Pulse-field-gel-electrophoresis development for Salmonella species using PaeR7 I enzyme

Pulse field gel electrophoresis (PFGE) currently has been preformed on 22 Salmonella spp. isolates using a new method that distinguishes between different species of Salmonella and gives reproducible results using Pae R7 1 enzyme. This PFGE data, when using the Pae R7 1 enzyme, was compared to the Xba 1 restriction enzyme that is used by CDC (Center for Disease Control) for Salmonella spp isolate comparisons. PFGE results were analyzed using cluster analysis and results were comparable between Pae R7 1 and Xba 1 enzymes for distinguishing differences

The Sero-prevalence of Salmonella spp. in Finishing Swine in Iowa

This study represents the first attempt to classify Iowa production sites for Salmonella spp. sero-prevalence. The data suggest that the Iowa herds are similar in their distribution with respect to sero-prevalence of salmonella as Danish herds. Ignoring herd size, 91.2 of surveyed herds were negative or level 1, 8.2 % were level 2 herds, and 1.6 % level 3. These results are similar to previous Danish studies (Alban et al., 2002, Mousing et al., 1997). The current data suggests that larger herds tend to have a higher sero-prevalence than smaller units; however, formal analysis has yet to be conducted to determine the direct association between herd size and salmonella sero-prevalence. Studies by Carstensen et al. (1998) suggested that herd size was statistically associated, albeit weakly, with Salmonella sero-prevalence, but the authors concluded the relationship was probably not biologically significant

A question of trust: can we build an evidence base to gain trust in systematic review automation technologies?

Background Although many aspects of systematic reviews use computational tools, systematic reviewers have been reluctant to adopt machine learning tools. Discussion We discuss that the potential reason for the slow adoption of machine learning tools into systematic reviews is multifactorial. We focus on the current absence of trust in automation and set-up challenges as major barriers to adoption. It is important that reviews produced using automation tools are considered non-inferior or superior to current practice. However, this standard will likely not be sufficient to lead to widespread adoption. As with many technologies, it is important that reviewers see “others” in the review community using automation tools. Adoption will also be slow if the automation tools are not compatible with workflows and tasks currently used to produce reviews. Many automation tools being developed for systematic reviews mimic classification problems. Therefore, the evidence that these automation tools are non-inferior or superior can be presented using methods similar to diagnostic test evaluations, i.e., precision and recall compared to a human reviewer. However, the assessment of automation tools does present unique challenges for investigators and systematic reviewers, including the need to clarify which metrics are of interest to the systematic review community and the unique documentation challenges for reproducible software experiments. Conclusion We discuss adoption barriers with the goal of providing tool developers with guidance as to how to design and report such evaluations and for end users to assess their validity. Further, we discuss approaches to formatting and announcing publicly available datasets suitable for assessment of automation technologies and tools. Making these resources available will increase trust that tools are non-inferior or superior to current practice. Finally, we identify that, even with evidence that automation tools are non-inferior or superior to current practice, substantial set-up challenges remain for main stream integration of automation into the systematic review process

Vaccination against Salmonella and the association with measures of Salmonella prevalence in live and slaughtered swine - A systematic review

A systematic review was conducted to evaluate the effectiveness of vaccination to reduce Salmonella prevalence in market weight finisher swine. To identify relevant studies, online databases and selected conference proceedings were searched. Two reviewers independently assessed the relevance screening and methodological quality of studies. Data of characteristics of study population, intervention, outcome, statistical analysis, and results were extracted. Four clinical trials and 21 challenge studies were identified for the final review as they described vaccination to reduce Salmonella in swine Present evidence suggests that vaccination is associated with reduced Salmonella prevalence in swine

Genetic relatedness of Salmonella enterica isolates from pens and swine at slaughter

The study aimed to determine if Salmonella enterica isolates from the floor of pre-slaughter holding pens were genetically related to isolates found in swine, held in those pens, post slaughter. Pulsed-field gel electrophoresis (PFGE) typing was used to determine genetic relatedness. On seven occasions, 100% homologous PFGE patterns were found, i.e. the pen and pig isolates were identical. This suggested that pen to pig transfer of Salmonella enterica occurred. Isolates from PFGE patterns associated with pig to pen transfers were more likely to occur in the S. Anatum, S. Heidelberg and S. Typhimurium serotypes. The ability of an isolate from a pen to rapidly infect animals housed in the pen may vary within serotype based on factors described by the PFGE pattern. This may explain why some S. enterica serotypes are prevalent in swine but not in pork products or humans

Interventions associated with feeding management practices and feed characteristics, and measures of Salmonella prevalence in live and slaughtered swine: A systematic review and summation of evidence

