Category Archives: Research

Research – Levels of microbial contamination of domestic refrigerators in Italy

Posted on March 7, 2014 by | Leave a comment

Science Direct iStock_000012710183Small

Aim

According to the EFSA Report 2013, 32.7% of outbreaks of foodborne illness registered in Europe occurs within the home, due to inadequate hygienic behaviour of consumers when preparing foods in the kitchen. The efficacy of proper cleaning of cutting boards, dishes and cutlery in limiting microbial cross-contaminations in the kitchen has been documented many times, whereas few researches have been performed to determine the microbial load of the internal walls of domestic refrigerators, in Italy. The aim of this investigation is to ascertain the role played by internal surfaces of home refrigerators as possible sources of microbial contamination of foods.

Material and methods

We analyzed 293 domestic refrigerators of students or workers at the university campus of Agripolis (Legnaro, Italy). For each refrigerator, 2 internal surfaces were sampled using sponge-bags. The amounts of total viable count (TVC), Gram-negative spoiling bacteria, moulds and yeasts and the main pathogenic bacterial species were determined.

Results

TVCs greater than 1 log CFU cm−2 are in a little over 50% of the samples analyzed and are found mainly on the bottom of the refrigerator (61%) compared to the walls (39%) (P < 0.001). Even for other microbial counts the risk ratio of finding them on the bottom of the refrigerator is significantly higher than on the walls; the possibility of there being a finding on the bottom with respect to the walls varies from 2.5 to 8.5 times respectively for moulds and Aeromonas spp. Salmonella spp. was found in 1.7% of the samples, Bacillus cereus in 5.6%, Coagulase-positive staphylococci (CPS) in 4%, the prevalence of which is always higher on the bottom of the refrigerator. Listeria monocytogenes and Yersinia enterocolitica were never found.

Conclusions

It is necessary to better educate consumers to clean their appliances more frequently.

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Posted in Bacillus cereus, Bacteria, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Poisoning, Food Safety, Food Testing, Hygiene, Illness, Listeria, Listeria monocytogenes, Microbiology, Pathogen, Research, Salmonella, Staphylococcus aureus

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Research Netherlands – Microbial Risk in Produce

Posted on March 4, 2014 by | Leave a comment

Ingentaconnect

The objective of this study was to evaluate the microbial hazard associated with the consumption of mixed salads produced under standard conditions. The presence of Salmonella, Campylobacter spp., and Escherichia coli O157 in the Dutch production chain of mixed salads was determined. Microbial prevalence and concentration data from a microbiological surveillance study were used as inputs for the quantitative microbial risk assessment. Chain logistics, production figures, and consumption patterns were combined with the survey data for the risk assessment chain approach. The results of the sample analysis were used to track events from contamination through human illness. Wide 95% confidence intervals around the mean were found for estimated annual numbers of illnesses resulting from the consumption of mixed salads contaminated with Salmonella Typhimurium DT104 (0 to 10,300 cases), Campylobacter spp. (0 to 92,000 cases), or E. coli (0 to 800 cases). The main sources of uncertainty are the lack of decontamination data (i.e., produce washing during processing) and an appropriate dose-response relationship.

Ingentaconnect

Recent outbreaks with vegetable or fruits as vehicles have raised interest in the characterization of the public health risk due to microbial contamination of these commodities. Because qualitative and quantitative data regarding prevalence and concentration of various microbes are lacking, we conducted a survey to estimate the prevalence and contamination level of raw produce and the resulting minimally processed packaged salads as sold in The Netherlands. A dedicated sampling plan accounted for the amount of processed produce in relation to the amount of products, laboratory capacity, and seasonal influences. Over 1,800 samples of produce and over 1,900 samples of ready-to-eat mixed salads were investigated for Salmonella enterica serovars, Campylobacter spp., Escherichia coli O157, and Listeria monocytogenes. The overall prevalence in raw produce varied between 0.11% for E. coli O157 and L. monocytogenes and 0.38% for Salmonella. Prevalence point estimates for specific produce/pathogen combinations ranged for Salmonella from 0.53% in iceberg lettuce to 5.1% in cucumber. For Campylobacter, this ranged from 0.83% in endive to 2.7% in oak tree lettuce. These data will be used to determine the public health risk posed by the consumption of ready-to-eat mixed salads in The Netherlands.

