Category Archives: Uncategorized

Research – Modeling the interactions among Salmonella enteritidis, Pseudomonas aeruginosa , and Lactobacillus plantarum

Posted on August 24, 2020 by | Leave a comment

Wiley Online

This paper was to investigate the interactions among Salmonella enteritidis, Lactobacillus plantarum , and Pseudomonas aeruginosa at four combinations of initial concentration. Firstly, fitting the growth curves to obtain growth parameters—lag time (λ ), maximal growth rate ( μ max), initial concentration (N 0), and maximum population density (N max) for each strain in monocultures or cocultures. Then interactions among S. enteritidis, P. aeruginosa , and L. plantarum in cocultures at four combinations of initial concentration were quantified by the Lotka–Volterra model with six interaction coefficients. Results indicated that there were no interactions between S. enteritidis and P. aeruginosa ; S. enteritidis and P. aeruginosa had an inhibitory effect on L. plantarum , but L. plantarum had no effects on another two. Besides, the higher the initial concentrations of S. enteritidis or P. aeruginosa , the lower the growth potential of L. plantarum . This study provided more accurate predictions for the growth of bacteria under actual food contamination conditions.

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Lactobacillus, Lactobacillus plantarum, microbial contamination, Microbiology, Pseudomonas aeruginosa, Research, Salmonella, Uncategorized

Research – Comparative study of microbiological transfer from four materials used in direct contact with apples

Posted on August 24, 2020 by | Leave a comment

Science Direct

Several materials such as plastic, wood, cardboard or stainless steel are used as working surfaces or packaging in direct contact with foodstuffs. In food industries, the hygienic surface status is one of the criteria to product conform packaging as described in the European regulation ECR 1935/2004. Today in European Union, it exists one harmonized regulation specific for Food Contact material made of plastic called EU N°10/2011 (Anonymous 2011a). This regulation specifies that materials intended for safe foodstuff contact must not modify food characteristics in terms of chemical, microbiological and sensorial properties.

This study aims to compare the survival and transfer of Penicillium expansum conidia and Escherichia coli cells from several materials to apples. Poplar, cardboards, newly manufactured plastic and reusable plastic specimens were artificially inoculated with both microorganisms, subsequently put in contact with apples and stored under realistic storage conditions. After incubation for up to 1 week, apples and specimens were analysed to assess the survival of the microorganisms and their transfer from materials to apples.

While P. expansum survived and did not grow on any of the materials, E. coli mortality was observed after 1 h on wood and cardboard and after 1 week on both plastics. The proportion of microorganisms transferred was different according to the considered material. This transfer was lower than 1% for wood.

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Posted in E.coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiology, mold, Mould Toxin, Moulds, Research, Uncategorized

Research -Determination of Enterococcus faecium thermal reduction in normal and high oleic peanut products

Posted on August 23, 2020 by | Leave a comment

Wiley Online

During processing, peanut butter can become contaminated with pathogenic bacteria (e.g., Salmonella ). The introduction of an additional heat treatment step after roasting can help inactivate these microorganisms. In this study, trials were conducted to determine Enterococcus faecium (Salmonella surrogate) reduction rates during the roasting of high oleic (HO) peanuts and heat‐treatment of normal oleic (NO) and HO peanut butters. HO peanuts were inoculated with E. faecium and roasted in a convection oven at 190°C. There was a 2 and 6 log CFU/g reduction at 300 and 480 s, respectively. D ‐values for HO peanut butter at 110, 120, and 125°C were 438.9, 165.1, and 80.6 s, respectively. The z ‐value was calculated to be 20.8°C. There was no significant difference in D ‐values and z ‐values between NO and HO peanut butter. In a pilot scale experiment, HO peanut butter was inoculated with E. faecium and agitated in a heated mixer for 21.5 min. E. faecium was reduced by 5.1 log CFU/g after 16.5 min with no apparent change in viscosity or texture. This study demonstrated that significant reductions in E. faecium can be achieved during roasting and through an additional heat‐treatment step.

 

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Posted in Enterococcus faecium, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiology, Research, Salmonella, Uncategorized

Research – Variation of antibiotic resistance in Salmonella Enteritidis, Escherichia coli O157 :H7 , and Listeria monocytogenes after exposure to acid, salt, and cold stress

