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Understanding the global burden of enterotoxigenic E. coli (ETEC) and Shigella diarrhea as well as estimating the cost effectiveness of vaccines to control these two significant pathogens have been hindered by the lack of a diagnostic test that is rapid, simple, sensitive, and can be applied to the endemic countries. We previously developed a simple and rapid assay, Rapid Loop mediated isothermal amplification based Diagnostic Test (RLDT) for the detection of ETEC and Shigella spp. (Shigella). In this study, the RLDT assay was evaluated in comparison with quantitative PCR (qPCR), culture and conventional PCR for the detection of ETEC and Shigella. This validation was performed using previously collected stool samples from endemic countries, from the travelers to the endemic countries, as well as samples from a controlled human infection model study of ETEC. The performance of RLDT from dried stool spots was also validated. RLDT resulted in excellent sensitivity and specificity compared to qPCR (99% and 99.2% respectively) ranging from 92.3 to 100% for the individual toxin genes of ETEC and 100% for Shigella. Culture was less sensitive compared to RLDT. No significant differences were noted in the performance of RLDT using samples from various sources or stool samples from moderate to severe diarrhea or asymptomatic infections. RLDT performed equally well in detection of ETEC and Shigella from the dried stool samples on filter papers. This study established that RLDT is sufficiently sensitive and specific to be used as a simple and rapid diagnostic assay to detect ETEC and Shigella in endemic countries to determine disease burden of these pathogens in the national and subnational levels. This information will be important to guide public health and policy makers to prioritize resources for accelerating the development and introduction of effective preventative and/or treatment interventions against these enteric infections. Author summary: Enterotoxigenic E. coli (ETEC) and Shigella spp (Shigella) causes significant global morbidity and mortality, especially in low-and middle-income countries (LMICs). Since culture methods to detect Shigella are not sensitive, and the methods used to detect ETEC have not been feasible outside of specialized, well-equipped laboratories, the true burden of these pathogens at national and sub-national levels are mostly not available. Morbidity and mortality estimates, for these two pathogens are crucial to assess their relative public health importance in LMICs. We developed a simple and rapid diagnostic assay called the RLDT (Rapid Loop-mediated isothermal amplification based Diagnostic Test) for detection of ETEC and Shigella. In this study we evaluated RLDT compared to other currently available assays using previously collected stool samples. Our data showed that the RLDT assay exhibited high sensitivity and specificity for detection of ETEC and Shigella, with its result available within 50 minutes. The sensitivity of RLDT was higher than culture for these pathogens. We conclude that RLDT could be used as a rapid and simple diagnostic test to determine the burden of ETEC and Shigella in LMICs as well as in clinical vaccine trials of these pathogens. [ABSTRACT FROM AUTHOR]

Enterotoxigenic E. coli (ETEC) and Shigella spp (Shigella) are complex pathogens. The diagnostic assays currently used to detect these pathogens are elaborate or complicated, which make them difficult to apply in resource poor settings where these diseases are endemic. The culture methods used to detect Shigella are not sensitive, and the methods used to detect ETEC are only available in a few research labs. To address this gap, we developed a rapid and simple diagnostic assay–"Rapid LAMP based Diagnostic Test (RLDT)." The six minutes sample preparation method directly from the fecal samples with lyophilized reaction strips and using established Loop-mediated Isothermal Amplification (LAMP) platform, ETEC [heat labile toxin (LT) and heat stable toxins (STh, and STp) genes] and Shigella (ipaH gene) detection was made simple, rapid (<50 minutes), and inexpensive. This assay is cold chain and electricity free. Moreover, RLDT requires minimal equipment. To avoid any end user's bias, a battery-operated, handheld reader was used to read the RLDT results. The results can be read as positive/negative or as real time amplification depending on the end user's need. The performance specifications of the RLDT assay, including analytical sensitivity and specificity, were evaluated using fecal samples spiked with ETEC and Shigella strains. The limit of detection was ~105 CFU/gm of stool for LT, STh, and STp and ~104 CFU/gm of stool for the ipaH gene, which corresponds to about 23 CFU and 1 CFU respectively for ETEC and Shigella per 25uL reaction within 40 minutes. The RLDT assay from stool collection to result is simple, and rapid and at the same time sufficiently sensitive. RLDT has the potential to be applied in resource poor endemic settings for the rapid diagnosis of ETEC and Shigella. Author summary: Enterotoxigenic E. coli and Shigella are the leading causes of moderate to severe diarrhea in the low-and middle-income countries (LMICs). A critical constraint to determine the ETEC and Shigella disease burden at the country or sub-national level, is the complex diagnostic methods currently required for detecting these pathogens. These methods are neither sufficiently sensitive nor standardized and are not feasible in the resource poor settings where these infections occur most commonly. We developed a simple and rapid diagnostic assay called "Rapid Loop-mediated isothermal amplification based Diagnostic Test (RLDT)" for the detection of these pathogens in low-resource settings. Using RLDT, ETEC and Shigella were detected directly from the stool, in less than 1 hour with minimal hands-on time. The assay does not require maintaining a cold chain and is electricity-free. Being rapid, simple, and sensitive, RLDT can be scaled up and is appropriate to apply in the LMICs where ETEC and Shigella diarrhea are endemic. [ABSTRACT FROM AUTHOR]

