Public Health Research Resulting from One of the World's Largest Outbreaks Caused by Entero-Hemorrhagic Escherichia coli in Germany 2011: A Review

Precognition of Known And Unknown Biothreats: A Risk-Based Approach

Data mining and artificial intelligence algorithms can estimate the probability of future occurrences with defined precision. Yet, the prediction of infectious disease outbreaks remains a complex and difficult task. This is demonstrated by the limited accuracy and sensitivity of current models in predicting the emergence of previously unknown pathogens such as Zika, Chikungunya, and SARS-CoV-2, and the resurgence of Mpox, along with their impacts on global health, trade, and security. Comprehensive analysis of infectious disease risk profiles, vulnerabilities, and mitigation capacities, along with their spatiotemporal dynamics at the international level, is essential for preventing their transnational propagation. However, annual indexes about the impact of infectious diseases provide a low level of granularity to allow stakeholders to craft better mitigation strategies. A quantitative risk assessment by analytical platforms requires billions of near real-time data points from heterogeneous sources, integrating and analyzing univariable or multivariable data with different levels of complexity and latency that, in most cases, overwhelm human cognitive capabilities. Autonomous biosurveillance can open the possibility for near real-time, risk- and evidence-based policymaking and operational decision support.

The overlooked bacterial pandemic

The COVID-19 pandemic had a significant economic and health impact worldwide. It also reinforced the misperception that only viruses can pose a threat to human existence, overlooking that bacteria (e.g., plague and cholera) have severely haunted and shaped the course of human civilization. While the world is preparing for the next viral pandemic, it is again overlooking a silent one: antimicrobial resistance (AMR). This review proposes to show the impact of bacterial infections on civilization to remind the pandemic potential. The work will also discuss a few examples of how bacteria can mutate risking global spread and devastating outcomes, the effect on the global burden, and the prophylactic and therapeutic measures. Indeed, AMR is dramatically increasing and if the trend is not reversed, it has the potential to quickly turn into the most important health problem worldwide.

Protective Cultures in Food Products: From Science to Market

An ultimate goal in food production is to guarantee food safety and security. Fermented food products benefit from the intrinsic capabilities of the applied starter cultures as they produce organic acids and bactericidal compounds such as hydrogen peroxide that hamper most food pathogens. In addition, highly potent small peptides, bacteriocins, are being expelled to exert antibiotic effects. Based on ongoing scientific efforts, there is a growing market of food products to which protective cultures are added exclusively for food safety and for prolonged shelf life. In this regard, most genera from the order Lactobacillales play a prominent role. Here, we give an overview on protective cultures in food products. We summarize the mode of actions of antibacterial mechanisms. We display the strategies for the isolation and characterization of protective cultures in order to have them market-ready. A survey of the growing market reveals promising perspectives. Finally, a comprehensive chapter discusses the current legislation issues concerning protective cultures, leading to the conclusion that the application of protective cultures is superior to the usage of defined bacteriocins regarding simplicity, economic costs, and thus usage in less-developed countries. We believe that further discovery of bacteria to be implemented in food preservation will significantly contribute to customer's food safety and food security, badly needed to feed world's growing population but also for food waste reduction in order to save substantial amounts of greenhouse gas emissions.

Pervasive Listeria monocytogenes Is Common in the Norwegian Food System and Is Associated with Increased Prevalence of Stress Survival and Resistance Determinants

