The effectiveness of existing and modified cleaning regimens in a Welsh hospital.

Hospital cleaning currently has a high media profile. The effectiveness of an existing ward-cleaning regimen was assessed at selected sites over a 14 day period and shown to be highly variable. The cleaning regimen was subsequently modified in two stages, both changes involving a rinse stage and substituting cloths with disposable paper towels. One modification continued using the existing detergent; the other replaced detergent with a quaternary ammonium sanitiser. Both modifications yielded significantly lower and more consistent bacterial counts. Assessment of residual organic soil using adenosine triphosphate (ATP) detection demonstrated that failure rates (measurements exceeding benchmark clean value of 500 relative light units (RLU)) fell from 86-100% after existing cleaning methods, to 0-14% after modified cleaning. Maximum ATP readings fell from 163,870 to 2289 RLU. Incorporating a quaternary ammonium sanitiser into the cleaning regimen produced a further slight, but not significant, improvement in cleaning efficacy. These findings suggest that simple improvements can be made to existing cleaning regimens to increase their efficacy.

An evaluation of different methods for the recovery of meticillin-resistant Staphylococcus aureus from environmental surfaces.

Although the association between environmental surfaces contaminated with meticillin-resistant Staphylococcus aureus (MRSA) and hospital infection rates is not fully understood, monitoring programmes can provide an objective starting point for the development and assessment of infection control strategies incorporating improved cleaning. There is, however, no universally accepted method for the recovery of MRSA from environmental surfaces, and the aim of this study was to evaluate a selection of currently available methods. Using five clinical isolates of MRSA and seven protocols, known numbers of bacteria were inoculated on to a stainless steel surface and either recovered immediately (without drying or adsorption) or recovered after 30min (with drying at room temperature and adsorption of cells to the surface). Surfaces were either swabbed or sampled directly by contact methods, and four nutritive media (blood, tryptone soya, oxacillin and meticillin-resistant agars) were tested. Relative sampling efficiencies were determined and the sensitivity of each method per 100cm(2) was calculated. Wide variation in the ability to recover MRSA was found between the different protocols. In the recovery of dried (adsorbed) cells, direct contact methods demonstrated higher sampling efficiency than swabs. The sensitivity of all methods was lower in recovering adsorbed cells from surfaces than unadsorbed cells. Sampling methods consistently proved to be more important than the choice of medium. Dipslides coated with selective agar are recommended for recovering MRSA from flat environmental surfaces.

An assessment of food hygiene and safety at farmers' markets.

Farmers' markets are becoming a more significant part of the food-retailing sector. A survey of farmers' markets was conducted to assess aspects of food hygiene and safety. The views of the public using the markets were also examined. The range of farm products was wide and the methods utilised varied. The markets were usually temporary outdoor events with few facilities. Traders had received elementary food hygiene training and rated their hygiene standards highly. Less than half had risk management procedures in place, most did not perceive their produce as high-risk. They believed consumers to be mainly interested in food quality and to regard food safety issues highly. Consumers shopped at the markets because of the quality of the products sold. Their overall satisfaction with the markets was high and they raised no concerns about food safety. Given the restricted facilities at farmers' markets and the early phase of implementation of hygiene management systems by market traders, it may be precautionary to restrict the sale of farm products at farmers markets to those that are regarded as low-risk.

Study of cleaning standards and practices in food premises in the United Kingdom.

A study was undertaken to determine the microbiological status of surfaces used in the preparation of ready-to-eat foods, and to assess cleaning standards and practices in food premises in the UK. A total of 6,533 environmental samples were examined from 1,502 catering (such as restaurants, cafés, and sandwich bars) or retail premises (such as butchers, delicatessens, and bakers): 2,033 samples from chopping/cutting boards, 2,009 from worktop surfaces, 1,359 from food containers, and 1,132 from cleaning cloths. Cleaning cloths were more heavily contaminated with bacteria (Aerobic Colony Count (ACC), Enterobacteriaceae, E. coli, and Staph. aureus) compared to surfaces sampled. Campylobacter spp. were detected in two (0.2%) and Salmonella spp. from one (0.1%) of the cleaning cloths. Surfaces that were visually dirty, wet, last cleaned over 24 hours ago, and boards that were scored or damaged were found to have higher levels of bacteria. A hazard analysis system was in place in most (70%) food premises visited, and in 52% it was documented. Most managers (89%) had received some form of food hygiene training. Documented cleaning schedules and cleaning records were only present in approximately half (55% and 44%, respectively) of the premises. Most did not have separate implements for cleaning raw and ready-to-eat food areas (67%), or stored cleaning equipment for high risk (ready-to-eat food) areas away from those used in low risk (raw, non ready-to-eat food) areas (70%). Deficiencies in the correct use of cleaning products, such as the minimum contact time for disinfectants, were identified. Surface samples (chopping/cutting boards, worktops, and food containers) and cleaning cloths with ACC levels in excess of 10(3) cfu/cm2, swab or ml were associated with premises that did not have management food hygiene training, hazard analysis, cleaning schedules or cleaning records in place, and with little or no confidence in the food business management of food hygiene as indicated by Local Authority Inspectors' Confidence in Management scores.