The article discusses a study conducted by the authors to determine if computed tomography (CT) dose variation exists in breast cancer localization procedures in Irish radiation therapy (RT) centres and proposes diagnostic reference levels (DRLs) for the procedure. Topics discussed include variation in CT dose between centres, slice thickness for RT centres and proposed DRLs for breast cancer localization.

Cholera continues to inflict high rates of morbidity and mortality. Prompt identification of cholera cases facilitates rapid outbreak responses in the short term while providing reliable surveillance data to guide long-term policies and interventions. Microbiological stool culture, the current recognized gold standard for diagnosing cholera, has significant limitations. Rapid diagnostic tests (RDTs) represent promising alternatives for diagnosing cholera in areas with limited laboratory infrastructure. However, studies conducted with the current cholera RDTs demonstrated wide variations in sensitivity and specificity. To address this gap in the diagnosis of cholera, we developed a simple, rapid, and sensitive diagnostic assay, "Rapid LAMP based Diagnostic Test (RLDT)." With a novel, simple sample preparation method directly from the fecal samples along with lyophilized reaction strips and using established Loop-mediated Isothermal Amplification (LAMP) platform, cholera toxin gene (ctxA) and O1 (O1rfb) gene could be detected in less than an hour. Cholera RLDT assay is cold chain and electricity-free. To avoid any end-user bias, a battery-operated, handheld reader was used to read the RLDT results. The performance specifications of the cholera RLDT assay, including analytical sensitivity and specificity, were evaluated using direct fecal samples, dried fecal samples on filter paper, and environmental water samples spiked with cholera strain. The limit of detection (LOD) was ~104 CFU/gm of stool for both ctxA and O1 genes, corresponding to about 1 CFU of Vibrio cholerae per reaction within 40 minutes. The LOD was 10 bacteria per ml of environmental water when tested with RLDT directly, without enrichment. Being simple, RLDT has the potential to be applied in resource-poor endemic settings for rapid, sensitive, and reliable diagnosis of cholera. Author summary: Cholera is an acute diarrheal infection caused by Vibrio cholerae. Cholera continues to severely threaten the health of the impoverished and vulnerable populations in the endemic regions. The present laboratory-based cholera detection methods take time and require well-equipped facilities and well-trained staff that are often not available in the resource-poor settings. The available rapid diagnostic tests have a wide range of sensitivity and specificity. A rapid, simple, sensitive, and reliable diagnostic for cholera is required, which would identify cholera cases early on in outbreaks to facilitate a rapid response and provide reliable surveillance data. We developed a simple, rapid, and sensitive diagnostic assay, "Rapid LAMP based Diagnostic Test (RLDT)," to detect cholera in low-resource settings. Using RLDT, cholera could be detected directly from stool, dried stool on filter paper, and environmental water in less than one hour with minimum hands-on time. The RLDT assay does not require maintaining a cold chain and is electricity-free, facilitating point-of-care testing. The RLDT assay is sensitive, simple to use, and can be scaled up for rapid detection of cholera and surveillance in low-resource endemic settings. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is a major infectious disease that accounts for over 1.7 million deaths every year. Mycobacterium tuberculosis, the causative agent of tuberculosis, enters the human host by the inhalation of infectious aerosols. Additionally, one third of the world's population is likely to be infected with latent TB. The incidence of TB is on the rise owing in part to the emergence of multidrug-resistant strains. As a result, there is a growing need to focus on novel M. tuberculosis enzyme targets. M. tuberculosis triosephosphate isomerase (MtTPI) is an essential enzyme for gluconeogenetic pathways, making it a potential target for future therapeutics. In order to determine its structure, the X-ray crystal structure of MtTPI has been determined, as well as that of MtTPI bound with a reaction-intermediate analog. As a result, two forms of the active site were revealed. In conjunction with the kinetic parameters obtained for the MtTPI-facilitated conversion of dihydroxyacetone phosphate (DHAP) to d-glyceraldehyde-3-phosphate ( d-GAP), this provides a greater structural and biochemical understanding of this enzyme. Additionally, isothermal titration calorimetry was used to determine the binding constant for a reaction-intermediate analog bound to the active site of MtTPI. [ABSTRACT FROM AUTHOR]