Posted on August 23, 2020 by | Leave a comment

Wiley Online

Abstract

Bacteria with antibiotic‐resistant could seriously threaten to human health, increasing the treatment cost for infections and negatively affecting treatment outcomes. Stress adaptation is one possible mechanism for the acquisition or enhancement of antibiotic resistance in bacteria as a result of cross‐protection. In this study, the effects of acid, salt, and cold stress on the antibiotic resistance of Salmonella Enteritidis, Listeria monocytogenes , and Escherichia coli O157:H7 were investigated using the disc diffusion method. For S. Enteritidis, acidic growth conditions increased resistance to ciprofloxacin and erythromycin (p  < .05), and addition of 4% NaCl to growth media decreased resistance to chloramphenicol (p  < .05). Irrespective of pH and the NaCl concentration of the growth medium, refrigerated E. coli O157:H7 showed increased resistance to amoxycillin, ciprofloxacin, gentamicin, streptomycin, and erythromycin (p  < .05). Acid‐adapted L. monocytogenes showed decreased the resistance to amoxycillin, ampicillin, chloramphenicol, ciprofloxacin, erythromycin, gentamicin, streptomycin, and tetracycline (p  < .05). In conclusion, prolonged exposure of foodborne pathogens to acid, salt, and cold stress alters their antibiotic resistance. However, the effect of acid, salt, and cold stress on bacterial antibiotic resistance depend on both the bacterial species and the specific antibiotic. Therefore, multiple factors need to be considered for a foodborne antimicrobial resistant risk assessment.

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Posted in Antibiotic Resistance, antimicrobial resistance, Antimicrobials, E.coli O157, E.coli O157:H7, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Research, Salmonella, Uncategorized

Research – The effect of royal jelly and propolis alone and in combination on inhibition of Aspergillus parasiticus growth, aflatoxin production, and aflR gene expression

Posted on August 22, 2020 by | Leave a comment

Wiley Online

The objective of this study was to determine the inhibitory effect of royal jelly (RJ) and propolis on growth, aflatoxin production and aflR gene expression in Aspergillus parasiticus . Inhibitory effect of RJ and propolis against a standard strain of A. parasiticus (ATCC 15517) was determined alone and in combination in accordance with the CLSI M38‐A2 and checkerboard methods, respectively. The aflatoxin concentrations in the control and treated media were determined by HPLC. Also, the quantitative changes in the aflR gene expression were analyzed. The minimum inhibitory concentrations (MIC) of RJ and propolis alone were 3,200 and 100μg/ml, respectively. Also, the MICs of RJ and propolis in combination were 200 and 25μg/ml, respectively. When combined, a synergistic interaction was observed with a FICI of 0.312. Total levels of aflatoxin decreased from 386.1ppm to 8.72, 3.01 and 1.75ppm at 1,600μg/ml of RJ, 50μg/ml of propolis and 100+12.5μg/ml of RJ and propolis, respectively. In addition, the level of afIR gene expression was significantly decreased after treatment with RJ and propolis extracts alone and with their combination. The findings reveal that RJ and propolis extracts, either alone or in combination, have a significant inhibitory effect on aflR gene expression in aflatoxin production.

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Posted in Aflatoxin, Aspergillus, Food Microbiology Research, Food Technology, Food Toxin, Mould Toxin, Mycotoxin, Research, Uncategorized

Research – Quantitative microbial spoilage risk assessment (QMSRA) of pasteurized strawberry purees by Aspergillus fischeri (teleomorph Neosartorya fischeri)

Posted on August 22, 2020 by | Leave a comment

Science Direct

Aspergillus fischeri ascospores are known as potential spoilage microorganisms of pasteurized fruit products due to their high incidence in fruits, the ability to survive pasteurization and to grow in acidic conditions. This study aimed to develop a quantitative microbial spoilage risk assessment (QMSRA) model approach to estimate the spoilage risk of packaged strawberry purees due to A. fischeri under various scenarios regarding product formulation, processing and storage conditions. The development of the risk assessment comprised three steps: (1) initial contamination level of raw material by ascospores (N0), (2) inactivation of ascospores during thermal processing (Np) and (3) determination of the number of ascospores which are able to survive thermal processing and develop visible mycelia (D = 2 mm) during storage (Nf). Data of visible growth (tv, days) comprised distributions previously obtained as function of water activity (aw) (0.860–0.985), oxygen (0–21%), temperature (8–30 °C) and pasteurization (95–105 °C/15 s). The simulations were performed in triplicate with 100,000 iterations using the software R. The outcome “spoilage risk” was defined as the probability of having at least one ascospore (Nf) capable of forming visible colonies in 100 g-pack strawberry puree within the typical use-by dates. Overall, high probabilities of spoilage were estimated for purees pasteurized at milder treatments at 85 °C/15–60 s (67%) and 90 °C/15–60 s (≥40%) stored at ambient temperature (22 °C). The spoilage risk was only effectively reduced (0.02%) by increasing pasteurization conditions to 95 °C for at least 45 s. Moreover, the microbial stability of such purees, i.e., spoilage risk <0.001% (=less than 1 spoilage pack out of 105 produced units) was predicted to occur for purees treated at 100 °C/15 s or stored at chilled conditions (≤8 °C) or at strict anaerobic conditions or produced as concentrates (aw ≤ 0.860). Based on the outcomes obtained, a set of specifications for Heat-Resistant Moulds (HRMs) in raw material and pasteurized purees aimed to be used as an ingredient was suggested. Furthermore, the results can be used to support risk management decisions in identifying and quantifying the impact of possible interventions during formulation, processing and storage conditions of fruit purees to effectively reduce this risk.

