Category Archives: microbial contamination

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

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.

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

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

 

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

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.

USA – Illinois: Legionnaires’ Disease reported at Quincy Veterans home

Outbreak News Today

CDC legionella

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The Illinois Department of Veterans’ Affairs (IDVA) and the Illinois Department of Public Health (IDPH) are investigating a single case of Legionnaires’ disease in a resident at the Illinois Veterans Home – Quincy (IVHQ). The resident has received medical treatment and is recovering at IVHQ. No other cases have been identified and IVHQ continues to follow its plans to monitor residents for respiratory illness. The last case of Legionnaires’ disease at IVHQ was February 2018.

IDPH infectious disease staff are working with the facility to collect information and further investigate the resident’s illness. IVHQ has notified residents, staff, and families or power-of-attorneys. IVHQ continues to operate a robust water management program and is implementing best practices to control the growth and spread of waterborne pathogens. IVHQ provides additional water treatment, including filtration and disinfection, prior to use on its campus. IVHQ also maintains point of use filters on all fixtures in residential areas to reduce the possibility of transmission to susceptible individuals. IVHQ continues to conduct active surveillance for Legionella by monitoring residents and reviewing water quality data on an ongoing basis.

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

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.

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

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.

Research – High mycotoxin levels pose risk to dairy farmers this winter

Dairy Global

A high risk of mycotoxin contamination in this year’s forage is posing a challenge for many producers and could be responsible for struggling milk yields and excessive feed waste and underutilisation, experts warn.

According to a press release, Bob Kendal, regional sales manager at Alltech U.K. says, while many producers have lots of forage available this year due to a bumper harvest, we have had a record number of mycotoxin related enquiries, and a number of silage test results have shown high levels of penicillium.

Research – Effects of edible coating containing Williopsis saturnus var. saturnus on fungal growth and aflatoxin production by Aspergillus flavus in peanuts

Wiley Online

Abstract

Production of aflatoxin by Aspergillus flavus in peanuts is both a health hazard and major problem. This study investigated the ability of a whey protein concentrate (WPC)‐based edible coating containing Williopsis saturnus var. saturnus to prevent growth of A. flavus and aflatoxin production in peanuts. WPC with/without W. saturnus (7 log colony‐forming unit [CFU]/g) or W. saturnus alone was sprayed on peanuts inoculated with A. flavus (3 log CFU/g) and stored for 84 days at 25°C. Application of coating with W. saturnus reduced both growth of A. flavus and aflatoxin level by 82 and 69.5% compared with the control, respectively. Thiobarbituric acid values were around 60% lower in peanuts coated with WPC compared with the control. Sensory and chemical properties of peanuts were not significantly affected by coating treatment (p < .05). Based on results, coating with W. saturnus appears useful in preventing both growth of A. flavus and aflatoxin production in peanuts.

Practical Applications

Improved WPC based coating containing W. saturnus can be applied on surface of roasted peanuts to prevent growth of A. flavus and aflatoxin production.

RASFF Alerts – Animal Feed – Salmonella – Rapeseed Meal – Fish Meal

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RASFF – Salmonella enterica ser. Havana (presence /250ml) in rapeseed meal from Germany in Germany

RASFF – Salmonella enterica ser. Oranienburg (in 1 out of 5 samples /25g) in fish meal from the United States in Greece

RASFF – Salmonella (presence /25g) in fish meal from the United States in Greece

 

Research – Aflatoxin cross‐contamination during mixing of shelled almonds

Wiley Online

Abstract

Reports indicate that aflatoxin contamination in almonds comprise a few highly contaminated kernels among a much larger bulk with low concentrations, hypothetically due to cross‐contamination during processing. To test this, kernels exhibiting this distribution were generated by distributing 141.5 µg of aflatoxin between 20 almonds (approximately 7 µg each) which were then mixed with 5 kg (approximately 4,000 kernels) of local raw unroasted almonds for 20 min using an industrial mixer. A second 5 kg lot of noncontaminated kernels was marked for later identification then similarly mixed with the contaminated group. The groups were re‐separated and aflatoxin content was measured using High Performance Liquid Chromatography (HPLC) analysis. Twenty‐three micrograms of aflatoxin was recovered from the initially noncontaminated group, indicating cross‐contamination during mixing. Approximately 0.10 µg of aflatoxin was recovered from equipment surfaces. The results emphasize the need to reduce the potential for cross‐contamination between nuts by removing contaminated nuts and routinely cleaning processing equipment.

Practical applications

Shelled almonds have an atypical aflatoxin distribution that appears consistent with a combination of two distributions: first, infrequent highly contaminated nuts and second, a uniform low‐level aflatoxin contamination. This second distribution appears to come from cross‐contamination during postharvest processing, but this has not been previously tested. Results of this study confirmed that aflatoxin can transfer between contaminated nuts and uncontaminated nuts via simple mechanical mixing contact, as would occur during postharvest processing. Almond producers will want to take this finding into account when reviewing their processing and cleaning procedures and reduce any opportunity for nut to nut cross‐contamination by removing contaminated nuts as early as possible and routinely cleaning processing equipment.