Category Archives: microbial contamination

RASFF Alert – Animal Feed – Bacillus subtilis- Vitamin B2

Posted on September 20, 2019 by | Leave a comment

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RASFF – unauthorised genetically modified (Bacillus subtilis bacteria) vitamin B2 from China in Belgium

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Posted in Bacillus Subtilis, Food Micro Blog, Food Microbiology Blog, microbial contamination, Microbiology, RASFF, Uncategorized

RASFF Alerts – Animal Feeds – Aflatoxins – Groundnuts

Posted on September 20, 2019 by | Leave a comment

Last two weeks catch up

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RASFF – aflatoxins (B1 = 0.049 mg/kg – ppm) in groundnuts for wildbirds from the United States

RASFF – aflatoxins (B1 = 5700; Tot. = 8500 µg/kg – ppb) in groundnut kernels for birdfeed from Argentina in the Netherlands

 

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Posted in Aflatoxin, Food Micro Blog, Food Microbiology Blog, microbial contamination, Microbiology, Uncategorized

RASFF Alerts – Animal Feed – Salmonella – Frozen Sausages – Dog Chews – Rapeseed Meal – Rape Seed Expeller -Lamb Meal – Pig Ears -Palm Flakes

Posted on September 20, 2019 by | Leave a comment

Last two weeks catch up.

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RASFF – Salmonella (1 out of 5 samples /25g) in frozen sausages for dogs from Croatia in Croatia

RASFF – Salmonella enterica ser. Infantis (in 1 out of 5 samples /25g) in dog chews from Germany in Austria

RASFF – Salmonella group E4 (presence /25g) in rapeseed meal from Ukraine in Poland

RASFF – Salmonella enterica ser. Mbandaka (presence /25g) in rape seed expeller from Estonia in Finland

RASFF – Salmonella enterica ser. Brandenburg (presence /25g) and Salmonella enterica ser. Derby (presence /25g) in lamb meal from New Zealand in Belgium

RASFF – Salmonella enterica ser. Kottbus (presence /25g) in rapeseed meal from Germany in Finland

RASFF – Salmonella (presence /25g) in dog chews from Germany in Germany

RASFF – Salmonella (presence /25g) in dog chews from the Netherlands in Germany

RASFF – Salmonella (presence /25g) in pig ears from Poland in Germany

RASFF – Salmonella enterica ser. Mbandaka (presence /25g) in palm flakes from the Netherlands in Belgium

 

 

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Posted in Animal Feed, Food Micro Blog, Food Microbiology Blog, microbial contamination, Microbiology, Pet Food, RASFF, raw pet food, Salmonella, Salmonella Dog Food, Uncategorized

Research – Modelling the interaction of the sakacin-producing Lactobacillus sakei CTC494 and Listeria monocytogenes in filleted gilthead sea bream (Sparus aurata) under modified atmosphere packaging at isothermal and non-isothermal conditions

Posted on September 18, 2019 by | Leave a comment

Science Direct

Highlights

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L. sakei CTC494 inhibited L. monocytogenes growth in sea bream fillets during chilled and moderate abuse temperature storage.

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L. sakei CTC494 did not increase deterioration of filleted sea bream at an initial level of ≤4 log cfu/g.

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L. sakei CTC494 showed potential as bioprotective culture for fish products.

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An approach from broth to food was developed for modelling microbial interaction.

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Models simulated the bioprotective effect of L. sakei CTC494 on L. monocytogenes in sea bream.

