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In Rio Grande do Sul, southern Brazil, Salmonella Enteritidis is one of the principal microorganisms responsible for foodborne disease. The present study was conducted to compare the sodium hypochlorite resistance of Salmonella Enteritidis SE86 with that of other strains of Salmonella Enteritidis isolated from different regions of the world and to investigate the involvement of the rpoS and dps genes in resistance to this disinfectant. We tested five Salmonella Enteritidis wild-type (WT) strains isolated from different countries, two mutant strains of Salmonella Enteritidis SE86, and two tagged (3XFLAG) strains of Salmonella Enteritidis SE86 for their resistance to sodium hypochlorite (200 ppm). The survival of the WT and attenuated strains was determined based on bacterial counts, and tagged proteins (Dps and RpoS) were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with anti-FLAG antibodies. None of the WT strains of Salmonella Enteritidis were totally inactivated after 20 min. The SE86 strain lacking dps was more sensitive to sodium hypochlorite than was the WT SE86 strain, with a 2-log reduction in counts after 1 min. The RpoS and Dps proteins were actively expressed under the conditions tested, indicating that in Salmonella Enteritidis SE86 these genes, which are expressed when in contact with sodium hypochlorite, are related to oxidative stress. [ABSTRACT FROM AUTHOR]

Salmonella enterica serovar Enteritidis strain SE86 has been associated with several foodborne diseases occurring in Southern Brazil, becoming and important causative agent of human salmonellosis. In this work, the complete genome of the bacterium Salmonella Enteritidis SE86 was sequenced using the Illumina MiSeq platform. An in silico analysis of the SE86 genome was performed in order to compare it with different Salmonella strains as well as to investigate the presence of stress-resistance and virulence genes. This strain showed a variety of genes that can be involved in antimicrobial and biocide resistance, acid and thermal resistance as well as virulence and adhesion. These genetic features could explain its increased resistance and the prevalence of this strain in foodborne outbreaks in Southern Brazil. • Complete genome sequence of foodborne associated Salmonella Enteritidis SE86 • Detection of several genes associated with antimicrobial, pH and thermal resistance • Virulence and adhesion genes are present in the SE86 genome. • Genetic features could explain the prevalence of SE86 in foodborne outbreaks. [ABSTRACT FROM AUTHOR]

Antimicrobial activity of thymol, carvacrol and thymol/carvacrol liposomes (TCL) was evaluated against two bacterial pools, each one consisting of four strains of Staphylococcus aureus or Salmonella enterica . TCL were prepared using thin-film hydration, showing 270.20 nm average diameter (polydispersity index of 0.33) and zeta potential of + 39.99 mV. Minimum inhibitory concentration (MIC) of thymol, carvacrol and TCL against S. aureus pool was 0.662 mg/ml, while MIC for Salmonella pool was 0.331 mg/ml for thymol and carvacrol, and for TCL was 0.662 mg/ml. Bacterial pools (8.0 log CFU/ml), allowed in contact on stainless steel AISI 304 coupons in UHT skim milk for 15 min, resulted in adhered populations of 5.6–6.1 log CFU/cm 2 . Adhered S. aureus (± 6.1 log CFU/cm 2 ) were inhibited after 1-min and 10-min treatments using thymol or carvacrol at MIC and 2.0 MIC. Reductions of 1.47–1.76 log CFU/cm 2 and 1.87–2.04 log CFU/cm 2 were obtained using 0.5 MIC of thymol and carvacrol, respectively. A 10-min contact with free (MIC and 2.0 MIC) and encapsulated (MIC) antimicrobials inhibited attached Salmonella (± 6.0 log CFU/cm 2 ); however, after 1-min of contact, 2.0 MIC of thymol and carvacrol were not able to inactivate adhered Salmonella MIC of TCL inactivated S. aureus and Salmonella after 10 min; however, after 1-min contact, adhered S. aureus and Salmonella populations were decreased in 1.62 log CFU/cm 2 and 2.01 log CFU/cm 2 , respectively. Considering antimicrobial concentrations and contact times, thymol, carvacrol, and TCL could be employed in food-contact surfaces to prevent biofilm formation at early stages of bacterial attachment. Further investigations should be performed considering long-term antibacterial effects of TCL. [ABSTRACT FROM AUTHOR]

