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1.
Campbell Syst Rev ; 20(2): e1403, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38756221

ABSTRACT

This is the protocol for a Campbell systematic review. The objectives are as follows. The primary aim of this mixed methods review is to synthesise the available evidence regarding the effectiveness of restorative justice interventions (RJIs) for reducing offending and reoffending outcomes in children and young people. We are also particularly interested in the impact of RJIs on children and young peoples' violent offending and violent reoffending. A second aim of the review is to examine whether the magnitude of effectiveness of RJIs may be influenced by study characteristics such as the population (e.g., age, ethnicity, or sex), the form of intervention (e.g., face-to-face mediation compared to family group conferencing), the place of delivery of the intervention (e.g., in independent office, in court), implementation (e.g., trained facilitators, dose, fidelity) and methodology (e.g., randomised controlled trial). The third aim of the review is to synthesise the qualitative evidence about RJ to develop a better contextual understanding of how these programmes may work and to elucidate factors that might increase the efficacy and implementation of RJ interventions. The specific research questions this systematic review aims to address are: (1) Do RJ interventions reduce children and young people's involvement in offending or reoffending relative to a comparison group? [RQ1]. (2) Is there variation in the impact of different RJ approaches on young people's involvement in offending or reoffending? [RQ2]. (3) Is there variation in the impact of RJIs on children and young people's offending or reoffending depending on the characteristics of the participants taking part in the RJI (e.g., sex, age, ethnicity)? [RQ3]. (4) What characteristics of RJIs, influence the effectiveness of RJIs for children and young people's offending and reoffending? [RQ4]. (5) What are the most notable barriers and facilitators, as reported by participants (e.g., the victims, children/young people, or mediators who have taken part in an evaluation of an RJI, or those children or young people who were meant to take part in an evaluation but ultimately did not), to the implementation of RJIs to reduce later offending or reoffending? [RQ5].

