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PubMed2001

Comparative soil sampling in the Dornach site (Switzerland) for soil three-dimensional pollution description.

Fifteen institutions from 13 European countries and Switzerland participated in a comparative test sampling at the Dornach site, near Basel in Switzerland. They received the site description and were asked to develop their own sampling plans, based on their national guidelines for a three-dimensional description of the Pb, Zn, Cu and Cd pollution, with a maximum of 15 samples. The comparative sampling test took place in late August 1997. The sampling plans and records, provided by the participants, were compared and evaluated in terms of sampling strategy throughout the site, the sampling strategy inside the sampling unit, strategy at the sampling point and last minute alteration of the sampling plans in the field. The object of this was to define the similarities and the differences in the sampling plans and identify the crucial steps inducing error or uncertainty which should be harmonized throughout Europe. The number of the total composite samples varied from 4 to 16, while the number of sampling points varied from 4 to 224 and the sampling density varied from 0.25 to 16 single samples per 100 m2. The number of 10 x 10 m2 quadrats from which samples were taken varied from 3 to 56, out of the total 61. The number of sampling units varied between 3 and 12. The criteria in descending order of frequency were: both land use and pedology, land use, pedology. The majority of the national participants divided the sampling units into two or three sub-units, while seven participants collected replicate composite samples from the same sampling unit. Only one sampled from the existing profiles, eight national representatives ignored the plough depth. The sampling pattern inside the sampling unit was in descending order of frequency: random, point sampling, regular, 'W' and 'X' shaped sampling. The number of single samples in the composite varied from 1 to 20. Most of the national participants sampled to pre-defined (ad-hoc) sampling depths, while others sampled soil horizons and others both. The maximum soil depth sampled also varied from 20 to 117 cm. Most participants mixed in the top organic matter horizon while others sampled it separately. Most sampled separately the top Ah horizon in the forest while the rest mixed it with the underlying soil horizon. The last-minute sampling plan alterations were in: the sampling depth (nine), the movement of sampling points (five), the reduction of sub-samples in the composite sample (four), changes in the number of sampling units (three), ignoring the bottom sample (three), not sampling the L/H layer (three) although this was planned, unplanned sampling of the L/H layer (two) and changing the number of planned samples (two). This study has highlighted the need for soil sampling harmonization throughout Europe for pollution and soil quality determination.

Environmental Monitoring↗
PubMed2007

Comparison of four sampling methods for the detection of Salmonella in broiler litter.

Experiments were conducted to compare litter sampling methods for the detection of Salmonella. In experiment 1, chicks were challenged orally with a suspension of naladixic acid-resistant Salmonella and wing banded, and additional nonchallenged chicks were placed into each of 2 challenge pens. Nonchallenged chicks were placed into each nonchallenge pen located adjacent to the challenge pens. At 7, 8, 10, and 11 wk of age the litter was sampled using 4 methods: fecal droppings, litter grab, drag swab, and sock. For the challenge pens, Salmonella-positive samples were detected in 3 of 16 fecal samples, 6 of 16 litter grab samples, 7 of 16 drag swabs samples, and 7 of 16 sock samples. Samples from the nonchallenge pens were Salmonella positive in 2 of 16 litter grab samples, 9 of 16 drag swab samples, and 9 of 16 sock samples. In experiment 2, chicks were challenged with Salmonella, and the litter in the challenge and adjacent nonchallenge pens were sampled at 4, 6, and 8 wk of age with broilers remaining in all pens. For the challenge pens, Salmonella was detected in 10 of 36 fecal samples, 20 of 36 litter grab samples, 14 of 36 drag swab samples, and 26 of 36 sock samples. Samples from the adjacent nonchallenge pens were positive for Salmonella in 6 of 36 fecal droppings samples, 4 of 36 litter grab samples, 7 of 36 drag swab samples, and 19 of 36 sock samples. Sock samples had the highest rates of Salmonella detection. In experiment 3, the litter from a Salmonella-challenged flock was sampled at 7, 8, and 9 wk by socks and drag swabs. In addition, comparisons with drag swabs that were stepped on during sampling were made. Both socks (24 of 36, 67%) and drag swabs that were stepped on (25 of 36, 69%) showed significantly more Salmonella-positive samples than the traditional drag swab method (16 of 36, 44%). Drag swabs that were stepped on had comparable Salmonella detection level to that for socks. Litter sampling methods that incorporate stepping on the sample material while in contact with the litter appear to detect Salmonella in greater incidence than traditional sampling methods of dragging swabs over the litter surface.

Animals↗
PubMed2005

Changes of viability and composition of the Escherichia coli flora in faecal samples during long time storage.

