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Escherichia coli O157: H7 is one of the most important foodborne pathogens nowadays, since it has been responsible for severe outbreaks worldwide. Even though this food pathogen has been isolated in many countries, Brazilian foods were considered E. coli O157:H7-free until recently. However, the presence of E. coli O157:H7 has been reported in diverse foods produced in Brazil and an increasing number of isolation from cattle feces has been observed, demonstrating that this pathogen is present in different parts of Brazil, and severe foodborne outbreaks may occur in the near future if adequate control measures are not implemented. [ABSTRACT FROM AUTHOR]

Foodborne diseases are typically caused by the ingestion of food contaminated with micro-organisms or their toxins, resulting in gastrointestinal disorders and in some severe cases hospitalization and death. In Brazil, foodborne illnesses are caused mainly by Salmonella, Staphylococcus aureus and Escherichia coli. The most important contributing factors for outbreaks are exposure of foods to unsuitable temperatures, inadequate food preparation and contamination of raw material or water used to prepare food. Recently, aiming to prevent foodborne illnesses during the 2014 FIFA World Cup, Brazil has developed a risk-based evaluation tool able to assess and grade Brazilian food services in cities that will host football matches. This tool has been used by the Brazilian sanitary surveillance officers during the inspection of facilities where food services. This is considered an innovative preventative sanitary action because it was created based on scientific information, statistical calculation and on risks of foodborne diseases occurrence. In this mini-review we summarize general data, control measures and how travellers can prevent foodborne illness in Brazil during the 2014 FIFA World Cup. [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]

Cooked ham is one of the most consumed meat products in Brazil. It is sensitive to the deterioration caused by the growth of lactic acid bacteria (LAB). The objective of this study was to evaluate the antimicrobial activity of nisin over the naturally present LAB on sliced cooked ham stored at 8°C. For this, nisin was added to the cooked ham at two different stages of processing: Injected together with the brine (assay 1) and added during tumbling (assay 2). Results from assay 1 showed LAB inhibition for 2 days, whereas, results from assay 2 showed LAB inhibition for up to 10 days. These results demonstrated that 12.5 mg/kg (dosage approved in Brazil for dairy products) of nisin significantly inhibited LAB growth, suggesting its effectiveness as an appropriate barrier in the control of LAB spoilage in cooked ham. Practical applications: When evaluating the antimicrobial activity of nisin for its biopreservation capacity, it is important to consider that meat products are complex systems with several factors influencing the microbial growth and subsequent metabolite production. Therefore, the influence of the medium formulation and technology on the process needs to be tested. Addition of nisin at the tumbling step had a better inhibitory effect against LAB. Thus, it can deliver an important contribution to improve food quality by optimizing the storage management. [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]

Introduction: Previous studies have identified Salmonella as the main causative agent of foodborne diseases in the state of Rio Grande do Sul (RS), southern Brazil, between 1997 and 2006. This study aimed to describe the Salmonella serotypes, antimicrobial patterns, and food vehicles of salmonellosis that occurred in RS between 2007 and 2012. Methodology: Information about Salmonella isolates and salmonellosis outbreaks registered in the official records of the Central Laboratory of RS (FEEPS/IPB-LACEN/RS) was analyzed. Results: Among the 163 isolates investigated, 138 (84.7%) were identified as S. Enteritidis. The second and third most frequent serovars identified were S. Schwarzengrund (5.5%) and S. Typhimurium (3.7%). Homemade mayonnaise was the food vehicle most frequently identified (17.39%), followed by pastry products (15.94%) and beef (12.32%). Antimicrobial resistance was analyzed; 12 drugs were tested. Higher percentages of resistance were observed to nitrofurantoin (94.2%) and nalidixic acid (89.1%). The resistance to these two drugs was verified in 80.43% of the isolates. Multi-resistance to three and five drugs was verified in four and two isolates, respectively. Conclusions: Comparing the results of the present study with results of previous reports, it was possible to conclude that S. Enteritidis and homemade mayonnaise are still the main serotype and food vehicle of salmonellosis in RS and that antimicrobial resistance has been increasing among S. Enteritidis responsible for foodborne outbreaks in southern Brazil. [ABSTRACT FROM AUTHOR]