2.
Cochrane Database Syst Rev ; 4: CD012746, 2023 04 28.
Article in English | MEDLINE | ID: mdl-37115724

ABSTRACT

BACKGROUND: Conduct problems are a range of disruptive behaviours in childhood that are associated with long-term adverse outcomes in adolescence and adulthood, including antisocial behaviour, substance misuse, and poor academic achievement. Children with conduct problems can vary according to age of onset, comorbidities, and environmental factors, and it has been suggested that certain groups of children may have different treatment outcomes. Therefore, it is important to assess the extent to which personalised interventions for different groups of children with conduct problems may affect outcomes. To our knowledge, this is the first review to systematically identify and appraise the effectiveness of personalised interventions, adapted, or developed, for prespecified subgroups of children with conduct problems. OBJECTIVES: To assess whether personalised interventions, adapted or developed for subgroups of children with conduct problems are effective in improving outcomes. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search was 1 February 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs), in any setting, in children (aged two to 12 years) with conduct problems and within a prespecified subgroup, comparing a personalised intervention with a non-personalised intervention, waitlist control, or treatment as usual. Personalised interventions included adaptations to standard practice, such as parent-training programmes; other recommended interventions for children with conduct problems; or interventions developed specifically to target subgroups of children with conduct problems. We excluded non-personalised and non-psychological interventions (e.g. pharmacological or dietary intervention). Prespecified subgroups of children with conduct problems, however defined, were eligible for inclusion. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. child conduct problems or disruptive behaviour and 2. ADVERSE EVENTS: Our secondary outcomes were 3. personalised treatment outcomes relevant to each subgroup, 4. parenting skills and knowledge, 5. family functioning, engagement and decreased dropout, and 6. educational outcomes. We used GRADE to assess the certainty of the evidence. MAIN RESULTS: We identified 13 RCTs (858 participants). Seven studies were conducted in the USA, five in Australia, and one in Germany. Eleven studies reported their source of funding, with five studies receiving grants from the National Institute of Mental Health. In total, 15 different funders supported the studies included in the review. We separated subgroups of children with conduct problems into three broad categories: children with co-occurring conditions (e.g. emotional difficulties), parent characteristics (e.g. conflict between parents), or familial/environmental circumstances (e.g. rural families). All studies delivered a personalised intervention that was adapted or developed for a prespecified subgroup of children with conduct problems. We rated all trials at unclear or high risk of bias in most domains. Below, we report the results of improvement in child conduct problems and disruptive behaviour, personalised treatment outcomes, and parenting skills and knowledge for our main comparison: personalised versus non-personalised interventions. Improvement in child conduct problems and disruptive behaviour Compared with a non-personalised intervention, a personalised intervention may result in a slight improvement in child conduct problems or disruptive behaviour measured using the Eyberg Child Behavior Inventory (ECBI) Problem subscale in the short term (mean difference (MD) -3.04, 95% confidence interval (CI) -6.06 to -0.02; 6 studies, 278 participants; P = 0.05), but may have little to no effect on improving child conduct problems or disruptive behaviour measured by the ECBI Intensity subscale (MD -6.25, 95% CI -16.66 to 4.15; 6 studies, 278 participants; P = 0.24), or the Externalising subscale of the Child Behaviour Checklist (CBCL) (MD -2.19, 95% CI -6.97 to 2.59; 3 studies, 189 participants, P = 0.37) in the short term. We graded the certainty of evidence as very low for all three outcomes, meaning any estimate of effect is very uncertain.  Personalised treatment outcomes, relevant to each subgroup Although six studies reported personalised treatment outcomes, relevant to each subgroup, we were unable to pool the data due to differences between the measures used in the studies and the heterogeneity this would produce in analysis. The results for this outcome were inconclusive. Parenting skills and knowledge Although seven studies reported parenting skills and knowledge, we were unable to pool the data due to differences between the measures used in the studies and the heterogeneity this would produce in analysis. The results for this outcome were inconclusive.  Adverse events None of the trials reported monitoring adverse events. Summary of results In summary, there is limited evidence that personalised intervention improves child conduct problems, personalised treatment outcomes, relevant to each subgroup, or parenting skills and knowledge compared with a non-personalised intervention. AUTHORS' CONCLUSIONS: There is limited evidence for the effectiveness of personalised interventions for subgroups of children with conduct problems. The certainty of evidence for all outcomes was very low, meaning that we have very little confidence in the estimated effects and the true effects may be different to our findings, which will limit the relevance of our findings to clinical decisions. To overcome the limitations of the evidence, large-scale RCTs are needed to determine whether personalised interventions, adapted or developed, for subgroups of children with conduct problems are effective in improving outcomes. Consensus on the most appropriate measures to use in these studies is needed in order to facilitate cross-study comparisons. Persistent conduct problems predict a range of adverse long-term outcomes, so future research should investigate the medium- and long-term effects of personalised treatments. Studies are needed in low- and middle-income countries as well as studies recruiting children aged between nine and 12 years, as they were under-represented in the studies.


Subject(s)
Problem Behavior , Adolescent , Child , Humans , Child Behavior , Child Rearing , Emotions , Parents/psychology , United States
4.
Int J Offender Ther Comp Criminol ; 67(8): 757-782, 2023 06.
Article in English | MEDLINE | ID: mdl-34963375

ABSTRACT

Research suggests that convicted persons are more likely than non-convicted persons to suffer poor health. However, few longitudinal studies have investigated associations between health and offending across generations. Using the Cambridge Study in Delinquent Development, this article prospectively investigates the relationship between health and offending across generations and between genders. At the average age of 25, third generation convicted males and females reported a higher incidence of serious drug use than non-convicted persons. Convicted males reported a higher incidence of mental illness and self-harm, whereas convicted females reported a lower incidence of physical illness, mental illness, self-harm and hospitalizations when compared to non-convicted females. Convicted males reported a higher incidence of industrial accidents, sports injuries and fight injuries, but a lower incidence of road accidents, whereas convicted females were more likely to report road accidents. Like their fathers, convicted males show worse health compared to non-convicted individuals.


