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PubMed1986

[Microbial contamination of the air in the housing of laying hens].

Studied were buildings of one and the same design, sizing 92/12/3.5 m. Building A of mechanical ventilation through negative pressure housed 9,000 layers of the White Leghorn breed, and building B of ventilation with equated pressure, providing the same debit per kg biomass, housed 20,000 layers. The air in the buildings, in the close surrounding as well as the feed and soil were investigated with regard to the total counts of organisms as cultured in meat and peptone agar and with regard to the individual counts of coli bacteria, microscopic fungi and hemolytic cocci, and Salmonellae. It was found that the microbial contamination of air on the productional premises and of atmospheric air closely surrounding the buildings, was higher in building A. There were differences in the microflora of the air at the level of the individual stories in building B. The differences in the microbial contamination of air between the two buildings was the result of reconstructions concerning the ventilation system as well as of making it more effective.

Air Microbiology↗
PubMed2006

Potential sources of microbial contamination in unpasteurized apple cider.

A study was conducted to identify possible sources of microbial contamination and to assess the effect of good cleaning and sanitation practices on the microbial quality and safety of unpasteurized apple cider. Raw unwashed apples, washed apples, cleaning water, fresh cider, and finished cider samples were collected from five Ontario producers over 4 months and microbiologically tested. Total coliforms were found in 31, 71 and 38% of the unwashed apple, water, and washed apple samples, respectively. Escherichia coli was found in 40% of the water samples from one producer alone. The washing step was identified as a potential source of contamination, possibly due to water in the dump tanks seldom being refreshed, and because scrubbers, spray nozzles, and conveyors were not properly cleaned and sanitized. Higher total coliform counts (P < 0.0001) and prevalence (P < 0.0001) in fresh cider compared with those in unwashed apples and washed apples indicated considerable microbial buildup along the process, possibly explained by the lack of appropriate equipment sanitation procedures. Results showed that producers who had better sanitary practices in place had lower (P < 0.001) total coliform prevalence than the rest of the producers. Overall results show that good sanitation procedures are associated with improved microbial quality of fresh cider in terms of total coliforms and that operators who pasteurize and/or UV treat their product should still be required to have a sound good manufacturing practices program in place to prevent recontamination. Cryptosporidium parvum, an important pathogen for this industry, was found in different sample types, including washed apples, water, and fresh and finished cider.

Animals↗
PubMed1992

Microbial contamination of enteral feeding solution and its prevention.

In an investigation of microbial contamination of enteral feeding solutions, all 22 residual solutions obtained immediately after administration were contaminated at concentrations of 10(3) to 10(6) viable counts/ml. Major contaminants were glucose-nonfermenting gram-negative bacilli such as Pseudomonas aeruginosa and Acinetobacter calcoaceticus var anitratus. Contamination seemed to have been caused by frequent reuse of bag-type containers and the infusion tubes connected to the bags, neither of which can be washed or dried. Decontamination methods were evaluated by using polypropylene containers that can be washed and disinfected for administration. Few Serratia marcescens on the inside wall of the container were removed by rinsing with tap water, alone or in combination with detergent scrub. Tap water and detergent plus air-drying at 56 degrees C for 1 hour reduced Serratia marcescens only somewhat. Tap water and detergent plus immersion in 0.01% sodium hypochlorite for 1 hour or in water at 70 degrees C for 3 minutes eliminated all 10(11) cells of Serratia marcescens.

Colony Count, Microbial↗
PubMedDate not supplied

Alcohol loss arising from microbial contamination of drivers' blood specimens.

This paper describes the circumstances in which some drivers' blood specimens containing added sodium fluoride (1% w/v concentration) deteriorated as a result of microbial contamination, accompanied by a decrease of alcohol concentration. Strains of the bacteria Serratia marcescens and a Pseudomonas sp. were isolated from the specimens and proven capable of growing at ambient temperature in blood containing sodium fluoride at 1% w/v concentration. They were shown to be active in alcohol degradation in preservatised blood, the activity being dependent on sodium fluoride concentration and storage temperature. Blood diluters were assumed to be a source of microbial cross contamination from one blood specimen to the next. It is recommended that postmortem blood specimens be analysed in separate batches from drivers' specimens when automated blood diluters are used, that the content of fluoride ions be increased to an equivalent of 2% w/v sodium fluoride, and that storage of specimens at temperatures above 4 degrees C be minimised.

Azides↗
PubMed2005

Particulate and microbial contamination in in-use admixed parenteral nutrition solutions.

