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Biomedical subjects

C L Little

Publications and source records attributed to C L Little.

33 records · Page 2Linked to original sources
PubMed2001

The microbiological examination of ready-to-eat organic vegetables from retail establishments in the United Kingdom.

AIMS: A microbiological study of uncooked ready-to-eat organic vegetables was undertaken to determine the microbiological quality of these vegetables on retail sale in the UK. METHODS AND RESULTS: Organic vegetables were collected and examined according to a standardized protocol. The majority (3185 of 3200; 99.5%) of samples were found to be of satisfactory/acceptable quality whilst only 15 (0.5%) were of unsatisfactory quality. Unsatisfactory results were due to Escherichia coli and Listeria spp. (not L. monocytogenes) levels in excess of 102 cfu g-1. CONCLUSIONS: The absence of pathogens (L. monocytogenes, Salmonella, Campylobacter and E. coli O157) and the low incidence (1.5%) of E. coli and Listeria spp. associated with these organic vegetables indicates that overall agricultural, hygiene, harvesting and production practices were good. SIGNIFICANCE AND IMPACT OF THE STUDY: There has been a significant expansion of the UK organic market since 1998/99. Of the various commodity sectors making up the organic market, fruit and vegetables is the largest sector and this has been reflected in an increased interest in their microbiological safety. This is the first study to provide information on the microbiological quality of organic vegetables.

Colony Count, Microbial↗
PubMed2001

Microbiological examination of ready-to-eat quiche from retail establishments in the United Kingdom.

A microbiological study of ready-to-eat quiche from retail establishments was undertaken to identify risk factors in the production, storage and handling of quiche and to establish their effect on microbiological quality. Examination of cold ready-to-eat quiche from supermarket and other delicatessens, bakers, butchers, cafés, sandwich bars and other retail premises revealed that most (2354 of 2513; 94%) were of acceptable quality; 157 samples (6%) were of unsatisfactory quality and two (< 1%) were unacceptable. Unsatisfactory results were mostly due to high aerobic colony counts. Unacceptable results were due to high levels (> 10(4) cfu/g) of Escherichia coli in two samples. Salmonella spp. were not detected in any of the samples. Satisfactory microbiological quality of ready-to-eat quiche was associated with premises that had management food hygiene training and hazard analysis in place. The microbiological quality of this food was also associated with premises type, quiche type, slicing and serving methods, and existing Local Authority Inspectors' Consumer at Risk scores.

Communicable Disease Control↗
PubMed2001

Microbiological examination of ready-to-eat burgers sampled anonymously at the point of sale in the United Kingdom.

During May and June 1999 a microbiological study of ready-to-eat burgers purchased anonymously from burger outlets (combined take-away and burger restaurants, take-away-only fixed premises, mobile vendors, temporary stalls and other burger outlets) was undertaken. The intention was to determine the microbiological quality of ready-to-eat burgers as purchased by customers of take-away premises and to ascertain, where information was available, whether the Chief Medical Officer's advice on cooking burgers was being followed. Examination of 3,128 ready-to-eat burgers found that 2,868 (92%) were of acceptable quality and 260 (8%) were of unsatisfactory quality. Unsatisfactory results were mostly due to high aerobic colony counts (ACCs). Salmonella spp., Campylobacter spp. and Escherichia coli O157 were not detected in any of the samples examined. Acceptable microbiological quality of ready-to-eat burgers was associated with outlets, such as combined take-away and burger restaurants and in particular national franchise outlets, which had management food hygiene training and hazard analysis in place. Poor microbiological quality was associated with undercooking and local outlets as indicated by Local Authority Inspectors' Consumers at Risk scores.

Bacteria↗
PubMed1999

Health risks associated with unpasteurized goats' and ewes' milk on retail sale in England and Wales. A PHLS Dairy Products Working Group Study.

A pilot study to determine the microbiological quality of unpasteurized milk from goats and ewes sampled from farm shops, health food shops, and other retail premises found that 47%, (47/100) of goats' and 50% (13/26) of ewes' milk samples failed the standards prescribed by the Dairy Products (Hygiene) Regulations 1995. In addition, Staphylococcus aureus, haemolytic streptococci or enterococci, were present in excess of 10(2) c.f.u./ml in 9 (7 %) 2 (2 %) and 19 (15%) samples, respectively. Salmonella, campylobacter, verocytotoxin-producing Escherichia coli O157:H7 and Listeria monocytogenes were not detected in the samples. At the time of purchase approximately half of the milk samples (58 %) were frozen, the rest were liquid. Farm outlets sold predominantly liquid milk, other retail premises sold a frozen product. The microbiological quality of goats' and ewes' milk, whether frozen or liquid, was not significantly different. Milk sold from farm shops was of lower quality than that from health food shops and other retail premises. In this pilot study most producers (92 %) supplied, and most retailers (76 %) sold unpasteurized goats' and ewes' milk that contained unacceptable levels of indicator organisms. The study was carried out during the winter when goats' milk production is reduced. The results indicate the need for a full representative study of unpasteurized goats' and ewes' milk on retail sale throughout the year.

