Summary: The apicomplexan parasite Toxoplasma gondii was discovered a little over 100 years ago, but knowledge of its biological life cycle and its medical importance has grown in the last 40 years. This obligate intracellular parasite was identified early as a pathogen responsible for congenital infection, but its clinical expression and the importance of reactivations of infections in immunocompromised patients were recognized later, in the era of organ transplantation and HIV infection. Recent knowledge of host cell-parasite interactions and of parasite virulence has brought new insights into the comprehension of the pathophysiology of infection. In this review, we focus on epidemiological and diagnostic aspects, putting them in perspective with current knowledge of parasite genotypes. In particular, we provide critical information on diagnostic methods according to the patient's background and discuss the implementation of screening tools for congenital toxoplasmosis according to health policies.

https://hal.archives-ouvertes.fr/hal-00696903/document

Epidemiology of and Diagnostic Strategies for Toxoplasmosis

Current methods for screening Enterohemorrhagic Escherichia coli (EHEC) O157 and non-O157 in beef enrichments typically rely on the molecular detection of stx, eae, and serogroup-specific wzx or wzy gene fragments. As these genetic markers can also be found in some non-EHEC strains, a number of “false positive” results are obtained. Here, we explore the suitability of five novel molecular markers, espK, espV, ureD, Z2098, and CRISPRO26:H11 as candidates for a more accurate screening of EHEC strains of greater clinical significance in industrialized countries. Of the 1739 beef enrichments tested, 180 were positive for both stx and eae genes. Ninety (50%) of these tested negative for espK, espV, ureD, and Z2098, but 12 out of these negative samples were positive for the CRISPRO26:H11 gene marker specific for a newly emerging virulent EHEC O26:H11 French clone. We show that screening for stx, eae, espK, and espV, in association with the CRISPRO26:H11 marker is a better approach to narrow down the EHEC screening step in beef enrichments. The number of potentially positive samples was reduced by 48.88% by means of this alternative strategy compared to the European and American reference methods, thus substantially improving the discriminatory power of EHEC screening systems. This approach is in line with the EFSA (European Food Safety Authority) opinion on pathogenic STEC published in 2013.

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Revisiting the STEC Testing Approach: Using espK and espV to Make Enterohemorrhagic Escherichia coli (EHEC) Detection More Reliable in Beef.

Antimicrobial resistance (AMR) became in the last two decades a global threat to public health systems in the world. Since the antibiotic era, with the discovery of the first antibiotics that provided consistent health benefits to human medicine, the misuse and abuse of antimicrobials in veterinary and human medicine have accelerated the growing worldwide phenomenon of AMR. This article presents an extensive overview of the epidemiology of AMR, with a focus on the link between food producing-animals and humans and on the legal framework and policies currently implemented at the EU level and globally. The ways of responding to the AMR challenges foresee an array of measures that include: designing more effective preventive measures at farm level to reduce the use of antimicrobials; development of novel antimicrobials; strengthening of AMR surveillance system in animal and human populations; better knowledge of the ecology of resistant bacteria and resistant genes; increased awareness of stakeholders on the prudent use of antibiotics in animal productions and clinical arena; and the public health and environmental consequences of AMR. Based on the global nature of AMR and considering that bacterial resistance does not recognize barriers and can spread to people and the environment, the article ends with specific recommendations structured around a holistic approach and targeted to different stakeholders.

Antimicrobial Resistance: A Global Emerging Threat to Public Health Systems

Members of the genus Bacillus are known to produce a wide arsenal of antimicrobial substances, including peptide and lipopeptide antibiotics, and bacteriocins. Many of the Bacillus bacteriocins belong to the lantibiotics, a category of post-translationally modified peptides widely disseminated among different bacterial clades. Lantibiotics are among the best-characterized antimicrobial peptides at the levels of peptide structure, genetic determinants and biosynthesis mechanisms. Members of the genus Bacillus also produce many other nonmodified bacteriocins, some of which resemble the pediocin-like bacteriocins of the lactic acid bacteria (LAB), while others show completely novel peptide sequences. Bacillus bacteriocins are increasingly becoming more important due to their sometimes broader spectra of inhibition (as compared with most LAB bacteriocins), which may include Gram-negative bacteria, yeasts or fungi, in addition to Gram-positive species, some of which are known to be pathogenic to humans and/or animals. The present review provides a general overview of Bacillus bacteriocins, including primary structure, biochemical and genetic characterization, classification and potential applications in food preservation as natural preservatives and in human and animal health as alternatives to conventional antibiotics. Furthermore, it addresses their environmental applications, such as bioprotection against the pre- and post-harvest decay of vegetables, or as plant growth promoters.

Diversity and applications of Bacillus bacteriocins

We have shown that it is possible to transmit bovine spongiform encephalopathy (BSE) to a sheep by transfusion with whole blood taken from another sheep during the symptom-free phase of an experimental BSE infection. BSE and variant Creutzfeldt-Jakob disease (vCJD) In human beings are caused by the same infectious agent, and the sheep-BSE experimental model has a similar pathogenesis to that of human vCJD. Although UK blood transfusions are leucodepleted--a possible protective measure against any risk from blood transmission--this report suggests that blood donated by symptom-free vCJD-infected human beings may represent a risk of spread of vCJD infection among the human population of the UK.

