Category Archives: Research

Research -Inactivation of Bacillus cereus Spores on Stainless Steel by Combined Superheated Steam and UV-C Irradiation Treatment

Posted on January 11, 2020 by | Leave a comment

Journal of Food Protection

ABSTRACT

Bacillus cereus spore contamination on food contact surfaces is of great concern in the food industry. Thus, in the present study, superheated steam (SHS) was used alone or combined with UV-C irradiation for inactivation of B. cereus spores inoculated on stainless steel coupons. Temperatures higher than 250°C were needed to effectively inactivate B. cereus spores by SHS treatment alone, while a synergistic bactericidal effect resulted from the sequential treatment of SHS before or after UV-C irradiation. The increased dipicolinic acid ratio obtained by the combined treatment had a significant role in the synergistic bactericidal effect. Therefore, the combined treatment of SHS and UV-C could be used effectively to inactivate B. cereus on stainless steel. It is recommended to use hurdle technology with reduced energy consumption to ensure microbiological safety on food contact surfaces.

HIGHLIGHTS

  • Inactivation of Bacillus cereus spores on stainless steel was identified in this study.

  • Superheated steam (SHS) was applied solely or combined with UV-C irradiation.

  • A synergistic effect was observed by combination treatment for spore inactivation.

  • The dipicolinic acid (DPA) release level increased significantly by combination treatment.

  • The combination treatment can be applied to sanitize food processing equipment.

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Posted in Bacillus, Bacillus cereus, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Food Technology, microbial contamination, Microbiology, Research, Technology, Uncategorized

Information USA – What Are the Symptoms of Common Foodborne Pathogens?

Posted on January 10, 2020 by | Leave a comment

CDC

Burden of Foodborne Illness: Findings

CDC estimates that each year roughly 1 in 6 Americans (or 48 million people) gets sick, 128,000 are hospitalized, and 3,000 die of foodborne diseases.

 

These estimates provide the most accurate estimates yet of which known foodborne pathogens (bacteria, viruses, and parasites) are causing the most illnesses in the United States, and how many foodborne illnesses are caused by unspecified agents. The estimates also show that much work remains to be done—specifically in focusing efforts on the top known pathogens and identifying the additional causes of foodborne illness and death.

CDC provides estimates for two major groups of foodborne illnesses

Known foodborne pathogens — 31 pathogens known to cause foodborne illness. Many of these pathogens are tracked by public health systems that track diseases and outbreaks. Read the report >

Unspecified agents — Agents with insufficient data to estimate agent-specific burden; known agents not yet identified as causing foodborne illness; microbes, chemicals, or other substances known to be in food whose ability to cause illness is unproven; and agents not yet identified. Because you can’t “track” what isn’t yet identified, estimates for this group of agents started with the health effects or symptoms that they are most likely to cause, such as acute gastroenteritis. Read the report >

Total number of foodborne illnesses each year

CDC estimated the number of illnesses, hospitalizations, and deaths caused by both known and unspecified agents. CDC then estimated what proportion of each were foodborne. The first table below provides estimates for domestically acquired foodborne illnesses, and the second table provides estimates for domestically acquired illnesses caused by all transmission routes (foodborne, waterborne, person-to-person contact, animal contact, environmental contamination, and others).

Estimated annual number of domestically acquired, foodborne illnesses, hospitalizations, and deaths due to 31 pathogens and the unspecified agents transmitted through food, United States
Foodborne agents Estimated annual number of illnesses Estimated annual number of hospitalizations Estimated annual number of deaths
Number (90% credible interval) % Number (90% credible interval) % Number (90% credible interval) %
31 known pathogens 9.4 million
(6.6–12.7 million)		 20 55,961
(39,534–75,741)		 44 1,351
(712–2,268)		 44
Unspecified agents 38.4 million
(19.8–61.2 million)		 80 71,878
(9,924–157,340)		 56 1,686
(369–3,338)		 56
Total 47.8 million
(28.7–71.1 million)		 100 127,839
(62,529–215,562)		 100 3,037
(1,492–4,983)		 100
Estimated annual number of illnesses, hospitalizations, and deaths due to 31 pathogens and the unspecified agents, United States
Foodborne agents Estimated annual number of illnesses Estimated annual number of hospitalizations Estimated annual number of deaths
Number (90% credible interval) % Number (90% credible interval) % Number (90% credible interval) %
31 known pathogens 37.2 million
(28.4–47.6 million)		 21 228,744
(188,326–275,601)		 47 2,612
(1,723–3,819)		 42
Unspecified agents 141.8 million 79 258,033 53 3,574 58
Total 179 million 100 486,777 100 6,186 100