Animals↗
PubMed1999

The microbiological quality of cooked rice from restaurants and take-away premises in the United Kingdom.

The microbiological quality of 4,162 samples of cooked rice from restaurants and take-away premises in the United Kingdom was examined, including ready-to-eat rice purchased at point-of-sale and rice that was stored precooked for reheating on demand. The majority of point-of-sale cooked rice samples (1,855 of 1,972; 94%) were of acceptable microbiological quality, but 15 (1%) samples were of unacceptable quality (Bacillus spp. and B. cereus, > or = 10(5) CFU/g; Escherichia coli, > or = 10(4) CFU/g), indicating a potential risk to health. The prevalence of Bacillus spp., B. cereus, and E. coli was significantly greater in precooked stored rice than in point-of-sale cooked rice (P < 0.005 to 0.0005). Bacillus spp. (> or = 10(4) CFU/g), B. cereus (> or = 10(4) CFU/g), and E. coli (> or = 10(2) CFU/g) were present in 7%, 2%, and 9% of precooked stored samples, respectively, compared to 2%, 0.5%, and 1%, respectively in point-of-sale samples. Although final heating at the point of sale reduces the levels of microorganisms present in rice it will not inactivate the B. cereus emetic toxin if present. Rice from Indian premises was of poorer microbiological quality than that from Chinese and other premises. Although most point-of-sale cooked rice samples (94%) were of an acceptable microbiological quality, evidence from this study indicates that the microbiological quality of cooked rice sold from certain outlets in the UK is of concern.

Bacillus↗
PubMed1998

The microbiological examination of butchery products and butchers' premises in the United Kingdom.

In a study of 1400 manufacturing butchers' premises, 2330 raw prepared meats, 2192 cooked meats and 4635 environmental samples were examined. Verocytotoxin-producing Escherichia coli O157:H7 (O157 VTEC) was isolated from five of 1400 (0.4%) premises. Three raw meat products contained O157 VTEC, and two raw meat preparation areas and two items of equipment used exclusively for cooked meats were contaminated with O157 VTEC. Salmonella spp. and Campylobacter spp. were detected in 84 of 2330 (4%) and 15 of 2330 (0.6%) raw meat products, respectively. Of the cooked meats examined, seven of 2192 (0.3%) samples were of unacceptable microbiological quality and a further 352 (16%) were of unsatisfactory quality. Of the unacceptable samples, two contained Salmonella spp. (Salm. typhimurium DT193, Salm. typhimurium PT104), three contained Staphylococcus aureus in excess of 10(4) cfu g-1, and two contained E. coli in excess of 10(4) cfu g-1. Neither Campylobacter spp. nor O157 VTEC were detected in cooked meats. In the majority of premises, raw and unwrapped cooked meat products were physically separated in displays (94%) and refrigerators (81%), and dedicated equipment/utensils (69-89%) were used for raw meat and unwrapped cooked meat products and other ready-to-eat foods. In approximately half (48%), there were separate serving counters and in 13%, separate staff for raw and cooked meats. Most managers (75%) had received some food hygiene training. However, in 29% of premises, one or more members of staff handled raw and then cooked or ready-to-eat foods without washing their hands, and in 11%, one or more staff members handled raw and cooked meats directly with bare hands. A documented hazard analysis and critical control point (HACCP) system was present in 17% of premises and in a further 31%, an undocumented HACCP system was in place. The low incidence of food-borne pathogens in cooked meat products and in the environmental areas examined, together with a high level of physical separation of raw and cooked meats, indicate that most manufacturing butchers' premises have appropriate physical control measures in place. However, HACCP and hygienic practice are areas that require improvement to reduce the risk of cross-contamination with food-borne pathogens from raw to cooked meats.

Campylobacter↗
PubMed1994

Application of a log-logistic model to describe the survival of Yersinia enterocolitica at sub-optimal pH and temperature.

A log-logistic model previously used to describe the thermal inactivation of microorganisms has been applied to predict accurately the survival of Yersinia enterocolitica under conditions of sub-optimal temperatures (0-23 degrees C) and growth inhibitory pH values for a number of different acidulants. Predictions from the model were also compared to observed survival times of Y. enterocolitica in mayonnaise and were found to be in excellent agreement. However in yoghurt the model overestimated survival of this organism at both 20 and 4 degrees C but would 'fail safe' if used for predictive purposes. The discrepancy in yoghurt is discussed.

Food Microbiology↗
PubMed1994

Growth and survival of Yersinia enterocolitica, Salmonella and Bacillus cereus in Brie stored at 4, 8 and 20 degrees C.

