Category Archives: Food Microbiology Research

Netherlands and France – Listeria Guidence

Posted on July 13, 2020 by | Leave a comment

Netherlands

France

Page 1
1
Federal Agency for the Safety of the Food Chain
Circular relating to Listeria monocytogenes in cheese
farm produce
1. Objective
The purpose of this circular is to inform operators in the “milk processing at the
firm ”of what is acceptable to the Agency in applying the microbiological criterion for
Listeria monocytogenes , listed in Regulation (EC) No. 2073/2005, and in particular for
cheese made from raw milk and heat-treated milk produced on the farm. It follows the advice of
AFSCA Scientific Committee (Cfr 3.2). These opinions were given based in particular on
results of studies implemented by the Agency. These studies, funded by the FASFC, were carried out
to support operators in the “milk processing on the farm” sector. They aim to
determine whether or not their products allow the growth of Listeria monocytogenes or not and
on the other hand, if growth is possible, if the limit of 100 cfu / g can be applied
during self-checking

 

 

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Posted in Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Safety, Food Testing, Listeria, Listeria monocytogenes, Uncategorized

USA – With over 500 with Cyclospora in the United States and Canada, what do consumers need to know?

Posted on July 13, 2020 by | Leave a comment

Food Poison Journal

Cyclospora is a parasite composed of one cell, too small to be seen without a microscope. The organism was previously thought to be a blue-green alga or a large form of cryptosporidium. Cyclospora cayetanensis is the only species of this organism found in humans. The first known human cases of illness caused by Cyclospora infection (that is, cyclosporiasis) were first discovered in 1977. An increase in the number of cases being reported began in the mid-1980s, in part due to the availability of better diagnostic techniques. Over 15,000 cases are estimated to occur in the United States each year. The first recorded Cyclospora outbreak in North America occurred in 1990 and was linked to contaminated water. Since then, several cyclosporiasis outbreaks have been reported in the U.S. and Canada, many associated with eating fresh fruits or vegetables. In some developing countries, cyclosporiasis is common among the population and travelers to those areas have become infected as well.

More information at the link above.

 

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Posted in Cyclospora, Cyclosporiasis, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Uncategorized

Research – Microbiological Quality of Cooked Chicken: Results of Monitoring in England (2013-17)

Posted on July 12, 2020 by | Leave a comment

JFP

Results from monitoring of the microbiological quality of 2,721 samples of ready-to-eat cooked chicken collected between 2013 to 2017 in England were reviewed: 70% of samples were from retail, catering or manufacture and 30% were imported and collected at English ports. Samples were tested for a range of bacterial pathogens and indicator organisms. Six samples (<1%) had unsatisfactory levels of pathogens which were potentially injurious to health. Neither Salmonella nor Campylobacter were recovered from any sample. Two samples from catering settings contained either an unsatisfactory level of Bacillus cereus (5 x 10 6 CFU/g) or an unsatisfactory level of coagulase positive staphylococci (1.6 x 10 4 CFU/g). Listeria monocytogenes was recovered from 36 samples (one at manufacture, 26 at catering and nine at retail) and in four instances, unsatisfactory levels (≥10 2 CFU/g) were detected (three samples collected at catering and one at retail). For L. monocytogenes there were no significant differences between the rates of contamination with between the samples collected from ports, manufacture, retail supermarkets and other retailers (p = 0.288). There were no differences between the rates of contamination for other potential pathogens detected between samples from different settings. The prevalence of hygiene indicators ( Escherichia coli , Enterobacteriaceae and Aerobic Colony Counts) at import was significantly lower than in samples collected from manufacturers, retail or catering (p < 0.01). Samples collected from catering gave poorer results than all other settings. Regardless of the stage in the food chain, samples from Thailand and from other non-EU countries were of significantly better microbiological quality with respect to indicator organisms than those from the UK or from other EU countries (p = <0.001).

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Posted in Bacillus cereus, Campylobacter, E.coli, Enterobacteriaceae, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Listeria, Listeria monocytogenes, microbial contamination, Microbiology, Research, Salmonella, Salmonella in Chicken, Staphylococcus aureus, Uncategorized

Research – Scientists uncover Campylobacter’s swimming tactics

Posted on July 12, 2020 by | Leave a comment

Food Safety News

campy2

Image CDC

Researchers have found out how Campylobacter can swim faster in stickier liquids, such as in human guts.

Findings could help scientists halt the foodborne bacteria, because they show how the shape of its body and components that help it swim are all dependent on each other to work. This means any disruption to one part could stop the bacteria from getting through the body and into the gut.

