Outbreaks Of Foodborne Pathogens Research Articles

Foodborne pathogens in horticultural production systems: Ecology and mitigation

Foodborne pathogen outbreaks have become an increasing problem in the horticultural industry due to changes in diets, production, processing and distribution practices, as well as greater awareness and detection. Once produce is infected, outbreaks can spread rapidly resulting in illness and even death among large groups of people. Strict new food safety laws have been implemented to reduce risks, but outbreaks are still occurring. Pathogens with the greatest threat in ready-to-eat horticultural crops include Salmonella enterica, Escherichia coli (STEC), and Listeria monocytogenes, with contamination introduced through animal manure, water, seeds and plant debris. While previously thought to be only transient inhabitants of horticultural production systems, it is now clear that enteric pathogens are adapted to survive for prolonged periods outside of their animal hosts, attaching tenaciously to plants via biofilm formation and internalization in plant tissues. Management practices including treating animal manure, water and seeds, increasing soil biological diversity and activity, and limiting damage to plants via pests and equipment can help reduce food safety risks in pre-harvest production systems. Further reducing food safety risks in these systems will require innovative, interdisciplinary research that integrate the fields of soil microbial ecology, plant pathology, plant breeding and engineering. Specifically, we advocate for additional research to: 1) better understand how soil and phyllosphere ecology affects pathogen residence time, 2) identify key traits and markers to integrate selection for enteric pathogens into crop breeding programs, and 3) develop new detection technologies that rapidly and accurately detect enteric pathogens on produce.

MentaLiST - A fast MLST caller for large MLST schemes.

MLST (multi-locus sequence typing) is a classic technique for genotyping bacteria, widely applied for pathogen outbreak surveillance. Traditionally, MLST is based on identifying sequence types from a small number of housekeeping genes. With the increasing availability of whole-genome sequencing data, MLST methods have evolved towards larger typing schemes, based on a few hundred genes [core genome MLST (cgMLST)] to a few thousand genes [whole genome MLST (wgMLST)]. Such large-scale MLST schemes have been shown to provide a finer resolution and are increasingly used in various contexts such as hospital outbreaks or foodborne pathogen outbreaks. This methodological shift raises new computational challenges, especially given the large size of the schemes involved. Very few available MLST callers are currently capable of dealing with large MLST schemes. We introduce MentaLiST, a new MLST caller, based on a k-mer voting algorithm and written in the Julia language, specifically designed and implemented to handle large typing schemes. We test it on real and simulated data to show that MentaLiST is faster than any other available MLST caller while providing the same or better accuracy, and is capable of dealing with MLST schemes with up to thousands of genes while requiring limited computational resources. MentaLiST source code and easy installation instructions using a Conda package are available at https://github.com/WGS-TB/MentaLiST.

차추출물과 마늘식초를 이용한 생선회용 소스의 항균활성 및 관능특성

This study was conducted to investigate the antibacterial activities and sensory properties of a sauce containing tea extract and garlic vineger against raw fish. The sauce was evaluated antibacterial activity against Vibrio parahaemolyticus and Vibrio vulnificus which is considered as one of the major food borne pathogens. As a result, the sauce inhibited the growth of V. parahaemolyticus and V. vulnificus distinctly. In addition, the sauce with soy sauce and Kochujang showed the restricted growth of Vibrio parahaemolyticus and Vibrio vulnificus in sliced raw flatfish. Sensory evaluations were measured by 7-point hedonic scale using sliced raw flatfish with the sauce mixed with Kochujang and soy sauce. The score of texture in the sauce with Kochujang was significantly higher than that of regular Chokochujang (p<0.05). Moreover, total preference including appearance, texture, aroma and taste were significantly higher in the sauce with soy sauce than those of regular soy sauce (p<0.05). Consequently, the soy sauce with tea extract and garlic vinegar may enhance the satisfaction of consumer and antimicrobial activity that against V. parahaemolyticus and V. vulnificus, resulting in potential reduction the outbreaks of food borne pathogens.

