Molecular ecology of foodborne pathogens in primary production agriculture environments in northern Colorado and investigations in internalin A diversity in Listeria monocytogenes DUP-1039C strains

2011 Fall.Includes bibliographical references.Listeria monocytogenes, Salmonella, and Shiga toxin-producing Escherichia coli (STEC) represent clinically important human foodborne pathogens. The presence, transmission, and molecular epidemiology of these pathogens in primary agricultural environments (i.e., grazing pastures and produce farms) is understudied and represents a significant knowledge gap. We conducted a two year longitudinal sampling study in Northern Colorado to assess the presence, genetic diversity, and potential transmission patterns of these pathogens in production agriculture environments. Five produce farms and five grazing pastures in Northern Colorado were selected and sampled during the spring, summer, and fall in 2009 and 2010. Microbiological analysis was performed on composite soil (228 samples), composite fecal (105 samples), composite water (80 samples), and individual drag swabs (227 samples) to detect Listeria (i.e., L. monocytogenes and other Listeria spp.), Salmonella, E. coli O157:H7, and non-O157 STEC. Samples were evaluated to detect each target organism using modified versions of the U.S. Food and Drug Administration Bacteriological Analytical Manual and presumptive colonies for each target organism were confirmed by PCR. Overall, eight (1.25%), eleven (1.7%), and 22 (3.4%) of samples tested positive for L. monocytogenes, Salmonella, and STEC, respectively. Thirty-one samples contained Listeria spp. other than L. monocytogenes, the majority of which were determined to be Listeria innocua by sigB allelic typing. Additionally, 20 samples were positive for a proposed novel Listeria spp. that displayed unique phenotypic traits, i.e., non-motility and impaired growth at 37oC. Pulse field gel electrophoresis analysis indicated isolates obtained in this study to exhibit significant genetic diversity. These results demonstrate a rare presence of foodborne pathogens in agricultural environments in Northern Colorado. Prevalence and molecular subtyping data generated by this study provides important insight into the molecular epidemiology of these pathogens in the pre-harvest agriculture environment. Listeria monocytogenes uses the key virulence factor internalin A (InlA; encoded by inlA) to traverse host cell barriers during establishment of a systemic infection. Multiple naturally occurring mutations leading to a premature stop codon (PMSC) in inlA have been reported worldwide, and these mutations have been shown to be virulence attenuating in guinea pig infection models. Ribotype DUP-1039C is a broadly distributed molecular subtype within L. monocytogenes that has been commonly isolated along the food continuum. Ribotyope DUP-1039C isolates have been shown to carry three distinct PMSC mutations in inlA, including a frameshift mutation in a 5' homopolymeric tract of adenine restudies (PMSC4), a C to T substitution leading to a PMSC at aa 562 (PMSC 7), and a G to A substitution leading to a PMSC at aa 684 (PMSC 12). Additionally, DUP-1039C isolates carry one of three allelic types of a 5' hypermutable region of inlA, which may have a role in phase variation. A selection of DUP-1039C isolates available from the PathogenTracker database (n=368) were screened for known inlA PMSCs and the allelic type of the 5' hypermutable region by two multiplex single nucleotide polymorphism (SNP) genotyping assays. SNP genotyping assays included (i) a previously described single nucleotide extension assay and (ii) a newly developed probe-based assay, which uses differentially labeled probes to differentiate between wild type (WT; AAAAAAA), frameshift (FS; AAAAAA), and interrupted HT (IHT; AAGAAAA) 5' allelic types of inlA. DUP-1039C isolates carrying a PMSC in inlA were not uniformly distributed among isolation sources. inlA PMSC type 4 (n=19) and PMSC type 7 (n=25) were associated (P < 0.05) with isolation from food and food environments, while WT isolates encoding a full-length InlA (n=184) were associated (P < 0.05) with non-food environments and mammalian hosts. Interestingly, all DUP-1039C isolates carrying inlA PMSC7 also had the IHT inlA allele in the hypermutable 5' region, and these isolates persisted within a single NY state seafood processing plant. The 5' IHT allelic type was frequently encountered among isolates from diverse sources, though at lower frequencies as compared to the WT allele. Together, the results may help to explain the underlying mechanisms behind the ability of lineage II L. monocytogenes isolates to adapt to both human and environmental niches