Subject(s)
Antisocial Personality Disorder , Hospitalization , Humans , Male , Female , Adult , Risk Factors , Longitudinal Studies , Incidence , Antisocial Personality Disorder/epidemiology
7.
Anal Bioanal Chem ; 414(8): 2767-2774, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35106614

ABSTRACT

Analysis of the dipicolinic acid (DPA) released from Clostridium botulinum spores during thermal processing is crucial to obtaining a mechanistic understanding of the factors involved in spore heat resistance and related food safety applications. Here, we developed a novel mixed-mode liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection of the DPA released from C. botulinum type A, nonproteolytic types B and F strains, and nonpathogenic surrogate Clostridium sporogenes PA3679 spores. DPA was retained on a mixed-mode C18/anion exchange column and was detected using electrospray ionization (ESI) positive mode within a 4-min analysis time. The intraday and interday precision (%CV) was 1.94-3.46% and 4.04-8.28%, respectively. Matrix effects were minimal across proteolytic type A Giorgio-A, nonproteolytic types QC-B and 202-F, and C. sporogenes PA3679 spore suspensions (90.1-114% of spiked DPA concentrations). DPA recovery in carrot juice and beef broth ranged from 105 to 118%, indicating limited matrix effects of these food products. Experiments that assessed the DPA released from Giorgio-A spores over the course of a 5-min thermal treatment at 108 °C found a significant correlation (R = 0.907; P < 0.05) between the log reduction of spores and amount of DPA released. This mixed-mode LC-MS/MS method provides a means for rapid detection of DPA released from C. botulinum spores during thermal processing and has the potential to be used for experiments in the field of food safety that assess the thermal resistance characteristics of various C. botulinum spore types.


Subject(s)
Clostridium botulinum , Picolinic Acids , Chromatography, Liquid , Clostridium botulinum/chemistry , Hot Temperature , Picolinic Acids/analysis , Spores, Bacterial/chemistry , Tandem Mass Spectrometry
8.
Campbell Syst Rev ; 18(4): e1286, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36908837

ABSTRACT

This is the protocol for a Campbell systematic review. The review will address the following research questions: What is the evidence on the effects of adult mentoring programmes in reducing anti-social, violent and offending behaviour in children aged under 18 years? Are these effects sustained after the end of mentoring? Which aspects/features of adult mentoring programmes promote the reduction of anti-social, violent and criminal behaviour in children aged under 18 years? What are the hindering factors/barriers that affect the successful implementation of adult mentoring programmes in children aged under 18 years? What are the supporting factors/facilitators that contribute to the successful implementation of adult mentoring programmes in children aged under 18 years? What is the evidence on programme costs and incremental cost effectiveness? (The incremental (or marginal cost) is the cost of providing the intervention over and above the cost of usual services).

9.
Crim Behav Ment Health ; 31(3): 211-219, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33951229

ABSTRACT

BACKGROUND: Previous research has suggested that people with a history of offending have worse health compared to non-offenders, but it is less clear whether all types of offenders are at similar health risks. In a New Zealand birth cohort study, Moffitt evidenced three main offending trajectories-life-course-persistent (LCP), adolescence-limited (AL) and late-onset (LO) offending, subsequently confirmed in other substantial longitudinal studies. AIMS: Our aim was to explore the relationship between these offending trajectories and both self-reported (SR) and general practitioner (GP) (primary care) recorded health indicators. METHODS: Self-reported medical data at age 48 were obtained for 394 men followed since age 8 years in the Cambridge Study in Delinquent Development. In addition, medical records were obtained from GPs for 264 of them. Health indicators from both sources were compared between each of the three established trajectories of offenders across the life course-LCP, AL, LO and the non-offenders. RESULTS: LCP offenders were found to have over twice the likelihood of disabling medical conditions according to both self-report and GP records. They were also more likely to have GP records indicating mental health problems and treatment for them. According to GP records alone, the LO offenders were also more likely to have mental health problems. The health of AL offenders appeared to be no different from that of the crime-free controls. CONCLUSIONS: Our findings add weight to the growing evidence that LCP offending and offending that only occurs relatively late in life are likely to be the indicators of generally unhealthy and disrupted lives. This suggests that if lifestyle is to change for the better, interventions are likely to be needed for health as well as antisocial behaviour.


