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1.
Zoonoses Public Health ; 70(6): 523-541, 2023 09.
Article in English | MEDLINE | ID: mdl-37337320

ABSTRACT

Campylobacter is a major cause of food poisoning and is typically the most common cause of gastroenteritis in the UK. Data collected at broiler farm and abattoir level, for slaughter batches that were sampled for UK-wide monitoring, were used to generate two epidemiological risk factor models. A total of 483 batches slaughtered between January 2016 and March 2017 were used in the analysis, coming from 19 abattoirs representing more than 85% of UK broiler production. For each selected slaughter batch, one carcase was sampled after primary chilling and 10 randomly sampled birds had caecal samples collected at the evisceration point. Samples were used for Campylobacter identification and quantification. Two multivariable mixed-effects models were designed, one with the binary outcome for the detection of a highly contaminated (>1000 colony forming units (CFU)/g) Campylobacter-positive carcase, whereas the other used the Campylobacter colony count (CFU/g) carcase outcome. The results suggest that caecal colonization within the batch was a key factor for the occurrence of Campylobacter on carcases, and many factors that were identified in the model were also likely to be related to colonization or related to the risk of introduction of Campylobacter from partial depopulation (referred to as thinning) of ~30% of the flock approximately 1 week before full flock depopulation events. The amount of neck skin in the sample was another key factor identified and was included in both models as a risk factor. The models have also identified other factors which may be related to the general health and husbandry on-farm (use of prebiotics or vaccines, and identification of the product used for drinking line cleaning), whereas the other factors may identify control points related to transmission within a farm. The identification of these variables could help focus control efforts on-farm, especially for relatively easy improvements, such as improving the provision of house-specific bird-weighing buckets/cages in houses.


Subject(s)
Campylobacter Infections , Campylobacter , Animals , Food Microbiology , Chickens , Campylobacter Infections/epidemiology , Campylobacter Infections/veterinary , Risk Factors , Abattoirs , United Kingdom/epidemiology
2.
J Food Prot ; 85(12): 1696-1707, 2022 12 01.
Article in English | MEDLINE | ID: mdl-36135722

ABSTRACT

ABSTRACT: As part of a program to reduce numbers of the human pathogen Campylobacter on retail chickens, 22 broiler processing lines, representing more than 90% of UK production, were characterized by enumerating Campylobacter on pooled neck skins after exsanguination, scalding, defeathering, evisceration, crop removal, inside-outside washing, and air-chilling stages of processing. Sixteen of the processing lines investigated showed significant (P < 0.05) reductions in Campylobacter numbers because of carcass scalding. However, in all of these lines, the following defeathering stage caused a significant increase in Campylobacter contamination that effectively negated the reductions caused by scalding. On four processing lines, primary chilling also caused a significant reduction in numbers of Campylobacter. On three lines, there was a significant microbiological benefit from inside-outside washing. The stages where Campylobacter numbers were reduced require further investigation to determine the specific mechanisms responsible so that the observed pathogen reductions can be optimized and then more widely implemented. The transfer of up to 4 log CFU Campylobacter per g of neck skin from a colonized flock to a following uncolonized flock was observed. Cross-contamination was substantial and still detectable after 5,000 carcasses from an uncolonized flock had been processed. Numbers of Campylobacter recovered from the uncolonized flocks were highest on the first of the uncolonized birds to pass along the line, and in general, the numbers declined as more uncolonized birds were processed. Air sampling recovered low numbers at the processing stages monitored, indicating that airborne transmission was unlikely to be the primary transfer mechanism operating for cross-contamination between flocks.