Salmonella is the main human pathogen present in the poultry chain. Salmonella Heidelberg is one of the most important serovars for public health since it has been frequently isolated in broiler chickens from different countries and may present multidrug resistance (MDR). This study was carried out with 130 S. Heidelberg isolates collected from pre-slaughter broiler farms in 2019 and 2020 in 18 cities from three Brazilian states to study relevant aspects regarding their genotypic and phenotypic resistance. The isolates were tested and identified using somatic and flagellar antiserum (0:4, H:2, and H:r), and an antimicrobial susceptibility test (AST) was performed against 11 antibiotics for veterinary use. The strains were typed by Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR, and representatives of the main clusters of the identified profiles were sequenced by Whole Genome Sequencing (WGS). AST results showed that all isolates were resistant to sulfonamide, 54 % (70/130) were resistant to amoxicillin, and only one was sensitive to tetracycline. Twelve isolates (15.4 %) were MDR. The dendrogram obtained from the ERIC-PCR showed that the strains were grouped into 27 clusters with similarity above 90 %, with some isolates showing 100 % similarity but with different phenotypic profiles of antimicrobial resistance. Identical strains collected on the same farm on other dates were identified, indicating that they were residents. WGS identified 66 antibiotic-resistance genes. The sul 2 (present in all sequenced samples) and tet (A) genes were highlighted and validated in the experimental analysis. The fos A7 gene was also identified in all sequenced samples, but resistance was not observed in the phenotypic test, possibly due to the heteroresistance of the S. Heidelberg strains evaluated. Considering that chicken meat is one of the most consumed meats in the world, the data obtained in the present study can corroborate the mapping of the origin and trends of antimicrobial resistance. • Antibiotic multiresistant Salmonella Heidelberg strains were identified. • The whole genome sequencing identified resistance genes. • The sul 2 and tet (A) genes were highlighted and validated in the experimental analysis. • The use of antibiotics in the poultry production chain needs better strategies. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the impact of practices adopted for preparation, storage and consumption of homemade mayonnaise salad (HMS) as contributor factors for the occurrence of salmonellosis. A total of 493 individuals answered a questionnaire composed of demographic and socioeconomic questions and, preparing, storage and consumption practices of HMS. The level of good hygiene practices (GHP) of respondents was calculated using Good Practice and Outbreak Prevention Indexes. The consumer behavior and the correlation between practices were performed using Multiple Correspondence Analysis (MCA). 75% of respondents consume HMS, being 43% of interviewers doing this at least once per month. HMS was prepared from 30 min to 1 h before being served by 46% of individuals, it remaining for 30 min to 1 h at room temperature during the meal by 63% of people. Furthermore, 51% of respondents left the HMS container open or improperly closed, which may lead to cross-contamination. Most respondents (66%) stated reuse the HMS for less than one day (44%), at once (76%). 77% of participants declared that they prepare HMS, being only 7% preparing HMS without eggs. The majority (51%) used a cooked and a raw egg yolk. In addition, 75% of the cases showed raw eggs in recipe. The Weighted Good Practice Index, Weighted Outbreak Prevention Index and Weighted Harmonic Outbreak Prevention Index were 63%, 62% and 27% of participants, respectively. The MCA gathered the participants into two groups one commits various errors and other commits few errors on GHP. Thus, a consumer would probably perform multiple either good or bad practices simultaneously. [ABSTRACT FROM AUTHOR]