Incidence of Campylobacter and Salmonella isolated from retail chicken and associated packaging in South Wales.

AIMS: To investigate the incidence of Campylobacter and Salmonella contamination associated with supermarket and butchers' shop chicken and related packaging. METHOD AND RESULTS: Three hundred raw samples (whole chicken, chicken breast with skin or chicken pieces) were purchased on a monthly basis for seven months. Packaging associated with the chicken was also sampled to provide isolation data for external and whole packaging. Campylobacter and Salmonella were isolated from 68% and 29% of retail chicken, respectively. Campylobacter was isolated from 3% of external and 34% of whole packaging overall. Salmonella was absent from external packaging but was isolated from 11% of whole packaging. No significant trends in isolation rates of the organisms were obtained during the period of sampling. CONCLUSIONS: The food industry and consumers should be made aware of the potential risk of Campylobacter and Salmonella on both the external and internal surfaces of packaging in addition to chicken itself. SIGNIFICANCE AND IMPACT OF THE STUDY: Chicken and chicken packaging is a potential vehicle for the introduction of pathogens in retail and domestic kitchens and in particular for the cross-contamination of Campylobacter and Salmonella.

An assessment of cleaning regimes and standards in butchers' shops.

Cleaning regimes and standards in retail butchers taking part in the Accelerated HACCP project initiative, were assessed by means of visual inspection, examination of cleaning schedules and ATP bioluminescence assays of selected food and hand contact sites. There was a wide variation in surface ATP results, both within and between butchers' shops, but overall they indicated that food and hand contact surfaces were heavily soiled during food production and service. Although separate preparation equipment/utensils were provided, staff undertook raw and cooked product handling throughout the day, with the concomitant danger of contaminating hand and food contact surfaces. The extent of soiling was generally underestimated when assessed visually, the technique used most commonly by the food retail trade and inspection authorities. Periodic or interim cleaning practices produced a significant improvement in cleanliness assessed visually and with ATP assay; however, these results were generally less satisfactory than those obtained by the use of best practice protocols. A lack of written cleaning schedules and records, training in the correct use of cleaning products and awareness of the importance of cleaning hand contact sites were identified as common defects. The results are discussed in relation to the establishment of an effective HACCP system and recommendations for improving cleaning standards are given.

An evaluation of hospital cleaning regimes and standards.

A four-part study assessing cleanliness in up to 113 environmental surfaces in an operating theatre and a hospital ward is reported. Surfaces were assessed visually, using microbiological methods and ATP bioluminescence. Results from a preliminary random survey indicated variability in cleanliness. These results were then used to select sites for monitoring before and after routine cleaning, over a 14-day period. Using published microbiological and ATP specifications 70 and 76% of these sites were unacceptable after cleaning. Visual assessment was a poor indicator of cleaning efficacy with only 18% considered unacceptable. Sites most likely to fail in the ward were in the toilet and kitchen, areas which are frequently implicated in the spread of infectious intestinal disease. Operating theatre sites had lower ATP results but 61% of sites would be considered unacceptable. There was no significant difference in general microbiological or ATP results overall before and after routine cleaning. Although some important hand contact sites showed no significant difference, overall there was a significant decrease in staphylococcal and enterobacteria counts in the ward but not in the operating theatre after cleaning. The routine cleaning programmes used did not include a biocide and cleaning using a hypochlorite based sanitizer gave much lower values. The results are discussed in relation to infection control, cleaning audits and cleaning schedules: an integrated cleaning monitoring programme using ATP bioluminescence in conjunction with visual and microbiological assessments is recommended.

Evaluation of two methods for monitoring surface cleanliness-ATP bioluminescence and traditional hygiene swabbing.

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.

Food hygiene and hazard analysis critical control point in the United Kingdom food industry: practices, perceptions, and attitudes.

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.

Breathing pattern awake and asleep in patients with myotonic dystrophy.

