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Category Archives: pathogenic
Research – A Comprehensive Review for the Surveillance of Human Pathogenic Microorganisms in Shellfish
Bivalve molluscan shellfish have been consumed for centuries. Being filter feeders, they may bioaccumulate some microorganisms present in coastal water, either naturally or through the discharge of human or animal sewage. Despite regulations set up to avoid microbiological contamination in shellfish, human outbreaks still occur. After providing an overview showing their implication in disease, this review aims to highlight the diversity of the bacteria or enteric viruses detected in shellfish species, including emerging pathogens. After a critical discussion of the available methods and their limitations, we address the interest of technological developments using genomics to anticipate the emergence of pathogens. In the coming years, further research needs to be performed and methods need to be developed in order to design the future of surveillance and to help risk assessment studies, with the ultimate objective of protecting consumers and enhancing the microbial safety of bivalve molluscan shellfish as a healthy food.
Posted in Amnesic Shellfish Poisoning, Decontamination Microbial, Diarrhoeic Shellfish Poisoning, Enteropathogenic E. coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, paralytic shellfish poisoning, Pathogen, pathogenic, Shellfish, shellfish toxin
Research – Trends in Food Pathogens Risk Attenuation
Abstract
Foodborne pathogens represent one of the most dangerous threats to public health along the food chain all over the world. Over time, many methods were studied for pathogen inhibition in food, such as the development of novel packaging materials with enhanced properties for microorganisms’ growth inhibition (coatings, films) and the use of emerging technologies, like ultrasound, radio frequency or microwave. The aim of this study was to evaluate the current trends in the food industry for pathogenic microorganisms’ inhibition and food preservation in two directions, namely technology used for food processing and novel packaging materials development. Five technologies were discussed in this study, namely high-voltage atmospheric cold plasma (HVACP), High-Pressure Processing (HPP), microwaves, radio frequency (RF) heating and ultrasound. These technologies proved to be efficient in the reduction of pathogenic microbial loads in different food products. Further, a series of studies were performed, related to novel packaging material development, by using a series of antimicrobial agents such as natural extracts, bacteriocins or antimicrobial nanoparticles. These materials proved to be efficient in the inhibition of a wide range of microorganisms, including Gram-negative and Gram-positive bacteria, fungi and yeasts.
Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Pathogen, pathogenic
Research – Prevalence of Listeria monocytogenes in RTE Meat Products of Quevedo (Ecuador)
Abstract
Listeria monocytogenes is a foodborne pathogen that causes listeriosis and can be a problem in areas where meat products are sold at unregulated storage temperatures. In this work, the prevalence of L. monocytogenes was determined in the five most widely traded meat products in the province of Quevedo (Ecuador): bacon, “chorizo paisa”, grilled hamburger meat, mortadella, and salami. A total of 1000 samples of these products were analyzed in two seasons of the year (dry season/rainy season). All L. monocytogenes isolates were confirmed by PCR with primers designed for the iap gene. Furthermore, the positive samples were quantified for L. monocytogenes. Of the 1000 meat products analyzed, 163 were positive for L. monocytogenes (16.3%). The prevalence of L. monocytogenes in the two seasons in different meat products was as follows: 22.5% in mortadella, 19% in hamburger meat, 15% in bacon, 14.5% in chorizo paisa and 10.5% in salami. In addition, the concentration of L. monocytogenes in most of the positive samples was in the range of 4–6 log CFU/g or even higher. The results show the need for improvements in the hygienic measures and meat storage temperatures in Quevedo (Ecuador) to avoid risks of foodborne listeriosis.
Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, Food Pathogen, Listeria, Listeria monocytogenes, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Pathogen, pathogenic
Research – Inactivation of foodborne and other pathogenic bacteria with pyrrolidine based fatty acid amide derivatives
Abstract
Foodborne pathogens are a persistent threat to food and consumer safety. To mitigate outbreaks and contamination incited by these pathogens, the development of novel preventative safety controls and biorational inactivation measures are paramount. The objectives of this research were to evaluate the efficacy of pyrrolidine-based amide derivatives of decanoic (DEPY), lauric (LAPY), myristic (MYPY) and palmitic (PAPY) fatty acids for in-vitro inhibition and inactivation of various Gram-positive bacterial strains including Listeria monocytogenes (typically associated with foodborne illness), Bacillus subtilis, and Streptococcus mutans and Streptococcus sobrinus (both normally present in the oral cavity and involved with dental caries). Compared to no treatment (control), significant differences (P < 0.05) in the growth of Listeria strains were seen in-vitro with increased inhibition at higher amide concentrations (10,000–20,000 ppm). Furthermore, in-vitro growth inhibition of B. subtilis, S. sobrinus, and S. mutans was also observed with an effectiveness of LAPY>MYPY>PAPY>DEPY. In co-inoculation assays, LAPY treatment significantly reduced Listeria growth from 1.55 to >5.0 Log CFU/mL when a concentration range of 5 to 250 ppm was applied. Moreover, Listeria populations on pathogen-inoculated produce were significantly (P < 0.05) reduced from 0.51 to >3.00 Log CFU/g with greater inactivation on carrots compared to alfalfa, soybean, and pistachio. These results demonstrated the potential value of these FA amides against Gram-positive pathogenic bacteria. Biorational applications of antibacterial FA amides on fresh produce as a postharvest intervention process offers a great potential for enhancement of food safety.
Scotland mulls pathogen action levels
Food Standards Scotland (FSS) is considering introducing thresholds for action for some pathogens based on either a UK or Scottish approach.
Using targets based on reported infections of key pathogens could help monitor trends and be used as a trigger to act. However, figures would need to be interpreted carefully because of underreporting, inability to separate food and non-food sources, changes in demographics, and impacts of year to year fluctuations in environmental factors, such as weather.
When reported cases breach the threshold, different steps would be considered including an investigation to identify reasons behind the increase; additional food sampling associated with the pathogen and risk communication to consumers using tailored messages.
FSS currently uses Public Health Scotland data on confirmed laboratory reports for five pathogens to monitor how foodborne illness is changing.
Research – Identification of genetic variations related to pathogenicity by whole genome sequencing of Listeria monocytogenes SMFM2019-FV16 isolated from enoki mushroom
Abstract
In this study, the characteristics of Listeria monocytogenes isolated from enoki mushroom (Flammulina velutipes) collected from May to July 2019 were analyzed. The isolates were analyzed for strain characteristics, hemolysis, antibiotic resistance, heat resistance, and virulence genes (inlA, inlB, actA, plcB, and hlyA) were analyzed, and whole genome sequencing (WGS) analysis was performed for the strain with the highest risk. Seven isolates were obtained from some enoki mushroom samples. All isolates were β-hemolytic and had virulence genes. Antibiotic resistance test showed multi-drug resistance in L. monocytogenes strain SMFM2019-FV15 and SMFM2019-FV16. L. monocytogenes SMFM2019-FV16 showed higher heat resistance than the other isolates. According to the results L. monocytogenes SMFM2019-FV16 was selected as the strain with the highest risk. WGS for L. monocytogenes SMFM2019-FV16 showed that it had 14 antibiotic resistance genes and 43 virulence genes, and 35 single nucleotide variants in the 43 virulence genes were observed. These results indicate that these genetic variations might be related to the high risk of L. monocytogenes SMFM2019-FV16.
Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Listeria, Listeria Enoki Mushrooms, Listeria monocytogenes, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Pathogen, pathogenic
USA – Cronobacter infections in babies are now a reportable disease
The CDC has announced it will begin tracking infections caused by cronobacter, which was behind an outbreak in 2021-22 among babies and caused an infant formula shortage that plagued the nation for months.