Long-time storage of faecal samples is necessary for investigations of intestinal microfloras. The aim of the present study was to evaluate how the viability and the composition of the Escherichia coli flora are affected in faecal samples during different storage conditions. Four fresh faecal samples (two from calves and two from infants) were divided into sub-samples and stored in four different ways: with and without addition of glycerol broth at -20 degrees C and at -70 degrees C. The viability and the phenotypic diversity of the E. coli flora in the sub-samples were evaluated after repeated thawings and after storage during 1 year. The samples stored for 1 year without thawing were also kept at room temperature for 5 days and subsequently analysed. According to phenotyping (PhP analysis) of 32 isolates per sample on day 0, all four samples contained two dominating strains of E. coli each, and between one and eight less common strains. Samples that were stored at -70 degrees C in glycerol broth showed equal or even higher bacterial numbers as the original samples, even after repeated thawings, whereas samples stored at -20 degrees C showed a considerably lower survival rate, also with addition of glycerol. Sub-samples containing glycerol broth that were kept at room temperature after storage for 1 year showed a clear increase in the number of viable cells as well as in diversity. The diversities in each sub-sample showed a tendency to decrease after several thawings as well as after storage. Generally, the E. coli populations in samples stored at -20 degrees C were less similar to the population of the original sample than that in samples stored at -70 degrees C. Samples that had been mixed with glycerol broth had an E. coli flora more similar to that in the original sample than those without glycerol broth. Furthermore, the sub-samples that were kept at room temperature after storage for 1 year generally were more similar to the original samples than if they were processed directly. We conclude that for long time storage of faecal samples, storage at -70 degrees C is preferable. If samples have to be thawed repeatedly, addition of glycerol is preferable both for samples stored at -70 degrees C and for samples stored at -20 degrees C. Our data also have indicated that when E. coli isolates from faecal samples are selected for, e.g. analysis of virulence factors, it is necessary to pick several isolates per sample in order to obtain at least one isolate representing the dominating strain(s).

Animals↗
PubMed2001

European soil sampling guidelines for soil pollution studies.

The soil sampling guidelines used in European countries (ESSG), as kindly provided by the national institutions which participated in the project, have been recorded, studied, evaluated and presented in this paper. The aim has been to ascertain what soil sampling guidelines exist in Europe; to detect similarities and differences (comparable results), advantages and deficiencies; to identify incompatible strategies and evaluate how methodologies might affect data quality; to investigate sources of deviations or uncertainties; to improve comparability and representativeness of soil sampling; to investigate the need for harmonised sampling guidelines; and to develop suggestions for standard operating procedures (SOP). Soil sampling guidelines throughout Europe differ as to whether they are applied by law, or used throughout the country. In some countries these are ISO/DIS related or based (ISO 10381-1, 1995; ISO 10381-2, 1995), or are produced by a scientific society or a standardisation body. As far as sampling strategy is concerned, not all sampling guidelines clearly describe the sampling scale, the specifications for contamination risk precautions, the sampling plan and protocol structure and the pre-analysis treatment of the soil samples. The purpose for sampling, in descending order of frequency, is soil pollution, soil fertilisation, general soil monitoring, background risk assessment, or else it is not specified. The majority of countries do not sample the top organic matter separately. Sampling depth is either related to the morphogenetic horizon or to ad hoc sampling depth, which is not specified in all cases. They suggest mass- and volume-related soil sampling, while the sampling pattern is not presented in all national guidelines. The criteria for area, site, unit, sub-unit, and point selection are mainly based on pedology and land use, following the history and pre-screening information or geology, or is site related. Some guidelines suggest the division of sampling units into sub-units. The sampling pattern is mainly grid sampling, grid and random sampling, or not mentioned. Sampling density inside the sampling unit either varies greatly or it is not mentioned, while the size of the sampling unit varies widely. Most guidelines require the collection of composite instead of simple samples, while some prefer sampling soil profiles. In the European SSG many technical details and steps are either not defined or vary, while in the pre-analysis treatment quality assurance (QA) and quality control (QC) approaches are used either both in the lab and in the field, or only in the field, or are not mentioned. The common points and the points in which harmonisation could be started or achieved are discussed.

Agriculture↗
PubMed2000

A physician survey of the effect of drug sample availability on physicians' behavior.

