Christopher J. Griffith
Cardiff Metropolitan University
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Publication
Featured researches published by Christopher J. Griffith.
Journal of Hospital Infection | 2008
T. Lewis; Christopher J. Griffith; M. Gallo; M. Weinbren
Hospital cleaning continues to attract patient, media and political attention. In the UK it is still primarily assessed via visual inspection, which can be misleading. Calls have therefore been made for a more objective approach to assessing surface cleanliness. To improve the management of hospital cleaning the use of adenosine triphosphate (ATP) in combination with microbiological analysis has been proposed, with a general ATP benchmark value of 500 relative light units (RLU) for one combination of test and equipment. In this study, the same test combination was used to assess cleaning effectiveness in a 1300-bed teaching hospital after routine and modified cleaning protocols. Based upon the ATP results a revised stricter pass/fail benchmark of 250 RLU is proposed for the range of surfaces used in this study. This was routinely achieved using modified best practice cleaning procedures which also gave reduced surface counts with, for example, aerobic colony counts reduced from >100 to <2.5 cfu/cm(2), and counts of Staphylococcus aureus reduced from up to 2.5 to <1 cfu/cm(2) (95% of the time). Benchmarking is linked to incremental quality improvements and both the original suggestion of 500 RLU and the revised figure of 250 RLU can be used by hospitals as part of this process. They can also be used in the assessment of novel cleaning methods, such as steam cleaning and microfibre cloths, which have potential use in the National Health Service.
Luminescence | 1999
C. A. Davidson; Christopher J. Griffith; Adrian C. Peters; L. M. Fielding
The minimum bacterial detection limits and operator reproducibility of the Biotrace Clean-Tracetrade mark Rapid Cleanliness Test and traditional hygiene swabbing were determined. Areas (100 cm2) of food grade stainless steel were separately inoculated with known levels of Staphylococcus aureus (NCTC 6571) and Escherichia coli (ATCC 25922). Surfaces were sampled either immediately after inoculation while still wet, or after 60 min when completely dry. For both organisms the minimum detection limit of the ATP Clean-Tracetrade mark Rapid Cleanliness Test was 10(4) cfu/100 cm2 (p < 0.05) and was the same for wet and dry surfaces. Both organism type and surface status (i.e. wet or dry) influenced the minimum detection limits of hygiene swabbing, which ranged from 10(2) cfu/100 cm2 to >10(7) cfu/100 cm2. Hygiene swabbing percentage recovery rates for both organisms were less than 0.1% for dried surfaces but ranged from 0.33% to 8.8% for wet surfaces. When assessed by six technically qualified operators, the Biotrace Clean-Tracetrade mark Rapid Cleanliness Test gave superior reproducibility for both clean and inoculated surfaces, giving mean coefficients of variation of 24% and 32%, respectively. Hygiene swabbing of inoculated surfaces gave a mean CV of 130%. The results are discussed in the context of hygiene monitoring within the food industry.
Letters in Applied Microbiology | 2001
W.A. Harrison; Christopher J. Griffith; D. Tennant; Adrian C. Peters
Aims: To investigate the incidence of Campylobacter and Salmonella contamination associated with supermarket and butchers’ shop chicken and related packaging.
British Food Journal | 2004
Elizabeth C. Redmond; Christopher J. Griffith; Jenny Slader; Tom J. Humphrey
The use of an observational approach in conjunction with isolation techniques for campylobacter and salmonella detection has facilitated a detailed evaluation of the risk of cross contamination during food preparation. Identification of suspected exposure routes has linked naturally contaminated raw foods with important food‐handling malpractices, contaminated contact surfaces and ready‐to‐eat foods. In a model domestic kitchen, 29 per cent of food preparation sessions resulted in positive campylobacter isolations from prepared salads, cleaning materials and food‐contact surfaces. Typing results showed that specific campylobacter strains isolated from prepared chicken salads were the same as the strains isolated from the raw chicken pieces, indicating microbial transfer during food preparation. Data obtained from this study can be used for exposure assessment, risk management and in the development of consumer risk communication strategies.
British Food Journal | 2004
Deborah A. Clayton; Christopher J. Griffith
Observations of food handlers’ practices have many uses. Describes the use of a notational analysis technique to monitor and analyse specific food safety actions of caterers. A total of 115 food handlers from 29 catering businesses were observed carrying out 31,050 food preparation and hygiene actions in their workplace. Notational analysis was found to offer little advantage, compared to traditional observation methods. However, this technique did allow tracking of sequential events and was successful in identifying and recording a greater number of cross‐contamination events than would have been highlighted using traditional approaches. The results demonstrated that, based on hygiene guidelines, food handlers were required to implement de‐contamination actions on a large number of occasions. These de‐contamination actions were frequently inadequately conducted. To improve standards of food hygiene in catering there is a need to minimise the requirements for de‐contamination activities thereby reducing the potential for cross‐contamination.