Subject(s)
Criminals , General Practitioners , Adolescent , Child , Cohort Studies , Humans , Male , Middle Aged , New Zealand/epidemiology , Self Report
10.
Attach Hum Dev ; 23(4): 355-374, 2021 08.
Article in English | MEDLINE | ID: mdl-33978553

ABSTRACT

Attachment concepts are used in diverging ways, which has caused confusion in communication among researchers, among practitioners, and between researchers and practitioners, and hinders their potential for collaboration. In this essay we explore how attachment concepts may vary in meaning across six different domains: popular discourses, developmental science, social psychological science, psychiatric diagnosis, psychotherapy, and child welfare practice. We attempt to typify these forms of attachment discourse by highlighting points of convergence, divergence, and relay between the different domains. Our general conclusions are that diversity in the use of attachment concepts across different domains of application has been largely unrecognised, and that recognition of these differences would reduce confusion, help identify sites where infrastructure needs to be developed to support coordination, and strengthen opportunities for collaboration to mutual benefit. We suggest that academic attachment discourse would benefit from clarification of core terminology, including: "attachment", "internal working model", "trauma", and "dysregulation".


Subject(s)
Mental Disorders , Object Attachment , Child , Humans , Psychotherapy
11.
J Food Prot ; 84(3): 442-448, 2021 Mar 01.
Article in English | MEDLINE | ID: mdl-33125074

ABSTRACT

The microbial safety concern associated with thermally processed extended shelf life (ESL) refrigerated foods is based on adequate elimination of spore-forming pathogens such as nonproteolytic Clostridium botulinum types B, E, and F. These pathogens are traditionally regarded as targets for validation of thermally processed ESL foods. However, their use for research is restricted due to their designation as select agents. In this study, the thermal resistances of spores of 10 nonproteolytic C. botulinum types B and F and seven psychrotrophic Bacillus cereus strains were evaluated in ACES (N-(2-acetamido)-2-aminoethanesulfonic acid) buffer (0.05 M, pH 7.00) and compared to determine whether any of the B. cereus strains could serve as a nonselect agent for establishing thermal processes for ESL refrigerated foods. Thermal decimal reduction times (DT-values) of both nonproteolytic C. botulinum types B and F and psychrotrophic B. cereus strains decreased as process temperature increased from 80 to 91°C, and the highest values were obtained at 80°C. All psychrotrophic B. cereus strains tested were more thermally resistant than nonproteolytic C. botulinum types B and F. DT-values of nonproteolytic C. botulinum types B and F decreased to <1.0 min at 87°C, whereas all psychrotrophic B. cereus strains had higher DT-values (i.e., 52.35 to 133.69 min) at the same temperature. Among all psychrotrophic B. cereus strains tested, BC-6A16 had the highest DT-values at any given temperature. The DT-values indicated that the psychrotrophic B. cereus strains were more thermally resistant than the nonproteolytic C. botulinum strains and therefore may be potential target pathogens for thermal process validation of ESL refrigerated foods. However, further comparative challenge studies are needed with a model food system or an ESL refrigerated food to confirm these results.


