Monthly Archives: January 2020

Research – Use of Phyllosphere-Associated Lactic Acid Bacteria as Biocontrol Agents To Reduce Salmonella enterica Serovar Poona Growth on Cantaloupe Melons

Posted on January 2, 2020 by KSW | Leave a comment

ABSTRACT

Foodborne illness associated with fresh, ready-to-eat produce continues to be a significant challenge to public health. In this study, we created a phyllosphere-associated lactic acid bacteria (PLAB) library and screened it via a high-throughput in vitro fluorescent assay to identify bacteria capable of inhibiting the growth of the pathogenic bacterium Salmonella enterica. One isolate, 14B4, inhibited the growth of S. enterica by >45-fold in vitro; it was able to grow and persist on the surfaces of cantaloupe melons at both ambient (25°C) and refrigerator (5°C) temperatures. Isolate 14B4 inhibited the growth of S. enterica on the surfaces of cantaloupes by >3 log when incubated at 25°C for 24 h and by >4 log when the cantaloupes were stored at 5°C for 3 days and the temperature was shifted to 25°C for 2 days. Genomic DNA sequence analysis of isolate 14B4 revealed that it was Lactococcus lactis and that it did not contain any known antibiotic biosynthesis gene clusters, antibiotic resistance genes, or genes encoding any known virulence factors. Organic acid analysis revealed that L. lactis produces substantial amounts of lactic acid, which is likely the inhibitory substance that reduced the growth of Salmonella on the cantaloupes.

HIGHLIGHTS

L. lactis isolate 14B4 inhibited the growth of Salmonella on cantaloupe rinds.
Storage of contaminated rinds at 5°C increased the growth inhibition by 1 log.
L. lactis isolate 14B4 is a potentially safe and effective biological control agent.

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Posted in food contamination, Food Hygiene, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Safety, Food Testing, lactic acid bacteria, Research, Salmonella, Uncategorized

USA – Almark Eggs Secondary Recalls For Listeria Monocytogenes Listed

Posted on January 2, 2020 by KSW | Leave a comment

Food Poisoning Bulletin

These are all of the recalls of Almark Foods hard boiled eggs to date:

The first recall was for Almark hard cooked and peeled eggs in pails within expiration dates. The company has suspended production of the eggs while an investigation is being conducted. Some of the brand names recalled in this initial recall include Nic’s, Rainbow Farms, and Sutherland’s Food Service.
Almark expanded that recall on December 23, 2019 to include al hard boiled eggs that were manufactured at the firm’s Gainesville, Georgia facility. Some brand names of those eggs include Egglands Best, Fresh Thyme, Giant Eagle, Great Value, and Kroger.
Bakkavor Foods recalled Trader Joe’s egg salad and potato salad on December 23, 2019. None of those products are linked to any illnesses.
Dierbergs Markets recalled potato and egg salads and remoulade on December 24, 2019 because they were made with the recalled Almark hard cooked eggs.
Reichel Foods recalled Pro2Snax in two varieties on December 26, 2019. These products were sold in retail outlets nationwide.
Great American Deli recalled egg salads sandwiches on December 24, 2019 because they were made with recalled Almark Foods hard cooked eggs.
Cece’s Veggie Fresh Ramen Salad with Chicken Broth was recalled on December 30, 2019 because the product was made with Almark Foods Eggs.
Meijer recalled diced hard cooked eggs used on salad bars in two of its stores in Grand Rapids, Michigan on December 31, 2019.

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Posted in food contamination, food death, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, Food Pathogen, food recall, Food Safety, Food Safety Alert, Food Testing, Listeria, Listeria monocytogenes, Uncategorized

USA – Cyclospora Number One Multistate Food Poisoning Outbreak For 2019

Posted on January 2, 2020 by KSW | Leave a comment

Food Poisoning Bulletin cardcyclosporasme

Cyclospora is the number one multistate food poisoning outbreak for 2019, with more than 2400 people sick. This wasn’t an individual outbreak, but many individual cases and several outbreaks linked to a venue or product. The overall number of domestically acquired cases is higher than those from 2017 and 2018.

hese are the outbreaks of cyclosporiasis linked to a venue or food:

An outbreak associated with workplace cafeterias in Virginia that sickened at least 39 people.
A large cyclospora outbreak at Cooper’s Hawk Winery in the Jacksonville, Florida area sickened at least 132 people in 11 states.
An outbreak in Minnesota sickened 35 people and was associated with three restaurants located in different areas of the state.
Cyclosporiasis illnesses in New York City in July sickened more than 90 people.
A Boston Cyclospora outbreak, also in July, sickened more than 100 people.
A cyclospora outbreak linked to Siga Logistics de RL de CV basil imported from Mexico sickened more than 240 people. this was the largest individual outbreak in the overall case count.

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Posted in Cyclospora, food bourne outbreak, food contamination, food handler, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, Food Pathogen, food recall, Food Safety, Food Safety Alert, Food Testing, foodborne disease, Foodborne Illness, foodborne outbreak, foodbourne outbreak, Uncategorized

Research – Modeling the Effects of the Preculture Temperature on the Lag Phase of Listeria monocytogenes at 25°C

Posted on January 1, 2020 by KSW | Leave a comment

Journal of Food Protection

ABSTRACT

In predictive microbiology, the study of the microbial lag phase, i.e., the time needed for bacteria to adapt to a new environment before multiplying, has received a great deal of attention in the research literature. The microbial lag phase is more difficult to estimate than the specific growth rate because the lag phase is impacted by the previous and actual growth environments. In this study, the growth of Listeria monocytogenes preincubated at 0, 5, 10, and 15°C and subsequently grown at 25°C was investigated at the single-cell and population levels. The population lag phase of L. monocytogenes was obtained by fitting the Baranyi model, and the single-cell lag time was estimated by the time to detection method. The lag phase at the single-cell and population levels of L. monocytogenes presented a downward trend as the preculture temperature ranged from 0 to 15°C. The population lag phase of L. monocytogenes was lower than the single-cell lag time at the same preculture temperature. In addition, except for the zero-lag distribution at a preculture temperature of 15°C, all the single-cell lag time distributions of L. monocytogenes followed a Weibull distribution under all preculture temperatures. The preculture temperature had a significant impact on the rapid variation in the single-cell lag time distribution. Thus, the influence of preculture temperature on the lag phase needs to be quantitatively analyzed for better assessment of microbiological risk.

HIGHLIGHTS

The variability of single-cell lag time could be described by the Weibull distribution.
The population lag was shorter than the single-cell lag at the same preculture temperature.
The preculture temperature had no significant effects on the growth rate.