Category Archives: Pathogen

Research – Foodborne Parasites and Their Complex Life Cycles Challenging Food Safety in Different Food Chains

MDPI

Abstract

Zoonotic foodborne parasites often represent complex, multi host life cycles with parasite stages in the hosts, but also in the environment. This manuscript aims to provide an overview of important zoonotic foodborne parasites, with a focus on the different food chains in which parasite stages may occur. We have chosen some examples of meat-borne parasites occurring in livestock (Taenia spp., Trichinella spp. and Toxoplasma gondii), as well as Fasciola spp., an example of a zoonotic parasite of livestock, but transmitted to humans via contaminated vegetables or water, covering the ‘farm to fork’ food chain; and meat-borne parasites occurring in wildlife (Trichinella spp., Toxoplasma gondii), covering the ‘forest to fork’ food chain. Moreover, fish-borne parasites (Clonorchis spp., Opisthorchis spp. and Anisakidae) covering the ‘pond/ocean/freshwater to fork’ food chain are reviewed. The increased popularity of consumption of raw and ready-to-eat meat, fish and vegetables may pose a risk for consumers, since most post-harvest processing measures do not always guarantee the complete removal of parasite stages or their effective inactivation. We also highlight the impact of increasing contact between wildlife, livestock and humans on food safety. Risk based approaches, and diagnostics and control/prevention tackled from an integrated, multipathogen and multidisciplinary point of view should be considered as well.

Research – Campylobacter contamination in broiler meat

Poultry World

Campylobacter in broiler meat is one of the leading foodborne pathogens associated with health risks and negative economic impacts worldwide. Campylobacter has several adaptive responses throughout the broiler production chain. Thus, it survives from broiler farm to slaughterhouse and processing plant.

Pakistan- LOOSE MILK SALE TO BE BANNED IN PUNJAB – Aflatoxin

Ary News

LAHORE: Punjab Food Authority (PFA) has decided to ban sale of loose milk in Lahore and then implement the decision gradually across the province, sources told ARY News on Tuesday.

According to sources, the PFA has decided to impose a ban on the sale of loose milk citing a number of reasons including presence of aflatoxin (a cancer-causing chemical) and lack of  pasteurization (heating to a specified temperature and time to kill pathogens that may be found in the raw milk) recommended for sale of milk.

Research – Bacterial pathogens and climate change

The Lancet

Read the full article at the link above

A systematic analysis of the literature showed that 58% of infectious diseases in humans have been aggravated at some point by climatic hazards, such as changes in temperatures and water and food availability.

The leading pathogens responsible (eg, S aureus, E coli, K pneumoniae, S pneumoniae, and non-typhoidal Salmonella) have all been found to have climate-dependent reactions, causing an increase in their diffusion and even resistance to treatment.

 For example, sharp temperature decreases have been associated with an increased incidence of pneumonia, and increased morbidity in cold and humid weather.

 

Research – Listeria monocytogenes—How This Pathogen Uses Its Virulence Mechanisms to Infect the Hosts

MDPI

Abstract

Listeriosis is a serious food-borne illness, especially in susceptible populations, including children, pregnant women, and elderlies. The disease can occur in two forms: non-invasive febrile gastroenteritis and severe invasive listeriosis with septicemia, meningoencephalitis, perinatal infections, and abortion. Expression of each symptom depends on various bacterial virulence factors, immunological status of the infected person, and the number of ingested bacteria. Internalins, mainly InlA and InlB, invasins (invasin A, LAP), and other surface adhesion proteins (InlP1, InlP4) are responsible for epithelial cell binding, whereas internalin C (InlC) and actin assembly-inducing protein (ActA) are involved in cell-to-cell bacterial spread. L. monocytogenes is able to disseminate through the blood and invade diverse host organs. In persons with impaired immunity, the elderly, and pregnant women, the pathogen can also cross the blood–brain and placental barriers, which results in the invasion of the central nervous system and fetus infection, respectively. The aim of this comprehensive review is to summarize the current knowledge on the epidemiology of listeriosis and L. monocytogenes virulence mechanisms that are involved in host infection, with a special focus on their molecular and cellular aspects. We believe that all this information is crucial for a better understanding of the pathogenesis of L. monocytogenes infection.

Research – Recent Trends and Applications of Nanoencapsulated Bacteriocins against Microbes in Food Quality and Safety

MDPI

Abstract

Bacteriocins are ribosomal-synthesized peptides or proteins produced by bacterial strains and can inhibit pathogenic bacteria. Numerous factors influence the potential activity of bacteriocins in food matrices. For example, food additives usage, chemical composition, physical conditions of food, and sensitivity of proteolytic enzymes can constrain the application of bacteriocins as beneficial food preservatives. However, novel bacteriocin nanoencapsulation has appeared as an encouraging solution. In this review, we highlight the bacteriocins produced by Gram-negative bacteria and Gram-positive bacteria including lactic acid bacteria that have shown positive results as potential food preservatives. In addition, this review encompasses the major focus on bacteriocins encapsulation with nanotechnology to enhance the antimicrobial action of bacteriocins. Several strategies can be employed to encapsulate bacteriocins; however, the nanotechnological approach is one of the most effective strategies for avoiding limitations. Nanoparticles such as liposomes, chitosan, protein, and polysaccharides have been discussed to show their importance in the nanoencapsulation method. The nanoparticles are combined with bacteriocins to develop the nano-encapsulated bacteriocins from Gram-negative and Gram-positive bacteria including LAB. In food systems, nanoencapsulation enhances the stability and antimicrobial functionality of active peptides. This nanotechnological application provides a formulation of a broad range of antimicrobial peptides at the industry-scale level. Nano-formulated bacteriocins have been discussed along with examples to show a broader antimicrobial spectrum, increase bacteriocins’ applicability, extend antimicrobial spectrum and enhance stability.

