Assessing the impact of heat treatment of food on antimicrobial resistance genes and their potential uptake by other bacteria - A critical review

The dissemination of antibiotic resistance genes (ARGs) is a global health concern. This study identifies and critically reviews the published evidence on whether cooking (heating) food to eliminate bacterial contamination induces sufficient damage to the functionality of ARGs. Overall, the review found that there is evidence in the literature that Antimicrobial Resistant (AMR) bacteria are no more heat resistant than non-AMR bacteria. Consequently, recommended heat treatments sufficient to kill non-AMR bacteria in food (70 °C for at least 2 min, or equivalent) should be equally effective in killing AMR bacteria. The literature shows there are several mechanisms through which functional genes from AMR bacteria could theoretically persist in heat-treated food and be trans-ferred to other bacteria. The literature search found sparce published evidence on whether ARGs may actually persist in food after effective heat treatments, and whether functional genes can be transferred to other bacteria. However, three publications have demonstrated that functional ARGs in plasmids may be capable of persisting in foods after effective heat treatments. Given the global impact of AMR, there is clearly a need for further practical research on this topic to provide suffi-cient evidence to fully assess whether there is a risk to human health from the persistence of func-tional ARGs in heat-treated and cooked foods

A social contract for cyberspace

The current standards for the Internet and its services and devices are set and developed by multiple standards organisations, and national governments. In this paper, we argue that a social contract is needed between these organisations, and the entities (individual users, organisations, devices, and service providers) which use the Internet to communicate. Criteria which a social contract should meet are proposed; fourteen major current cybersecurity or ethical issues are then discussed; the necessity and feasibility of a social contract are considered. A draft social contract is then proposed and solutions or strategies to address the fourteen issues identified previously, on the basis of this draft social contract, are presented

Assessing the impact of heat treatment on antimicrobial resistance genes and their potential uptake by other ‘live’ bacteria

Antimicrobial resistance (AMR) is a complex issue driven by a variety of interconnected factors enabling microorganisms to withstand the killing or microstatic effects of antimicrobial treatments, such as antibiotics, antifungals, disinfectants, preservatives. Microorganisms may be inherently resistant to such treatments or can change and adapt to overcome the effects of such treatments. Microorganisms can acquire antimicrobial resistance genes (ARGs) because of mutation or from other microorganisms through a range of mechanisms. The widespread use of antimicrobial treatments is known to result in selection for AMR in microorganisms. AMR and ARGs are a major public health issue worldwide and it is estimated that unless action is taken now to tackle AMR the global impact of AMR could be 10 million deaths annually by 2050 and cost up to US $100 trillion in cumulative lost economic output (O’Neill Report, 2014). It is recognised that anthropogenic, commensal, and environmental microorganisms all contribute to the reservoir of ARGs, collectively forming the antimicrobial resistome (Wright, 2007). Relatively little is known regarding the role of heat�treated/cooked food in disseminating AMR, and whether heating/cooking is sufficient to inactivate ARGs to the extent that resistance is not passed onto other ‘live’ bacteria. This study was undertaken to critically review the available scientific literature for assessing the impact of heat treatment of food on ARGs, and the potential uptake of such ARGs by surrounding viable bacterial communities resident in other foods and the human gut. For the purpose of this review, heat treatments were regarded as any thermal processes that are undertaken during the processing or prior to consumption of any foods. The review focused particularly, but not exclusively, on what scientific evidence exists that provides an understanding on whether cooking (heating) food to eliminate bacterial contamination can also induce sufficient damage to ARGs to 8 of 91 prevent their uptake by surrounding viable bacteria present in other settings, including other foods and the human gut. The review question was defined as: “Do different heat treatments applied to eliminate bacterial contamination in foods also induce sufficient damage to ARGs to prevent or inhibit their uptake by surrounding viable bacteria present in other settings, including the human gut and other foods?” Systemic searching of two literature databases (Web of Science, and PubMed) was undertaken, supplemented by additional records identified through other sources. A total of 2681 of publications were identified between 1990 and May 2021, which were reduced to 247 after screening the titles and abstracts. This total was further reduced to 53, from which some data were extracted after appraising the full publications. This clearly indicated that literature relating to AMR bacteria and ARGs and heat treatments was sparse. Of these 53 publications identified that were considered eligible for some data extraction, only four were found that had studied the impact of heat treatments on ARGs. The majority of publications identified related to the relative heat resistance of various AMR bacteria in comparison to non-AMR strains and serotypes/serovars. Nine publications were reviews with some mention of the impact of heat on AMR bacteria, while 17 had evidence on the relative heat resistance of AMR bacteria in comparison to non-AMR bacteria. These publications provide evidence that AMR bacteria are likely to be no more heat-resistant than non-AMR bacteria. There is therefore evidence that heat treatments sufficient to kill non-AMR bacteria (such as 70°C for at least 2 min, or the equivalent) will be equally effective in killing AMR bacteria. 9 of 91 Most of these publications have not considered whether ARGs may persist after such heat treatments, and whether these genes could be transferred to other bacteria. Only four publications were identified that provide some evidence on the fate of ARGs after heat treatments. Due to the small number of publications identified and different laboratory methodologies used in the studies no statistical analysis was possible. Three of the four studies provided evidence that ARGs can at least be identified after heat treatments that are effective at inactivating AMR bacteria, but there is no certainty that such ARGs are intact and functional. Of the four studies identified, one (Koncan et al., 2007) used in vitro experiments to mimic cooking processes. Another in vitro study (Taher et al., 2020a) mimicked commercial milk pasteurisation, whilst the third (Le Devendec et al., 2018) was not designed to mimic any particular heat treatment but did use strains originating from animal sources and temperatures and times similar to thermal processes used to treat and cook food. A further study on autoclaving (Masters et al., 1998) was considered relevant, but was not applied to food. The in vitro mimic of cooking processes study (Koncan et al., 2007) detected the presence of ARGs after cooking but did not demonstrate that these genes were transferable to other bacteria. The other three studies did demonstrate that plasmid�encoded ARGs could be transferred to other bacteria following heat treatments under laboratory conditions. The ARG considered by Koncan et al. (2007) was aac(6’)-Ie-aph(2’’)-Ia, while Taher et al. (2020a) considered blaZ, mecC, tetK, and Le Devendec et al. (2018) considered blaCTX-M-1, blaCMY-2, tetA, strA. Masters et al. (1998) did not give any details of the gene considered. 10 of 91 These studies did not establish how likely was the occurrence of such transfer in the field. One of the studies (Le Devendec et al., 2018) theorised that natural transfer is probably rare. None of the studies demonstrated whether ARGs from heat-treated AMR bacteria could be taken up by other live bacteria in the human gut after ingestion. In conclusion, only a small number of studies were identified on the persistence of ARGs in heat-treated foods and their possible uptake by surrounding viable bacteria present in other settings, such as the human gut and other foods. Because of differences in conditions, these studies were not directly comparable. While the literature suggests that adequate heat treatment / cooking (e.g., cooking until the middle of the food commodity reaches 70°C for at least 2 min, or the equivalent) should be effective in ‘killing’ AMR bacteria in food, there is very little evidence if intact and functional ARGs are released from AMR bacteria following such heat treatments. Similarly, there does not appear to be any convincing data for the ready transfer of ARGs to the commensal bacteria of the mammalian gastrointestinal tract following cooking. Evidence to determine if there is a risk of transfer is sparse. We would therefore recommend further focused practical research be undertaken to provide evidence for a full assessment of risk in relation to transfer of ARGs from heat-treated foods to bacteria in other matrices