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]

• 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]

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]

In December 2019, four children of the same school were hospitalized due to severe diarrhea, vomiting, and fever, and the mother of one child was diagnosed with hemolytic uremic syndrome (HUS). Escherichia coli O157 NM was isolated from the stool of one child, whereas Campylobacter jejuni isolates were found in feces, raw foods, environmental samples, and tap water. In addition, the same pulsed-field gel electrophoresis profile was identified in C. jejuni isolated from feces and tap water. One child died of renal failure and another due to respiratory failure. Based on symptoms and bacterial isolation, the deaths were assigned to E. coli O157 NM, but coinfection with C. jejuni may have contributed to the severity of symptoms. These were the first deaths assigned to E. coli O157 NM registered in Brazil.

Introduction: This study aimed to evaluate the prevalence of Salmonella on poultry carcasses produced in slaughterhouses of Southern Brazil participating of the Official Pathogen Reduction Program conducted by the Ministry of Agriculture, Livestock, and Supply., Methodology: From 2006 to 2015, 77,165 poultry carcasses were analyzed for presence/absence of Salmonella spp. and the results were statistically evaluated., Results: Prevalence varied from 2.92% to 5.24%, with a mean percentage of 4.04%. The difference in prevalence numbers was not significant during all the period analyzed. Higher Salmonella prevalence has been reported worldwide, indicating the efficacy of Brazilian control measures implemented in the productive chain and the low risk associated to Brazilian poultry meat consumption. However, additional information about the acceptable and safe prevalence of Salmonella on poultry should be defined by risk analysis studies, considering the reality of Brazilian companies and scientific data., Conclusions: The results of the present study can be the first step for a national Risk Assessment and may contribute to improvements in self-controlling programs and with the current Brazilian poultry regulation., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2018 Claudia Titze Hessel, Mateus Silva de Lima, Eduardo Cesar Tondo, Leonardo Werlang Isolan, João Pedro Pessoa.)

This study aimed to assess the growth of Salmonella and Escherichia coli O157:H7 on lettuce exposed to isothermal and non-isothermal conditions. Pathogens were inoculated on lettuce separately and stored under isothermal condition at 5 °C, 10 °C, 25 °C, 37 °C for both bacteria, at 40 °C for Salmonella and 42 °C for E. coli O157:H7. Growth curves were built by fitting the data to the Baranyi's DMFit, generating R 2 values greater than 0.92 for primary models. Secondary models were fitted with Ratkowsky equations, generating R 2 values higher than 0.91 and RMSE lower than 0.1. Experimental data showed that both bacteria could grow at all temperatures. Also, the growth of both pathogens under non-isothermal conditions was studied simulating temperatures found from harvest to supermarkets in Brazil. Models were analysed by R 2 , RMSE, bias factor (Bf) and accuracy factor (Af). Salmonella and E. coli O157:H7 were able to grow in this temperature profile and the models could predict the behavior of these microorganisms on lettuce under isothermal and non-isothermal conditions. Based on the results, a negligible growth time (ς) was proposed to provide the time which lettuce could be exposed to a specific temperature and do not present an expressive growth of bacteria. The ς was developed based on Baranyi's primary model equation and on growth potential concept. ς is the value of lag phase added of the time necessary to population grow 0.5 log CFU/g. The ς of lettuce exposed to 37 °C was 1.3 h, while at 5 °C was 3.3 days., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A total of 120 beef carcasses were analyzed during processing at a slaughterhouse in southern Brazil. The carcasses were sampled by swab at three different steps of the slaughter line and then they were tested for Salmonella and E. coli. The Salmonella isolates were also examined for antimicrobial susceptibility. Salmonella prevalence distribution was modeled and the probability of contamination was simulated using @Risk program and 10,000 interactions. Results demonstrated that 4 beef carcasses (3.3%) were positive for Salmonella only in the first point. The six isolates of Salmonella were classified: S. Newport (n = 3), S. Saintpaul (n = 2) and S. Anatum (n = 1). No Salmonella strains exhibited resistance to any of the antimicrobials tested. As expected, the most contaminated point with E. coli was the first point (hide), presenting counts from 0.31 to 5.07 log cfu/100 cm(2). Much smaller E. coli counts were observed in the other points. Results indicated low levels of Salmonella and E. coli on the beef carcasses analyzed and also low probability of contamination of the carcasses by Salmonella, suggesting adequate microbiological quality.

