What is the Purpose of Microbial Testing of Food Products at the Time of Shipment in Food Manufacturing Plants? How Reliable is it?
Ensuring that food products meet the microbial standards set for each type of food is, of course, essential. However, in the case of voluntary testing, the effectiveness of microbial testing of products at the time of shipment varies. Some foods benefit significantly from such tests, while for others, the efficacy is minimal. So, which foods benefit from microbial testing at shipment, and which do not? This article introduces a scientific paper that investigates this issue. The author is Dr. Zwietering, Chair of the International Commission on Microbiological Specifications for Foods (ICMSF) as of May 2022.
Controlling Listeria monocytogenes in Ready-to-Eat Foods with Nisin and Organic Acids
Listeria monocytogenes is a notorious risk in food processing facilities, particularly known for forming biofilms that make it hard to eliminate entirely from ready-to-eat (RTE) products. A promising solution gaining attention in the US is the combined use of nisin and organic acids during distribution. This article delves into how this method helps control Listeria monocytogenes in RTE foods, enhancing their safety.
Peracetic Acid Preparations as a Bactericide for Campylobacter and Salmonella from Broilers
In this article, I'll be discussing a fascinating paper that examines the effectiveness of peracetic acid as a disinfectant in poultry processing plants, particularly in the chilling process of broilers. This study was conducted by Dr. Nagel from Auburn University in the United States.
Summer holiday
Due to summer holiday, the blog will not be updated from 7 July to 11 August. Updates will resume on 18 August.
Chilled Food Spoilage and Psychrotrophic Lactic Acid Bacteria
This article delves into the spoilage of chilled foods and the role of psychrotrophic bacteria, specifically lactic acid bacteria. We explore findings revealed through 16S rRNA amplicon sequencing analysis, which identifies bacteria undetectable at a culture temperature of 30°C. In a previous article, we discussed a study by Dr. Pokasos and his team from Ghent University, Belgium. Their research demonstrated that culturing at 30°C fails to detect psychrotrophic bacteria, leading to an underestimation of microbial counts. This article serves as a continuation of that discussion.
How Effectively Does the ISO-Standard Aerobic Plate Count (30°C, 72 Hours) Test Measure Cold-Tolerant Bacteria?
The measurement of aerobic plate counts is divided into two methods: the AOAC method used in the United States (35°C for 48 hours) and the ISO method used in the EU (30°C for 72 hours). The ISO method uses a lower incubation temperature for a longer duration compared to the US method. This approach is intended to detect cold-tolerant bacteria more effectively, as discussed in a previous article. However, even the ISO method is insufficient for detecting all cold-tolerant microorganisms. How effectively does the ISO method for aerobic plate count testing detect cold-tolerant bacteria and spoilage lactic acid bacteria?
Estimating the Total Number of Food Poisoning Cases (Patients, Hospitalisations, Deaths) in a Country
Estimating the total number of food poisoning cases, including the number of patients, hospitalisations, and deaths, as well as ranking the number of incidents, is not an easy task. The paper I am introducing today, authored by Dr. Scallan and his team from the U.S. Centers for Disease Control and Prevention, attempts to estimate the number of food poisoning cases in the United States caused by different pathogens. This estimation is based on statistical data, active surveillance, passive surveillance, and other sources of data.
Over Disinfection and Rough Hands: The Role of the Good Indigenous Skin Bacterium Staphylococcus epidermidis
Staphylococcus aureus, often referred to as S. aureus, is a notorious bacterium known for causing inflammation on the skin. This "bad guy" of the microbial world can lead to food poisoning and opportunistic infections. But is there a "good guy" that can combat S. aureus on our skin? For a long time, there was no clear scientific evidence. However, in 2017, Dr. Nakatsuji and colleagues from the University of California, San Diego, provided groundbreaking evidence that indeed there is a beneficial bacterium capable of eliminating S. aureus. They discovered that Staphylococcus epidermidis, a common skin bacterium, plays a crucial role in keeping S. aureus at bay.
Listeriolysin O (LLO) in Listeria monocytogenes: Defence Against Protozoa in Animal Gut and Soil?
When Listeria monocytogenes infect humans, they invade the epithelial cells of the intestines and cleverly evade immune responses, such as macrophage predation, by parasitizing inside cells. This cunning infection mechanism leads to Listeria infections, which are particularly dangerous for pregnant women, causing miscarriages, and for the elderly, resulting in severe conditions like sepsis and meningitis. A critical factor in Listeria infection is Listeriolysin O (LLO). This article introduces research by Dr. Pushkareva and colleagues from the Russian Academy of Medical Sciences, which suggests that Listeriolysin O originally evolved in the natural ecosystem as part of a predator-prey relationship with the ciliate Tetrahymena.
Did Human Pathogenic Genes of Vibrio Species Evolve in Deep-Sea Vents?
What exactly is pathogenicity when it comes to pathogenic microorganisms affecting humans? Were the genes responsible for pathogenicity specifically developed to infect humans and cause food poisoning? In this article, we’ll explore how the genes that make Vibrio parahaemolyticus and Vibrio cholerae pathogenic to humans have evolved in the natural world, completely independent of any human infection routes.