Abstract

The objective of this work was to quantitatively evaluate the effect of Lactobacillussakei CTC494 (sakacin-producing bioprotective strain) against Listeria monocytogenesin fish juice and to apply and validate three microbial interaction models (Jameson, modified Jameson and Lotka Volterra models) through challenge tests with gilthead sea bream (Sparus aurata) fillets under modified atmosphere packaging stored at isothermal and non-isothermal conditions. L. sakei CTC494 inhibited L. monocytogenes growth when simultaneously present in the matrix (fish juice and fish fillets) at different inoculation ratios pathogen:bioprotector (i.e. 1:1, 1:2 and 1:3). The higher the inoculation ratio, the stronger the inhibition of L. monocytogenes growth, with the ratio 1:3 yielding no growth of the pathogen. The maximum population density (Nmax) was the most affected parameter for L. monocytogenes at all inoculation ratios. According to the microbiological and sensory analysis outcomes, an initial inoculation level of 4 log cfu/g for L. sakei CTC494 would be a suitable bioprotective strategy without compromising the sensory quality of the fish product. The performance of the tested interaction models was evaluated using the Acceptable Simulation Zone approach. The Lotka Volterra model showed slightly better fit than the Jameson-based models with 75–92% out of the observed counts falling into the Acceptable Simulation Zone, indicating a satisfactory model performance. The evaluated interaction models could be used as predictive modelling tool to simulate the simultaneous behaviour of bacteriocin-producing Lactobacillus strains and L. monocytogenes; thus, supporting the design and optimization of bioprotective culture-based strategies against L. monocytogenes in minimally processed fish products.

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Posted in Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Lactobacillus saki, Listeria, Listeria monocytogenes, microbial contamination, Microbiology, Uncategorized

Research – Inactivation of Salmonella, Listeria monocytogenes and Enterococcus faecium NRRL B-2354 in a selection of low moisture foods

Posted on September 17, 2019 by | Leave a comment

Science Direct

Highlights

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Pathogens or surrogate survived well in samples during storage (21 days at 16 °C).

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Heat resistance did not change significantly throughout the storage period.

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Viability of pathogens or surrogate was adequate for inactivation/validation studies.

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E. faecium NRRL B2354 was a suitable surrogate in tested products except confectionery.

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Pathogens were inactivated by heating to 112 °C solid foods in sealed thermal cells.

Abstract

The aims of this study were to obtain data on survival and heat resistance of cocktails of Salmonella, Listeria monocytogenes and the surrogate Enterococcus faecium(NRRL B-2354) in four low moisture foods (confectionery formulation, chicken meat powder, pet food and savoury seasoning) during storage before processing. Inoculated samples were stored at 16 °C and cell viability examined at day 0, 3, 7 and 21. At each time point, the heat resistance at 80 °C was determined. The purpose was to determine a suitable storage time of inoculated foods that can be applied in heat resistance studies or process validations with similar cell viability and heat resistance characteristics. The main inactivation study was carried out within 7 days after inoculation, the heat resistance of each bacterial cocktail was evaluated in each low moisture food heated in thermal cells exposed to temperatures between 70 and 140 °C. The Weibull model and the first order kinetics (D-value) were used to express inactivation data and calculate the heating time to achieve 5 log reduction at each temperature.

Results showed that the pathogens Salmonella and L. monocytogenes and the surrogate E. faecium NRRL B-2354, can survive well (maximum reduction < 0.8 log) in low moisture foods maintained at 16 °C, as simulation of warehouse raw material storage in winter and before processing. The D80 value of the pathogens and surrogate did not significantly change during the 21 day storage (p > 0.05). The inactivation kinetics of the pathogens and surrogate at temperatures between 70 and 140 °C, were different between each organism and product. E. faecium NRRL B-2354 was a suitable Salmonella surrogate for three of the low moisture foods studied, but not for the sugar-containing confectionery formulation. Heating low moisture food in moisture-tight environments (thermal cells) to 111.2, 105.3 or 111.8 °C can inactivate 5 log of Salmonella, L. monocytogenes or E. faecium NRRL B-2354 respectively.

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Posted in Enterococcus, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Listeria, Listeria monocytogenes, microbial contamination, Microbiology, Salmonella, Uncategorized

Research – Comparison of pH effects on ohmic heating and conventional heating for inactivation of Escherichia coli O157:H7, Salmonella enterica Serovar Typhimurium and Listeria monocytogenes in orange juice

Posted on September 16, 2019 by | Leave a comment

Science Direct

Highlights

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Effect of pH on ohmic heating compared to conventional heating was investigated.

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Adjusting pH has significant effect on the heating rate of ohmic heating.

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Unusual tendency of pathogen inactivation was identified in ohmic heating.

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Quality aspects of samples were not severely degraded regardless of pH.