Subject(s)
Bacillus cereus , Clostridium botulinum , Food Microbiology , Hot Temperature , Spores, Bacterial
12.
Proc Math Phys Eng Sci ; 476(2242): 20200319, 2020 Oct.
Article in English | MEDLINE | ID: mdl-33214761

ABSTRACT

We propose an extension of the axial next nearest neighbour Ising (ANNNI) model to a general number of interactions between spins. We apply this to the calculation of stacking fault energies in magnesium-particularly challenging due to the long-ranged screening of the pseudopotential by the free electron gas. We employ both density functional theory (DFT) using highest possible precision, and generalized pseudopotential theory (GPT) in the form of an analytic, long ranged, oscillating pair potential. At the level of first neighbours, the Ising model is reasonably accurate, but higher order terms are required. In fact, our ' AN N NI model' is slow to converge-an inevitable feature of the free electron-like electronic structure. In consequence, the convergence and internal consistency of the AN N NI model is problematic within the most precise implementation of DFT. The GPT shows the convergence and internal consistency of the DFT bandstructure approach with electron temperature, but does not lead to loss of precision. The GPT is as accurate as a full implementation of DFT but carries the additional benefit that damping of the oscillations in the AN N NI model parameters are achieved without entailing error in stacking fault energies. We trace this to the logarithmic singularity of the Lindhard function.

14.
J R Soc Med ; 113(3): 110-118, 2020 03.
Article in English | MEDLINE | ID: mdl-32160121

ABSTRACT

OBJECTIVES: Research suggests that antisocial lifestyles constitute significant health risks. However, there are marked individual differences in the stability of antisocial behaviour. These different offending pathways may bear differential risks for adult health. DESIGN: Injury and illness data were collected prospectively in the longitudinal Cambridge Study in Delinquent Development. SETTING: Working-class inner-city area of South London. PARTICIPANTS: Participants included the 411 men from the Cambridge Study in Delinquent Development, with interview data collected at ages 18, 32 and 48 years for each individual. MAIN OUTCOME MEASURES: Organic illness, hospitalisation and injuries. RESULTS: By age 48, adjusted odds ratios showed that the incidence of organic illness was higher among Life-Course-Persistent, Late-Onset offenders and offenders in general. Based on adjusted odds ratios at age 32, the incidence of hospitalisations was higher for Late-Onset offenders. Adjusted odds ratios at age 48 also showed that the incidence of hospitalisations was higher for all three offender types and offenders in general. Our results also provide evidence that offenders were more likely to suffer injuries than non-offenders. CONCLUSIONS: The findings of this study imply that preventing individuals from offending is likely to have substantial benefits for health.


Subject(s)
Antisocial Personality Disorder/epidemiology , Crime/statistics & numerical data , Criminals/statistics & numerical data , Life Style , Mental Health , Patient Admission/trends , Risk Assessment , Adolescent , Adult , Child , Female , Follow-Up Studies , Humans , Incidence , London/epidemiology , Male , Middle Aged , Prospective Studies , Risk Factors , Social Environment , Young Adult
15.
Genome Announc ; 6(26)2018 Jun 28.
Article in English | MEDLINE | ID: mdl-29954889

ABSTRACT

Clostridium botulinum is a strictly anaerobic, Gram-positive, spore-forming bacterium that produces botulinum neurotoxin, a potent and deadly proteinaceous exotoxin. Clostridium botulinum strain CFSAN064329 (62A) produces an A1 serotype/subtype botulinum neurotoxin and is frequently utilized in food challenge and detection studies. We report here the closed genome sequence of Clostridium botulinum strain CFSAN064329 (62A).