Estimation of the Risk Associated to Marketing of Swine Meat Contaminated with Salmonella spp., Employing the William T. Fine Method

Swine meat is a growing market in Colombia, reaching 3.1 million of carcasses sold in 2014. However, it is estimated that the proportion of hogs illegally marketed can be up to 50%, which exposes the population to foodborne pathogens such as Salmonella. The aim of this study was to estimate the risk associated to the marketing of swine meat contaminated with Salmonella, using the William T. Fine method in Tolima Department. The risk scenarios applied to four municipalities positive for Salmonella showed a medium and low level of risk, and an exposed population of 114,000 people, representing 8.7% of the Department's population. In the worst-case scenario, costs for hospitalization and compensation could represent more than US$ 145 billion for the biggest municipality. It can be concluded that the William T. Fine method is applicable for biological risk analysis focused on foodborne pathogen outbreaks.

Postharvest treatments of fresh produce.

Postharvest technologies have allowed horticultural industries to meet the global demands of local and large-scale production and intercontinental distribution of fresh produce that have high nutritional and sensory quality. Harvested products are metabolically active, undergoing ripening and senescence processes that must be controlled to prolong postharvest quality. Inadequate management of these processes can result in major losses in nutritional and quality attributes, outbreaks of foodborne pathogens and financial loss for all players along the supply chain, from growers to consumers. Optimal postharvest treatments for fresh produce seek to slow down physiological processes of senescence and maturation, reduce/inhibit development of physiological disorders and minimize the risk of microbial growth and contamination. In addition to basic postharvest technologies of temperature management, an array of others have been developed including various physical (heat, irradiation and edible coatings), chemical (antimicrobials, antioxidants and anti-browning) and gaseous treatments. This article examines the current status on postharvest treatments of fresh produce and emerging technologies, such as plasma and ozone, that can be used to maintain quality, reduce losses and waste of fresh produce. It also highlights further research needed to increase our understanding of the dynamic response of fresh produce to various postharvest treatments.

Genomic paradigms for food-borne enteric pathogen analysis at the USFDA: case studies highlighting method utility, integration and resolution

Modern risk control and food safety practices involving food-borne bacterial pathogens are benefiting from new genomic technologies for rapid, yet highly specific, strain characterisations. Within the United States Food and Drug Administration (USFDA) Center for Food Safety and Applied Nutrition (CFSAN), optical genome mapping and DNA microarray genotyping have been used for several years to quickly assess genomic architecture and gene content, respectively, for outbreak strain subtyping and to enhance retrospective trace-back analyses. The application and relative utility of each method varies with outbreak scenario and the suspect pathogen, with comparative analytical power enhanced by database scale and depth. Integration of these two technologies allows high-resolution scrutiny of the genomic landscapes of enteric food-borne pathogens with notable examples including Shiga toxin-producing Escherichia coli (STEC) and Salmonella enterica serovars from a variety of food commodities. Moreover, the recent application of whole genome sequencing technologies to food-borne pathogen outbreaks and surveillance has enhanced resolution to the single nucleotide scale. This new wealth of sequence data will support more refined next-generation custom microarray designs, targeted re-sequencing and “genomic signature recognition” approaches involving a combination of genes and single nucleotide polymorphism detection to distil strain-specific fingerprinting to a minimised scale. This paper examines the utility of microarrays and optical mapping in analysing outbreaks, reviews best practices and the limits of these technologies for pathogen differentiation, and it considers future integration with whole genome sequencing efforts.

