Occurrence, diversity and temperature-dependent growth kinetics of Aeromonas spp. in lettuce.

Bagged, pre-cut and prewashed lettuce products are marketed as ready to eat. This concept poses a food safety concern, due to lack of efficient hurdles to eliminate possible microbial contaminants from the fresh produce and/or the processing itself. Aeromonas spp. are potential foodborne pathogens that are frequently isolated from lettuce. High counts of, e.g., A. hydrophila have been found in retail ready-to-eat (RTE) vegetable salads. The aim of this study was to assess the general microbiological quality, the occurrence and diversity of potential human pathogenic mesophilic Aeromonas spp. of retail RTE lettuce products. Additionally, temperature-dependent growth kinetic parameters of Aerobic Plate Counts (APC) and Aeromonas spp. in one selected RTE lettuce product, rocket lettuce, were quantified by performing storage experiments at 4 °C, 8 °C and 12 °C. The Aeromonas isolates were further characterized regarding pathogenic traits and phylogenetic relationship. The overall hygienic quality of the lettuce products was unsatisfactory, as 60% of the products had an APC level higher than 7.0 log CFU/g. Presumptive Aeromonas spp. were detected in 52% of the samples, levels ranging from approximately 2.0-6.0 log CFU/g. Significantly lower counts of APC and Aeromonas spp. were found in uncut and unwashed products. Presumptive Aeromonas spp. were able to proliferate in rocket lettuce stored at 4 °C (µmax = 0.39 ± 0.06/d and µmax = 0.43 ± 0.05/d for lettuce from producers A and B, respectively), and µmax was approximately 2× higher at 8 °C and 3× higher at 12 °C. Eighty-four percent of the collected isolates were identified as A. media, based on partial gyrB sequencing. Additionally A. salmonicida and A. bestiarum were detected. The pathogenic potential in this material was high, most of the isolates harbored at least one of the toxin genes, act, ast, alt.

Prevalence of self-reported knee symptoms and management strategies among elderly individuals from Frederiksberg municipality: protocol for a prospective and pragmatic Danish cohort study.

INTRODUCTION: The Global Burden of Disease 2010 study ranked osteoarthritis (OA) as a leading cause of years lived with disability. With an ageing population, increasing body weight and sedentary lifestyle, a substantial increase especially in knee OA (KOA) is expected. Management strategies for KOA include non-pharmacological, pharmacological and surgical interventions. Meanwhile, over-the-counter pain medications have been discredited as they are associated with several risks with long-term usage. By consequence, the use of exercise and all sorts of complementary and alternative medicine (CAM) for joint pain has increased. The available self-management strategies are plenty, but there is no overview of their use at a population level and whether they are used along with doctors' prescriptions or replace these. The aim of this study is to estimate the population incidence of developing knee symptoms and analyse the association between (and impact of) the use of self-reported preventive measures and knee symptoms. METHODS AND ANALYSIS: This prospective cohort study pragmatically recruits individuals from the municipality of Frederiksberg, Denmark. All citizens aged 60-69 years old will be contacted annually for 10 years and asked to participate in a web-based survey. The major outcomes are self-reported knee symptoms and their association with use of various management strategies, including use of non-pharmacological treatments and CAM. Secondary outcomes include the influence of treatments on use of healthcare system and surgical procedures. Descriptive and analytic statistics (eg, logistic regression) will be used to provide summaries about the sample and observations made and the associations between self-management and development of knee symptoms. ETHICS AND DISSEMINATION: This study can be implemented without permission from the Health Research Ethics Committee. Permission has been obtained from the Danish Data Protection Agency. Study findings will be disseminated in peer-reviewed journals and presented at relevant conferences. TRIAL REGISTRATION NUMBER: NCT03472300.