Subject(s)
Campylobacter , Humans , Animals , Chickens/microbiology , Abattoirs , Food Microbiology , Colony Count, Microbial , United Kingdom , Food Handling , Food Contamination/analysis , Meat/microbiology
3.
J Inj Violence Res ; 14(1): 115-124, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35137693

ABSTRACT

BACKGROUND: The precision of emergency medical services (EMS) triage criteria dictates whether an injured patient receives appropriate care. The trauma triage protocol is a decision scheme that groups patients into triage categories of major, moderate and minor. We hypothesized that there is a difference between trauma triage category and injury severity score (ISS). METHODS: This retrospective, observational study was conducted to investigate a difference between trauma triage category and ISS. Bivariate analysis was used to test for differences between the subgroup means. The differences between the group means on each measure were analyzed for direction and statistical significance using ANOVA for continuous variables and chi square tests for categorical variables. Logistic and linear regressions were performed to evaluate factors predicting mortality, ICU length of stay. RESULTS: With respect to trauma triage category, our findings indicate that minor and moderate triage categories are similar with respect to ISS, GCS, ICU LOS, hospital LOS, and mortality. However, after excluding for low impact injuries (falls), differences between the minor and moderate categories were evident when comparing to ISS, GCS, ICU LOS, and hospital LOS. Additionally, after excluding for low impact injures, ISS, ICU LOS, and hospital stay were found to correlate well with trauma triage category. CONCLUSIONS: In this retrospective, observational study significant differences were not seen when comparing ISS with the trauma triage categories of moderate and minor during our initial analysis. However, a difference was found after excluding for low impact injuries. These findings suggest that CDC criteria accurately predicts outcomes in high impact trauma.


Subject(s)
Triage , Wounds and Injuries , Centers for Disease Control and Prevention, U.S. , Humans , Injury Severity Score , Retrospective Studies , Trauma Centers , Triage/methods , United States , Wounds and Injuries/therapy
4.
Sci Rep ; 11(1): 6862, 2021 03 25.
Article in English | MEDLINE | ID: mdl-33767293

ABSTRACT

There is a growing body of literature using functional MRI to study the acute and long-term effects of concussion on functional brain networks. To date, studies have largely focused on changes in pairwise connectivity strength between brain regions. Less is known about how concussion affects whole-brain network topology, particularly the "small-world" organization which facilitates efficient communication at both local and global scales. The present study addressed this knowledge gap by measuring local and global efficiency of 26 concussed athletes at acute injury, return to play (RTP) and one year post-RTP, along with a cohort of 167 athletic controls. On average, concussed athletes showed no alterations in local efficiency but had elevated global efficiency at acute injury, which had resolved by RTP. Athletes with atypically long recovery, however, had reduced global efficiency at 1 year post-RTP, suggesting long-term functional abnormalities for this subgroup. Analyses of nodal efficiency further indicated that global network changes were driven by high-efficiency visual and sensorimotor regions and low-efficiency frontal and subcortical regions. This study provides evidence that concussion causes subtle acute and long-term changes in the small-world organization of the brain, with effects that are related to the clinical profile of recovery.


Subject(s)
Athletic Injuries/physiopathology , Brain Concussion/physiopathology , Brain/pathology , Connectome , Functional Neuroimaging/methods , Adult , Athletic Injuries/diagnostic imaging , Brain/diagnostic imaging , Brain Concussion/diagnostic imaging , Case-Control Studies , Cross-Sectional Studies , Female , Humans , Longitudinal Studies , Male , Young Adult
5.
J Child Fam Stud ; 30(2): 325-337, 2021.
Article in English | MEDLINE | ID: mdl-33456294

ABSTRACT

Caregivers have primary responsibility for teaching their children self-protective behaviors, including those behaviors recommended by the Center for Disease Control (CDC) to prevent the spread of COVID-19. Parents have an important role in scaffolding adherence to the CDC recommendations and in managing stress and regulate their emotions to adaptively cope during uncertain times like those facing communities nationwide. The present study is a qualitative, thematic analysis of parent-reported (n = 210; 64.8% female; average age = 39.33; 14.3% ethnic/racial minority) interactions with children (focal child age: 25.2% birth to 5 years old, 36.7% 6 to 11 years old, 37.6% 12 to 18 years old) about topics associated to COVID-19-related viral transmission suppression guidelines and stress/coping behaviors. Themes included discussions about personal and social hygiene, and parent reported sources of child stress, and child stress management efforts. Findings from our thematic analysis indicate parents are motivated to make scaffolding personal hygiene fun and engaging, signaling a positive, developmentally appropriate native approach to their role as sources of coping socialization. These findings also underscore the importance of providing information to parents in ways that can be translated to children in developmentally appropriate conversations about viral transmission suppression activities and stress management during disasters.