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Posted in Bacteria, Campylobacter, E.coli O157, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Safety, Food Testing, Hygiene, Microbiology, Pathogen, Research, Salmonella

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Europe – German 2012 – Norovirus Oubreak Report

Posted on February 28, 2014 by | Leave a comment

Eurosurveillance Norwalk_Caspid

From 20 September through 5 October 2012, the largest recorded food-borne outbreak in Germany occurred. Norovirus was identified as the causative agent. We conducted four analytical epidemiological studies, two case–control studies and two surveys (in total 150 cases) in secondary schools in three different federal states. Overall, 390 institutions in five federal states reported nearly 11,000 cases of gastroenteritis. They were predominantly schools and childcare facilities and were supplied almost exclusively by one large catering company. The analytical epidemiological studies consistently identified dishes containing strawberries as the most likely vehicle, with estimated odds ratios ranging from 2.6 to 45.4. The dishes had been prepared in different regional kitchens of the catering company and were served in the schools two days before the peaks of the respective outbreaks. All affected institutions had received strawberries of one lot, imported frozen from China. The outbreak vehicle was identified within a week, which led to a timely recall and prevented more than half of the lot from reaching the consumer. This outbreak exemplifies the risk of large outbreaks in the era of global food trade. It underlines the importance of timely surveillance and epidemiological outbreak investigations for food safety.

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Posted in Eurofins Laboratories, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Poisoning, Food Safety, Food Testing, Food Virus, Foodborne Illness, Norovirus, Pathogen, Research

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Research – Poultry Food Safety Control Interventions in the Domestic Kitchen

Posted on February 27, 2014 by | Leave a comment

Wiley Online Library imagesCAYZ5I84

Research was undertaken to investigate cross-contamination of the domestic kitchen environment during poultry fillet preparation using a streptomycin-resistant strain of Pseudomonas fluorescens as a model organism. The potential role of a cook-in-the-bag technology to control this cross-contamination was also investigated. Poultry fillets were inoculated with P. fluorescens (6.06 log10 CFU/cm2). Six people were challenged to unpack, defrost, cut and cook without contaminating the preparation environment. After preparation, the chopping board, knife blade, dishcloth, refrigerator handle, oven handle, oven buttons, draining board, tap, microwave handle, microwave buttons, plate, tinfoil and press handle were tested for the presence of the P. fluorescens strain, before and after washing. The experiment was then repeated with a precut cook-in-the-bag product. In a separate experiment, the effect of freezing and frozen storage (−20C) on Campylobacter and the sensory attributes of chicken fillets were investigated. The cook-in-the-bag approach considerably reduced the incidence and levels of cross-contamination in the domestic kitchen. Freezing significantly (P < 0.05) reduced the Campylobacter counts on inoculated fillets after 7 days at −20C (1.73 log10 CFU/g). While there was no adverse effect on taste, fillets that had been frozen were significantly more “firm” and “less moist” as compared with fresh product.

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Posted in Bacteria, Campylobacter, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Poisoning, Food Safety, Food Spoilage, Food Testing, Hygiene, Illness, Laboratory, Microbiology, Pathogen, Pseudomonas, Research

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Research – Impact of Temperature Abuse of Leafy Greens in Transport – Safety Impact