Pathogenic microorganisms are able to adhere on equipment surfaces, being possible to contaminate food during processing. Salmonella spp. and Listeria monocytogenes are important pathogens that can be transmitted by food, causing severe foodborne diseases. Most surfaces of food processing industry are made of stainless steel joined by welds. However currently, there are few studies evaluating the influence of welds in the microorganism's adhesion. Therefore the purpose of the present study was to investigate the adhesion of Salmonella Enteritidis and L. monocytogenes on surface of metal inert gas (MIG), and tungsten inert gas (TIG) welding, as well as to evaluate the cell and surface hydrophobicities. Results demonstrated that both bacteria adhered to the surface of welds and stainless steel at same levels. Despite this, bacteria and surfaces demonstrated different levels of hydrophobicity/hydrophilicity, results indicated that there was no correlation between adhesion to welds and stainless steel and the hydrophobicity. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to evaluate and classify the sanitation and hygiene conditions in Porto Alegre/Rio Grande do Sul (RS) public schools using an analysis of surfaces that come in contact with food and a food safety checklist validated for the school environment. The following mesophilic heterotrophic bacteria count medians were observed on each piece of equipment or utensil studied: countertops, 27.3 Colony-Forming Units (CFU)/cm2; cutting boards, 15 CFU/cm2; blenders, 14.5 CFU/cm2; dishes, 2 CFU/cm2; and refrigerators, 1 CFU/cm2. The median of the surface measurements analyzed by adenosine triphosphate (ATP) bioluminescence was less than 40 Relative Light Units (RLU)/100 cm2 for all equipment and utensils, except for the countertop surface, which had a median of 52.5 RLU/100 cm2. The data from 120 schools showed that 33, 64 and 3% were classified as high, regular and low health risk, respectively. The results showed that most schools were exposed to cross-contamination with failures especially with regard to environmental hygiene and procedures. Failures related to both factors potentially raise the risk of outbreaks in this environment. The scores used enabled the classification of school meal services and the identification of the points that need more attention. Intervention strategies that target different aspects of food handling, not only knowledge, may be promising in this scenario, which may address problems that mainly involve the food handler and promote changes in food handling practices. [Copyright &y& Elsevier]

Abstract: This study aimed to explain the elaboration process of a risk-based instrument to evaluate the hygienic and sanitary conditions and grading of food services in the host cities of the 2014 FIFA World Cup. Twenty-four Brazilian experts were invited for this elaboration. They were asked to determine the likelihood of different food handling situations that could lead to an outbreak. The nominal group technique was used for this purpose. A draft of the evaluation instrument was then created, based on Brazilian good manufacturing practices regulation and the opinion of the food safety experts. The draft evaluation instrument was used to evaluate 354 food services located in 10 cities that will host games as part of the 2014 FIFA World Cup and 141 food services in seven state capitals that will not host the games. In 25 establishments, the application of the evaluation instrument was conducted by two health surveillance auditors at the same time to measure the inter-rater reliability using the kappa statistic. For each item a raw score was determined by the experts and adjusted based on the results of a factor analysis. Approximately 55% of the items exhibited almost perfect agreement, with values between 0.81 and 1.00, and another 26% agreed substantially. The lowest raw score assigned was 10, and the highest was 240. Factor loadings ranging from 0.0001 to 0.6274 were determined for each of the items. Based on the assigned scores, the overall scores of the establishments could range from 0 (all items in compliance with the law) to 2565.95 (all items inadequate) resulting in five classification categories when using the evaluation instrument. In summary, an evaluation instrument to be applied to food services to permit the evaluation and grading of food service establishments regarding the sanitary aspects of food handling has been developed. The release of the results of the evaluation and grading of the food services has the potential to improve the food services in the areas covered by the Brazilian sanitary legislation. [Copyright &y& Elsevier]

Abstract: This study aimed to characterize Salmonella Enteritidis (SE) isolated from blood (n=12) and feces (n=68) of salmonellosis victims in Southern Brazil. All isolates were submitted to antimicrobial susceptibility testing, PCR-ribotyping, and XbaI macrorestriction Pulsed-Field Gel Eletrophoresis (PFGE). Results demonstrated high levels of ampicillin and nalidixic acid resistance, and strains isolated in different geographic regions were clustered together, presenting a common resistance profile. All strains demonstrated similar and related PCR-ribotyping patterns (R1, R2, and R3); being that the predominant profile R1 grouped 47.5% of the strains. PFGE profile P1 grouped the majority of the strains (96.25%), suggesting a clonal relationship among the strains or inability of molecular typing methods to discriminate strains of this serovar. Results suggested on an increase in antimicrobial resistance and that strains of S. Enteritidis with similar PFGE and PCR-ribotyping profiles were involved in several salmonellosis outbreaks in Southern Brazil. [Copyright &y& Elsevier]

