Control Of Human Pathogens Research Articles

Inactivation and risk control of pathogenic microorganisms in municipal sludge treatment: A review.

The rapid global spread of coronavirus disease 2019 (COVID-19) has promoted concern over human pathogens and their significant threats to public health security. The monitoring and control of human pathogens in public sanitation and health facilities are of great importance. Excessive sludge is an inevitable byproduct of sewage that contains human and animal feces in wastewater treatment plants (WWTPs). It is an important sink of different pollutants and pathogens, and the proper treatment and disposal of sludge are important to minimize potential risks to the environment and public health. However, there is a lack of comprehensive analysis of the diversity, exposure risks, assessment methods and inactivation techniques of pathogenic microorganisms in sludge. Based on this consideration, this review summarizes the control performance of pathogenic microorganisms such as enterovirus, Salmonella spp., and Escherichia coli by different sludge treatment technologies, including composting, anaerobic digestion, aerobic digestion, and microwave irradiation, and the mechanisms of pathogenic microorganism inactivation in sludge treatment processes are discussed. Additionally, this study reviews the diversity, detection methods, and exposure risks of pathogenic microorganisms in sludge. This review advances the quantitative assessment of pathogenic microorganism risks involved in sludge reuse and is practically valuable to optimize the treatment and disposal of sludge for pathogenic microorganism control.

Regulatory oversight of human pathogens and toxins in Canada.

From 1994 to 2009, federal oversight of human pathogens and toxins was limited to facilities importing human pathogens and toxins into Canada under the Human Pathogens Importation Regulations (HPIR). This narrow focus of authority restricted the Government of Canada's ability to regulate and monitor a full range of activities, including those involving human pathogens and toxins acquired from domestic sources. In 2009, the Human Pathogens and Toxins Act (the Act) received Royal Assent to establish a national safety and security regime and expand oversight through a national, standardized process to verify safe and secure use of human pathogens and toxins in Canada. The Act and the Human Pathogens and Toxins Regulations (the Regulations), in full force since December 1, 2015, provides legislative and statutory requirements for the comprehensive oversight of the control of human pathogens and toxins in Canada. Expanded regulation and monitoring program activities aim to reduce the risks posed by human pathogens and toxins and strengthen biosafety management systems that serve to protect the health of Canadians.

The chicken gastrointestinal microbiome

The domestic chicken is a common model organism for human biological research and of course also forms the basis of a global protein industry. Recent methodological advances have spurred the recognition of microbiomes as complex communities with important influences on the health and disease status of the host. In this minireview, we provide an overview of the current state of knowledge of the chicken gastrointestinal microbiome focusing on spatial and temporal variability, the presence and importance of human pathogens, the influence of the microbiota on the immune system, and the importance of the microbiome for poultry nutrition. Review and meta-analysis of public data showed cecal communities dominated by Firmicutes and Bacteroides at the phylum level, while at finer levels of taxonomic resolution, a phylogenetically diverse assemblage of microorganisms appears to have similar metabolic functions that provide important benefits to the host as inferred from metagenomic data. This observation of functional redundancy may have important implications for management of the microbiome. We foresee advances in strategies to improve gut health in commercial operations through management of the intestinal microbiota as an alternative to in-feed subtherapeutic antibiotics, improvements in pre- and probiotics, improved management of polymicrobial poultry diseases, and better control of human pathogens via colonization reduction or competitive exclusion strategies.

A Sunflower Lectin with Antifungal Properties and Putative Medical Mycology Applications

Lectins are carbohydrate-binding proteins with a high specificity for a variety of glycoconjugate sugar motifs. The jacalin-related lectins (JRL) are considered to be a small sub-family composed of galactose- and mannose-specific members. Using a proteomics approach, we have detected a 16 kDa protein (Helja) in sunflower seedlings that were further purified by mannose-agarose affinity chromatography. The aim of this work was to characterize the biological activity of Helja and to explore potential applications for the antifungal activity of this plant lectin against medically important yeasts. To initially assess the agglutination properties of the lectin, Saccharomyces cerevisiae cells were incubated with increasing concentrations of the purified lectin. At a concentration of 120 μg/ml, Helja clearly agglutinated these cells. The ability of different sugars to inhibit S. cerevisiae cell agglutination determined its carbohydrate-specificity. Among the monosaccharides tested, D-mannose had the greatest inhibitory effect, with a minimal concentration of 1.5 mM required to prevent cell agglutination. The antifungal activity was evaluated using pathogenic fungi belonging to the Candida and Pichia genera. We demonstrate that 200 μg/ml of Helja inhibited the growth of all yeasts, and it induced morphological changes, particularly through pseudohyphae formation on Candida tropicalis. Helja alters the membrane permeability of the tested fungi and is also able to induce the production of reactive oxygen species in C. tropicalis cells. We concluded that Helja is a mannose-binding JRL with cell agglutination capabilities and antifungal activity against yeasts. The biological properties of Helja may have practical applications in the control of human pathogens.

Interactions Affecting the Proliferation and Control of Human Pathogens on Edible Plants

ABSTRACT: Pathogens on edible plants present a significant potential source of human illness. From 1991 to 2002, 21% of Escherichia coli O157:H7 outbreaks were from produce‐related sources. E. coli O157 and other enteric bacteria can contaminate the surface of edible plants both pre‐ and postharvest. Some pathogens do not survive on the leaf surface or are removed by washing, but a significant portion of these enteric pathogens can persist on the surface and proliferate. Proliferation of these dangerous pathogens can increase the likelihood of foodborne disease associated with fresh or minimally processed produce. Several intrinsic and extrinsic factors determine the ability of enteric pathogens to attach and proliferate in the phyllosphere of plants. These include motility of the pathogen, leaching of nutrients by the plant, and interaction with epiphytic organisms. The interaction of enteric pathogens with the environment can lead to internalization into tissue, incorporation into biofilms, and genetic transfer. Current produce sanitation practices can reduce the microbial load from 1 log10 to 3 log10, so there are many new treatments possible. Understanding the ecology of enteric pathogens on plants is important to the development of sanitation methods and biocontrol agents. This knowledge can also assist the farmer in preventing contamination. With increasing consumption and importation of produce, its safety is a high priority for processors and U.S. consumers. Food safety may be markedly improved with proper attention to pathogens on edible plants.

Social network research and human subjects protection: Towards more effective infectious disease control

The issue of human subject protection in relation to social network research on the spread and control of human pathogens is considered. As this area derives most of its concepts and methods from social network analysis more generally, the present discussion has wider relevance. One problem is that some Institutional Review Boards (IRBs) have assumed that if a participant (who gave informed consent) is to be asked to name network associates these too — automatically — would be human subjects from whom informed consent also must be obtained. Invariably, if this occurs proposed research — whatever its funding and potential contributions might be — is blocked. A conservative approach is taken here. The Common Rule is assumed to provide relevant guidance, the responsibility of IRBs is to make decisions based on the Common Rule, and in consequence the burden is on those proposing social network research to design — and defend — their planned work with this in mind. At the same time, it is argued that it is important not to stifle beneficial research by adding to one inherently conservative review process (of grant proposals) another (of IRBs) so that work is prevented simply because it is research at the frontiers rather than ‘safe’ research.