Search

Lettuce (Lactuca sativa), one of the most consumed leafy vegetables in the world, is frequently implicated with foodborne disease (FBD) outbreaks, with Salmonella spp. and Escherichia coli O157:H7 being the most common bacteria to cause this illness. Estimates of prevalence and levels of these pathogens on lettuce are scarce in developed or in developing countries, which hinders risk assessment attempts. In here, we present a systematic review and meta-analysis of reported prevalence and levels of Salmonella spp. and E. coli O157:H7 on lettuce using the worldwide available data. Literature was reviewed and examined the results for inclusion of articles in the meta-analysis. Data (prevalence and/or concentration of Salmonella spp. and E. coli O157:H7 on lettuce, sample characteristic, country of origin, and Salmonella identified serovars) were extracted, and meta-analysis was performed using Open Meta-Analyst, Task Order # 2 software. Although only one work reported the presence of E coli O157:H7 on lettuce, several reports indicated the presence of other, distinct enterohemorrhagic E. coli (EHEC) strains, with a mean prevalence of 0.041 (95% CI: 0.005-0.078) and concentration varying from <3.0 MPN/g to >1100 MPN/g. Furthermore, the mean prevalence of Salmonella spp. on lettuce was 0.041 (95% CI: 0.030-0.052), with reported concentrations varying between 0.054 ± 0.058 CFU/g to 218.78 MPN/g. In addition, subgroup analysis of the presence of Salmonella spp. in lettuce revealed a mean prevalence of the bacteria of 0.028 (95% CI: 0.014-0.042) in developed nations and 0.064 (0.041-0.087) in developing nations, with reports varying from 0.001 in Japan to 0.5 in Burkina Faso. Despite a relatively low prevalence, consumption of lettuce is inherently risky because it usually is eaten raw, without thermal treatment to inactivate pathogens. This potential risk further supports performance of quantitative risk assessments to quantify the probability of FBD caused by Salmonella spp. and E. coli O157:H7 transmitted to lettuce., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

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.

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]

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]