 

Pathogens causing the most foodborne illnesses, hospitalizations, and deaths each year

Top five pathogens contributing to domestically acquired foodborne illnesses
Pathogen Estimated number of illnesses 90% credible interval %
Norovirus 5,461,731 3,227,078–8,309,480 58
Salmonella, nontyphoidal 1,027,561 644,786–1,679,667 11
Clostridium perfringens 965,958 192,316–2,483,309 10
Campylobacter spp. 845,024 337,031–1,611,083 9
Staphylococcus aureus 241,148 72,341–529,417 3
Subtotal 91

 Top of Page

Top five pathogens contributing to domestically acquired foodborne illnesses resulting in hospitalization
Pathogen Estimated number of hospitalizations 90% credible interval %
Salmonella, nontyphoidal 19,336 8,545–37,490 35
Norovirus 14,663 8,097–23,323 26
Campylobacter spp. 8,463 4,300–15,227 15
Toxoplasma gondii 4,428 2,634–6,674 8
E. coli (STEC) O157 2,138 549–4,614 4
Subtotal 88
Top five pathogens contributing to domestically acquired foodborne illnesses resulting in death
Pathogen Estimated number of deaths 90% credible interval %
Salmonella, nontyphoidal 378 0–1,011 28
Toxoplasma gondii 327 200–482 24
Listeria monocytogenes 255 0–733 19
Norovirus 149 84–237 11
Campylobacter spp. 76 0–332 6
Subtotal 88
References

Scallan E, Hoekstra RM, Angulo FJ, Tauxe RV, Widdowson M, Roy SL, et al. Foodborne illness acquired in the United States—major pathogens. Emerg Infect Dis. 2011;17(1):7-15. https://dx.doi.org/10.3201/eid1701.p11101External

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Posted in Campylobacter, Clostridium perfringens, food contamination, food death, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Poisoning, Food Poisoning Death, Food Safety, Food Toxin, Listeria monocytogenes, Norovirus, Research, Salmonella, Staphylococcus aureus, STEC, STEC E.coli, Toxoplasma gondii, Toxoplasmosis, Uncategorized

Research -Enumeration and Survival of Salmonella enterica in Live Oyster Shellstock Harvested from Canadian Waters

Posted on January 8, 2020 by | Leave a comment

Journal of Food Protection

ABSTRACT

Since 2015, 11 recalls of live oyster shellstock have been issued in Canada due to the presence of Salmonella enterica. Six of those recalls took place in 2018. To understand this increase, fundamental information is needed on the relationship between S. enterica and oysters. The aims of this study were to address important data gaps concerning the levels of Salmonella in naturally contaminated oysters and the ability of this pathogen to survive in live oyster shellstock. Enumeration data were evaluated for five oyster and clam samples collected from the east coast of Canada from 2015 to 2018. The reported levels were <0.0015 to 0.064 most probable number per g of oyster tissue. The S. enterica isolates recovered from these animals belonged to serovars Typhimurium, Infantis, Enteritidis, and I 4,5:i:−. Filter feeding by the oysters was exploited to assess the Salmonella accumulation that would occur following a natural contamination event. Detectable levels of the pathogen were observed after 30 min of exposure and began to plateau at 60 min. A survival study in live oyster shellstock indicated that after 4 days of storage at ambient temperatures, the Salmonella level declined slightly from 4.3 to 3.7 log CFU/g. These data indicate that the levels of Salmonella found in naturally contaminated oysters are low and are not expected to increase between the point of harvest and the point of consumption. The changing ecology of shellfish environments requires continued monitoring and testing to safeguard public health. The data presented here will be useful for the evaluation and design of sampling plans and risk management approaches for the control of Salmonella in live oyster shellstock.