A collection of open problems in celebration of Imre Leader's 60th birthday

One of the great pleasures of working with Imre Leader is to experience his infectious delight on encountering a compelling combinatorial problem. This collection of open problems in combinatorics has been put together by a subset of his former PhD students and students-of-students for the occasion of his 60th birthday. All of the contributors have been influenced (directly or indirectly) by Imre: his personality, enthusiasm and his approach to mathematics. The problems included cover many of the areas of combinatorial mathematics that Imre is most associated with: including extremal problems on graphs, set systems and permutations, and Ramsey theory. This is a personal selection of problems which we find intriguing and deserving of being better known. It is not intended to be systematic, or to consist of the most significant or difficult questions in any area. Rather, our main aim is to celebrate Imre and his mathematics and to hope that these problems will make him smile. We also hope this collection will be a useful resource for researchers in combinatorics and will stimulate some enjoyable collaborations and beautiful mathematics

A Role for the Unfolded Protein Response (UPR) in Virulence and Antifungal Susceptibility in Aspergillus fumigatus

Filamentous fungi rely heavily on the secretory pathway, both for the delivery of cell wall components to the hyphal tip and the production and secretion of extracellular hydrolytic enzymes needed to support growth on polymeric substrates. Increased demand on the secretory system exerts stress on the endoplasmic reticulum (ER), which is countered by the activation of a coordinated stress response pathway termed the unfolded protein response (UPR). To determine the contribution of the UPR to the growth and virulence of the filamentous fungal pathogen Aspergillus fumigatus, we disrupted the hacA gene, encoding the major transcriptional regulator of the UPR. The ΔhacA mutant was unable to activate the UPR in response to ER stress and was hypersensitive to agents that disrupt ER homeostasis or the cell wall. Failure to induce the UPR did not affect radial growth on rich medium at 37°C, but cell wall integrity was disrupted at 45°C, resulting in a dramatic loss in viability. The ΔhacA mutant displayed a reduced capacity for protease secretion and was growth-impaired when challenged to assimilate nutrients from complex substrates. In addition, the ΔhacA mutant exhibited increased susceptibility to current antifungal agents that disrupt the membrane or cell wall and had attenuated virulence in multiple mouse models of invasive aspergillosis. These results demonstrate the importance of ER homeostasis to the growth and virulence of A. fumigatus and suggest that targeting the UPR, either alone or in combination with other antifungal drugs, would be an effective antifungal strategy

Technacy: towards a holistic understanding of technology teaching and learning among Aboriginal Australians

Abstract not available

Basic science under threat: Lessons from the Skirball Institute

Support for basic science has been eclipsed by initiatives aimed at specific medical problems. The latest example is the dismantling of the Skirball Institute at NYU School of Medicine. Here, we reflect on the achievements and mission underlying the Skirball to gain insight into the dividends of maintaining a basic science vision within the academic enterprises

Basic science under threat: Lessons from the Skirball Institute

Support for basic science has been eclipsed by initiatives aimed at specific medical problems. The latest example is the dismantling of the Skirball Institute at NYU School of Medicine. Here, we reflect on the achievements and mission underlying the Skirball to gain insight into the dividends of maintaining a basic science vision within the academic enterprises