16.
J Food Prot ; 81(2): 261-271, 2018 02.
Article in English | MEDLINE | ID: mdl-29360398

ABSTRACT

The impact of high pressure processing on the inactivation of spores of nonproteolytic Clostridium botulinum is important in extended shelf life chilled low-acid foods. The three most resistant C. botulinum strains (Ham-B, Kap 9-B, and 610-F) were selected for comparison of their thermal and pressure-assisted thermal resistance after screening 17 nonproteolytic C. botulinum strains (8 type B, 7 type E, and 2 type F). Spores of strains Ham-B, Kap 9-B, and 610-F were prepared using a biphasic media method, diluted in N-(2-acetamido)-2-aminoethanesulfonic acid (ACES) buffer (0.05 M, pH 7.00) to 105 to 106 CFU/mL, placed into a modified sterile transfer pipette, heat sealed, and subjected to a combination of high pressures (600 to 750 MPa) and high temperatures (80 to 91°C) using laboratory and pilot-scale pressure test systems. Diluted spores from the same crops were placed in nuclear magnetic resonance tubes, which were heat sealed, and subjected to 80 to 91°C in a Fluke 7321 high precision bath with Duratheram S oil as the heat transfer fluid. After incubation for 3 months, survivors in both studies were determined by the five-tube most-probable-number method using Trypticase-peptone-glucose-yeast extract broth. The highest (>5.0) log reductions in spore counts for Ham-B, Kap 9-B, and 610-F occurred at the highest temperature and pressure combination tested (91°C and 750 MPa). Thermal D-values of Ham-B, Kap 9-B, and 610-F decreased as the process temperature increased from 80 to 87°C, decreasing to <1.0 min at 87°C for these strains. Pressure-assisted thermal D-values of Ham-B, Kap 9-B, and 610-F decreased as the process temperature increased from 80 to 91°C with any pressure combination and decreased to <1.0 min as the pressure increased from 600 to 750 MPa at 91°C. Based on the pressure-assisted thermal D-values, pressure exerted a more protective effect on spores of Ham-B, Kap 9-B, and 610-F when processed at 83 to 91°C combined with pressures of 600 to 700 MPa when compared with thermal treatment only. No protective effect was observed when the spores of Ham-B, Kap9-B, and 610-F were treated at lower temperatures (80 to 83°C) in combination with 750 MPa. However, at higher temperatures (87 to 91°C) in combination with 750 MPa, a protective effect was seen for Ham-B, Kap9-B, and 610-F spores based on the calculated pressure-assisted thermal D-values.


Subject(s)
Clostridium botulinum/physiology , Hot Temperature , Pressure , Spores, Bacterial/physiology
17.
ACS Appl Mater Interfaces ; 9(37): 31446-31457, 2017 Sep 20.
Article in English | MEDLINE | ID: mdl-28840718

ABSTRACT

Botulinum neurotoxin (BoNT) is the most potent toxin known. The ingestion of food contaminated with biologically active BoNT causes foodborne botulism, which can lead to respiratory paralysis, coma, and death after ingestion of as little as 70 µg for a 70 kg human. Because of its lethality and challenges associated with current detection methods, there is an urgent need for highly sensitive rapid screening techniques capable of detecting biologically active BoNT. Here, we describe a Förster resonance energy transfer-based nanobiosensor that uses quantum dots (QDs) and two specific quencher-labeled peptide probes to detect and differentiate two biologically active forms of BoNT, serotypes A and B, which were responsible for 80% of human foodborne botulism cases in the U.S. from 2012 to 2015. Each peptide probe contains an enzymatic cleavage site specific to only one serotype. QDs were selected based on the spectral overlap with the quenchers. In the presence of the target BoNT serotype, the peptide probe is cleaved and the quenching of QD photoluminescence (PL) is reduced, giving a signal that is easily detected by a PL spectrophotometer. This sensor performance was evaluated with light chains of BoNT/A and BoNT/B (LcA and LcB), catalytic domains of the respective serotypes. LcA and LcB were detected in 3 h with limits of detection of 0.2 and 2 ng/mL, respectively. The specificity of the sensor was evaluated, and no cross-reactivity from nontarget serotypes was observed with 2 h of incubation. Because each serotype-specific peptide is conjugated to a QD with a unique emission wavelength, multiple biologically active BoNT serotypes could be detected in one PL spectrum. The sensor was also shown to be responsive to BoNT/A and BoNT/B holotoxins. Good performance of this sensor implies its potential application as a rapid screening method for biologically active BoNT/A and BoNT/B in the laboratory and in the field.