Introduction: The objective of this study was to evaluate the involvement of the ompR gene in the acid adaptation and thermal resistance of S. Enteritidis SE86, responsible agent of more than 95 % of investigated food-borne diseases, throughout the last decade in Southern Brazil. In this study, we constructed a mutant strain of S. Enteritidis SE86 (ΔompR) that was attenuated by a knockout technique. The OmpR protein expression was determined in a tagged (3XFLAG) strain of S. Enteritidis SE86., Methodology: The mutant strains were cultivated separately in nutrient broth and nutrient broth supplemented with 1% glucose (NBG) to induce acid adapted cells. The organisms were exposed to different temperature such as 37 ºC, 52 ºC, and 60ºC. The survival of the SE86 wild type (WT) and attenuated strain was determined by bacterial count, and the tagged protein (ompR::3XFLAG cat::FLAG) was detected by SDS-PAGE and immunoblotting with anti-FLAG antibodies., Results: Results showed that when exposed at 52ºC, the acid-adapted SE86 WT cells were completely inactivated after 300 minutes; however, non-adapted cells (WT and ΔompR) and acid-adapted ΔompR demonstrated higher thermal sensitivity, since they were completely inactivated in 240 minutes. At 60ºC, the acid-adapted SE86 ΔompR also demonstrated higher sensitivity that SE86 WT, being totally inactivated after 15 minutes, while the WT cells were inactivated in 20 minutes., Conclusion: The acid adapted cells showed increased expression of OmpR when exposed to 52 ºC and 60ºC, this confirmed the requirement of acid adaptation  for S. Enteritidis SE86 to resist elevated temperatures.

In the State of Rio Grande do Sul (RS), Southern Brazil, a good manufacturing practices regulation was published recommending two disinfection methods for cleaning cloths used in food services. The aim of the present study was to evaluate the efficacy of those methods. Cleaning cloths were sampled without prior notice at food services, on common working days. For the analyses, the cloths were divided in two sub-samples, being one of them microbiologically analyzed. The second sub-sample was further divided in two pieces and submitted to hand washing for two minutes. After that, one piece was boiled in water for 15 min and the other one was soaked in a 200 ppm sodium hypochlorite solution for 15 min. Both pieces of cloth were submitted to microbiological analyses. Cleaning cloths presented total aerobic mean counts of 6.9 ± 6.7 log/cm(2). All cleaning cloths presented coliform contamination, and 40% demonstrated mean counts of 6.2 ± 5.6 log/cm(2). Presumptive S. aureus mean counts of 5.5 ± 4.9 log/cm(2) were found. No statistic correlation was observed among the number of meals served daily in the food services and the microbiological contamination levels. After washing and disinfection, microbiological counts were significantly (p < 0.05) reduced by both methods, achieving an approximately 5 log reduction. The reductions achieved by the sodium hypochlorite soaking method and the boiling method were not significantly different. Thus, it was possible to conclude that both recommended methods were suitable to disinfect cleaning cloths used in food services.

Salmonella has been identified as the main aetiological agent responsible for foodborne diseases in several countries worldwide, including Brazil. In the State of Rio Grande do Sul (RS), southern Brazil, previews studies analysed official foodborne illnesses data, identifying Salmonella as the main bacterial agent of foodborne diseases during the period of 1997 to 2001. The present study aimed to analyse the official epidemiological data on salmonelloses occurred in the State of RS, during the period of 2002 to 2004. Even though data on recent salmonelloses were available, only data concerning the period comprising in 2002 to 2004 were analysed because the official worksheet records presented more consistent information about the salmonellosis outbreaks. Results indicated that, among the 624 foodborne outbreaks officially investigated, 202 (32.37%) were confirmed as salmonellosis. Among them 23,725 people were involved, 4,148 became sick, 1,878 were hospitalized and one person died. The season with the highest incidence of salmonelloses was spring, and the most affected age group was composed of people aged between 20 to 49 years old (56.66%). Animal origin foods--especially eggs and meat products--were very often involved with the outbreaks, however homemade mayonnaise was identified as the main food vehicle for salmonelloses (53.51%). The majority of the cases occurred inside private homes (55.81%) and food services (12.1%), and the main factors contributing to the occurrence of the outbreaks were the consumption of products without sanitary inspection (26.7%) and exposure of food at room temperature for more than two hours (18.58%). Similarly to what was previously reported for the period of 1997 to 2001, Salmonella spp. was the most prevalent foodborne disease agent in the State of RS during the years of 2002 to 2004.