RESEARCH AIM: This research aimed to provide an anecdotal perception of student substance use according to the teachers 'personal experience in the Irish secondary level educational setting. METHODOLOGY: Sampling Interviews were conducted with teachers (n=95) at 10 randomly selected schools in Count Carlow in the South East of Ireland, as part of a doctoral research programme assessing youth substance use in the South Eastern Region. The school type included vocational secondary in disadvantaged area, secondary in non- disadvantaged area, youth training centre, private school and both mixed/single sex schools. A letter from the researcher and a follow up phone call to each research site initiated contact with the school principal and explained briefly the nature and purpose of the research. Teachers .from all grades were randomly sampled at each school after informed consent was gained Research Design The research emphasis was to access the views, perspectives and concerns of teachers and their experience of substance use and its impact in the classroom. Ethical approval of the interview basis was granted by the Ethics and Research Sub Group of Waterford Institute of Technology. The interview schema was piloted on a small sample of teachers in another region not partaking in this study. The interview contained questions regarding experience of substance abuse within the school setting, knowledge and recognition of substance use in students, awareness of school drug and alcohol policy, attitude toward substance misuse and drug education, awareness of drug availability in the area and knowledge of drug related services in their area. All interviews were coded to ensure confidentiality and participants gave permission for audio recording. The interviews" took place in open plan areas and in the presence of an independent colleague. All interviews were transcribed The themes analysis of interviews reported on the issues surrounding student substance use that arose for teachers, but also aimed to identify areas of similar and contrasting opinions. As such themes arose, the interviewee was encouraged to expand in a: "lengthy conversation piece" (Simons, 1982, p, 37). Data Analysis Zemke and Kramlinger's (1985) thematic analysis procedures were adopted and consisted of generating "a list of key ideas, words, phrases, and verbatim quotes; using ideas to formulate categories and placing ideas and quotes in appropriate categories; and examining the contents of each category for subtopics and selecting the most frequent and most useful illustrations for the various categories" (Anderson, 2003). CONCLUSION: It was reported that the drug education in schools was "haphazard. dissimilar and rather hit and miss" with not every class receiving drug education, others as part of religious education and Social Personal Health Education and the remainder being visited by the local drug education officer, a former addict or juvenile liaison officer Teachers highlighted the need for information and teacher specific training in order to recognize the warning signs of adolescent problematic substance use, as many felt this social problem was impacting on their classroom and the academic performance of some students. Some teachers also reported not feeling comfortable with the delivery of drug educational material within their class time due to lack of appropriate training and lack of available time in their curriculum, in addition to feeling that this was not compatible with their role as educator. [ABSTRACT FROM AUTHOR]

This report presents the findings of an exploratory study aimed at assessing the nature and extent of drug use amongst a group of young Travellers (aged twelve to eighteen years) in the South Eastern Region of Ireland. The results are intended to inform the Irish policy debate by providing data on patterns of youth drug use, drug-related risk behaviours, the impact of drug use on the Traveller community and issues regarding access to services. The young Travellers exhibited similar trends to "settled" adolescents with regard to drug use trends and attitudes but reported poor levels of health awareness and knowledge of drug services. The social exclusion of young Travellers puts them at risk of problematic drug use due to issues of poor literacy levels, family crisis, discrimination, poor knowledge of service provision relating to drug education and treatment, and the location of halting sites in areas of high drug usage. [ABSTRACT FROM AUTHOR]

A reliable and effective human challenge model is needed to help down-select the most promising ETEC vaccines currently under development. Such a model would need to reliably induce diarrhea in a high proportion of volunteers using the lowest possible inoculum to maximize safety and sensitivity. Previously we validated a challenge model that utilized a dose of 2x107 CFU of ETEC strain H10407 (LT+, ST+, CFA/I+ and O78+) to induce attack rates for moderate to severe diarrhea (MSD) of ~60–70%. Here we detail efforts to further refine the model in an attempt to determine if a lower challenge dose of H10407 can be used. Thirty subjects were randomized 1:1 to receive an oral administration of H10407 at doses of 106 or 105 CFU in bicarbonate buffer. After challenge, subjects were monitored for signs and symptoms of enteric illness and stool samples were collected to detect shedding of the challenge strain. Systemic and mucosal immune responses were measured using serum, antibody in lymphocyte supernatant and fecal samples. The attack rate was 13.3% (2/15) and 26.7% (4/15) for MSD in the 105 and 106 groups, respectively. Four MSD cases met criteria for early antibiotic treatment. All subjects but one shed the challenge strain in fecal samples. The frequency and magnitude of anti-LT toxin, CFA/I and LPS O78 immune responses were antigen, dose, severity of diarrhea and shedding levels dependent. Notably, although of lower magnitude, there were considerable immune responses in the subjects with no diarrhea. This may indicate that immune responses to asymptomatic infections of ETEC in children in the endemic countries may contribute to protection. Based on this and our prior studies, we conclude that a dose of 2x107 H10407 remains the lowest practical dose for use in future volunteer studies evaluating candidate vaccines and other preventive or therapeutic ETEC interventions. Trial registration: ClinicalTrials.gov . [ABSTRACT FROM AUTHOR]