Abstract

The objective of the current study is to identify the influence of acidity on ohmic heating compared to conventional heating for inactivation of food-borne pathogensin orange juice. For conventional heating, the heating rate was not significantly different (P > 0.05) regardless of pH and pathogens were inactivated more effectively at lower pH. However, different patterns were observed for ohmic heating. Although temperature and electrical conductivity were not greatly affected by lowering pH, temperature increased more rapidly with increasing pH due to higher electrical conductivity. Also, the inactivation patterns were significantly different (P < 0.05) from conventional heating. While Salmonella Typhimurium was inactivated most rapidly at pH 2.5, Escherichia coli O157:H7 and Listeria monocytogenes were inactivated most rapidly at pH 4.5. When pathogens were exposed to each heating method at a fixed temperature, additional effects of ohmic heating were not observed. Also, the overall quality of orange juice subjected to ohmic heating was not greatly affected at any pH level. Therefore, increasing as well as lowering pH can also be considered effective ways to optimize pasteurization of orange juice when using ohmic heating. The different characteristics of ohmic heating compared to conventional heating indicate the necessity of a new approach.

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Posted in E.coli, E.coli O157, E.coli O157:H7, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Food Pathogen, Food Technology, microbial contamination, Microbiology, Pathogen, pathogenic, Salmonella, Technology, Uncategorized

Research – Antibiotic resistant phenotypes of Staphylococcus aureus isolated from fresh and fermented milk in parts of Nasarawa State, Nigeria

Posted on September 15, 2019 by | Leave a comment

Academic Journals

Abstract

This work was aimed at determining the occurrence and antibiogram of Staphylococcus aureusisolated from fresh and fermented milk samples in parts of Nasarawa State, Nigeria. A total of 180 samples comprising of fresh raw milk, bulk milk, nono, and kindirmo were collected over a period of 6 months (May to October, 2017). Standard microbiological procedures were employed in the isolation, identification, characterisation, and determination of the antibiogram of S. aureus from the milk samples. Characterisation of the S. aureus isolates was by morphological, biochemical characteristics using conventional methods, Microgen® STAPH-ID kits. Confirmed isolates were tested for susceptibility or resistance to a panel of 11 commonly used antibiotics using the agar disc diffusion technique. Out of the 180 milk samples examined, 9 S. aureus were isolated giving a prevalence of 5.0%. The occurrence of S. aureus was higher in nono (12.1%) and kindirmo (10.6%) than in fresh raw milk (5.9%). The high occurrence of S. aureus in nono disproved the assertion that fermented foods are not good media for the survival and growth of S. aureus. The antibiotic susceptibility profile of the S. aureus isolates indicated all of the nine isolates were completely resistant to cefoxitin, ampicillin, and amoxicillin/clavulanic acid. The isolates were moderately resistant to erythromycin (22.2%), sulphamethoxazole/trimethoprim (22.2%), and tetracycline (44.4%). Five antibiotic resistance patterns were recorded among the isolates. All of the isolates had a multiple antibiotics resistance (MAR) index of 0.3 and above, an indication of possible antibiotic misuse in the areas studied.

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Posted in Antibiotic Resistance, antimicrobial resistance, Antimicrobials, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, microbial contamination, Microbiology, Staphylococcus aureus, Uncategorized

Research – Antimicrobial resistance profile of Escherichia coli isolates recovered from diarrheic patients at Selam Health Center, Addis Ababa, Ethiopia