6.
Biomol NMR Assign ; 15(1): 65-71, 2021 04.
Article in English | MEDLINE | ID: mdl-33159807

ABSTRACT

The international Covid19-NMR consortium aims at the comprehensive spectroscopic characterization of SARS-CoV-2 RNA elements and proteins and will provide NMR chemical shift assignments of the molecular components of this virus. The SARS-CoV-2 genome encodes approximately 30 different proteins. Four of these proteins are involved in forming the viral envelope or in the packaging of the RNA genome and are therefore called structural proteins. The other proteins fulfill a variety of functions during the viral life cycle and comprise the so-called non-structural proteins (nsps). Here, we report the near-complete NMR resonance assignment for the backbone chemical shifts of the non-structural protein 10 (nsp10). Nsp10 is part of the viral replication-transcription complex (RTC). It aids in synthesizing and modifying the genomic and subgenomic RNAs. Via its interaction with nsp14, it ensures transcriptional fidelity of the RNA-dependent RNA polymerase, and through its stimulation of the methyltransferase activity of nsp16, it aids in synthesizing the RNA cap structures which protect the viral RNAs from being recognized by the innate immune system. Both of these functions can be potentially targeted by drugs. Our data will aid in performing additional NMR-based characterizations, and provide a basis for the identification of possible small molecule ligands interfering with nsp10 exerting its essential role in viral replication.


Subject(s)
Magnetic Resonance Spectroscopy , SARS-CoV-2/chemistry , Viral Regulatory and Accessory Proteins/chemistry , Amino Acid Motifs , Carbon Isotopes , Exoribonucleases/chemistry , Hydrogen , Hydrogen Bonding , Ligands , Methyltransferases , Nitrogen Isotopes , Protein Structure, Secondary , RNA, Viral , Viral Envelope , Viral Nonstructural Proteins/chemistry , Virus Replication , Zinc Fingers
7.
Biomol NMR Assign ; 14(2): 339-346, 2020 10.
Article in English | MEDLINE | ID: mdl-32803496

ABSTRACT

The SARS-CoV-2 genome encodes for approximately 30 proteins. Within the international project COVID19-NMR, we distribute the spectroscopic analysis of the viral proteins and RNA. Here, we report NMR chemical shift assignments for the protein Nsp3b, a domain of Nsp3. The 217-kDa large Nsp3 protein contains multiple structurally independent, yet functionally related domains including the viral papain-like protease and Nsp3b, a macrodomain (MD). In general, the MDs of SARS-CoV and MERS-CoV were suggested to play a key role in viral replication by modulating the immune response of the host. The MDs are structurally conserved. They most likely remove ADP-ribose, a common posttranslational modification, from protein side chains. This de-ADP ribosylating function has potentially evolved to protect the virus from the anti-viral ADP-ribosylation catalyzed by poly-ADP-ribose polymerases (PARPs), which in turn are triggered by pathogen-associated sensing of the host immune system. This renders the SARS-CoV-2 Nsp3b a highly relevant drug target in the viral replication process. We here report the near-complete NMR backbone resonance assignment (1H, 13C, 15N) of the putative Nsp3b MD in its apo form and in complex with ADP-ribose. Furthermore, we derive the secondary structure of Nsp3b in solution. In addition, 15N-relaxation data suggest an ordered, rigid core of the MD structure. These data will provide a basis for NMR investigations targeted at obtaining small-molecule inhibitors interfering with the catalytic activity of Nsp3b.