To investigate the diversity, distribution, persistence, and prevalence of stress survival and resistance genes of Listeria monocytogenes clones dominating in food processing environments in Norway, genome sequences from 769 L. monocytogenes isolates from food industry environments, foods, and raw materials (512 of which were sequenced in the present study) were subjected to whole-genome multilocus sequence typing (wgMLST), single-nucleotide polymorphism (SNP), and comparative genomic analyses. The data set comprised isolates from nine meat and six salmon processing facilities in Norway collected over a period of three decades. The most prevalent clonal complex (CC) was CC121, found in 10 factories, followed by CC7, CC8, and CC9, found in 7 factories each. Overall, 72% of the isolates were classified as persistent, showing 20 or fewer wgMLST allelic differences toward an isolate found in the same factory in a different calendar year. Moreover, over half of the isolates (56%) showed this level of genetic similarity toward an isolate collected from a different food processing facility. These were designated as pervasive strains, defined as clusters with the same level of genetic similarity as persistent strains but isolated from different factories. The prevalence of genetic determinants associated with increased survival in food processing environments, including heavy metal and biocide resistance determinants, stress response genes, and inlA truncation mutations, showed a highly significant increase among pervasive isolates but not among persistent isolates. Furthermore, these genes were significantly more prevalent among the isolates from food processing environments compared to in isolates from natural and rural environments (n = 218) and clinical isolates (n = 111) from Norway.

IMPORTANCEListeria monocytogenes can persist in food processing environments for months to decades and spread through the food system by, e.g., contaminated raw materials. Knowledge of the distribution and diversity of L. monocytogenes is important in outbreak investigations and is essential to effectively track and control this pathogen in the food system. The present study presents a comprehensive overview of the prevalence of persistent clones and of the diversity of L. monocytogenes in Norwegian food processing facilities. The results demonstrate extensive spread of highly similar strains throughout the Norwegian food system, in that 56% of the 769 collected isolates from food processing factories belonged to clusters of L. monocytogenes identified in more than one facility. These strains were associated with an overall increase in the prevalence of plasmids and determinants of heavy metal and biocide resistance, as well as other genetic elements associated with stress survival mechanisms and persistence.

Molecularly imprinted polymer as a synthetic receptor mimic for capacitive impedimetric selective recognition of Escherichia coli K-12

We fabricated an electrochemical molecularly imprinted polymer (MIP) chemosensor for rapid identification and quantification of E. coli strain using 2-aminophenyl boronic acid as the functional monomer. This strain is a modified Gram-negative strain of Escherichia coli bacterium, an ordinary human gut component. The E. coli strongly interacts with a boronic acid because of porous and flexible polymers of the cell wall. The SEM imaging showed that the bacteria template was partially entrapped within the polymeric matrix in a single step. Moreover, this imaging confirmed E. coli K-12 cell template extraction effectiveness. The prepared MIP determined the E. coli K-12 strain up to 2.9 × 10⁴ cells mL^-1. The interference study performed in the presence of E. coli variants expressing different surface appendages (type 1 fimbriae or Antigen 43 protein) or Shewanella oneidensis MR1, another Gram-negative bacteria, demonstrated that the bacterial surface composition notably impacts sensing properties of the bacteria imprinted polymer.

On the strong connection between nanoscale adhesion of Yad fimbriae and macroscale attachment of Yad-decorated bacteria to glycosylated, hydrophobic and hydrophilic surfaces

Yad fimbriae are currently viewed as versatile bacterial adhesins able to significantly mediate host or plant-pathogen recognition and contribute to the persistence of Escherichia coli in both the environment and within hosts. To date, however, the underlying adhesion process of Yad fimbriae on surfaces defined by controlled coating chemistries has not been evaluated on the relevant molecular scale. In this work, the interaction forces operational between Yad fimbriae expressed by genetically modified E. coli and self-assembled monolayers (SAM) differing in terms of charge, hydrophobicity or the nature of decorating sugar units are quantified by Single Molecule Force Spectroscopy (SMFS) on the nanoscale. It is found that the adhesion of Yad fimbriae onto probes functionalized with xylose is as strong as that measured with probes decorated with anti-Yad antibodies (ca. 80 to 300 pN). In contrast, the interactions of Yad with galactose, lactose, mannose, -OH, -NH₂, -COOH and -CH₃ terminated SAMs are clearly non-specific. Interpretation of SMFS measurements on the basis of worm-like-chain modeling for polypeptide nanomechanics further leads to the estimates of the maximal extension of Yad fimbriae upon stretching, of their persistence length and of their polydispersity. Finally, we show for the first time a strong correlation between the adhesion properties of Yad-decorated bacteria determined from conventional macroscopic counting methods and the molecular adhesion capacity of Yad fimbriae. This demonstration advocates the effort that should be made to understand on the nanoscale level the interactions between fimbriae and their cognate ligands. The results could further help the design of potential anti-adhesive molecules or surfaces to better fight against the virulence of bacterial pathogens.