Posted on February 17, 2014 by | Leave a comment

Ingenta ConnectEurofins Food Testing UK

Temperature abuse during commercial transport and retail sale of leafy greens negatively impacts both microbial safety and product quality. Consequently, the effect of fluctuating temperatures on Escherichia coli O157:H7 and Listeria monocytogenes growth in commercially-bagged salad greens was assessed during transport, retail storage, and display. Over a 16-month period, a series of time-temperature profiles for bagged salads were obtained from five transportation routes covering four geographic regions (432 profiles), as well as during retail storage (4,867 profiles) and display (3,799 profiles). Five different time-temperature profiles collected during 2 to 3 days of transport, 1 and 3 days of retail storage, and 3 days of retail display were then duplicated in a programmable incubator to assess E. coli O157:H7 and L. monocytogenes growth in commercial bags of romaine lettuce mix. Microbial growth predictions using the Koseki-Isobe and McKellar-Delaquis models were validated by comparing the root mean square error (RMSE), bias, and the acceptable prediction zone between the laboratory growth data and model predictions. Monte Carlo simulations were performed to calculate the probability distribution of microbial growth from 8,122,127,472 scenarios during transport, cold room storage, and retail display. Using inoculated bags of retail salad, E. coli O157:H7 and L. monocytogenes populations increased a maximum of 3.1 and 3.0 log CFU/g at retail storage. Both models yielded acceptable RMSEs and biases within the acceptable prediction zone for E. coli O157:H7. Based on the simulation, both pathogens generally increased <2 log CFU/g during transport, storage, and display. However, retail storage duration can significantly impact pathogen growth. This large-scale U.S. study—the first using commercial time/temperature profiles to assess the microbial risk of leafy greens—should be useful in filling some of the data gaps in current risk assessments for leafy greens.

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Posted in Bacteria, Food Hygiene, Food Micro Blog, Food Microbiology, Food Safety, Food Testing, Microbiology, Pathogen, Research

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Scotland – Food Safety Manual for Butchers

Posted on February 12, 2014 by | Leave a comment

HPS <!– –>

The ‘ButcherSafe’ manual has been developed to help butchers comply with the Hazard Analysis and Critical Control Point (HACCP) requirements of food safety legislation. The guidance was developed by the Scottish Food Enforcement Liaison Committee (SFELC) HACCP Working Group.

The FSA in Scotland has been given the rights to print and distribute the manual to this sector and, while the text is available electronically (at http://multimedia.food.gov.uk/multimedia/pdfs/publication/butchersafe-manua…), those wishing to request hard copy should contact their nearest local authority. [Source: FSA in Scotland News Release, 31 January 2014. http://www.food.gov.uk/scotland/news-updates/news/2014/jan/butchers]

Link To Brochure

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Posted in Bacteria, Food Hygiene, Food Inspections, Food Microbiology, Food Safety, Food Safety Alert, Food Testing, Hygiene, Microbiology, Research

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Research – Brasil – Risk of Infection by Salmonella and Listeria from RTE Vegetables

Posted on February 10, 2014 by | Leave a comment

Science DirectEurofins Food Testing UK

The current study was carried out to estimate the risks of infection due to consumption of RTE vegetables contaminated with Salmonella and Listeria monocytogenes in Brazil. The risk assessment model was composed of five different modules comprising the retail-consumption steps. Scenarios were simulated using prevalence and concentration levels reported in RTE vegetables in Brazil as well as considering values 10 times lower. In addition, scenarios in which temperature during transportation and storage are maintained below 5 °C were also evaluated. Models built in Excel spreadsheets were run (100,000 iterations) using @Risk software. The two outputs were risk of infection per month (probability of infection per month due to consumption of RTE vegetables) and number of infections per month (number of people that consumed RTE vegetables and get infected per month). The QMRA models predicted that the mean risk of Salmonella infection per month is 5.7E-03, while the mean risk of infection for L. monocytogenes was 8.1E-06 per month. The reduction of prevalence of Salmonella from 1.7% to 0.17% resulted in a decrease of risk of infection per month by about 6 times. In the case of L. monocytogenes, the reduction of prevalence from 2.2% to 0.22% resulted in decrease of risk of infection from 8.1E-06 to 1.0E-06. The risks and number of cases predicted in scenarios in which temperature was kept below 5 °C were reduced for both pathogens studied when compared to scenarios where this was not the case. The scenario where prevalence and concentration of pathogens was reduced and where temperature was <5 °C led to the lowest number of infections due by Salmonella and L. monocytogenes (187 and 3.3E-05 cases, respectively). The results suggest that effective mitigation strategies need to be adopted. The strict control of temperature during transportation, storage and consumption was more effective to reduce risk and number of cases due to L. monocytogenes than to Salmonella. More data is needed to improve the accuracy of risk assessment models developed.