Abstract: The growth of Staphylococcus aureus inoculated onto poultry meat was investigated under different incubation periods and temperature patterns. Transfer of this microorganism to surface materials and their disinfection was also evaluated. The evaluation of transfer was carried out by placing the contaminated meat cubes on stainless steel and polyethylene surfaces for 10s and 10min each, and the surfaces were disinfected with 0.5% chlorhexidine digluconate (CHXdG) for 1 and 10min each. After 24h, there was a significant increase of the bacteria count at 20°C, but not at temperatures between 7 and 15°C. Significant counts of S. aureus were transferred after a few seconds of contact of the cubes with both materials, and significant differences of transferred cell counts were not detected among the surface materials or durations of contact. The CHXdG solution was able to inactivate all the transferred cells after 10min of exposure; however, the same result was not observed with 1-min exposure. The time of contact and the type of surface material did not influence the quantity of the transferred cells. The 0.5% CHXdG solution was effective for the disinfection of the contaminated surfaces without previous cleaning. [Copyright &y& Elsevier]

• Salmonella grew in sushi under isothermal and non-isothermal conditions (7–37 °C). • The model was validated in the worst-case scenario, built through restaurant visits. • Total Aerobic Mesophilic lag phase in sushi was ~11 h at 15 °C. • Salmonella lag phase in sushi was ~14 h at 15 °C. • Considering Salmonella , 6 h at 15 °C can be used in sushi buffet distribution. In this study mathematical models to predict Salmonella enterica growth in sushi at different temperatures were developed considering data obtained in 26 restaurants in Southern Brazil. The sushi type chosen to develop the models was the one that presented the highest total aerobic mesophilic counts among sushis collected in the establishments. Salmonella was inoculated (2–3 log UFC/g) in this sushi type prepared in the laboratory (pH 4.8; aw 0.98) and incubated under isothermal conditions at 7, 15, 20, 25 and 37 °C. Baranyi and Roberts model was used to describe Salmonella growth curves, generating R2 values of ≥0.98 and RMSE values of <0.24 log CFU/g/h for primary models. Ratkowsky's equation was used in secondary model, generating R2 of 0.99 and RMSE of 0.02 log CFU/g/h. The model validation was simulated under non-isothermal conditions, using the worst-case scenario that was built through data from the environmental conditions and data obtained from the restaurants. The non-isothermal conditions were performed at 36.3 °C for 6 h, 10 °C for 24 h and 29.5 °C for 6 h sequentially, reaching 6.7 log CFU/g of Salmonella and generating RMSE of 0.06 log CFU/g/h, Bias factor of 0.97 and Accuracy factor of 1.03. The negligible growth time (ς) for Salmonella , considering the average of higher distribution temperatures of chosen sushi type (approximately 18 °C), was 8.9 h. However, growth rates of total aerobic mesophilic demonstrated that at 15 °C and 20 °C, the lag phases were approximately 11 and 5 h respectively. Based on these results, we suggest for sushi distribution the use of temperatures of ≤15 °C for 6 h (maximum time of distribution allowed in Brazil) considering the Salmonella growth. [ABSTRACT FROM AUTHOR]

Food distribution temperature is one of the most important factors to be controlled in order to prevent foodborne illnesses in food services. In this study, 339,548 records of food temperatures were collected from corporate catering food services and were analyzed, aiming to identify different scenarios and possible factors predictive of Salmonella and Listeria monocytogenes growth. Data fitting showed a Beta General distribution as the most appropriate model to describe the distribution temperature for most of the cold foods while the Triangular distribution fit best for hot foods. Temperature profiles and intrinsic parameters of the most frequently consumed cold foods were considered to predict Salmonella and L. monocytogenes growth using ComBase models. Salmonella exposed to temperatures of 7, 10, 15, 21, 36.5 and 40 °C was able to grow from 0.11 to 1.06 log CFU/g after 6 h, considering this period to be the maximum time of distribution of foods. L. monocytogenes exposed to temperatures of 1, 5, 10, 15, 21, 36.5 and 40 °C showed growth between 0.05 and 2.09 log CFU/g during the same time period. According to the predictive model, Salmonella spp. and L. monocytogenes were not able to grow on cold foods stored for 6 h at temperatures below 10 °C. These temperatures therefore can be suggested as safe for the distribution of cold foods over periods shorter than 6 h. Controlling the time elapsed in different distribution scenarios is necessary to prevent microbial multiplication. • Cold meals demonstrated more inadequate temperatures than hot meals. • Warm external temperatures influence the distribution temperatures of cold meals. • Cold meals distribution temperatures were described by Beta General distribution. • Hot meals distribution temperatures were described by Triangular distribution. • Until 10 °C there is no growth of Salmonella and L. monocytogenes in cold meals. [ABSTRACT FROM AUTHOR]