The potential of stabilised Brie to support growth of the food-borne pathogens, Yersinia enterocolitica serotypes 0:3 and 0:9, Salmonella typhimurium, S. dublin (both dairy isolates), S. thompson, and Bacillus cereus (3 dairy isolates), after contamination on opening the cheese package was evaluated. Growth kinetics of the different pathogens was determined in relation to inoculum size and storage temperature (4 degrees C, 8 degrees C and 20 degrees C). Only Y. enterocolitica was found to grow on the surfaces (outer and exposed) of Brie at all three storage temperatures. Growth of this pathogen during refrigerated storage must be avoided to ensure safety. The numbers of B. cereus and Salmonella increased at 20 degrees C but declined at a slow rate during storage at 4 degrees C and 8 degrees C. However, survival of these two pathogens for extended periods at abuse temperatures could pose a health hazard. Predictions from a predictive modelling program (MFS model) and a modelling database (Food Micromodel) were compared to observed growth values in Brie. Although accurate in the case of B. cereus at 20 degrees C, predicted generation times were in general found to be considerably shorter than the observed values, i.e., overall they were 'fail safe'. Predicted lag times, however, were generally longer compared to observed values in the case of Y. enterocolitica and at low inocula for Salmonella, and would 'fail dangerous' if used for predictive purposes.

Bacillus cereus↗
PubMed1994

Mathematical modelling of the growth, survival and death of Yersinia enterocolitica.

This paper discusses the development of a novel mathematical equation capable of handling the growth, survival and death of microorganisms. The equation was used in combination with second-order polynomials to fit a response surface to data representing the growth, survival and death of Yersinia enterocolitica as affected by temperature (0-30 degrees C), sodium chloride (0-10.5% w/v), pH (3.5-7.0) and undissociated lactic acid (0-9.63 g/l). The resulting predictive model showed a good correlation over the entire range of the experimental data. Predictions from the model have been compared with independent data from both published literature and inoculated food studies. Analysis of the results showed a good correlation, particularly for data from milk and meat products.

Hydrogen-Ion Concentration↗
PubMed1991

Modelling the effect of pH, acidulant and temperature on the growth rate of Yersinia enterocolitica.

Growth of two pathogenic and one environmental serotype of Yersinia enterocolitica under acidic conditions and at 4 and 25 degrees C was investigated. At both temperatures the maximum growth inhibitory pH depended on the acidulant used and was in the order acetic greater than lactic greater than citric greater than sulphuric. At the lower temperature the maximum growth inhibitory pH was 0.3-0.5 pH units higher than at 25 degrees C. No difference was observed between the behaviour of pathogenic and environmental serotypes in this respect. Measurement of growth at a number of sub-optimal temperatures and pH values showed that the variation of growth rate with temperature could be represented by a square root plot. The effect of different pH values could be incorporated into the model by replacing the regression coefficient b by its relationship with pH. Values of maximum growth inhibitory pH derived from the model were in good agreement with experimental values with the exception of acetic acid.

Acetates↗
PubMed1987

External ventricular drainage for initial treatment of neonatal posthemorrhagic hydrocephalus: surgical and neurodevelopmental outcome.

Thirty-seven infants were treated for posthemorrhagic hydrocephalus (PHH) with external ventricular drainage (EVD) in 1977-1985. The mean age at EVD placement was 13 days; the mean duration of drainage was 21 days, and an average of 1.8 drains was used per patient. Complications were apnea (10%), hemorrhage (8%) and ventriculitis (6%). Ten infants died from pulmonary disease unrelated to the surgery. Thirty-two percent of the survivors did not require a permanent shunt. Neurodevelopmental outcome was evaluated at a mean age of 38 months. Eighteen of the twenty-seven survivors (67%) had normal cognitive function, 3 had borderline and 6 (22%) had moderate to profound mental retardation. Nine of the children (33%) had a normal neuromuscular exam. One child had mild, 11 had moderate and 6 had severe cerebral palsy. Four children had serious visual impairment. The worst outcomes were in the children with parenchymal or large intraventricular hemorrhages.

Cerebral Hemorrhage↗
PubMedDate not supplied

Evaluation of a 20 minute 14C urea breath test for the diagnosis of Helicobacter pylori infection.

The use of 14C-urea breath testing for diagnosis of Helicobacter pylori infection in gastric mucosa has gained widespread acceptance and utilisation. We evaluated a 14C urea breath test (UBT) in 116 patients undergoing endoscopy. Seventy four patients were administered 185 kBq (5 mCi-conventional dose), and 42 patients reduced dose (92.5 IBq, 2.5 mCi) of 14C-urea. All were tested for H. pylori using culture, direct microscopy of gastric biopsies and histological evaluation of paraffin stained sections. Using the mean + three standard deviations as the cut-off value, a sensitivity of 96% and specificity of 100% was found for the conventional dose test. At reduced dose, sensitivity was 100% and specificity 96%. Positive and negative predictive values were 100% and 93% for the conventional dose test, and 96% and 100% for testing at reduced dose. We conclude that the UBT is a simple, non-invasive and useful diagnostic alternative for detection of H. pylori in infected patients. We advocate its use in patients less than 45 years of age without alarm symptoms, and also in cases where the need for endoscopic evaluation is not vital, such as after eradication therapy.

Adult↗