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Posted in Campylobacter, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, microbial contamination, Microbiology, Research, Uncategorized

Research – Optimization on antimicrobial effects of surfactin against Bacillus cereus spore

Posted on July 11, 2020 by | Leave a comment

JFP

Abstract :The purpose of this study was to establish a three-variable bactericidal model of temperature, time, and concentration to determine the optimal conditions for Bacillus cereus  spore inactivation by surfactin. In order to obtain the binary regression equation of the inactivated spore model, a total of 17 simulations were performed using response surface methodology. The experimental results showed that the three factors each had a discernible but non-equal impact on the inactivation response value. Multiple regression analysis of experimental results using Design-Expert software yielded as the following equation: Optimal inactivation of spores was achieved by treatment with surfactin at a concentration of 4 mg/ml for 40 h at 53 °C, with the response value reaching 1.8. The spores were treated with surfactin under these conditions; the microstructural changes of spores were observed by scanning electron microscopy. We found that the structures of the outer wall of the spores were damaged, while the spores in the control sample showed no visible damage.

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Posted in Antibiotic Resistance, antimicrobial resistance, Antimicrobials, Bacillus, Bacillus cereus, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, microbial contamination, Microbiology, Research, Spores, Uncategorized

Research – Survival and Virulence of Listeria monocytogenes During Storage on Chocolate Liquor, Corn Flakes, and Dry-Roasted, Shelled Pistachios at 4ºC and 23ºC

Posted on July 11, 2020 by | Leave a comment

JFP

The survival and virulence of Listeria monocytogenes was assessed during storage on three low-moisture foods (LMFs), chocolate liquor, corn flakes and shelled, dry-roasted pistachios (a w 0.18, 0.27, 0.20). The LMFs were inoculated with a 4-strain cocktail of L. monocytogenes at 8 log CFU/g, dried, equilibrated and then stored at 4°C, 25–81% relative humidity (RH) and 23°C, 30–35% RH for at least 336 days. At 4°C, L. monocytogenes remained stable on the LMFs for at least 336 days. At 23°C, L. monocytogenes levels declined on the chocolate liquor, corn flakes and pistachios at initial rates of 0.84, 0.88 and 0.32 log CFU/g/month, respectively. After 8 months at 23°C, L. monocytogenes concentrations on the chocolate liquor and corn flakes decreased to below the limit of detection (i.e., 0.48 log CFU/g). Relative populations of each strain were assessed before (i.e., day 0) and after 6 and 12 months of storage at 23°C and 4°C, respectively. Generally, a decline in the relative abundance of the serotype 1/2a strain was observed during storage, coupled with the relative increase of other strains, depending on the LMF and storage temperature. The total viable populations of L. monocytogenes quantified by PMAxx-qPCR after 12-plus months of storage at 4°C were significantly higher than that obtained by plating on TSA-YE by 1.8 to 3.7 logs. Decreases in the culturable population of L. monocytogenes during storage on the LMFs were the result of both cellular inactivation and transition to a viable-but-non-culturable state. The surviving cells, specifically after long-term storage at 4°C on the chocolate liquor and pistachios, remained infectious and capable of intracellular replication in Caco-2 enterocytes. These results have great relevance for predictive modeling used in microbial health risk assessments and support the addition of LMFs to food safety questionnaires conducted during listeriosis outbreaks.

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

RASFF Alerts – Salmonella – Chicken Fillet in Pepper Marinade – Sesame Seeds- Black Pepper – Chicken Leg Quarters – Live Mussels – MSM Chicken and Turkey Meat

Posted on July 10, 2020 by | Leave a comment

RASFF-Logo

RASFF – Salmonella (group O:8, in 3 out 5 samples /25g) in chilled chicken fillet in pepper marinade from Poland in Poland

RASFF – Salmonella enterica ser. Hvittingfoss (one of out five samples /25g) in hulled sesame seeds from India in Greece

RASFF – Salmonella enterica ser. Infantis (presence /25g) in frozen chicken leg quarters from Poland in Bulgaria

RASFF – Salmonella (presence /25g) in black pepper from Brazil in the Netherlands

RASFF -Salmonella enterica ser. Blockley (in 1 out of 5 samples /25g) in live mussels (Mytilus galloprovincialis) from Italy in Italy

RASFF – Salmonella (presence /25g) in sesame seeds from Uganda in Belgium

RASFF – Salmonella (presence /25g) in black pepper from Brazil in Spain

RASFF – Salmonella (presence /25g) in frozen mechanically separated (MSM) chicken and turkey meat from France and Germany in Belgium

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Posted in food contamination, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Pathogen, food recall, Food Safety, Food Safety Alert, RASFF, Salmonella, Salmonella in Black Pepper, Salmonella in Chicken, Salmonella Sesame Seeds, Uncategorized

Research – Thermal Resistance of Foodborne Pathogens and Enterococcus faecium NRRL B-2354 on Inoculated Pistachios