Subject(s)
Adenosine Diphosphate Ribose/metabolism , Apoproteins/chemistry , Betacoronavirus/metabolism , Carbon-13 Magnetic Resonance Spectroscopy , Nitrogen Isotopes/chemistry , Proton Magnetic Resonance Spectroscopy , Viral Nonstructural Proteins/chemistry , Amino Acid Sequence , Apoproteins/metabolism , Protein Domains , Protein Structure, Secondary , SARS-CoV-2 , Viral Nonstructural Proteins/metabolism
8.
Child Psychiatry Hum Dev ; 51(5): 671-682, 2020 10.
Article in English | MEDLINE | ID: mdl-32749568

ABSTRACT

Research confirms that the mental health burdens following community-wide disasters are extensive, with pervasive impacts noted in individuals and families. It is clear that child disaster outcomes are worst among children of highly distressed caregivers, or those caregivers who experience their own negative mental health outcomes from the disaster. The current study used path analysis to examine concurrent patterns of parents' (n = 420) experience from a national sample during the early months of the U.S. COVID-19 pandemic. The results of a multi-group path analysis, organized by parent gender, indicate good fit to the data [X2(10) = 159.04, p < .01]. Results indicate significant linkages between parents' caregiver burden, mental health, and perceptions of children's stress; these in turn are significantly linked to child-parent closeness and conflict, indicating possible spillover effects for depressed parents and compensatory effects for anxious parents. The impact of millions of families sheltering in place during the COVID-19 pandemic for an undefined period of time may lead to unprecedented impacts on individuals' mental health with unknown impacts on child-parent relationships. These impacts may be heightened for families whose caregivers experience increased mental health symptoms, as was the case for fathers in the current sample.


Subject(s)
Burnout, Psychological , Caregivers/psychology , Child Welfare/psychology , Coronavirus Infections , Mental Health/trends , Pandemics , Parent-Child Relations , Parenting/psychology , Pneumonia, Viral , Adult , Anxiety/diagnosis , Anxiety/etiology , Betacoronavirus , Burnout, Psychological/etiology , Burnout, Psychological/prevention & control , Burnout, Psychological/psychology , COVID-19 , Child , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Coronavirus Infections/psychology , Depression/diagnosis , Depression/etiology , Female , Humans , Male , Pandemics/prevention & control , Parents/psychology , Pneumonia, Viral/epidemiology , Pneumonia, Viral/prevention & control , Pneumonia, Viral/psychology , Psychological Distress , SARS-CoV-2 , Social Isolation/psychology
9.
J Food Prot ; 82(7): 1124-1129, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31210546

ABSTRACT

HIGHLIGHTS: Campylobacter levels on chicken neck and breast skin were compared. Neck skin was significantly more contaminated (P < 0.05) than breast skin. No relationship between the two skin types was found for Campylobacter levels. A UK government reduction target for highly contaminated chicken was not achieved.


Subject(s)
Campylobacter , Chickens , Food Microbiology , Meat , Skin , Animals , Campylobacter/physiology , Chickens/microbiology , Cold Temperature , Colony Count, Microbial , Meat/microbiology , Skin/microbiology
10.
Mol Psychiatry ; 23(9): 1970, 2018 09.
Article in English | MEDLINE | ID: mdl-29459796

ABSTRACT

In Figure 1e and f, "F4 control" should be "Cre/tdTomato" and "F4Cre KO" should be "F4Cre/tdTomato". In addition, in the Figure1f legend, the first sentence should end with "(Cre/tdTomato: n = 10, F4Cre/tdTomato: n = 14)".In the 'Materials and Methods' section, under 'Electrophysiology,' the n values for evoked action potential recordings were omitted. The sentence 'For high-frequency stimulus-induced action potentials, the stimulus electrode was placed in the rostral part of VTA and a train of 100 Hz stimuli (1 s) was applied' should end with '(Cre/tdTomato: n=10, F4Cre/tdTomato: n=14).'Later in the same paragraph, in 'For recording evoked EPSCs (Cre/tdTomato, n=13, F4Cre/tdTomato, n=15; AMPA EPSCs were recorded at -70 mV and NMDA EPSCs were recorded at +40 mV)', the phrase 'Cre/tdTomato, n=13, F4Cre/tdTomato, n=15' should be deleted; those n values should have appeared at the end of the later sentence beginning 'Miniature ESPCs...'. The complete, corrected sentence is 'Miniature EPSCs (mEPSCs) were acquired in the presence of 0.5-1 µM TTX and 100 µM picrotoxin and semiautomatically detected by offline analysis using in-house software in Igor Pro (Wavemetrics, Portland, OR, USA) (Cre/tdTomato, n=13, F4Cre/tdTomato, n=15).'Finally, in the 'Materials and Methods' section, third sentence under 'Immunohistochemistry,' information for one TH antibody was omitted. The list of antibodies should end with 'or Millipore MAB5280, 1:1000-1:2000.'