Microbial Safety of Tropical Fruits

There are approximately 140 million tons of over 3,000 types of tropical fruits produced annually worldwide. Tropical fruits, once unfamiliar and rare to the temperate market, are now gaining widespread acceptance. Tropical fruits are found in a variety of forms, including whole, fresh cut, dried, juice blends, frozen, pulp, and nectars in markets around the world. Documented outbreaks of foodborne disease associated with tropical fruits have occurred. Norovirus and Salmonella are the leading viral and bacterial pathogens, respectively, documented to have caused outbreaks of infections associated with consumption of tropical fruits. Sources of contamination of tropical fruit have been identified in the production environment and postharvest handling, primarily related to sanitation issues. Limited data exist on the specific route of transmission from these sources. Research on the microbial safety of tropical fruits is minimal; with the growing market for tropical fruit expected to increase by 33% in 2010 this research area needs to be addressed. The aim of this review is to discuss the foodborne pathogen outbreaks associated tropical fruit consumption, research previously completed on pathogen behavior on tropical fruits, preventive strategies for pathogen contamination, and research needs.

Antimicrobial activity of lactic acid and copper on growth of Salmonella and Escherichia coli O157:H7 in laboratory medium and carrot juice

Outbreaks of food-borne pathogens, such as Escherichia coli O157:H7 and Salmonella, continue to draw public attention to food safety. Several reports have demonstrated the efficacy of using natural ingredients to control the growth of food-borne pathogens. The objective of this study was to investigate antimicrobial effects of lactic acid and copper, alone and in combination, on the survival and growth of Salmonella spp. and E. coli O157:H7 in laboratory medium and carrot juice. Survival and growth of 38 Salmonella spp. and six E. coli O157:H7 strains were compared when grown in brain heart infusion (BHI) broth and carrot juice under conditions including either lactic acid (0.2%) alone, copper sulfate (50ppm) alone or the combination of the two. The growth inhibition was negligible when copper sulfate was added to BHI broth and carrot juice. Lactic acid (0.2%) retarded the growth of bacterial strains. However, the growth of bacterial strains was significantly inhibited when both lactic acid and copper were in BHI broth and carrot juice within the time frame of this study. These findings indicated that lactic acid, in combination with copper sulfate, could be used to inhibit the growth of pathogens. Natural ingredients, such as lactic acid and low dose of copper ions, can be used to improve the safety of food products.

The Enter-net and Salm-gene databases of foodborne bacterial pathogens that cause human infections in Europe and beyond: an international collaboration in surveillance and the development of intervention strategies

The free movement of people and foodstuffs between countries are effective ways of distributing disease internationally. There is a requirement for a mechanism whereby data and information on potential outbreaks of foodborne pathogens can be disseminated rapidly to those who need to know. The Enter-net dedicated surveillance network provides this mechanism, complemented by the Salm-gene molecular typing network. Data on epidemiological and microbiological features on current cases, as well as background levels of infections are immediately available within the Enter-net databases. The Salm-gene network with its database of harmonized salmonella PFGE patterns from the participating European countries provides immediate, and electronically exchangeable, DNA fingerprints of outbreak strains. This prompt electronic dissemination of information regarding unusual events with international implications ensures that public health interventions can be implemented and cases of foodborne disease prevented.

Food safety and the consumer – perils of poor risk communication

The potential for stigmatisation of food is enormous. Well-publicised outbreaks of foodborne pathogens and the furore over agricultural biotechnology are but two current examples of the interactions between science, policy and public perception. Current risk management research indicates that it is essential for risk managers to show that they are reducing, mitigating or minimising a particular risk. Those responsible must be able to effectively communicate their efforts and must be able to prove they are actually reducing levels of risk.The components for managing the stigma associated with any food safety issue involve the following factors:• effective and rapid surveillance systems;• effective communication about the nature of risk;• a credible, open and responsive regulatory system;• demonstrable efforts to reduce levels of uncertainty and risk; and,• evidence that actions match words.Appropriate risk management strategies, such as on-farm food safety programs, are essential to demonstrate to consumers and others in the farm-to-fork supply chain that producers and regulators are cognisant of their concerns about food safety. Key words: Agricultural biotechnology, microbial food safety, genetically engineered food, risk perception, risk communication, risk management