Restaurants used to prepare tenderloin beef medallions using different frying parameters in order to satisfy their customers. However, some of those cooking methods are not in accordance with food safety recommendations, because they do not reach internal temperatures recognized as save, in countries such as US, Canada and Brazil. This study aimed to assess the microbial inactivation in tenderloin beef medallions fried to five pre-determined degrees of doneness. Two different frying techniques were investigated, allowing beef pieces to reach the following degrees of doneness: rare, medium-rare, medium, medium-well and well-done. Before thermal processing, tenderloin beef medallions were artificially contaminated with approximately 106 CFU/g of Escherichia coli and the survival of this microorganism and mesophilic total counts were measured using VRBA + MUG and BHI plates, respectively. Bacterial colonies grew on BHI plates were also analyzed by Matrix-Assisted Laser and Time-Of-Flight desorption/ionization mass spectrometry (MALDI-TOF/MS) in order to identify survivors. Results indicated that complete E. coli inactivation was only observed on tenderloin beefs subjected to well-done degree established by both techniques, given that Technique 1 recommended a final heating inside oven after frying. Without this final oven processing, which is not always done in restaurants, more than 2 log CFU/g of viable E. coli were detected. Modeling of the kinetic parameters by GInaFIT revealed a D value (time needed to reduce 90% of the bacterial population) of 1.67 min for Technique 1 and D = 3.81 min for Technique 2 and this difference was associated to the difference of temperatures of olive oil. MALDI-TOF analyses demonstrated high diversity in natural microbiota of tenderloin beef pieces and among the main identified survivor genera was Citrobacter, Enterobacter, Hafnia, Serratia, Raoultella, Bacillus, Lactobacillus, Micrococcus, Pseudomonas, Serratia and Staphylococcus. Pathogens such as Salmonella and Listeria monocytogenes were not found. Based on the results, we recommend the use of high microbiological quality beef for the preparation of tenderloin beef medallions and the validation of frying process considering specific conditions of restaurants, because different degrees of fried may result in different counts and types of bacterial survivors. • E. coli was not observed only on well-done tenderloin beefs. • Temperature control was more effective than time control in reducing E. coli. • E. coli was not found when the center of medallions reached 70 °C. • Predicted D value of technique 1 was lower than D value of technique 2. • MALDI-TOF showed high diversity of survivors after all degrees of doneness. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the risk of occurrence of a foodborne outbreak and point practices determinant to achieve high Good Hygienic Practice level during handling practice from purchase to consumption of chicken meat and eggs. The risk behavior of respondents and the risk of the occurrence of a foodborne outbreak were measured using Weighted Harmonic Outbreak Prevention Index (WHOPI). WHOPI were not correlated to socioeconomic data and perception of risks. Different profiles of handling practices were identified inside each WHOPI level. Chicken meat defrost, time and temperature of egg cooking and the point of yolk were identified as the most important procedures responsible for the WHOPI level upgrades. The consumption of chicken meat and eggs were characterized as discrete distributions. The average consumption of chicken meat was 113.48 g/per day and eggs daily intake distribution was 0.92 units/day. Our results can be applied for future microbiological food safety risk assessments related to the consumption of chicken meat and eggs. Unlabelled Image • 1217 records were collected from different common consumers and analyzed. • Most respondents showed medium level of good hygienic practices procedures. • Risk behavior were not correlated to socioeconomic data and to perception of risks. • The most important controls needed to the upgrade of risk behavior level were ranked. • Specific minor changes had impact in good practices. [ABSTRACT FROM AUTHOR]