We evaluated particulate and microbial contamination in a total of 192 samples of in-use admixed and unadmixed parenteral nutrition solutions remaining in infusion bags in 10 hospitals. The mean numbers (range) of drug glass ampoules, plastic ampoules, and vials used in a total of 192 admixed solutions were 3.38 (1-13), 0.79 (0-7), and 1.2 (0-8), respectively. The mean number of particles (range) contained in the 192 samples according to the particle size (diameter) was 960.9 (30-9,539)/ml for particles >or=1.3 microm, 42.8 (0-587)/ml for those >or=5 microm, 6.4 (0-146)/ml for those >or=10 microm, and 0.09 (0-1)/ml for those >or=50 microm. The number of particles >or=1.3 microm in diameter was significantly higher in the 192 samples than in 7 samples (controls) of solutions not mixed with any ampoule or vial (p<0.0001). In addition, the number of particles >or=1.3 microm in diameter was significantly higher in samples of solutions mixed with 4-13 glass ampoules than in those of solutions mixed with 1-3 glass ampoules (p<0.01). On the other hand, none of the 199 samples showed bacteria or fungi/5 ml residual solution. Measures against particulate contamination of admixed parenteral nutrition solutions are necessary.

Biofilms↗
PubMed1999

[Monitoring of microbial contamination of stick wound in swine carcasses].

This study was done to evaluate the microbial contamination by Salmonella spp., Escherichia coli, fecal coliforms, and total aerobic count of the stick wound of swine carcasses. The effectiveness of trimming the stick wound in the 2 Québec slaughterhouses visited was evaluated. A bacteriological analysis was done on 276 stick wounds. Results indicated that, before trimming, 0.9% stick wounds were contaminated by Salmonella spp. Contamination by coliforms was observed in 40.6% of samples, and 27.7% were positive for E. coli. After trimming the stick wounds, 1.1% were contaminated by Salmonella spp., 34.1% were contaminated by coliforms, and 26.2% were positive for E. coli. The results showed that trimming contributes to reducing significantly the bacterial total count at the site and that the bacterial load at this site was less important than that found on the brisket.

Abattoirs↗
PubMed1996

Relevance of abattoir hygiene assessment to microbial contamination of British beef carcases.

Eleven beef abattoirs were visited, each on five separate occasions. On each occasion, an audit was carried out according to the official Hygiene Assessment System (HAS) and 10 carcases were sampled at four different sites to assess total viable counts and counts of presumptive coliform bacteria. The HAS scores ranged from 11 to 84 (maximum 100), and the logarithmic mean total viable counts for all sampling sites on each batch of carcases varied between 1.98 and 4.14 colony forming units/cm2. The mean prevalence of coliform contamination ranged from 0 to 85 per cent. There was a significant negative correlation (P < 0.001) between the mean HAS scores and the mean total viable count for each abattoir, but not between the HAS scores and the numbers of coliforms. Within the HAS, the mean scores for all five categories, before weighting, showed a significant correlation with the mean total viable count (P < 0.001); however, the categories concerned with slaughter and dressing, and personnel and practices were of most value in determining trends in carcase contamination. A new advisory classification is proposed for levels of microbial contamination on beef carcases.

Abattoirs↗
PubMed2004

Microbial contamination of carcasses, meat, and equipment from an Iberian pork cutting plant.

An assessment and follow-up of the microbial contamination of an Iberian pork cutting room is presented. Samples were taken from carcasses (n = 76), meat pieces (three types, n = 71), meat for dry-cured sausages (3 types, n = 66), and surfaces of equipment (n = 158). Aerobic plate counts (APC) at 37 degrees C on meat pieces (primal cuts) were lower than on carcasses (3.62 log CFU/10 cm2 against 4.63 log CFU/10 cm2), probably owing to the removal of the skin. However, more than 80% of the meat pieces showed presence of Escherichia coli. For the three types of meat intended for dry-cured sausages, higher counts (P < 0.001) were found for meat type 3--an important cut obtained from the vertebral column--at 2.62 log CFU/g for E. coli; the particular surface used in the handling of meat type 3 also showed high counts (P < 0.001) for E. coli. Consequently, attention should be paid to the hazard analysis critical control point plan at this stage. Salmonella was isolated from 3.94% of the carcass surfaces (perianal zone), 4.46% of meat pieces, and 13.58% of meat for dry-cured sausages. Moreover, the percentages for isolation of Salmonella from carcasses of Iberian pigs (extensive rearing) in our study were lower than those generally reported in the literature for "white pigs" (intensive rearing). Coagulase-positive Staphylococcus aureus was isolated in 31.82% of meat samples for dry-cured sausages, in 16.90% of meat pieces, and in 15.50% of the equipment after 4 h of work. Of the coagulase-positive strains isolated, 47.61% were producers of enterotoxin.

Animals↗
PubMed2003

Microbial contamination of embryos and semen during long term banking in liquid nitrogen.