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Posted in Aspergillus, food contamination, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Poisoning, microbial contamination, Microbiology, Mould Toxin, Moulds, Research, Uncategorized

USA – Possible Hepatits A Exposure at PF Chang’s in Destiny, USA, NY

Posted on August 21, 2020 by | Leave a comment

Possible Hepatits A Exposure at PF Chang’s in Destiny, USA, NY

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RASFF Alerts – Salmonella – Chilled Chicken Meat – Chilled Raw Sausages – Betel Leaves – Scrambled Egg Mix – Egg Powder – Poultry Trimmings – Mixed Condiments – Beef Shreds – Marinated Chicken Fillets – Chicken Hearts – Blue Mussels – Brazil Nuts – Turkey Meat Preparation

Posted on August 21, 2020 by | Leave a comment

RASFF

Salmonella enterica ser. Enteritidis (presence /25g), Salmonella group C (presence /25g) and Salmonella group C1 (presence /25g) in chilled chicken meat from Poland in Poland

RASFF

Salmonella enterica ser. Typhimurium (presence /25g) in chilled raw sausages for frying from Italy in Germany

RASFF

Salmonella enterica ser. Typhimurium (presence /25g) in chilled chicken meat from France in France

RASFF

Salmonella (in 3 out of 5 samples /25g) and high count of Escherichia coli (19000 CFU/g) in betel leaves from Thailand in the UK

RASFF

Salmonella enterica ser. Enteritidis (presence /25g) in scrambled eggs mix from Ukraine in Latvia

RASFF

Salmonella enterica ser. Enteritidis (in 1 out of 5 samples /25g) in egg powder from Bulgaria in Poland

RASFF

Salmonella enterica ser. Infantis (presence /25g) in frozen poultry trimmings from Spain in France

RASFF

Salmonella (presence /25g) in mix of condiments from Belgium in the Netherlands

RASFF

Salmonella (presence /25g) in beef shreds from the Netherlands in the Netherlands

RASFF

Salmonella enterica ser. Enteritidis (presence /25g), Salmonella enterica ser. Newport (presence /25g) and Salmonella enterica ser. Virchow (presence /25g) in frozen marinated chicken fillets from Poland in Italy

RASFF

Salmonella enterica ser. Infantis (presence /25g) in chilled chicken hearts from Poland in Bulgaria

RASFF

Salmonella enterica ser. anatum in brazil nuts from Bolivia in the UK

RASFF

Salmonella (in 5 out of 5 samples /25g) in frozen turkey meat preparation from Germany, with raw material from Poland in Germany

 

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Scotland – STEC in Scotland, 2019. Enhanced surveillance and reference Laboratory data

Posted on August 19, 2020 by | Leave a comment

HPS

Shiga toxin-producing Escherichia coli (STEC), previously referred to as Verotoxigenic E. coli (VTEC), are a group of bacteria which can cause gastrointestinal illness in humans.

We undertake enhanced surveillance of E. coli O157 and other STEC in close collaboration with the Scottish E. coli O157/STEC Reference Laboratory (SERL) and NHS board health protection teams. 

Data is also integrated with other surveillance systems, in particular ObSurv, the system for the surveillance of all general outbreaks of infectious intestinal disease.

In addition to E. coli O157, laboratory and surveillance data is also captured on non-O157 STEC infections which account for around 40% of all STEC infections in Scotland.

  • During 2019, there were 150 cases of E. coli O157 and 108 cases of non-O157 STEC reported to us.
  • This was a slight decrease on the 156 cases of E. coli O157 and the 110 cases of non-O157 STEC reported in 2018.
  • Most isolates were reported in the summer months. This trend is consistent with previous years.
  • E. coli O157 and non-O157 STEC infection rates vary across the population, with overall higher rates observed in children under 5 years of age.
  • Enhanced surveillance information was available for 91% of cases.​​​

Documents

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Information South Africa- Tiger Brands to sell processed meat division traced to deadly outbreak

Posted on August 19, 2020 by | Leave a comment

Food Safety News

Tiger Brands is to sell its processed meats division, which includes the business implicated in the Listeria outbreak in South Africa in 2017 and 2018.

The transaction includes two separate deals — Molare Proprietary Ltd. will buy the abattoir business at Olifantsfontein and Silver Blade Abattoir Proprietary Ltd., a wholly-owned subsidiary of Country Bird Holdings, will acquire the meat processing businesses at Germiston, Polokwane and Pretoria.

Molare, a major supplier of pigs to the abattoir business, will pay 117 million Rand ($6.7 million) for this deal while Silver Blade has agreed a 311 million Rand ($17.8 million) purchase for the meat processing businesses and all the inventories with the transaction expected to be effective beginning in November this year.

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