The council is the body that recommends what diseases are “reportable.” That list already includes illnesses from other foodborne pathogens, including E. coli, Salmonella, and Listeria. About 120 other illnesses are on the list of “nationally notifiable” pathogens. The council and the CDC manage the list.
When the recommendation becomes active, cronobacter infections identified in infants less than 1-year-old will be reported by doctors and laboratories to state health departments. Those departments will then notify the CDC.
Posted in Cronobacter sakazakii, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Pathogen, pathogenic
France sees a rise in outbreaks in 2021
The number of outbreaks in France went up in 2021 but was still below 2018 and 2019 levels.
Figures from Santé publique France show there were 1,309 outbreaks affecting 11,056 people in 2021. A total of 512 people went to hospitals and 16 died.
Reported outbreaks rose from 1,010 in 2020 when figures were strongly impacted by the COVID-19 pandemic, according to officials.
For 327 incidents in 2021, a pathogen could be microbiologically confirmed in food or in at least one sick person per outbreak. A pathogen was suspected without microbiological confirmation for 734 outbreaks.
16 deaths in outbreaks
The most frequently microbiologically confirmed pathogen was Salmonella 147 times. It was mostly Salmonella Enteritidis, followed by monophasic Salmonella Typhimurium but the type was not known in 92 incidents. Confirmed Salmonella outbreaks were responsible for 935 patients and 166 hospitalizations.
Campylobacter caused 52 outbreaks with 178 patients and Bacillus cereus had 46 with 665 patients. Nineteen norovirus outbreaks sickened 493 and 11 histamine outbreaks affected 35 people.
Seven outbreaks were due to E. coli, six to Yersinia enterocolitica, four to Shiga toxin-producing E. coli (STEC), and one each because of Listeria monocytogenes, Clostridium botulinum, and Shigella.
The pathogen was identified in patients for 208 outbreaks, of which 143 were confirmed with Salmonella. Identification of the agent took place in food samples for 89 epidemics with 67 confirmed as Bacillus cereus, Staphylococcus aureus and Clostridium perfringens.
The top suspected pathogens based on epidemiological and clinical information, but not microbiologically confirmed, were the toxins Bacillus cereus, Staphylococcus aureus and Clostridium perfringens. For these three pathogens, 3,787 patients and 169 hospital trips were recorded.
Research – Antibacterial Activity against Four Fish Pathogenic Bacteria of Twelve Microalgae Species Isolated from Lagoons in Western Greece
Abstract
Microalgae may produce a range of high-value bioactive substances, making them a promising resource for various applications. In this study, the antibacterial activity of twelve microalgae species isolated from lagoons in western Greece was examined against four fish pathogenic bacteria (Vibrio anguillarum, Aeromonas veronii, Vibrio alginolyticus, and Vibrio harveyi). Two experimental approaches were used to evaluate the inhibitory effect of microalgae on pathogenic bacteria. The first approach used bacteria-free microalgae cultures, whereas the second approach used filter-sterilized supernatant from centrifuged microalgae cultures. The results demonstrated that all microalgae had inhibitory effects against pathogenic bacteria in the first approach, particularly 4 days after inoculation, where Asteromonas gracilis and Tetraselmis sp. (red var., Pappas) exhibited the highest inhibitory activity, reducing bacterial growth by 1 to 3 log units. In the second approach, Tetraselmis sp. (red var., Pappas) showed significant inhibition against V. alginolyticus between 4 and 25 h after inoculation. Moreover, all tested cyanobacteria exhibited inhibitory activity against V. alginolyticus between 21 and 48 h after inoculation. Statistical analysis was performed using the independent samples t-test. These findings suggested that microalgae produce compounds with antibacterial activity, which could be useful in aquaculture.