The aim of this review is to evaluate and summarize the evidence for associations between feeding management practices and feed characteristics, and Salmonella prevalence in swine, which may represent opportunities for interventions. Salmonella prevalence in the reviewed literature was measured either by culture or by the presence of antibodies. A systematic review of the area was conducted, the goal being to minimize the impact of bias. Systematic reviews include an assessment of the quality of studies and exclusion of studies that fail to meet standards for published material. The review evaluated evidence for an association between feed withdrawal from swine prior to slaughter, acidification of feed, heat treatment of feed, pellet vs. mash, course vs fine grind, and wet vs. dry. A large number of intervention studies were excluded from the review because they failed to report design features designed to limit the introduction of bias such as randomization and blinding. The majority of studies included were cross sectional studies, however these failed to provide strong evidence of an association because of the potential for confounding and the failure to document a temporal association between exposure to the risk factor and the outcome. The review concluded that title strongest body of work was available for pelleted feed and dry feed, however there was still uncertainty about the situations were this association may be effective. The conclusion was that there should be a low level of comfort among qualified scientists that the claimed association/relationship is scientifically valid. This ranking is primarily based on moderate to low quality studies, or insufficient numbers of tested individuals or herds, resulting in a low degree of confidence that results could be extrapolated to the target population

Determination of Toxoplasma gondii Antibody Prevalence in Midwest Market Swine

Pork has been identified as one of the food source(s) for human exposure to Toxoplasma gondii. This project was designed to determine the current prevalence of Toxoplasma gondii antibodies in the Midwestern USA market swine population. Test samples were selected, using random numbers generated from the Excel database, from approximately 2,500 daily meat juice samples submitted for Aujeszky’s Disease from eight Iowa abattoirs. Producer identification and lot size were recorded for each lot. Two hundred fifty samples were selected for 12 consecutive weeks – total of 15,014 samples. The presence of antibodies was determined using ELISA test kits by Safepath Laboratories. The prevalence for all samples was 0.75 % with a higher prevalence found in lots of 20 - 40 compared to 150 - 190 head. Additional on-farm evaluations of exposure risk factors are required to determine an association between sero-prevalence and lot size and to develop suitable prevention strategies

Where are the veterinarian shortage areas anyway?

This paper describes an econometric model to evaluate factors associated with a county’s likelihood of being designated as a private practice shortage area under the United States' Veterinary Medicine Loan Repayment Program (VMLRP). Study determinants of equilibrium food animal veterinarian location choices were also evaluated and used as a benchmark to assess the shortage designation process. On the whole the program appears to perform quite well. For several states, however, VMLRP shortage designations are inconsistent with the model of food animal veterinarian shortages. Comparative shortage is generally more severe in states that have no VMLRP designated private practice shortage counties than in states that do.economic externalities, food animal veterinarians, loan repayment program, Agricultural and Food Policy, Livestock Production/Industries,

A focus on cross-purpose tools, automated recognition of study design in multiple disciplines, and evaluation of automation tools: a summary of significant discussions at the fourth meeting of the International Collaboration for Automation of Systematic Reviews (ICASR)

The fourth meeting of the International Collaboration for Automation of Systematic Reviews (ICASR) was held 5–6 November 2019 in The Hague, the Netherlands. ICASR is an interdisciplinary group whose goal is to maximize the use of technology for conducting rapid, accurate, and efficient systematic reviews of scientific evidence. The group seeks to facilitate the development and acceptance of automated techniques for systematic reviews. In 2018, the major themes discussed were the transferability of automation tools (i.e., tools developed for other purposes that might be used by systematic reviewers), the automated recognition of study design in multiple disciplines and applications, and approaches for the evaluation of automation tools

Preparatory Work for the Future Development of Scientific Opinions on Animal Health

This final report summarizes the results of two reviews and a scoping study related to Canine leishmaniosis (CanL). Three objectives were addressed in this project. Objective 1 was to summarize relative sensitivity and specificity estimates of assays used to detect infection in dogs with Leishmania infantum in studies of naïve dogs in areas where Leishmania infantum infection is endemic. Objective 2 was to summarize data available to estimate the prevalence of parasitological cure (failure to detect organism) after a 12-month follow-up period in animals treated with meglumine antimoniate, miltefosine, and allopurinol or combinations of these drugs for canine leishmaniosis. Objective 3 was to assess diagnostic test characteristics of PCR assays and serological assays (ELISA or IFAT) from studies that use experimental models of Canine leishmaniosis. The same comprehensive search was used for all objectives. The searches yielded 7,405 records. After duplicates were removed, 3,865 records remained. Of these, 243 were broadly identified as diagnostic test evaluation studies and at the 2nd level of screening 18 were considered longitudinal studies. The 18 references were then assessed based on the full text and 7 were considered relevant to the review. The assays assessed by these studies were PCR on skin, buffy coat, bone marrow, blood and conjunctiva, and IFAT and ELISA. For objective 2, 40 potentially relevant records were identified as treatment comparison studies. After full-text screening, 13 studies were included in the review. The treatments varied greatly, and few comparative efficacy estimates were provided. No treatment was associated with 100% cure after 180 days follow-up. For objective 3, 513 citations were identified and the full texts of 169 articles were obtained. Sixty-two articles described at least one of the assays requested (PCR, ELISA or IFAT) and 18 articles described the use of a PCR and either ELISA and/or IFAT