International Journal of Environmental Health Research | 2002
Ginny Moore; Christopher J. Griffith
A rapid, instrument-free, hygiene monitoring system, based on protein detection, was assessed as a means to evaluate the cleanliness of food contact surfaces within four different food processing environments. Its performance was compared to that of both ATP bioluminescence and a traditional agar-based microbiological method. Each surface was sampled using all three hygiene monitoring systems both before and after each of the production plants had carried out their normal cleaning procedures. In both cases, there was a significant difference ( p < 0.05) between the number of surfaces that were passed or failed using each of the tests. In general the number of surfaces that were deemed acceptable for food production increased after cleaning but the level of agreement between test methods differed depending on the type of production facility sampled. Protein detection was most likely to fail surfaces within the baking facility, whereas ATP bioluminescence and traditional microbiology were most likely to fail surfaces within a frozen ready-meal and a cheese production unit respectively. The implications of these results are discussed in relation to plant trials of hygiene monitoring systems, the cleaning process itself, failures in disinfection, as well as the need for a combined methodological approach for monitoring cleanliness.
Journal of Food Protection | 2000
Ginny Moore; Christopher J. Griffith; Adrian C. Peters
The efficacy of ozone as a terminal disinfectant was evaluated under laboratory conditions. Different microorganisms of importance to the food industry were inoculated onto stainless steel squares and incubated at various temperatures and relative humidities for up to 4 h. Survival of microorganisms from these controls was compared with identically incubated squares exposed to ozone. Exposure of the contaminated surfaces to ozone (2 ppm for 4 h) resulted in a reduction in microbial viability that ranged, depending on organism type, from 7.56 to 2.41 log values. For all the microorganisms tested, this loss in viability was significantly greater (P < 0.05) than that observed in the absence of ozone. Gram-negative bacteria were more sensitive to ozone than gram-positive organisms; bacteria were more sensitive than the yeast strain tested. Exposure to ozone (2 ppm for 4 h) in the presence of ultra-high temperature (UHT) milk resulted in a reduction in bacterial viability that ranged from 5.64 to 1.65 log values. In most cases, this reduction was significantly less (P < 0.05) than that achieved in the absence of organic material, although still significantly greater (P < 0.05) than that observed in the absence of ozone. The presence of a meat-based broth reduced the effectiveness of ozone to a greater extent, although the number of surviving gram-negative organisms was still significantly less (P < 0.05) than in the absence of ozone. Less than 1 log unit of yeast cells was destroyed when exposed to ozone in the presence of UHT milk or meat-based broth. Results of this investigation suggest that if applied after adequate cleaning ozone could be used as an effective disinfectant.
Journal of Food Protection | 1999
Matthew P. Mortlock; Adrian C. Peters; Christopher J. Griffith
A mail survey was designed and distributed to 1,650 managers of food businesses across the manufacturing, retail, and catering sectors of the United Kingdom food industry. Respondents were asked about the food hygiene practices of their business, their use of systems such as hazard analysis critical control point (HACCP), and their attitudes toward a range of food hygiene-related issues. Complete responses were received from 254 businesses, a response rate of 15.3%. The results showed that 69% of manufacturers were using HACCP systems, significantly more than the 13% and 15% in the retail and catering sectors, respectively (P < 0.05); 53% of manufacturing, 59% of retail, and 48% of catering managers thought that their business represented a low risk to food safety. Among businesses using HACCP, specific training in the system was significantly related to the likelihood that businesses had adopted all seven of the HACCP principles (P < 0.05). Business size was a significant factor in the use of HACCP in both the manufacturing and retail sectors. Higher levels of food hygiene qualifications among business managers, business status, and higher perceptions among managers of the risk to food safety of the business were also significantly related to HACCP use in all sectors (P < 0.05). The results from this survey have implications for the future development of HACCP, particularly within the UK retail and catering sectors. Risk communication and training are highlighted as areas of concern for marketing HACCP within these industry sectors.
Journal of Food Protection | 1997
Denise Worsfold; Christopher J. Griffith
An evaluation of the food safety behavior of 108 consumers was conducted by means of an HACCP-based audit. The method employed direct observation and temperature measurement linked to a standardized risk-based scoring system based on epidemiological data. A food operation risk (FOR) score was allocated to each consumer and was based on the demerit points awarded for the violation or absence of recommended control or preventative measures, Temperature abuse during food transport and storage was exhibited by more than 40% of people. A great potential for indirect and direct cross-contamination during the preparation of food was identified. Safe cooking practices were used by the majority of consumers, however, more than half of the sample cooked well in advance of consumption and few used any method to speed the cooling of cooked food. Some consumers used potentially unsafe practices such as holding cooked food at ambient temperatures for prolonged periods and inadequate reheating. Expressed as a percentage, the FOR scores ranged from 0 to 65% with over half of the subjects (58%) scoring below 20%.
Food Control | 1998
Christopher J. Griffith; Denise Worsfold
An observational method for estimating the risk of food poisoning following domestic food preparation is described. A total of 108 consumers prepared one of four recipes and the results are of use in risk assessment. Whilst some consumers (4.6%) fully implemented appropriate food safety control measures, 3.7% prepared food in a way which seriously violated critical control points and exposed them to a high level of risk. The vast majority of consumers (95.4%) failed to implement one or more basic hygiene practices due to lack of knowledge or failure to implement known food safety procedures. Some of these meals could have posed a risk of food poisoning if eaten. The findings have implications for when and how food hygiene is taught and if extrapolated to food preparation in general indicates a potential for further increases in food poisoning notifications. The results are discussed within the context of risk communication.