d Salmonella enterica subsp. enterica serovar Newport (S. Newport) is the third most prevalent cause of food-borne salmonellosis. Rapid, efficient, and accurate methods for identification are required to track specific strains of S. Newport during outbreaks. By exploiting the hypervariable nature of virulence genes and clustered regularly interspaced short palindromic repeats (CRISPRs), we previously developed a sequence-based subtyping approach, designated CRISPR-multi-virulence-locus sequence typing (CRISPR-MVLST). To demonstrate the applicability of this approach, we analyzed a broad set of S. Newport isolates collected over a 5-year period by using CRISPR-MVLST and pulsed-field gel electrophoresis (PFGE). Among 84 isolates, we defined 38 S. Newport sequence types (NSTs), all of which were novel compared to our previous analyses, and 62 different PFGE patterns. Our data suggest that both subtyping approaches have high discriminatory abilities (>0.95) with a potential for clustering cases with common exposures. Importantly, we found that isolates from closely related NSTs were often similar by PFGE profile as well, further corroborating the applicability of CRISPR-MVLST. In the first full application of CRISPR-MVLST, we analyzed isolates from a recent S. Newport outbreak. In this blinded study, we confirmed the utility of CRISPR-MVLST and were able to distinguish the 10 outbreak isolates, as defined by PFGE and epidemiological data, from a collection of 20 S. Newport isolates. Together, our data show that CRISPR-MVLST could be a complementary approach to PFGE subtyping for S. Newport.

A study was conducted to determine the prevalence and spatial distribution of Salmonella infection in Pennsylvania raccoons (Procyon lotor), common wildlife mammals known to occupy overlapping habitats with humans and domestic food animals. The Pennsylvania Game Commission provided a total of 371 raccoon intestinal samples from trapped and road-killed raccoons collected between May and November 2011. Salmonella was isolated from the faeces of 56 (15.1%) of 371 raccoons in 35 (54%) of 65 counties across Pennsylvania. The five most frequently isolated serotypes were Newport (28.6%), Enteritidis (19.6%), Typhimurium (10.7%), Braenderup (8.9%) and Bareilly (7.1%). Pulsed-field gel electrophoresis (PFGE) analysis of the Salmonella isolates and subsequent comparison to the Pennsylvania Department of Health human Salmonella PFGE database revealed 16 different pulsetypes in Salmonella isolates recovered from raccoons that were indistinguishable from pulsetypes of Salmonella collected from clinically ill humans during the study period. The pulsetypes of seven raccoon Salmonella isolates matched those of 56 human Salmonella isolates by month and geographical region of sample collection. Results from Clustered Regularly Interspaced Short Palindromic Repeats and Multi-Virulence Locus Sequence Typing (CRISPR-MVLST) analysis corroborated the PFGE and serotyping data. The findings of this study show that several PFGE pulsetypes of Salmonella were shared between humans and raccoons in Pennsylvania, indicating that raccoons and humans might share the same source of Salmonella.

ABSTRACT The purpose of this study was to test the effectiveness of an intervention for consumer thermometer use by using a randomized experimental design and direct observation of meal preparation. The study was conducted in test kitchen facilities in two locations in North Carolina (one urban and one rural). Cameras recorded participants' actions at various locations throughout the kitchen and recorded the meal preparation from beginning to end. Before preparing the meal, a randomized treatment group watched a 3-min U.S. Department of Agriculture (USDA) food safety video “The Importance of Cooking to a Safe Internal Temperature and How to Use a Food Thermometer.” Participants in the control and treatment groups were observed while cooking turkey burgers and preparing a salad to determine whether a thermometer was used to check the doneness of the turkey patties. Following meal preparation, all participants responded to a postobservation interview about food handling behaviors. Treatment group participants were also asked about the intervention. A total of 383 people participated in the study (201 in the control group and 182 in the treatment group). Participants who viewed the video were twice as likely to use a thermometer to check the doneness of the turkey patties compared with the participants who were not exposed to the video (75 versus 34%) and twice as likely to place the thermometer in the correct location (52 versus 23%). Sixty-seven percent of participants who watched the video reported that it influenced their behavior in the kitchen. This study demonstrates the importance of timing and framing of a behavioral intervention for thermometer use and highlights considerations for the development of additional messages (e.g., proper insertion). HIGHLIGHTS

This study tested the effectiveness of an educational intervention on consumer poultry washing using video observation of meal preparation with participants who self-reported washing poultry. Treatment group participants received three emails containing messages the U.S. Department of Agriculture has used on social media (video and infographics) related to poultry preparation, including advising against washing it. Participants were observed cooking chicken thighs (inoculated with traceable nonpathogenic Escherichia coli strain DH-5 alpha) and preparing a salad to determine whether they washed the chicken and the extent of cross-contamination to the salad and areas of the kitchen. After meal preparation, participants responded to an interview about food handling behaviors, including questions about the intervention for treatment group participants. Three hundred people participated in the study (158 control, 142 treatment). The intervention effectively encouraged participants not to wash chicken before cooking; 93% of treatment group participants did not wash the chicken compared to 39% of control group participants (P<0.0001). High levels of the tracer detected in the sink and on the salad lettuce suggest that microbes transferred to the sink from the chicken, packaging, or contaminated hands are a larger cause for concern than splashing contaminated chicken fluids onto the counter. Among chicken washers, lettuce from the prepared salad was contaminated at 26% for the control group and 30% for the treatment group. For nonwashers, lettuce was contaminated at 31% for the control group and 15% for the treatment group. Hand-facilitated cross-contamination is suspected to be a factor in explaining this cross-contamination. This study demonstrates the need to change the frame of “don’t wash your poultry” messaging to instead focus on preventing contamination of sinks and continuing to emphasize the importance of handwashing and cleaning and sanitizing surfaces.

Cross-contamination of raw food to other surfaces, hands, and foods is a serious issue in foodservice.  With individuals eating more meals away from home, contracting a foodborne illness from a food service establishment is an increasing concern.  However, most studies have concentrated on hands or food contact surfaces and neglected atypical and unusual surfaces (surfaces that are not typically identified as a source of cross-contamination) and venues.  This review seeks to identify atypically cross-contaminated surfaces and atypical venues where cross-contamination could occur that have not been examined thoroughly in the literature.  Most surfaces that could be at risk for cross-contamination are frequently touched, rarely cleaned and sanitized, and can support the persistence and/or growth of foodborne pathogens.  These surfaces include, menus, spice and condiment containers, aprons and coveralls, mobile devices and tablets, and currency, among others.  Venues that are explored, temporary events, mobile vendors, and markets, are usually limited in space or infrastructure, have low compliance to proper handwashing, and provide the opportunity for raw and RTE foods to come into contact with one another. These factors all create an environment where cross-contamination can occur and potentially impact food safety.  A more comprehensive cleaning sanitizing regime encompassing these surfaces and venues could potentially help mitigate the cross-contamination described here.  This review highlights key surfaces and venues that have the potential to be cross-contaminated that have been underestimated in the past or are not fully explored in the literature.  These knowledge gaps demonstrate where further work is need to fully understand the role of these surfaces and venues in cross-contamination and how it can be prevented in the future.