11.
Mol Psychiatry ; 23(5): 1213-1225, 2018 05.
Article in English | MEDLINE | ID: mdl-28194005

ABSTRACT

Midbrain dopamine neurons are crucial for many behavioral and cognitive functions. As the major excitatory input, glutamatergic afferents are important for control of the activity and plasticity of dopamine neurons. However, the role of glutamatergic input as a whole onto dopamine neurons remains unclear. Here we developed a mouse line in which glutamatergic inputs onto dopamine neurons are specifically impaired, and utilized this genetic model to directly test the role of glutamatergic inputs in dopamine-related functions. We found that while motor coordination and reward learning were largely unchanged, these animals showed prominent deficits in effort-related behavioral tasks. These results provide genetic evidence that glutamatergic transmission onto dopaminergic neurons underlies incentive motivation, a willingness to exert high levels of effort to obtain reinforcers, and have important implications for understanding the normal function of the midbrain dopamine system.


Subject(s)
Dopaminergic Neurons/metabolism , Dopaminergic Neurons/physiology , Excitatory Amino Acid Agents/metabolism , Animals , Dopamine/physiology , Learning/physiology , Male , Mesencephalon/metabolism , Mice , Mice, Transgenic , Motivation , Reward , Synaptic Transmission/genetics , Synaptic Transmission/physiology
12.
J Appl Microbiol ; 123(6): 1597-1606, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28948664

ABSTRACT

AIMS: To determine the fate of Escherichia coli on vegetables that were processed through commercial wash treatments and stored under simulated retail conditions at 4°C or wholesale at fluctuating ambient temperatures (0-25°C, dependent on season). METHODS AND RESULTS: Bovine slurry that was naturally contaminated with E. coli O145 was applied without dilution or diluted 1:10 using borehole water to growing potatoes, leeks or carrots. Manure was applied 1 week prior to harvest to simulate a near-harvest contamination event by manure deposition or an application of contaminated water to simulate a flooding event or irrigation from a contaminated water source. At harvest, crops were contaminated at up to 2 log cfu g-1 . Washing transferred E. coli into the water of a flotation tank used for potato washing and did not completely remove all traces of contamination from the crop. Manure-contaminated potatoes were observed to contain 0·72 cfu E. coli O145 g-1 after processing and retail storage. Manure-contaminated leeks harboured 0·73-1·55 cfu E. coli O145 g-1 after washing and storage. There was no cross-contamination when leeks were spray washed. Washing in an abrasive drum resulted in less than perfect decontamination for manure-contaminated carrots. There were five post-distribution isolations from carrots irrigated with contaminated water 24 h prior to harvest. CONCLUSIONS: Standard commercial washing and distribution conditions may be insufficient to reliably control human pathogenic E. coli on fresh produce. SIGNIFICANCE AND IMPACT: Previous speculation that the cause of a UK foodborne disease outbreak was soil from imperfectly cleaned vegetables is plausible.