Subject(s)
Quantum Dots , Botulinum Toxins, Type A , Botulism , Fluorescence Resonance Energy Transfer , Humans , Peptides , Serogroup
18.
Philos Trans A Math Phys Eng Sci ; 375(2098)2017 07 28.
Article in English | MEDLINE | ID: mdl-28607196

ABSTRACT

This session concerned the political, economic and environmental impact on the hydrogen economy due to hydrogen embrittlement.This article is part of the themed issue 'The challenges of hydrogen and metals'.

19.
Philos Trans A Math Phys Eng Sci ; 375(2098)2017 07 28.
Article in English | MEDLINE | ID: mdl-28607202

ABSTRACT

This discussion session interrogated the current understanding of hydrogen embrittlement mechanisms in steels.This article is part of the themed issue 'The challenges of hydrogen and metals'.

20.
J Food Prot ; 79(2): 253-62, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26818986

ABSTRACT

The purpose of this study was to determine the inactivation kinetics of the spores of the most resistant proteolytic Clostridium botulinum strains (Giorgio-A and 69-A, as determined from an earlier screening study) and of Clostridium sporogenes PA3679 and to compare the thermal and pressure-assisted thermal resistance of these spores. Spores of these strains were prepared using a biphasic medium method. C. sporogenes PA3679 spores were heat treated before spore preparation. Using laboratory-scale and pilot-scale pressure test systems, spores of Giorgio-A, 69-A, and PA3679 suspended in ACES [N-(2-acetamido)-2-aminoethanesulfonic acid] buffer (pH 7.0) were exposed to various combinations of temperature (93 to 121°C) and pressure (0.1 to 750 MPa) to determine their resistance. More than a 5-log reduction occurred after 3 min at 113°C for spores of Giorgio-A and 69-A and after 5 min at 117°C for spores of PA3679. A combination of high temperatures (93 to 121°C) and pressures yielded greater log reductions of spores of Giorgio-A, 69-A, and PA3679 compared with reduction obtained with high temperatures alone. No survivors from initial levels (>5.0 log CFU) of Giorgio-A and 69-A were detected when processed at a combination of high temperature (117 and 121°C) and high pressure (600 and 750 MPa) for <1 min in a pilot-scale pressure test system. Increasing pressure from 600 to 750 MPa at 117°C decreased the time from 2.7 to 1 min for a >4.5-log reduction of PA3679 spores. Thermal D-values of Giorgio-A, 69-A, and PA3679 spores decreased (i.e., 29.1 to 0.33 min for Giorgio-A, 40.5 to 0.27 min for 69-A, and 335.2 to 2.16 min for PA3679) as the temperature increased from 97 to 117°C. Pressure-assisted thermal D-values of Giorgio-A, 69-A, and PA3679 also decreased as temperature increased from 97 to 121°C at both pressures (600 and 750 MPa) (i.e., 17.19 to 0.15 min for Giorgio-A, 9.58 to 0.15 min for 69-A, and 12.93 to 0.33 min for PA3679 at 600 MPa). At higher temperatures (117 or 121°C), increasing pressure from 600 to 750 MPa had an effect on pressure-assisted thermal D-values of PA3679 (i.e., at 117°C, pressure-assisted thermal D-value decreased from 0.55 to 0.28 min as pressure increased from 600 to 750 MPa), but pressure had no effect on pressure-assisted thermal D-values of Giorgio-A and 69-A. When compared with Giorgio-A and 69-A, PA3679 had higher thermal and pressure-assisted thermal D-values. C. sporogenes PA3679 spores were generally more resistant to combinations of high pressure and high temperature than were the spores of the C. botulinum strains tested in this study.


Subject(s)
Clostridium/growth & development , Disinfection/methods , Spores, Bacterial/growth & development , Clostridium/chemistry , Clostridium botulinum type A/drug effects , Clostridium botulinum type A/growth & development , Disinfection/instrumentation , Food Microbiology , Hot Temperature , Kinetics , Pressure , Spores, Bacterial/chemistry
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