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Posted in Bacteria, Food Inspections, Food Micro Blog, Food Microbiology, Food Safety, Food Testing, Listeria, Listeria monocytogenes, Microbiology, Pathogen, Research, Salmonella

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Research – Growth of Escherichia coli O157:H7 and Listeria monocytogenes in Packaged Fresh-Cut Romaine Mix at Fluctuating Temperatures during Commercial Transport, Retail Storage, and Display

Posted on February 4, 2014 by | Leave a comment

Ingentaconnect

Temperature abuse during commercial transport and retail sale of leafy greens negatively impacts both microbial safety and product quality. Consequently, the effect of fluctuating temperatures on Escherichia coli O157:H7 and Listeria monocytogenes growth in commercially-bagged salad greens was assessed during transport, retail storage, and display. Over a 16-month period, a series of time-temperature profiles for bagged salads were obtained from five transportation routes covering four geographic regions (432 profiles), as well as during retail storage (4,867 profiles) and display (3,799 profiles). Five different time-temperature profiles collected during 2 to 3 days of transport, 1 and 3 days of retail storage, and 3 days of retail display were then duplicated in a programmable incubator to assess E. coli O157:H7 and L. monocytogenes growth in commercial bags of romaine lettuce mix. Microbial growth predictions using the Koseki-Isobe and McKellar-Delaquis models were validated by comparing the root mean square error (RMSE), bias, and the acceptable prediction zone between the laboratory growth data and model predictions. Monte Carlo simulations were performed to calculate the probability distribution of microbial growth from 8,122,127,472 scenarios during transport, cold room storage, and retail display. Using inoculated bags of retail salad, E. coli O157:H7 and L. monocytogenes populations increased a maximum of 3.1 and 3.0 log CFU/g at retail storage. Both models yielded acceptable RMSEs and biases within the acceptable prediction zone for E. coli O157:H7. Based on the simulation, both pathogens generally increased <2 log CFU/g during transport, storage, and display. However, retail storage duration can significantly impact pathogen growth. This large-scale U.S. study—the first using commercial time/temperature profiles to assess the microbial risk of leafy greens—should be useful in filling some of the data gaps in current risk assessments for leafy greens.

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Posted in Bacteria, E.coli, E.coli O157, Food Micro Blog, Food Microbiology, Food Poisoning, Food Safety, Food Safety Alert, Food Testing, Foodborne Illness, Microbiology, Pathogen, Research

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USA – Food Sickness Outbreak in December was Norovirus – 282 People

Posted on January 20, 2014 by | Leave a comment

Food Poisoning BulletinNorwalk_Caspid

Norovirus was the cause of a December food poisoning outbreak that sickened 282 people who ate at a Jimmy John’s restaurant in Garden City, Kansas, the Kansas Department of Health and Environment (KDHE) has confirmed.  State and county officials worked together to determine the source of the outbreak which sickened customers who visited the restaurant from December 10 to December 24.

The restaurant was inspected by the Kansas Department of Agriculture on December 18 and again on December 24. It closed voluntarily from December 24 through December 26 to clean and disinfect the restaurant

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Posted in Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Poisoning, Food Safety, Food Testing, Food Virus, Foodborne Illness, Illness, Laboratory, Microbiology, Norovirus, outbreak, Pathogen, Research

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Research Salmonella Biofilm Resistance

Posted on January 16, 2014 by | Leave a comment

ASMOrg Salmonella

Salmonellosis is the second most common cause of food-borne illness worldwide. Contamination of surfaces in food processing environments may result in biofilm formation with a risk of food contamination. Effective decontamination of biofilm contaminated surfaces is challenging. Using the CDC biofilm reactor, the activity of sodium hypochlorite, sodium hydroxide and benzalkonium chloride were examined against an early (48 hours) and relatively mature (168 hours) Salmonella biofilm. All 3 agents result in reduction in viable counts of Salmonella, however only sodium hydroxide resulted in eradication of the early biofilm. None of the agents achieved eradication of mature biofilm, even at 90-minutes contact time. Studies of activity of chemical disinfection against biofilm should include assessment of activity against mature biofilm. The difficulty of eradication of established Salmonella biofilm serves to emphasise the priority of preventing access of Salmonella to post-cook areas of food production facilities.

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Posted in Bacteria, Biofilm, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Safety, Food Safety Alert, Food Testing, Foodborne Illness, Microbiology, Pathogen, Research, Salmonella

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