We report on microbial contamination of embryos and semen cryopreserved in sealed plastic straws and stored for 6-35 years in liquid nitrogen. There were 32 bacterial and 1 fungal species identified from randomly drawn liquid nitrogen, frozen semen, and embryos samples stored in 8 commercial and 8 research facility liquid nitrogen (LN) tanks. The identified bacteria represented commensal or environmental microorganisms and some, such as Escherichia coli, were potential or opportunistic pathogens for humans and animals. Stenotrophomonas maltophilia was the most common contaminant identified from the samples and was further shown to significantly suppress fertilization and embryonic development in vitro. Analysis of the strains by pulsed field gel electrophoresis revealed restriction patterns with no relatedness indicating that there was no apparent cross-contamination of S. maltophilia strains between the germplasm and liquid nitrogen samples. In addition, no transmission of bovine viral diarrhea virus (BVDV) and bovine herpesvirus-1 (BHV-1) from infected semen and embryos straws to clean germplasm stored in the same LN tanks or LN was detected.

Animals↗
PubMed1994

Influence of background air on microbial contamination during simulated i.v.-admixture preparation.

The effect of the cleanliness of environmental air on the microbial contamination of a simulated i.v.-admixture during its preparation by aseptic transfer was studied under three conditions: (i) in a laminar air flow (LAF) bench situated in a class 1000 clean room, (ii) in an LAF bench in a microbiology laboratory and (iii) on a bench in an ordinary laboratory. Three thousand bottles were manually filled with 10 ml of a nutrient broth under each of the three conditions. The liquid was transferred by means of a syringe and a needle that pierced through the rubber closures of the bottles. The numbers of contaminated bottles under those three conditions were 1, 1 and 2, respectively. Background contamination had no demonstrable effect on the incidence of contamination, provided that preparation of the simulated i.v.-admixture solution was performed by skilled personnel in an LAF cabinet and air contact is avoided.

Air Pollution, Indoor↗
PubMed2002

Microbial contamination in inoculated shell eggs: I. Effects of layer strain and hen age.

Three Ottawa control strains and a current commercial laying stock were reared and housed under identical environmental and management conditions. Eggs were collected from each strain when hens were 32, 45, 58, 71, and 84 wk of age. The eggs were inoculated with Salmonella enteritidis (SE), Pseudomonasfluorescens (PF), or a combination of the two. After storage at 26 C, bacterial counts were obtained from the exterior shell surfaces (rinse), air cell, egg contents, and shell structure. SE and PF survived at different rates on the shell surface with as much as a 1 log difference during a given collection period. Egg content counts tended to be higher than eggshell counts in PF, whereas the opposite was true for SE. These data suggest that PF is a primary invader of eggs that is more capable of contaminating egg contents through the shell membranes than SE. The PF and SE data suggest that bacterial contamination of air cells, shells, and egg contents is more easily achieved in eggs from older hens than from younger hens. There were also differences between the strains. Control Strain 10 consistently maintained a lower level of contamination for both organisms in each sampling location. The overall results of this study suggest that genetic selection has altered the ability of eggs to resist microbial contamination and that screening for microbial integrity should be considered in the selection process among the laying egg breeders.

Age Factors↗
PubMed2001

Microbial contamination of water-soaked cotton gauze and its cause.

Seven in-use cotton gauze samples and three cotton balls soaked in sterile distilled water in canisters were investigated 7 days after they were prepared in hospital. All samples were contaminated with bacteria including 10(6) to 10(7) colony forming units/ml of Pseudomonas aeruginosa. In vitro viability tests using cotton gauze and cotton balls soaked in sterile distilled water revealed rapid proliferation of P. aeruginosa, Serratia marcescens and Candida albicans. Since the cotton gauze and the cotton balls were soaked in water containing nutrients, such as protein and glucose, these materials may be readily contaminated with bacteria including P. aeruginosa. Thus, when using cotton gauze and cotton balls containing water, microbial contamination should be expected.

Candida albicans↗
PubMed2006

Estimation of microbial contamination of food from prevalence and concentration data: application to Listeria monocytogenes in fresh vegetables.