OBJECTIVE: Pharmaceutical companies often use drug samples as a marketing strategy in the ambulatory care setting. Little is known about how the availability of drug samples affects physicians' prescribing practices. Our goal was to assess: (1) under what circumstances and why physicians dispense drug samples, (2) if drug samples lead physicians to use medications other than their preferred drug choice, and (3) the physician characteristics that are associated with drug sample use. DESIGN: Cross-sectional survey. SETTING: University-based clinics at one academic medical center. PARTICIPANTS: 154 general medicine and family physicians. MEASUREMENTS AND MAIN RESULTS: Physicians' self-reported prescribing patterns for 3 clinical scenarios, including their preferred drug choice, whether they would use a drug sample and subsequently prescribe the sampled medication, and the importance of factors involved in the decision to dispense a drug sample. A total of 131 (85%) of 154 physicians responded. When presented with an insured woman with an uncomplicated lower urinary tract infection, 22 (17%) respondents reported that they would dispense a drug sample; 21 (95%) of 22 sample users stated that they would dispense a drug sample that differed from their preferred drug choice. For an uninsured man with hypertension, 35 (27%) respondents reported that they would dispense a drug sample; 32 (91%) of 35 sample users indicated that they would dispense a drug sample instead of their preferred drug choice. For an uninsured woman with depression, 108 (82%) respondents reported that they would dispense a drug sample; 53 (49%) of 108 sample users indicated that they would dispense a drug sample that differed from their preferred drug choice. Avoiding cost to the patient was the most consistent motivator for dispensing a drug sample for all 3 scenarios. For 2 scenarios, residents were more likely to report using drug samples than attendings (P <.05). When respondents who chose a drug sample for 2 or 3 scenarios were compared to those who never chose to use a drug sample, or chose a drug sample for only one scenario, only younger age was independently associated with drug sample use. CONCLUSION: In self-reports, the availability of drug samples led physicians to dispense and subsequently prescribe drugs that differ from their preferred drug choice. Physicians most often report using drug samples to avoid cost to the patient.

Adult↗
PubMed1995

[Studies on the occurrence of Listeria monocytogenes in fecal samples of domestic and companion animals].

Listeria (L.) monocytogenes was isolated from 33.3% fecal samples of 138 cattle (29 strains serovar 1/2b, 10 strains serovar 1/2a, 7 strains serovar 4ab), from 8% fecal samples of 100 hens (5 strains serovar 1/2b, 1 strain serovar 1/2a, 4ab and 4b each), from 8% fecal samples of 100 sheep (6 strains serovar 1/2a, 1 strain serovar 1/2b and 4ab each), from 5.9% fecal samples of 34 pigs (2 strains serovar 4ab), from 4.8% fecal samples of 400 horses (7 strains serovar 1/2a, 6 strains serovar 1/2b and 4ab each), from 1.3% fecal samples of 300 dogs (3 strains serovar 1/2b, 1 strain serovar 4ab), from 0.9% fecal samples of 350 pigeons (1 strains serovar 1/2a, 1/2b and 4ab each), from 0.4% fecal samples of 275 cats (1 strain serovar 4b) and from 5 respectively 2 fecal samples of 35 tortoises (3 strains serovar 4ab, 2 strains serovar 4b) respectively 5 amphibia (1 strain serovar 4ab and 4e each). Further 36.9% fecal samples of cattle, 15% fecal samples of hens, 6% fecal samples of horses, 5.9% fecal samples of pigs, 5% fecal samples of sheep, 4% fecal samples of dogs, 2.3% fecal samples of pigeons, 3 fecal samples of 35 tortoises and 1 fecal sample of 260 rabbits contained L. innocua. In further 2% fecal samples of hens, in further 1.5% fecal samples of horses and in further 0.6% fecal samples of pigeons was detected L. seeligeri. 3 fecal samples of horses and 1 fecal sample of dogs, lizards and amphibia each contained L. welshimeri, while in 1 fecal sample of tortoises and in 3 fecal samples of 33 lizards L. ivanovii was detected.

Amphibians↗
PubMed2003

An international study of the performance of sample collection from patients.