HIGHLIGHTS

  • Salmonella levels in naturally contaminated clams and oysters were <0.1 to 6.4 MPN/100 g.

  • Salmonella was detected in oysters after 30 min of exposure.

  • Salmonella did not grow in live oyster shellstock.

  • Salmonella was able to survive for at least 7 days in live oyster shellstock.

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

Research – Edible films containing carvacrol and cinnamaldehyde inactivate Escherichia coli O157:H7 on organic leafy greens in sealed plastic bags

Posted on January 7, 2020 by | Leave a comment

Wiley Online Eurofins Food Testing UK

The antimicrobial effects of apple‐, carrot‐, and hibiscus‐based edible films containing carvacrol and cinnamaldehyde against Escherichia coli O157:H7 on organic leafy greens in sealed plastic bags were investigated. Fresh‐cut Romaine and Iceberg lettuce, and mature and baby spinach leaves were inoculated with E. coli O157:H7 and placed into Ziploc® bags. Edible films were then added to the bags, which were stored at 4°C. The evaluation of samples taken at days 0, 3, and 7 showed that on all leafy greens, 3% carvacrol‐containing films had the greatest effect against E. coli O157:H7, reducing the bacterial population by about 5 log CFU/g on day 0. All three types of 3% carvacrol‐containing films reduced E. coli O157:H7 by about 5 log CFU/g at day 0. The 1.5% carvacrol‐containing films reduced E. coli O157:H7 by 1–4 logs CFU/g at day 7. Films with 3% cinnamaldehyde showed reduction of 0.6–3 logs CFU/g on different leafy greens.

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Posted in E.coli, E.coli O157, E.coli O157:H7, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, microbial contamination, Microbiology, Research, STEC E.coli, Technology, Uncategorized

Research – Control of Listeria monocytogenes in boned dry‐cured ham by E‐beam treatment

Posted on January 6, 2020 by | Leave a comment

Wiley Online listeria

Boning of dry‐cured hams involves additional handling which increases the risk of contamination with Listeria monocytogenes. This work studies the ability of E‐beam to eliminate this pathogen from boned dry‐cured ham (BDH). The destruction kinetics of four L. monocytogenes strains (S2, S4‐2, S12‐1, and S7‐2) and L. innocua NCTC 11288 as a surrogate were determined at doses up to 3 kGy. L. innocua and L. monocytogenes S4‐2 were the most radioresistant (D‐value = 0.55 kGy). E‐beam penetration was studied in blocks extracted from BDH and irradiated with 2–6 kGy. The bilateral treatment of 2 kGy allows the required dose (1.32 kGy) to be absorbed in the innermost part of the block to achieve the food safety objective of “zero tolerance” for this microorganism. This listericidal treatment was also confirmed in whole BDH intentionally contaminated with L. innocua. The sensory analysis of irradiated BDH showed off‐odors that were imperceptible after 15 days of storage at 4°C.

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

New Zealand -Campylobacter and E. coli infections climb in New Zealand; raw milk cited

Posted on January 6, 2020 by | Leave a comment

Food Safety News

Campylobacter, Yersinia, E. coli and Listeria infections all went up while Salmonella declined, according to the 2018 report on foodborne disease in New Zealand.

Campylobacter remained the top foodborne pathogen. The country has a performance target to reduce cases of foodborne campylobacteriosis by 10 percent from 88.4 to 79.6 per 100,000 per head of population by the end of 2020. The estimated incidence in 2018 was 78.3 per 100,000.