Combination of Isosorbide Dinitrate and Hydralazine in Blacks with Heart Failure

BACKGROUND We examined whether a fixed dose of both isosorbide dinitrate and hydralazine provides additional benefit in blacks with advanced heart failure, a subgroup previously noted to have a favorable response to this therapy. METHODS A total of 1050 black patients who had New York Heart Association class III or IV heart failure with dilated ventricles were randomly assigned to receive a fixed dose ofisosorbide dinitrate plus hydralazine or placebo in addition to standard therapy for heart failure. The primary end point was a composite score made up of weighted values for death from any cause, a first hospitalization for heart failure, and change in the quality of life. RESULTS The study was terminated early owing to a significantly higher mortality rate in the placebo group than in the group given isosorbide dinitrate plus hydralazine (10.2 percent vs. 6.2 percent, P=0.02). The mean primary composite score was significantly better in the group given isosorbide dinitrate plus hydralazine than in the placebo group (-0.1±1.9 vs. -0.5±2.0, P=0.01; range of possible values, -6 to + 2), as were its individual components (43 percent reduction in the rate of death from any cause [hazard ratio, 0.57; P=0.01] 33 percent relative reduction in the rate of first hospitalization for heart failure [16.4 percent vs. 22.4 percent, P=0.001], and an improvement in the quality of life [change in score, -5.6±20.6 vs. -2.7±21.2, with lower scores indicating better quality of life; P=0.02; range of possible values, 0 to 105]). CONCLUSIONS The addition ofa fixed dose of isosorbide dinitrate plus hydralazine to standard therapy for heart failure including neurohormonal blockers is efficacious and increases survival among black patients with advanced heart failure

Prácticas sexuales y conocimiento sobre el VIH/ sida entre usuarios de drogas en una comunidad urbana de bajos ingresos en Costa Rica

artículo -- Universidad de Costa Rica, Instituto de Investigaciones en Salud. 2014HIV/AIDS transmission among drug users is associated with education, sex practices and substance use. This study examined 159 drugs users’ knowledge, beliefs and sex behavior related to HIV/AIDS risk in Costa Rica. Results showed considerable use of marihuana, alcohol, crack and cocaine and a very low lifetime incidence of other drugs. All substance use patterns were higher than national averages. Respondents showed a high level of knowledge about HIV/AIDS transmission and prevention. However, there did not seem to be a relationship between knowledge and practice. Unprotected sex was common and having an HIV/AIDS test was not a regular practice. Knowledge about HIV/AIDS is not a determinant factor for condom use among this group. It is concluded that having the proper knowledge about transmission and prevention does not guarantee safe sex practices. Further research and public health evidence based practices for HIV/AIDS prevention should target drug user population.La transmisión del VIH/SIDA entre consumidores de drogas se asocia con factores como, educación, prácticas sexuales y consumo de sustancias. Este estudio examinó los conocimientos 159 usuarios de drogas, las creencias y el comportamiento sexual relacionado con el riesgo de VIH / SIDA en Costa Rica. Los resultados mostraron un uso considerable de marihuana, alcohol, crack y cocaína y una incidencia muy baja de otras drogas. Todos los patrones de consumo de sustancias fueron más altos que los promedios nacionales. Los encuestados mostraron un alto nivel de conocimiento sobre la transmisión y prevención del VIH/SIDA. Se concluye que el tener el conocimiento adecuado sobre la transmisión y prevención no garantiza las prácticas de sexo seguro. Nuevas investigaciones y prácticas basadas en la evidencia de salud pública para la prevención del VIH / SIDA deben dirigirse población de usuarios de drogasInstituto de investigaciones en Salud Universidad de Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Hypothesis-driven genome-wide association studies provide novel insights into genetics of reading disabilities

Peer reviewe

Genome-wide analyses of individual differences in quantitatively assessed reading- and language-related skills in up to 34,000 people