BACKGROUND AND OBJECTIVES: Collection of a blood sample from the correct patient is the first step in the process of safe transfusion. The aim of this international collaborative study was to assess the frequency of mislabelled and miscollected samples drawn for blood grouping. MATERIALS AND METHODS: Hospitals in 10 countries provided data on sample error rates during a period of at least 3 months, including the last quarter of 2001. Mislabelled samples were defined as those not meeting local criteria for acceptance by the laboratory. Miscollected samples [wrong-blood-in-tube (WBIT)] were defined as samples in which the blood group result differed from the result on file from prior testing. WBIT rates were corrected for the proportion of repeat samples and for undetectable errors occurring as a result of chance collection of blood from the wrong patient with the same ABO group. Participants also completed a questionnaire on current policies regarding sample collection. RESULTS: A total of 71 hospitals completed surveys describing policies related to sample collection. Sixty-two hospitals provided usable data on the frequency of mislabelled and miscollected samples. Mislabelled and miscollected samples were common. Based on results from over 690,000 samples, the median hospital performance resulted in a rate for mislabelling of 1 in every 165 samples (6.1 per 1000; interquartile range 1.2-17 per 1000). The presence of national patient identification systems in Sweden and Finland was associated with rates of miscollected samples that were too low to estimate. Outside these nations, miscollected samples demonstrating WBIT occurred at a median rate of 1 in every 1986 samples (0.5 per 1000; interquartile range <0.3-0.9 per 1000). There was great variation worldwide in the reported frequency of mislabelled samples, probably resulting from variation in policies for sample acceptance. Miscollected samples occurred at a more constant rate. CONCLUSIONS: The rate of mislabelled samples and miscollected samples is 1000-10,000-fold more frequent than the risk of viral infection. Rates of mislabelled samples and WBIT can be tracked as key indicators of performance of an important step in the clinical transfusion process. WBIT episodes represent important 'near-miss' errors. By providing baseline performance data for the collection of patient blood samples, this study may be useful in formulating future national standards of performance for sample collection from patients.

Blood Group Incompatibility↗
PubMed2003

Odor concentration decay and stability in gas sampling bags.

This paper presents results of an experimental study into factors contributing to decay of odor samples during storage, between 4 and 40 hr after sample collection. The odor studied was sampled from a tobacco processing plant as part of collaborative research with a view to establishing a manual outlining methods for odor annoyance management, specifically for the tobacco industry. In August and September 1997, an experimental program was carried out in which two types of tobacco odor were sampled: Burley Toaster and Mix. The dependent variable was odor concentration in the bag, measured by dynamic olfactometry in accordance with the draft Comité Européen de Normalisation (CEN) standard EN13725 "Air Quality-Determination of Odor Concentration by Dynamic Olfactometry." The independent variables were sampling bag material, degree of dilution during sampling, dilution gas used, particle removal during sampling, and age of sample in hours. In the first phase, 94 odor analyses were carried out. In a second test, 32 samples were analyzed for odor concentration. In addition, 16 samples were analyzed using gas chromatography-mass spectrometry (GC-MS). Analysis of the results (analysis of variance) led to the unexpected conclusion that Nalophan film bags performed significantly better than metalized Cali-Bond layered film as a bag material. The odor concentration of samples in Nalophan bags remained relatively stable between 4 and 12 hr after sampling. After 30 hr, decay to about half the initial concentration, as measured at 4 hr, was observed. Particle removal during sampling caused the odor concentration in the bags to be reduced by approximately 20%. For practical reasons, particle removal remains useful, to avoid contamination of equipment. Using air or nitrogen as the neutral gas for pre-dilution during sampling or the dilution factor used (between factor 2 and 6) did not appear to have an effect on the decay characteristic of odor samples. The following recommendations are suggested for the practice of collecting odor samples and apply specifically to tobacco processing emissions: Analyze samples as soon as possible, preferably within 12 hr; When samples age for more than 12 hr, decay is likely to cause a reduction in odor concentration to half the original concentration at age 30 hr; Use sampling bags made of Nalophan NA or benchmark performance of other materials against Nalophan NA before using alternative materials; Use pre-dilution when sampling only for the purpose of avoiding condensation during sample storage. Use an appropriate minimum dilution factor to avoid condensation; Both nitrogen and high-purity (synthetic) air are suitable to use as neutral gas for pre-dilution; and When sampling tobacco odors, use an odorless filter to remove particles. This practice removes a source of variation and avoids contamination of equipment. The effect on results, despite being consistently lower in odor concentration, is not meaningful in terms of perceived intensity or annoyance potential.

Air Pollutants↗
PubMed1991

Sampling issues in nursing home research.

It has been suggested that two common methods of sampling nursing home populations, cross-sectional sampling and discharge sampling, result in samples with different characteristics and lengths of stay. Comparison of these samples to a sample of nursing home admissions has not been studied. This study compares characteristics and lengths of stay among cross-sectional, discharge, and admission samples. All current residents of three nursing homes in February 1987 made up the cross-sectional sample, all admissions in the following year made up the admission sample, and all discharges in the same year made up the discharge sample. The results of comparing these three sampling techniques show that the most striking differences occur between the cross-sectional sample and the admission sample. Persons in the cross-sectional sample tended to have longer nursing home stays as well as less social support and more behavioral and functional problems than persons in the admission sample, who tended to have shorter stays and more acute medical problems. The discharge sample was more similar to the admission sample than it was to the cross-sectional sample; however, some differences were found between the discharge and admission samples. Based on the differences found among the three samples, appropriate uses for each sample are discussed.

Aged↗