New Zealand Food Safety (NZFS) is part of the Ministry for Primary Industries (MPI) and leads the country’s food safety system. EpiSurv is the country’s notifiable disease surveillance system

Full Report Link

 

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiology, Raw Milk, Research, Uncategorized

Research – Detection of Psychrophilic Clostridium spp. Causing “Blown Pack” Spoilage in Meat Juice Samples from Chilled Vacuum-Packed Beef and Lamb Meat Imported from Different Countries to Switzerland

Posted on January 6, 2020 by | Leave a comment

Journal of Food Protection

ABSTRACT

“Blown pack” spoilage (BPS) of chilled vacuum-packed meat is mainly caused by anaerobic and psychrophilic Clostridium spp., including C. estertheticum, C. gasigenes, C. frigoriphilum, and C. frigidicarnis. Recently, its occurrence has been reported in several countries, especially in internationally traded meat. Therefore, this study aimed at detecting the occurrence of psychrophilic Clostridium spp. causing BPS in meat juice samples (MJS) from chilled vacuum-packed beef and lamb meat imported from other countries to Switzerland. One hundred fifty-four MJS (n = 78 from beef; n = 76 from lamb meat) were screened for psychrophilic Clostridium spp. by quantitative PCR, whereby MJS with a crossing point PCR cycle value <35 and >35 were considered positive and negative, respectively. Psychrophilic Clostridium spp. were detected in 10 MJS, of which 2 were from beef and 8 were from lamb meat. The two beef MJS originated from Spain and Lithuania, whereas the lamb MJS originated from New Zealand (six) and Australia (two). This is the first report of psychrophilic Clostridium spp. in MJS from chilled vacuum-packed beef and lamb meat imported from other countries to Switzerland and provides further evidence that the risk of BPS in lamb meat is higher than in beef.

HIGHLIGHTS

  • Psychrophilic Clostridium spp. were detected in 10 of 154 meat juice samples.

  • Prevalence of psychrophilic Clostridium spp. in lamb meat was higher than in beef.

  • Prevalence of psychrophilic Clostridium spp. was highest in meat imported from New Zealand and Australia.

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Posted in Clostridium botulinum, Clostridium difficile, Clostridium perfringens, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, microbial contamination, Microbiology, Research, Sulphite Reducing Clostridia, Uncategorized

Research – Growth and Survival of Listeria monocytogenes on Intact Fruit and Vegetable Surfaces during Postharvest Handling: A Systematic Literature Review

Posted on January 5, 2020 by | Leave a comment

Journal of Food Protection

ABSTRACT

Listeria monocytogenes may be present in produce-associated environments (e.g., fields, packing houses); thus, understanding its growth and survival on intact, whole produce is of critical importance. The goal of this study was to identify and characterize published data on the growth and/or survival of L. monocytogenes on intact fruit and vegetable surfaces. Relevant studies were identified by searching seven electronic databases: AGRICOLA, CAB Abstracts, Center for Produce Safety funded research project final reports, FST Abstracts, Google Scholar, PubMed, and Web of Science. Searches were conducted using the following terms: Listeria monocytogenes, produce, growth, and survival. Search terms were also modified and “exploded” to find all related subheadings. Included studies had to be prospective, describe methodology (e.g., inoculation method), outline experimental parameters, and provide quantitative growth and/or survival data. Studies were not included if methods were unclear or inappropriate, or if produce was cut, processed, or otherwise treated. Of 3,459 identified citations, 88 were reviewed in full and 29 studies met the inclusion criteria. Included studies represented 21 commodities, with the majority of studies focusing on melons, leafy greens, berries, or sprouts. Synthesis of the reviewed studies suggests L. monocytogenes growth and survival on intact produce surfaces differ substantially by commodity. Parameters such as temperature and produce surface characteristics had a considerable effect on L. monocytogenes growth and survival dynamics. This review provides an inventory of the current data on L. monocytogenes growth and/or survival on intact produce surfaces. Identification of which intact produce commodities support L. monocytogenes growth and/or survival at various conditions observed along the supply chain will assist the industry in managing L. monocytogenes contamination risk.

HIGHLIGHTS

  • L. monocytogenes growth and/or survival on intact produce differed by commodity.

  • Intact produce held at ≥20°C had the highest L. monocytogenes growth rates.

  • Produce surface and storage conditions affected L. monocytogenes growth and/or survival.

  • Microbial carrying capacity is crucial to characterizing growth and/or survival patterns.