Retrospective assessment of rapid outbreak investigation for gastrointestinal diseases using only cases and background exposure data

For outbreaks of gastrointestinal disease, rapid identification of the source is crucial to enable public health intervention and prevent further cases. Outbreak investigation comprises analyses of exposure information from cases and, if required, undertaking analytical epidemiological studies. Hypothesis generation has been reliant on empirical knowledge of exposures historically associated with a given pathogen. Epidemiology studies are resource-intensive and prone to bias, one of the reasons being the difficulties in recruiting appropriate controls. For this paper, the information from cases was compared against pre-defined background exposure information. As exemplars, three past outbreaks were used, one of common and two of rare exposures. Information from historical case trawling questionnaires was used to define background exposure having removed any exposures implicated with the outbreak. The case-background approach showed good sensitivity and specificity, identifying correctly all outbreak-related exposures. One additional exposure related to a retailer was identified and four food items where all cases had been exposed. In conclusion, the case-background method, a development of the case-case design, can be used to assist with hypothesis generation or when a case-control study may not be possible to carry out.

Development of a multiplex PCR targeting eae, stx and cdt genes in genus Escherichia and detection of a novel cdtB gene in Providencia rustigianii

This study was aimed to develop a multiplex PCR (m-PCR) for the detection of Escherichia coli attaching and effacing (eae), Shiga toxin (stx) and cytolethal distending toxin (cdt) genes encoding important virulence factors of diarrheagenic E. coli such as EPEC, STEC, and Escherichia albertii. For this purpose, the m-PCR was designed to detect eae, all the subtypes of stx (stx1, stx2a-g except stx2f) and cdt (I-V) genes. The m-PCR was validated with 58 and 55 target gene-positive and negative strains of different sources, respectively. Sensitivity and specificity of the m-PCR were 100%. The m-PCR could also detect the eae, stx and cdt genes in bacteria spiked into stool specimens with or without enrichment culture. Clinical specimens collected from children with diarrhea were tested by the m-PCR, and 27 eae and 32 cdt genes were detected. Among them, three cdt-II and one untypable cdt gene-positive bacteria were isolated and identified as E. albertii and Providencia rustigianii, respectively. This is the first report demonstrating the presence of cdtB gene in P. rustigianii. These results indicate that the m-PCR is useful for surveillance of eae, stx and cdt gene-positive bacteria, not only EPEC, STEC and E. albertii but also P. rustigianii.

Fruit Decay to Diseases: Can Induced Resistance and Priming Help?

Humanity faces the challenge of having to increase food production to feed an exponentially growing world population, while crop diseases reduce yields to levels that we can no longer afford. Besides, a significant amount of waste is produced after fruit harvest. Fruit decay due to diseases at a post-harvest level can claim up to 50% of the total production worldwide. Currently, the most effective means of disease control is the use of pesticides. However, their use post-harvest is extremely limited due to toxicity. The last few decades have witnessed the development of safer methods of disease control post-harvest. They have all been included in programs with the aim of achieving integrated pest (and disease) management (IPM) to reduce pesticide use to a minimum. Unfortunately, these approaches have failed to provide robust solutions. Therefore, it is necessary to develop alternative strategies that would result in effective control. Exploiting the immune capacity of plants has been described as a plausible route to prevent diseases post-harvest. Post-harvest-induced resistance (IR) through the use of safer chemicals from biological origin, biocontrol, and physical means has also been reported. In this review, we summarize the successful activity of these different strategies and explore the mechanisms behind. We further explore the concept of priming, and how its long-lasting and broad-spectrum nature could contribute to fruit resistance.