Subject(s)
Escherichia coli O157/isolation & purification , Food Microbiology , Manure/microbiology , Soil Microbiology , Vegetables/microbiology , Animals , Cattle , Colony Count, Microbial , Crops, Agricultural/microbiology , Daucus carota/microbiology , Disease Outbreaks , Food Contamination/analysis , Food Industry/methods , Humans , Plant Leaves/microbiology , Solanum tuberosum/microbiology
13.
J Appl Microbiol ; 122(5): 1389-1401, 2017 May.
Article in English | MEDLINE | ID: mdl-28258625

ABSTRACT

AIMS: To identify production and processing practices that might reduce Campylobacter numbers contaminating chicken broiler carcasses. METHODS AND RESULTS: The numbers of campylobacters were determined on carcass neck skins after processing or in broiler house litter samples. Supplementary information that described farm layouts, farming conditions for individual flocks, the slaughterhouse layouts and operating conditions inside plants was collected, matched with each Campylobacter test result. Statistical models predicting the numbers of campylobacters on neck skins and in litter were constructed. Carcass microbial contamination was more strongly influenced by on-farm production practices compared with slaughterhouse activities. We observed correlations between the chilling, washing and defeathering stages of processing and the numbers of campylobacters on carcasses. There were factors on farm that also correlated with numbers of campylobacters in litter. These included bird gender, the exclusion of dogs from houses, beetle presence in the house litter and the materials used to construct the house frame. CONCLUSIONS: Changes in farming practices have greater potential for reducing chicken carcass microbial contamination compared with processing interventions. SIGNIFICANCE AND IMPACT OF THE STUDY: Routine commercial practices were identified that were correlated with lowered numbers of campylobacters. Consequently, these practices are likely to be both cost-effective and suitable for adoption into established farms and commercial processing.


Subject(s)
Campylobacter Infections/veterinary , Campylobacter/isolation & purification , Food Contamination/analysis , Meat/microbiology , Poultry Diseases/microbiology , Abattoirs/standards , Animals , Campylobacter/classification , Campylobacter/genetics , Campylobacter Infections/microbiology , Chickens , Colony Count, Microbial , Dogs , Food Microbiology
14.
Lett Appl Microbiol ; 62(4): 299-303, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26797849

ABSTRACT

UNLABELLED: A study was undertaken to simulate the likely effects of a field worker with poor hygienic practices that had returned to work too soon after recovering from an infection by an enteric pathogen. The studies simulated a variety of hand-washing practices from no washing to washing with soap and water followed by an application of alcohol gel after using a field latrine. The numbers of generic Escherichia coli isolated from workers' hands declined with increasing thoroughness of hand-washing treatments with unwashed hands > water > water and soap > water, soap and alcohol gel. Where gloves were worn the counts obtained for the treatments were significantly reduced, but it was observed that unwashed hands contaminated gloves during the process of putting them on. Hand contamination following the use of a field latrine transferred contamination to carrots. These results suggest that if no gloves are worn it would be best practice to wash hands with water and soap and apply alcohol gel after using a field latrine. Wearing gloves reduced the risk of contaminating handled produce but workers should still wash their hands after using a field latrine before applying gloves. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that inadequate hand hygiene in the field following the use of a field latrine can transfer bacterial contamination to hand-harvested carrots. Where fresh produce crops are to be handled by workers, wearing gloves reduces the risk of contaminating produce but workers should still wash their hands after using a field latrine before applying gloves. If no gloves are worn it would be best practice to wash hands with water and soap and apply alcohol gel after using a field latrine.


Subject(s)
Daucus carota/microbiology , Disinfectants/pharmacology , Escherichia coli/isolation & purification , Gloves, Protective/statistics & numerical data , Hand Disinfection/methods , Hand/microbiology , Toilet Facilities , Colony Count, Microbial , Escherichia coli/growth & development , Ethanol/pharmacology , Humans , Soaps
15.
Nature ; 507(7491): 221-4, 2014 Mar 13.
Article in English | MEDLINE | ID: mdl-24622201