Posted on July 5, 2020 by | Leave a comment

JFP

ABSTRACT

Process control validations require knowledge of the resistance of the pathogen(s) of concern to the target treatment and, in some cases, the relative resistance of surrogate organisms. Selected strains of Escherichia coli O157:H7 (five strains), Listeria monocytogenes (five strains), and Salmonella enterica (five strains) as well as Salmonella Enteritidis phage type (PT) 30 and nonpathogenic Enterococcus faecium NRRL B-2354 were inoculated separately (as individual strains) onto inshell pistachios. The thermal tolerance of each strain was compared via treatment of inoculated pistachios to hot oil (121°C) or hot water (80°C) for 1 min. Survivor curves in hot oil or hot water (0.5 to 6 min, n = 6 to 15) were determined for one or two of the most resistant strains of each pathogen, as well as E. faecium NRRL B-2354 and Salmonella Enteritidis PT 30, and the Weibull model was fit to the data. A pilot-scale air-impingement oven was used to compare the thermal tolerance of E. faecium NRRL B-2354 and Salmonella Enteritidis PT 30 on pistachios with or without a brining pretreatment and at either dry (no steam) or 30% humidity (v/v) oven conditions. No significant difference in the time to a 4-log reduction in hot oil or hot water was predicted for any of the strains evaluated, on the basis of the 95% confidence interval. In the pilot-scale oven, E. faecium NRRL B-2354 was more thermally resistant than Salmonella in a broad set of differing treatments, treatment times, and temperatures. Salmonella is a suitable target pathogen of concern in pistachios for thermal processes because no other pathogen tested was more thermally resistant under the conditions evaluated. E. faecium NRRL B-2354 was at least as thermally resistant as Salmonella under all conditions evaluated, making it a good potential surrogate for Salmonella on pistachios.

HIGHLIGHTS
  • Salmonella Enteritidis PT 30 is a reasonable target strain for laboratory-based studies.
  • E. coli O157:H7 or L. monocytogenes were less thermally resistant than Salmonella.
  • E. faecium NRRL B-2354 was at least as thermally resistant or more so than Salmonella.
  • E. faecium NRRL B-2354 is a good potential thermal-treatment surrogate for pistachios.

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Posted in E.coli, E.coli O157, E.coli O157:H7, Enterococcus faecium, Food Microbiology Research, Listeria, Listeria monocytogenes, Research, Salmonella, STEC E.coli, Uncategorized

Research – Survival and Histamine Production by Histamine-Forming Bacteria Exposed to Low Doses of Gamma Irradiation

Posted on July 5, 2020 by | Leave a comment

JFP

ABSTRACT

Histamine poisoning occurs when fish containing high amount of histamine are consumed. Because histamine is thermally stable, control of histamine-forming bacteria in seafood is an appropriate strategy for preventing the formation of histamine. One prevention method is the use of gamma irradiation on the histamine formers. To understand the effect of gamma irradiation on the histamine-forming bacteria, laboratory isolates of the prolific histamine formers Morganella morganii, Klebsiella variicola, and Proteus vulgaris were exposed to various doses of gamma radiation in nutrient broth and tuna muscle spiked with histamine formers. None of the test bacteria survived in tuna muscle irradiated at 2.0 kGy. K. variicola was highly sensitive to gamma irradiation and was eliminated at a dose of 1.5 kGy. Histamine production also was reduced significantly as the radiation dose increased. These results suggest that gamma irradiation can effectively eliminate histamine-forming bacteria and reduce the threat of histamine poisoning from seafood.

HIGHLIGHTS
  • Histamine-forming bacteria are highly susceptible to low levels of gamma irradiation.
  • Prolific histamine formers in tuna meat were eliminated by irradiation at 2.0 kGy.
  • Irradiation at 1.5 kGy reduced the level of histamine formers in tuna meat by 4 to 5 log CFU.
  • Histamine formation in tuna meat can be controlled by low levels of gamma irradiation.

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Posted in food contamination, Food Hygiene, Food Inspections, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Poisoning, Food Safety, Food Temperature Abuse, Food Testing, Food Toxin, Histamine, Klebsiella, Proteus, Research, Uncategorized

Research – Salmonella Dublin Makes Inroads In The Beef Industry

Posted on July 4, 2020 by | Leave a comment

BV

 

Salmonella Dublin (S. Dublin) issues tend to garner more headlines today in the dairy industry than in beef, but it’s still an issue in the latter, says Jackson McReynolds.

The first reported incidence of S. Dublin in beef that McReynolds says he found recorded in literature was in California in 2014, though veterinarians have told him they identified cases of it as early as the 1960s.

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Posted in food contamination, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Pathogen, Food Safety, Food Testing, Food Toxin, Research, Salmonella, Uncategorized