EFSA – Listeria monocytogenes Dashboard

EFSA

The EFSA dashboard on Listeria monocytogenes is a graphical user interface for searching and querying the large amount of data collected each year by EFSA from EU Member States and other reporting countries based on Zoonoses Directive 2003/99/EC. The Listeria monocytogenes dashboard shows summary statistics for the monitoring results of the pathogen with regard to major ready-to-eat food categories, Listeria monocytogenes-positive official samples in the context of food safety criteria in accordance with Regulation (EC) No 2073/2005 and official samples exceeding the food safety criteria limit of 100 CFU/g for specified food matrices. Other monitoring statistics for Listeria monocytogenes in ready-to-eat foods are also displayed. The Listeria monocytogenes data and related statistics can be displayed interactively using charts, graphs and maps in the online EFSA dashboard. The main statistics can also be viewed and downloaded in tabular format. Detailed information on the use and features of the Listeria monocytogenes dashboard can be found in the present user guide that can also be downloaded from the online tool.

EFSA – Salmonella Dashboard

EFSA

The EFSA dashboard on Salmonella is a graphical user interface for searching and querying the large amount of data collected each year by EFSA from EU Member States and other reporting countries based on Zoonoses Directive 2003/99/EC. The Salmonella dashboard shows summary statistics for the monitoring results of the pathogen with regard to major food categories and animal species, Salmonella-positive official samples in the context of food safety criteria and process hygiene criteria, the occurrence of Salmonella in major food categories and the achievement of Salmonella reduction targets in poultry populations. The Salmonella data and related statistics can be displayed interactively using charts, graphs and maps in the online EFSA dashboard. The main statistics can also be viewed and downloaded in tabular format. Detailed information on the use and features of the Salmonella dashboard can be found in the present user guide that can also be downloaded from the online tool.

EFSA – Listeria monocytogenes – Story Map

EFSA

Listeria bacteria are widespread in the environment and they are worldwide commonly found in soil and water, as well as in animal digestive tracts. There are more than 15  species  of bacteria in this genus, but human cases of Listeria infection are almost always caused by Listeria monocytogenes (L. monocytogenes) while Listeria ivanovii is pathogenic in animals but rarely in humans. The other species are not considered to be pathogenic in humans or animals.

L. monocytogenes are able to form communities of bacteria called biofilms and are therefore resistant to a wide range of stresses. This capacity varies among  genotypes . They can tolerate acidic, dry and salty conditions, in the presence or absence of oxygen. Moreover, unlike most pathogenic bacteria, they are able to survive and multiply in refrigerated foods, making ready-to-eat foods of particular concern.

Specific  strains  (identified by “ serogroups ” and “ serovars ”) are important for human health as they can differ in terms of geographical distribution and their ability to cause disease. Detection and isolation of Listeria strains, both by classic laboratory procedures and molecular and genomic methods, are therefore crucial to evaluate their relative presence in food, the environment and clinical settings, to address the  virulence  and to precisely trace  outbreaks , identifying the source of infection.

Research – Zoonotic diseases and foodborne outbreaks on the rise, but still below pre-pandemic levels

EFSA

In 2021 there was an overall increase in reported cases of zoonotic diseases and foodborne outbreaks compared to the previous year, but levels are still well below those of the pre-pandemic years, reveals the latest annual EU One Health zoonosis report released by EFSA and ECDC.

The general drop compared to pre-pandemic years in reported cases and outbreaks is probably linked to COVID-19 control measures, which were still in place in 2021. Among the few exceptions are the number of cases for yersiniosis and those of foodborne listeriosis outbreaks, which exceeded pre-pandemic levels.

Most foodborne outbreaks (773) were caused by Salmonella, which accounted for 19.3% of the total. Foodborne outbreaks differ from overall reported disease cases in that they are events in which at least two people contract the same illness from the same contaminated food. The most common sources of salmonellosis outbreaks were eggs, egg products, and “mixed foods”, which are meals composed of various ingredients.

The number of outbreaks caused by Listeria monocytogenes (23) was the highest ever reported. This might be linked to the increased use of whole genome sequencing techniques, which allow scientists to better detect and define outbreaks.

The report also covers overall reported zoonotic disease cases, which are not necessarily linked to outbreaks. Campylobacteriosis remains the most frequently reported zoonosis, with the number of reported cases increasing to 127,840 compared to 120,946 in 2020. Meat from chicken and turkeys was the most common source. Salmonellosis was the second most reported zoonotic disease, affecting 60,050 people compared to 52,702 in 2020. The next commonly reported diseases were yersiniosis (6,789 cases), infections caused by Shigatoxin-producing E. coli (6,084 cases), and listeriosis (2,183 cases).

The report also includes data on Mycobacterium bovis/caprae,BrucellaTrichinellaEchinococcus, Toxoplasma gondii, rabies, Q fever, West Nile virus infections and tularaemia.