The use of spoken and written language is a fundamental human capacity. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30 to 80% depending on the trait. The genetic architecture is complex, heterogeneous, and multifactorial, but investigations of contributions of single-nucleotide polymorphisms (SNPs) were thus far underpowered. We present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures (word reading, nonword reading, spelling, phoneme awareness, and nonword repetition) in samples of 13,633 to 33,959 participants aged 5 to 26 y. We identified genome-wide significant association with word reading (rs11208009, P = 1.098 x 10(-8)) at a locus that has not been associated with intelligence or educational attainment. All five reading-/language-related traits showed robust SNP heritability, accounting for 13 to 26% of trait variability. Genomic structural equation modeling revealed a shared genetic factor explaining most of the variation in word/nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence, and educational attainment. A multivariate GWAS of word/nonword reading, spelling, and phoneme awareness maximized power for follow-up investigation. Genetic correlation analysis with neuroimaging traits identified an association with the surface area of the banks of the left superior temporal sulcus, a brain region linked to the processing of spoken and written language. Heritability was enriched for genomic elements regulating gene expression in the fetal brain and in chromosomal regions that are depleted of Neanderthal variants. Together, these results provide avenues for deciphering the biological underpinnings of uniquely human traits.Peer reviewe

Genetic architecture of subcortical brain structures in 38,851 individuals

Subcortical brain structures are integral to motion, consciousness, emotions and learning. We identified common genetic variation related to the volumes of the nucleus accumbens, amygdala, brainstem, caudate nucleus, globus pallidus, putamen and thalamus, using genome-wide association analyses in almost 40,000 individuals from CHARGE, ENIGMA and UK Biobank. We show that variability in subcortical volumes is heritable, and identify 48 significantly associated loci (40 novel at the time of analysis). Annotation of these loci by utilizing gene expression, methylation and neuropathological data identified 199 genes putatively implicated in neurodevelopment, synaptic signaling, axonal transport, apoptosis, inflammation/infection and susceptibility to neurological disorders. This set of genes is significantly enriched for Drosophila orthologs associated with neurodevelopmental phenotypes, suggesting evolutionarily conserved mechanisms. Our findings uncover novel biology and potential drug targets underlying brain development and disease

Novel genetic loci associated with hippocampal volume

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness

Genetic architecture of subcortical brain structures in 38,851 individuals

Subcortical brain structures are integral to motion, consciousness, emotions and learning. We identified common genetic variation related to the volumes of the nucleus accumbens, amygdala, brainstem, caudate nucleus, globus pallidus, putamen and thalamus, using genome-wide association analyses in almost 40,000 individuals from CHARGE, ENIGMA and UK Biobank. We show that variability in subcortical volumes is heritable, and identify 48 significantly associated loci (40 novel at the time of analysis). Annotation of these loci by utilizing gene expression, methylation and neuropathological data identified 199 genes putatively implicated in neurodevelopment, synaptic signaling, axonal transport, apoptosis, inflammation/infection and susceptibility to neurological disorders. This set of genes is significantly enriched for Drosophila orthologs associated with neurodevelopmental phenotypes, suggesting evolutionarily conserved mechanisms. Our findings uncover novel biology and potential drug targets underlying brain development and disease

Novel genetic loci underlying human intracranial volume identified through genome-wide association

Intracranial volume reflects the maximally attained brain size during development, and remains stable with loss of tissue in late life. It is highly heritable, but the underlying genes remain largely undetermined. In a genome-wide association study of 32,438 adults, we discovered five novel loci for intracranial volume and confirmed two known signals. Four of the loci are also associated with adult human stature, but these remained associated with intracranial volume after adjusting for height. We found a high genetic correlation with child head circumference (ρgenetic=0.748), which indicated a similar genetic background and allowed for the identification of four additional loci through meta-analysis (Ncombined = 37,345). Variants for intracranial volume were also related to childhood and adult cognitive function, Parkinson’s disease, and enriched near genes involved in growth pathways including PI3K–AKT signaling. These findings identify biological underpinnings of intracranial volume and provide genetic support for theories on brain reserve and brain overgrowth

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700