Posted in Aeromonas, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Pathogen, pathogenic, Vibrio
USA – Foodborne Illness Outbreaks at Retail Food Establishments — National Environmental Assessment Reporting System, 25 State and Local Health Departments, 2017–2019
Abstract
Problem/Condition: Each year, state and local public health departments report hundreds of foodborne illness outbreaks associated with retail food establishments (e.g., restaurants or caterers) to CDC. Typically, investigations involve epidemiology, laboratory, and environmental health components. Health departments voluntarily report epidemiologic and laboratory data from their foodborne illness outbreak investigations to CDC through the National Outbreak Reporting System (NORS); however, minimal environmental health data from outbreak investigations are reported to NORS. This report summarizes environmental health data collected during outbreak investigations and reported to the National Environmental Assessment Reporting System (NEARS).
Period Covered: 2017–2019.
Description of System: In 2014, CDC launched NEARS to complement NORS surveillance and to use these data to enhance prevention efforts. State and local health departments voluntarily enter data from their foodborne illness outbreak investigations of retail food establishments into NEARS. These data include characteristics of foodborne illness outbreaks (e.g., etiologic agent and factors contributing to the outbreak), characteristics of establishments with outbreaks (e.g., number of meals served daily), and food safety policies in these establishments (e.g., ill worker policy requirements). NEARS is the only available data source that collects environmental characteristics of retail establishments with foodborne illness outbreaks.
Results: During 2017–2019, a total of 800 foodborne illness outbreaks associated with 875 retail food establishments were reported to NEARS by 25 state and local health departments. Among outbreaks with a confirmed or suspected agent (555 of 800 [69.4%]), the most common pathogens were norovirus and Salmonella, accounting for 47.0% and 18.6% of outbreaks, respectively. Contributing factors were identified in 62.5% of outbreaks. Approximately 40% of outbreaks with identified contributing factors had at least one reported factor associated with food contamination by an ill or infectious food worker. Investigators conducted an interview with an establishment manager in 679 (84.9%) outbreaks. Of the 725 managers interviewed, most (91.7%) said their establishment had a policy requiring food workers to notify their manager when they were ill, and 66.0% also said these policies were written. Only 23.0% said their policy listed all five illness symptoms workers needed to notify managers about (i.e., vomiting, diarrhea, jaundice, sore throat with fever, and lesion with pus). Most (85.5%) said that their establishment had a policy restricting or excluding ill workers from working, and 62.4% said these policies were written. Only 17.8% said their policy listed all five illness symptoms that would require restriction or exclusion from work. Only 16.1% of establishments with outbreaks had policies addressing all four components relating to ill or infectious workers (i.e., policy requires workers to notify a manager when they are ill, policy specifies all five illness symptoms workers need to notify managers about, policy restricts or excludes ill workers from working, and policy specifies all five illness symptoms requiring restriction or exclusion from work).
Interpretation: Norovirus was the most commonly identified cause of outbreaks reported to NEARS, and contamination of food by ill or infectious food workers contributed to approximately 40% of outbreaks with identified contributing factors. These findings are consistent with findings from other national outbreak data sets and highlight the role of ill workers in foodborne illness outbreaks. Although a majority of managers reported their establishment had an ill worker policy, often these policies were missing components intended to reduce foodborne illness risk. Contamination of food by ill or infectious food workers is an important cause of outbreaks; therefore, the content and enforcement of existing policies might need to be re-examined and refined.
Public Health Action: Retail food establishments can reduce viral foodborne illness outbreaks by protecting food from contamination through proper hand hygiene and excluding ill or infectious workers from working. Development and implementation of policies that prevent contamination of food by workers are important to foodborne outbreak reduction. NEARS data can help identify gaps in food safety policies and practices, particularly those concerning ill workers. Future analyses of stratified data linking specific outbreak agents and foods with outbreak contributing factors can help guide the development of effective prevention approaches by describing how establishments’ characteristics and food safety policies and practices relate to foodborne illness outbreaks.
Posted in CDC, Decontamination Microbial, food bourne outbreak, Food Illness, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Foodborne Illness, foodborne outbreak, foodbourne outbreak, Illness, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Norovirus, outbreak, Pathogen, pathogenic, Salmonella