Transmission of TSEs by blood transfusion in sheep

Monitoring of verotoxigenic Escherichia coli (VTEC) and identification of human pathogenic VTEC types 1 Scientific Opinion of the Panel on Biological Hazards

SUMMARY Following a request from the European Commission, the Panel on Biological Hazards was asked to deliver a scientific opinion on updating the scientific literature from the former SCVPH opinion on Listeria monocytogenes risk related to ready-to-eat foods and provide scientific advice on different levels of Listeria monocytogenes in ready-to-eat foods and the related risk for human illness. The BIOHAZ Panel concludes that after a general decline in the 1990s, the number of cases of listeriosis has increased since 2000 in Europe. The disease is still associated with pregnancy, but it is now predominantly associated with immuno-compromised persons amongst the older section of the population (> 60 years). At present, no routine methods permit the differentiation between virulent and avirulent strains of L. monocytogenes.

Request for updating the former SCVPH opinion on Listeria monocytogenes risk related to ready-to-eat foods and scientific advice on different levels of Listeria monocytogenes in ready-to-eat foods and the related risk for human

SUMMARY The European Food Safety Authority (EFSA) asked its Panel on Biological Hazards to deliver a scientific opinion on: The assessment of the Public Health significance of meticillin resistant Staphylococcus aureus (MRSA). There are different states of interaction between S. aureus and its host: infections, carriage or colonisation, and contamination. Meticillin resistant S. aureus (MRSA) can be persistently or intermittently carried by healthy humans, and colonisation is the major risk factor for infection. Infection can be mild to severe and, in some instances, fatal. MRSA are now a major cause of hospital acquired infection in many European countries, with large differences in prevalence and control policies. A limited number of lineages of MRSA tend to predominate in specific geographical locations. CC398 is the MRSA lineage most often associated with asymptomatic carriage in intensively reared food-producing animals. MRSA commonly carry enterotoxin genes but there has been only one report of food intoxication due to MRSA. On the question on what is the risk to human health posed by MRSA associated with foodproducing animals, the Panel concluded that: Livestock-associated MRSA (LA-MRSA) represent only a small proportion of the total number of reports of MRSA infections in the EU. However, this proportion differs between Member States. In some countries with low prevalence of human MRSA infection, CC398 is a major contributor to the overall MRSA burden. In countries with high overall human MRSA prevalence, CC398 is considered of less significance for the public health. CC398 has, albeit rarely, been associated with deep-seated infections of skin and soft tissue, pneumonia and septicaemia in humans. Where CC398 prevalence is high in food-producing animals, people in contact with these live animals (especially farmers and veterinarians, and their families) are 1 For citation purposes: Scientific Opinion of the Panel on Biological Hazards on a request from the European Commission on Assessment of the Public Health significance of meticillin resistant Staphylococcus aureus (MRSA) in animals and foods. The EFSA Journal (2009) 993, 1-73

Assessment of the Public Health significance of meticillin resistant Staphylococcus aureus (MRSA) in animals and foods 1

SUMMARY Following a request from the Health and Consumer Protection, Directorate General, European Commission, the Panel on Biological Hazards was asked to deliver a scientific opinion on Microbiological Risk Assessment in feedingstuffs for food-producing animals for both public health and animal health. In accordance with the terms of reference, this report does not consider hazards such as BSE/TSE agents, parasites and virus, or contamination by fungi and mycotoxins.

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Microbiological risk assessment in feedingstuffs for food-producing animals 1 Scientific Opinion of the Panel on Biological Hazards

SUMMARY Toxoplasmosis has the highest human incidence amongst the parasitic zoonoses. However, toxoplasmosis is considered to be an under-detected and underreported disease in the European Union. Toxoplasmosis and agents thereof have to be reported by Member States according to their epidemiological situation (Directive 2003/99/EC). Despite this fact, no representative data are available for Toxoplasma in the EU, neither for humans nor for animals or food. To improve data collection and to better evaluate the disease burden of toxoplasmosis, the Biological Hazard Panel is asked to give recommendations for optimising the surveillance and monitoring in humans, animals and foodstuffs and to give advice regarding methods for detection and identification of Toxoplasma from food and animals. The assessment incorporates general aspects of Toxoplasma and human toxoplasmosis such as the life cycle of agent, infection sources and risk factors, clinical aspects in humans as well as disease burden. Furthermore, existing surveillance and monitoring systems for humans, animals used for human consumption and foodstuffs and currently used methods for the direct or indirect detection of Toxoplasma in respective matrices are reviewed.

Hilde Kruse

Papers

Monitoring of verotoxigenic Escherichia coli (VTEC) and identification of human pathogenic VTEC types 1 Scientific Opinion of the Panel on Biological Hazards

Request for updating the former SCVPH opinion on Listeria monocytogenes risk related to ready-to-eat foods and scientific advice on different levels of Listeria monocytogenes in ready-to-eat foods and the related risk for human

Assessment of the Public Health significance of meticillin resistant Staphylococcus aureus (MRSA) in animals and foods 1

Microbiological risk assessment in feedingstuffs for food-producing animals 1 Scientific Opinion of the Panel on Biological Hazards

Certain Aspects related to the Feeding of Animal Proteins to Farm Animals 1 Scientific Opinion of the Panel on Biological Hazards