ABSTRACT

The ultimate origin of water in the Earth's hydrosphere is in the deep Earth--the mantle. Theory and experiments have shown that although the water storage capacity of olivine-dominated shallow mantle is limited, the Earth's transition zone, at depths between 410 and 660 kilometres, could be a major repository for water, owing to the ability of the higher-pressure polymorphs of olivine--wadsleyite and ringwoodite--to host enough water to comprise up to around 2.5 per cent of their weight. A hydrous transition zone may have a key role in terrestrial magmatism and plate tectonics, yet despite experimental demonstration of the water-bearing capacity of these phases, geophysical probes such as electrical conductivity have provided conflicting results, and the issue of whether the transition zone contains abundant water remains highly controversial. Here we report X-ray diffraction, Raman and infrared spectroscopic data that provide, to our knowledge, the first evidence for the terrestrial occurrence of any higher-pressure polymorph of olivine: we find ringwoodite included in a diamond from Juína, Brazil. The water-rich nature of this inclusion, indicated by infrared absorption, along with the preservation of the ringwoodite, is direct evidence that, at least locally, the transition zone is hydrous, to about 1 weight per cent. The finding also indicates that some kimberlites must have their primary sources in this deep mantle region.

16.
Lett Appl Microbiol ; 57(3): 206-13, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23647008

ABSTRACT

The aims of this study were (i) to determine the prevalence and numbers of campylobacters in 63 samples of raw livers purchased at retail across the UK and (ii) to investigate whether the freezing of chicken livers contaminated with Campylobacter was a reliable method for decontamination. Chicken livers naturally contaminated with campylobacters were subjected to freezing at -15 and -25°C for one day and 7 days. Numbers of campylobacters on the livers were determined immediately before and after a 24-h or 7-days freeze treatment and daily during 3 days post-thaw refrigerated storage. Freezing for 24 h at -25°C can reduce numbers of Campylobacter by up to 2 log10 CFU g(-1). Freezing the livers for 24 h at -25°C, thawing overnight in a fridge set to 4°C and refreezing for another 24 h at -25°C reduced the numbers of campylobacters by up to three logs. Reduction in the numbers of campylobacters was significantly greater following a second freeze treatment compared with a single freeze treatment.


Subject(s)
Campylobacter/isolation & purification , Chickens/microbiology , Food Handling/methods , Freezing , Liver/microbiology , Animals , Colony Count, Microbial , Food Contamination/prevention & control , Food Microbiology , United Kingdom
17.
J Appl Microbiol ; 112(5): 1007-19, 2012 May.
Article in English | MEDLINE | ID: mdl-22372934

ABSTRACT

AIMS: To improve our understanding of the survival and splash-mediated transfer of zoonotic agents and faecal indicator bacteria introduced into soils used for crop cultivation via contaminated irrigation waters. METHODS AND RESULTS: Zoonotic agents and an Escherichia coli marker bacterium were inoculated into borehole water, which was applied to two different soil types in early-, mid- and late summer. Decline of the zoonotic agents was influenced by soil type. Marker bacteria applied to columns of two soil types in irrigation water did not concentrate at the surface of the soils. Decline of zoonotic agents at the surface was influenced by soil type and environmental conditions. Typically, declines were rapid and bacteria were not detectable after 5 weeks. Selective agar strips were used to determine that the impact of water drops 24-87 µl could splash marker bacteria from soil surfaces horizontal distances of at least 25 cm and heights of 20 cm. CONCLUSIONS: Soil splash created by rain-sized water droplets can transfer enteric bacteria from soil to ready-to-eat crops. Persistence of zoonotic agents was reduced at the hottest part of the growing season when irrigation is most likely. SIGNIFICANCE AND IMPACT OF THE STUDY: Soil splash can cause crop contamination. We report the penetration depths and seasonally influenced declines of bacteria applied in irrigation water into two soil types.


Subject(s)
Escherichia coli/physiology , Food Contamination , Fresh Water/microbiology , Soil Microbiology , Zoonoses/microbiology , Agricultural Irrigation , Animals , Feces/microbiology , Humans , Rain
18.
J Appl Microbiol ; 105(3): 848-57, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18422957