Staphylococcal food poisoning is one of the most frequent foodborne illnesses worldwide and it is caused by the ingestion of food contaminated with enterotoxins produced by some strains of Staphylococcus (S.) aureus. In the State of Rio Grande do Sul (RS), Southern Brazil, S. aureus has been identified as the second most frequent agent of foodborne illnesses in the last two decades. The aim of the present study was to assess and analyse the epidemiological data of S. aureus food poisoning occurred in the State of RS during the years of 2000 to 2002. The official records of epidemiological investigations carried out by the Sanitary Surveillance Services of the State of RS were analysed. Among foodborne outbreaks for which aetiology was determined, S. aureus was identified as the responsible agent of 57 foodborne outbreaks, being 42 (74%) confirmed by microbiological analyses and 15 (26%) confirmed by clinical symptoms and/or epidemiological data. Staphylococcal outbreaks were responsible for the exposition of 5,991 persons, of which 1,940 (32%) were interviewed by the Sanitary Surveillance officers. The most affected age group corresponded to people with 20 to 49 years old (48%), where men (48%) and women (52%) were affected similarly. The main involved food vehicles were meats servings (35%), followed by pastries (25%), cheese (23%), pasta (11%) and potato salad with homemade mayonnaise (11%). The majority of the outbreaks occurred inside private homes (33%) followed by commercial food establishments (28%). Inadequate control of temperature and failures in general hygiene practices were identified as the main factors responsible for the outbreaks. In conclusion, S. aureus was an important food poisoning etiological agent in the State of RS during 2000 to 2002 and its prevention depends on control measures involving different parts of the food chain.

The objective of this study was to evaluate the presence of hygienic and sanitary indicator microorganisms in samples of food served in public schools in Porto Alegre. All the food served in the meal of the session visited was analyzed for Escherichia coli, coagulase-positive Staphylococcus, Salmonella sp. and Shigella sp. Of the total of 196 food products analyzed in 120 schools, 4 contained and Escherichia coli score above the permitted level, and 2 contained coagulase-positive Staphylococcus. Neither Shigella nor Salmonella genus were detected. In the majority of schools studied, it was found that food was of an adequate hygienic-sanitary standard. However, only municipal schools had the supervision of a technician responsible for school food. In the state schools, 60% had never been visited by a nutritionist and in these schools several procedures failed to comply with legal requirements. In most of the schools studied, the food served to students was within adequate standards, though the problems detected revealed the need for the implementation of Best Practices in the school environment.

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.

The antimicrobial resistance of Salmonella Enteritidis (n = 79) isolated from foods involved in human salmonellosis outbreaks in Southern Brazil during the period of 2001 to 2002 was analysed. The isolates were individually tested using the disc diffusion method against 10 antimicrobial agents. Most isolates were susceptible to all drugs tested. No S. Enteritidis isolates were resistant to sulfamethoxazole/trimethoprim or sulfazotrim and only one was resistant to chloramphenicol. The predominant resistance observed was to nalidixic acid (21.5%), gentamicin (12.7%), and streptomycin (11.4%), while intermediate resistance was observed most often for kanamycin (29.1%), neomycin (17.7%), and streptomycin (13.9%). Resistance was verified in 30 isolates (30.97%) grouped in 14 different patterns. Resistance to more than one agent was verified in 13 (16.46%) of the isolates. Two isolates were resistant to four drugs and only one strain presented resistance to three antibiotics.