Posted on September 14, 2019 by | Leave a comment

Academic Journals

Abstract

Antimicrobials have been playing an important role in preventing illness and death associated with infections due to bacteria. However, the emergence and spread of resistance by pathogens have decreased the effectiveness of the commonly prescribed antimicrobials. Intestinal Escherichia coli are among bacterial pathogens that are endowed with such resistance traits because they are important source and reservoir of genes that encode antimicrobial resistance. To determine the antimicrobial resistance profile of fecal isolates of E. coli from diarrheic patients. Stool samples were collected consecutively from 100 individuals who visited Selam Health Center during the study period, April to June 2018. Samples were collected and transported under sterile condition to the National Clinical Bacteriology and Mycology reference Laboratory, Ethiopian Public Health Institute. The samples were streaked on MacConkey agar and incubated overnight at 37°C. E. coli isolates were further confirmed using conventional biochemical tests. Antimicrobial susceptibility status was determined using the disk diffusion method on Mueller Hinton agar as recommended by the Clinical Laboratory Standard Institute. The raw data was compiled and entered to spreadsheet and analysis was done using SPSS Version 20 with p-value ≤0.05 considered statistically significant. Out of the 100 patients, 43 were female and the rest were male. Confirmed E. coli were isolated from 73 individuals. Antimicrobial susceptibility testing showed that E. coli isolated in this study were highly resistant to trimethoprim-sulfamethoxazole 49 (67.1%) and amoxicillin-clavulanic acid 47(64.4 %). No isolates showed resistance to gentamicin and tobramicin.  Of all the isolates, 11(15.1%) were multidrug resistant. No association was observed between antimicrobial resistance status and sex of individuals included in this study. However, there was an association between age and resistance patterns. Resistance to commonly prescribed antibiotics among E. coli isolated in this study was high and a considerable proportions of the strains were multidrug resistant. This is an indication for an alarming rate of resistance of intestinal E. coli to first line antimicrobials. To reduce the problem, regular monitoring and education for the community are very important.

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Posted in Antibiotic Resistance, antimicrobial resistance, Antimicrobials, E.coli, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Food Technology, microbial contamination, Microbiology, Uncategorized

Research – Feeding pets raw food is not considered by pet owners as a significant source of infections

Posted on September 13, 2019 by | Leave a comment

Science Daily 260px-YellowLabradorLooking_new

An extensive international survey conducted at the University of Helsinki indicates that pet owners do not consider raw food to considerably increase infection risk in their household. In the survey, targeted at pet owners, raw food was reliably determined to be a contaminant only in three households.

The safety of feeding raw food to pets has become a topic of debate on a range of forums, but so far, no outbreaks of contamination among humans caused by raw pet food have been reported. Raw food denotes any meat, internal organs, bones and cartilage fed to pets uncooked.

Now, a survey conducted at the Faculty of Veterinary Medicine investigated perceptions on food-transmitted pathogens among pet owners who feed their pets raw food.

A total of 16,475 households from 81 countries responded to the survey. Out of these, only 39 households (0.24%) reported having been contaminated by pet food, and were also able to name the pathogen. The most common pathogens reported were Campylobacteria followed by Salmonella, in addition to which there were occurrences of Escherichia coli, Clostridium, Toxoplasma and a single Yersinia infection.

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Posted in Food Micro Blog, Food Microbiology Blog, microbial contamination, Microbiology, Pet Food, raw pet food, Uncategorized

Research – H test for exclusion: A guide to an intervention approach to lessen the risk of aflatoxin‐contaminated foods in sorely contaminated regions

Posted on September 13, 2019 by | Leave a comment

Wiley Online

Abstract

This research was done on the assumption that the risk for hepatocellular carcinoma (HCC) development that attributed to the consumption of highly contaminated food (HCF) with aflatoxin, may have a major contribution to the total of expected risk. If this hypothesis is true, it is easy to apply an effective and low‐cost intervention approach by excluding HCF and then subjecting it to treatments before use. To examine this hypothesized, H test for exclusion (Hx) model was developed as a computer program, in order to estimates the daily intake, the margin of exposure, and HCC cases per 105individuals for selected groups of contaminated food samples. To show how this model works, the model was demonstrated in a real example. The obtained results showed that the actual application of excluding HCF would result in a reduction of the expected cancer cases by 58%. Further, this model illustrates comparisons between permitted and nonpermitted samples with regards to international legislation. The model is particularly suitable for regions where contaminated crops and foods are prevalent. It is also convenient for addressing chronic exposure of commonly consumed food commodities to lower contamination levels.

Practical applications

For aflatoxin in contaminated crops, the Hx program can be used in order to estimates the daily intake, the margin of exposure (MOE), and the expected hepatocellular carcinoma (HCC) cases per 105. Furthermore, it provides a smooth rapprochement between non‐permitted and permitted samples in accordance with international legislation. In fact, the actual application of the model in regions where contaminated crops and foods are predominant can lead to efficient treatments with limited economic losses by excluding HCF.

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Posted in Aflatoxin, Food Micro Blog, Food Microbiology Blog, Food Toxin, microbial contamination, Microbiology, Mycotoxin, Toxin, Uncategorized