Patients with myotonic dystrophy often have an irregular pattern of breathing at rest, implying abnormality of breathing control. No central medullary defect has been found in such patients. We postulated that irregular breathing in myotonic dystrophy due to abnormal central respiratory output would persist during slow-wave sleep. We examined the patterns of breathing whilst awake and asleep in seven patients with myotonic dystrophy, seven similarly weak nonmyotonic subjects and seven normal controls. Polysomnography was performed, and the coefficients of variation (CoV) of the breath intervals were analysed during different stages of sleep. The myotonic group showed significantly greater variation in breath intervals than the other two groups whilst awake (median CoV 37 vs 18% for nonmyotonics) and during light sleep (31 vs 13%). This difference was not evident during slow-wave sleep (median CoV 12 vs 9% in nonmyotonic). We conclude that irregular breathing in patients with myotonic dystrophy whilst awake and during light sleep, does not persist during slow-wave sleep. These results suggest that "behavioural" influences play a role in the abnormal breathing pattern found in myotonic dystrophy. The source of the irregular breathing is unlikely to be found in the medulla, but may originate from forebrain influences.

Purification of the N,N'-dicyclohexylcarbodiimide-binding proteolipid of a higher plant tonoplast H+-ATPase.

The H+-ATPase of Beta vacuolar membrane (tonoplast) comprises at least three functionally distinct subunits of Mr = 67,000, 57,000, and 16,000, respectively (Manolson, M. F., Rea, P. A., and Poole, R. J. (1985) J. Biol. Chem. 260, 12273-12279). The hydrophobic carboxyl reagent N,N'-dicyclohexylcarbodiimide (DCCD) inactivates the enzyme with pseudo-first order kinetics, and the concentration dependence of the reaction indicates that DCCD interacts with a single site on the enzyme to exert its inhibitory effect. The apparent pseudo-first order rate constant (k0) is reciprocally dependent on membrane protein concentration, which is expected if a large fraction of the DCCD partitions into the lipid phase. k0 has a nominal value of 1000 M-1 min-1 at a protein concentration of 250 micrograms/ml, although when phase partitioning is taken into account, the true, protein concentration-independent value of k0 is calculated to be about an order of magnitude lower. [14C]DCCD primarily labels the Mr = 16,000 polypeptide of native tonoplast vesicles. Binding is venturicidin-insensitive and occurs at a rate similar to the rate of enzyme inactivation, implying that inhibition is a direct result of covalent modification of the Mr = 16,000 polypeptide. Labeling of the containing Mr = 8,000 subunit of mitochondrial F0F1-ATPase is, on the other hand, faster by a factor of 5 and totally abolished by venturicidin. These results confirm that the Mr = 16,000 polypeptide which copurifies with tonoplast H+-ATPase activity is a subunit of the enzyme. Most of the DCCD-reactive Mr = 16,000 subunit is extracted from acetone:ethanol-washed tonoplast vesicles by chloroform:methanol. [14C]DCCD bound to the Mr = 16,000 polypeptide is enriched in the chloroform:methanol extract by 5-fold compared with native tonoplast and the specific activity (nmol of [14C]DCCD/mg of protein) can be increased a further 37-fold by chromatography on DEAE-Sephadex. It is concluded that the Mr = 16,000 subunit of the tonoplast H+-ATPase is a proteolipid.

Mechanism of Stimulation and Inhibition of Tonoplast H-ATPase of Beta vulgaris by Chloride and Nitrate.

The H(+)-ATPase of tonoplast vesicles isolated from red beet (Beta vulgaris L.) storage tissue was studied with respect to the kinetic effects of Cl(-) and NO(3) (-). N-Ethylmaleimide (NEM) was employed as a probe to investigate substrate binding and gross conformational changes of the enzyme. Chloride decreased the K(m) of the enzyme for ATP but caused relatively little alteration of the V(max). Nitrate increased K(m) only. Michaelis-Menten kinetics applied throughout with respect to ATP concentration. Nitrate yielded similar kinetics of inhibition in both the presence and absence of Cl(-). Other monovalent anions that specifically increased the K(m) of the ATPase for ATP were, in order of increasing K(i), SCN(-), ClO(4) (-), and ClO(3) (-). Sulfate, although inhibitory, manifested noncompetitive kinetics with respect to ATP concentration. ADP, like NO(3) (-), was a competitive inhibitor of the ATPase but ADP and NO(3) (-) did not interact cooperatively nor did either interfere with the inhibitory action of the other. It is concluded that NO(3) (-) does not show competitive kinetics because of its stereochemical similarity to the terminal phosphoryl group of ATP. NEM was an irreversible inhibitor of the tonoplast ATPase. Both Mg.ADP and Mg.ATP protected the enzyme from inactivation by NEM but Mg.ADP was the more potent of the two. Chloride and NO(3) (-) exerted little or no effect on the protective actions of Mg.ADP and Mg.ATP suggesting that neither Cl(-) nor NO(3) (-) are involved in substrate binding.