  • Studies need to describe experimental conditions (e.g., relative humidity) for modeling efforts.

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

Research -Evaluating Environmental Monitoring Protocols for Listeria spp. and Listeria monocytogenes in Frozen Food Manufacturing Facilities

Posted on January 4, 2020 by | Leave a comment

Journal of Food Protection

ABSTRACT

Food processors face serious challenges due to Listeria monocytogenes contamination. Environmental monitoring is used to control L. monocytogenes from the processing environment. Although frozen foods do not support the growth of L. monocytogenes, the moist and cold conditions in frozen food production environments are favorable for growth of L. monocytogenes. The purpose of the study was to determine the current state of awareness and practices applied across a variety of frozen food facilities related to environmental monitoring for Listeria. A survey tool was created to elicit information on existing environmental monitoring programs within the frozen food industry. The topics included cleaning and sanitizing applications and frequency, microbiological testing, and environmental areas of concern. The survey was reviewed by academic and industry experts with knowledge of microbiology and frozen food processing and was field tested by industry personnel with extensive knowledge of environmental monitoring. The survey was distributed and analyzed electronically via Qualtrics among 150 frozen food contacts. Data were gathered anonymously with a response rate of 31% (n = 46). The survey indicated that facilities are more likely to test for Listeria spp. in environmental monitoring zones 2 to 4 (nonfood contact areas) on a weekly basis. The major areas of concern in facilities for finding Listeria-positive results are floors, walls, and drains. At the time of the survey, few facilities incorporated active raw material and finished product testing for Listeria; instead, programs emphasized the need to identify presence of Listeria in the processing environment and mitigate potential for product contamination. Recognition of environmental monitoring as a key component of a comprehensive food safety plan was evident, along with an industry focus to further improve and develop verification programs to reduce prevalence of L. monocytogenes in frozen food processing environments.

HIGHLIGHTS

  • Environmental monitoring practices vary throughout the frozen food industry.

  • Areas of concern of processing facilities for Listeria are floors, drains, and walls.

  • Listeria spp. sampling is most commonly performed weekly on nonfood contact surfaces.

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Posted in food contamination, Food Hygiene, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Pathogen, Food Safety, Listeria, Listeria monocytogenes, Research, Uncategorized

Research – Combined ohmic heating and krypton‐chlorine excilamp treatment for the inactivation of Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7 in apple juice

Posted on January 4, 2020 by | Leave a comment

Wiley Online

Abstract

The combined effect of the 222‐nm krypton‐chlorine (KrCl) excilamp and ohmic heating for the inactivation of Listeria monocytogenes, Salmonella enterica serovar Typhimurium, and Escherichia coli O157:H7 in apple juice was investigated in this study. When ohmic heating and a KrCl excilamp were applied to apple juice simultaneously, the reduction level of E. coli O157:H7 following 70 s (target temperature of 65.9°C) of combination treatment reaching 4.6 log CFU/ml was significantly higher than that of each treatment alone (2.7 log CFU/ml). The same trend, indicating a synergistic bactericidal effect, was observed for L. monocytogenes and S. Typhimurium. Therefore, the combination treatment of the KrCl excilamp and ohmic heating can be used effectively to control bacterial pathogens in apple juice with a reduced processing time.

Practical applications

Demands for energy‐efficient and environmentally friendly bactericidal apparatuses have been increasing. Although the mercury UV lamp has been widely used to inactivate foodborne pathogens in water or juice products individually or combined with heat treatment, the use of this conventional lamp will be limited continuously in accordance with the Minamata Convention treaty, which restricts the use of mercury. Thus, it is of interest to identify the bactericidal effect of an alternative UV‐C lamp and its combination with heat treatment. The synergistic bactericidal effect of the KrCl excilamp and ohmic heating, which are alternative nonthermal and thermal technologies, respectively, was identified in the present study. The results indicated in this study could be utilized by juice processors to achieve a 5‐log reduction in foodborne pathogens.

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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 Microbiology Testing, Listeria, Listeria monocytogenes, microbial contamination, Microbiology, Research, Salmonella, Uncategorized