ah FatA in Escherichia coli affected bacterial growth and changed the fatty acid profiles of the membrane lipid, resulting in directed accumulation towards palmitoleic acid and oleic acid. These results indicate that AhFatA is at least partially responsible for determining the high palmitoleic acid and oleic acid composition of E. coli., 1. Introduction In higher plants, fatty acid biosynthesis is catalyzed by the action of a type II fatty acid synthase, located in plastids [1-4]. The reaction includes the condensation of [...]