ABSTRACT

AIMS: To assess the risks of zoonotic agents in dissemination of livestock wastes into the environment by airborne distribution. To subsequently assess the survival time of zoonotic agents, introduced in irrigation water, on the phylloplane of produce. METHODS AND RESULTS: An Escherichia coli marker was introduced into pig slurry which was spread using a rain gun sprayer. Air sampling was undertaken to determine the distance reached by the marker. No recoveries were observed at a distance of 250 m. Borehole water, contaminated with zoonotic agents, was used to irrigate field plots sown with lettuce and spinach. Decline in bacterial numbers on the phylloplane was observed with time. After initial rapid decreases, we were unable to detect any pathogen from the phylloplane, 1 month after contamination. CONCLUSIONS: These preliminary results suggest that the risks to public health from the aerosolized spread of bacteria during slurry spreading by rain gun are low. Although, zoonotic agents on crop phylloplanes perish quickly, the risks of overhead irrigation of fresh produce 3 weeks before harvest should still be considered. SIGNIFICANCE AND IMPACT OF THE STUDY: These preliminary results improve our understanding on the fate of zoonotic agents in the environment. Spreading liquid livestock wastes by an airborne mechanism may not pose a significant public health risk. Detection of zoonotic agents 3 weeks after contamination of lettuce and spinach means that consideration should be given by the farmers until the time of harvest, when irrigating fresh produce with water that may have been directly or indirectly contaminated by livestock wastes.


Subject(s)
Crops, Agricultural , Food Microbiology , Public Health , Zoonoses/transmission , Agriculture/methods , Air Microbiology , Animal Husbandry/methods , Animals , Colony Count, Microbial , Environmental Monitoring/methods , Escherichia coli Infections/transmission , Escherichia coli O157/isolation & purification , Feces/microbiology , Lactuca/microbiology , Manure/microbiology , Soil Microbiology , Zoonoses/microbiology
19.
Lett Appl Microbiol ; 44(4): 357-63, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17397472

ABSTRACT

AIMS: To determine if the temperatures used in feed manufacture are likely to destroy Escherichia coli O157. METHODS AND RESULTS: Two commercial feeds were ground and inoculated with E. coli O157 cells. The feeds were heated to 50, 55, 60, 65 or 70 degrees C. Heating produced quadratic survivor curves, with rapid initial decreases. The survival characteristics of E. coli O157 differed in the two feeds. The reductions observed in one feed may not have been due to heat alone. There was evidence that indigenous anti-E. coli O157 factor(s) in one feed acted with the heat and contributed to the observed rates of bacterial death. Heating at 70 degrees C for 20 or 120 s resulted in approx. 1.3 and 2.2 log reductions in E. coli O157 numbers respectively. Lesser reductions were observed at lower temperatures. CONCLUSIONS: The time/temperature combinations used in commercial pelleting processes would not effectively kill high numbers of E. coli O157. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to look at the survival of E. coli O157 strains after heat treatment within concentrated animal feed. The study provides information on the likely risk of E. coli O157 surviving the animal feed manufacturing process.


Subject(s)
Animal Feed/microbiology , Escherichia coli O157/physiology , Hot Temperature , Microbial Viability , Animals , Cattle , Colony Count, Microbial , Food Handling
20.
Meat Sci ; 75(3): 523-32, 2007 Mar.
Article in English | MEDLINE | ID: mdl-22063810

ABSTRACT

A survey of a large number of UK abattoirs was conducted via a questionnaire designed to obtain information on (i) throughput and species slaughtered; (ii) construction materials used; (iii) use and type of bedding and (iv) details of cleaning/sanitation regimes. A representative group of abattoirs were selected on the basis of the responses to the questionnaire, and the lairage at these plants investigated through enumeration of Escherichia coli remaining after routine cleansing operations. The aim of this study was to enable identification of "common lairage practices" and to assess the general status of the lairage hygiene and effectiveness of lairage cleaning in commercial UK abattoirs. The study shows that microbial contamination often remains in UK lairage holding pens after routine cleaning operations. It would appear that there are significant differences in the effectiveness of lairage cleaning programmes at commercial abattoirs, and that the stun-box-roll-out areas are often cleaned to a better standard than the holding areas. As a result of persistence of microbial contamination in the lairage, there is a possible risk of foodborne pathogens persisting in the environment and potentially contaminating animals and carcasses processed on subsequent days.

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