A normal distribution and a mixture model of two normal distributions in a Bayesian approach using prevalence and concentration data were used to establish the distribution of contamination of the food-borne pathogenic bacteria Listeria monocytogenes in unprocessed and minimally processed fresh vegetables. A total of 165 prevalence studies, including 15 studies with concentration data, were taken from the scientific literature and from technical reports and used for statistical analysis. The predicted mean of the normal distribution of the logarithms of viable L. monocytogenes per gram of fresh vegetables was -2.63 log viable L. monocytogenes organisms/g, and its standard deviation was 1.48 log viable L. monocytogenes organisms/g. These values were determined by considering one contaminated sample in prevalence studies in which samples are in fact negative. This deliberate overestimation is necessary to complete calculations. With the mixture model, the predicted mean of the distribution of the logarithm of viable L. monocytogenes per gram of fresh vegetables was -3.38 log viable L. monocytogenes organisms/g and its standard deviation was 1.46 log viable L. monocytogenes organisms/g. The probabilities of fresh unprocessed and minimally processed vegetables being contaminated with concentrations higher than 1, 2, and 3 log viable L. monocytogenes organisms/g were 1.44, 0.63, and 0.17%, respectively. Introducing a sensitivity rate of 80 or 95% in the mixture model had a small effect on the estimation of the contamination. In contrast, introducing a low sensitivity rate (40%) resulted in marked differences, especially for high percentiles. There was a significantly lower estimation of contamination in the papers and reports of 2000 to 2005 than in those of 1988 to 1999 and a lower estimation of contamination of leafy salads than that of sprouts and other vegetables. The interest of the mixture model for the estimation of microbial contamination is discussed.

Bayes Theorem↗
PubMedDate not supplied

Microbial contamination of "in use" bar soap in dental clinics.

Bar soap from 18 different dental clinics were investigated for microbial contamination, while it was "in-use". Of the 32 samples obtained from the bar soap, 100% yielded positive culture. A total of 8 different genera of organisms were isolated. Each bar soap was found to harbor 2-5 different genera of micro organisms. Heavily used soap had more micro organisms compared to less used soap. The microbial load of the "in-use" bar soap constituted a mixed flora of gram positive, gram negative, aerobes, anaerobes, and fungi. The results indicate that the bar soap under "in-use" condition is a reservoir of microorganisms and handwashing with such a soap may lead to spread of infection.

Aspergillus niger↗
PubMed1984

Microbial contamination of a vitamin A formulation, prepared in local pharmacies, and its preservation against yeasts and moulds.

The microbial contamination of 44 samples of a vitamin A preparation in sucrose syrup was investigated. The contaminants were almost exclusively yeasts and moulds. Microbiological and physicochemical studies showed that sorbic acid was the preservative of choice for this formulation. The results are discussed with respect to the preservation of non-sterile pharmaceuticals.

Drug Contamination↗
PubMedDate not supplied

Spatial and temporal modeling of microbial contaminants on grazing farmlands.

This paper introduces an integrated spatial and temporal modeling system developed mathematically for assessing microbial contaminants on animal-grazed farmlands. The model uses fecal coliform, specifically Escherichia coli, as an indicator of fecal contamination and describes the sources, sinks, transport processes, and fate of E. coli contaminants in catchments and associated streams. Spatial features include grazing location, land topography, distance to a nearby stream, and distance through the stream network to the outlet. Temporal features are population dynamics on the land surface, in flow, and on streambeds. The model applies the principles of conservation of mass balance on two different types of pools: grid cells on land surfaces and networked stream segments. The model aims to improve the prediction of the effects of different land management strategies on the fecal contamination of waterways. This is achieved by characterizing the movement of fecal contaminants from land to streams and in-stream mobilization. Processes of attenuation, diffusion, and transport govern the movement. Our study site is a hill land catchment with an area of 140 ha and is used exclusively for animal grazing. The model was calibrated with previous research results, and then tested using the data collected at the outlet of the catchment. The sensitivity of the model predictions was analyzed for different scenarios: effect of stock rate, attenuation rate, and flow volumes. The similar pattern between monitored and predicted E. coli concentration proved that the model captures the key features that control the population dynamics of fecal contaminants. Further experiments are required to expand the model's functionality for covering more mitigation options.

Animal Husbandry↗
PubMed1988

[Microbial contamination of liquid-soap wall dispensers with one-way bottles].

Hygienic examinations were performed relating to microbial contaminations of different kinds of fluid soaps in relation to various systems of dispensers. Totally 492 specimens of fluid soap were examined comprising 14 different kinds of trade names (Code A-O), sampled in 14 different hospitals including 4 different systems of dispensers. Out of 14 trade name products--containing antimicrobial additives--8 proved to be sterile. The rest--declared as free from antimicrobial additives--showed bacterial contaminations of different grade. One of them (Code "O"), without antimicrobial additives) proved to be excessively contaminated with P. cepacia in 108 specimens out of 281, i.e. 38% in the range from 10(3)-10(6) CFU/ml. Further investigations on origin and mechanism of this alarming event revealed, that the cause for this dilemma was a failure in the dosing system of the one-way bottle dispensers used. This seems to be of fundamental importance for a great number of one-way-dispensers used at presence for fluid soaps or disinfectants: Changing only the emptied bottles out of the wall-attached device of dispenser causes inevitably a rapid recontamination of the new bottles, if not the dosing-device is as well removed and effectively cleaned and disinfected before reinserting.

Bacteria↗