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Results for “microbial contamination”

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At least 145 records · Page 8Linked to original sources

PubMed2000

The effect of changing the excreta moisture of caged laying hens on the excreta and microbial contamination of their egg shells.

1. An experiment that included 1440 caged laying hens in 24 experimental units was conducted to determine the effect of differences in excreta moisture on the proportion of dirty eggs and the microbial contamination of eggs that were ostensibly uncontaminated by excreta. Excreta moisture contents were changed by giving the hens diets that contained 4 different concentrations of sodium. 2. Diets containing 1.6, 5, 10 or 15 g/kg dietary sodium were fed ad libitum to 1140 laying hens for a 12-week feeding period. A sample of excreta was collected from each experimental unit each week and its moisture content determined. All eggs produced were classified as clean or dirty according to the European Community Egg Marketing Regulations. A sample of eggs were collected from each experimental unit on 4 separate occasions in the last 4 weeks of the feeding period and the total bacterial numbers on ostensibly clean egg shells were determined. 3. Increasing dietary sodium concentration gave linear (P<0.01) increases in excreta moisture. Each 100 g/kg increase in excreta moisture increased (P<0.001) dirty egg numbers by 0.52% of the total eggs produced. Increasing excreta moisture gave a linear increase (P<0.001) in the (log-transformed) numbers of microorganisms that contaminated ostensibly clean egg shells.

Animals↗

PubMed2001

[A new application for the human whole blood test: development of an assay to assess the health risk of air-borne microbial contaminations].

The pathogenic properties of environmental microorganisms as well as pyrogens as fragments of those bacteria (especially endotoxins) for humans is increasingly recognised. Various clinical syndromes are described after contact with airborne microbial contaminants via the respiratory tract: Sick-building-syndrome, humidifier lung (a form of hypersensitive pneumonitis), "Monday sickness" etc. Air-conditioning and ventilation systems intensify this problem as well as storage of compost within the household which represents a considerable source of airborne pollutants. In 1995 a new method for the detection of pyrogenic (fever-inducing) hazardous substances was described by Hartung and Wendel. This whole blood assay utilises the natural reaction of the immune system in order to detect a broad spectrum of pyrogens very sensitively in the relevant species. Injectable drugs are the main area of application in which this innovative test has already proven effective and is currently validated for inclusion into European Pharmacopoeia. In co-operation with the FU Berlin we could demonstrate in ventilation systems in animal stables that the whole blood pyrogen test can also detect airborne environmental microorganisms very sensitively. The filtration technique for collection of these germs is an established method for air-conditioning and ventilation systems. In co-operation with the FU Berlin (Institut für Tier-und Umwelthygiene) and the filter producer Sartorius this method is currently developed for the detection of airborne contaminations.

Air Microbiology↗

PubMedDate not supplied

Evaluation of cytotoxicity and antimicrobial activity of Acticoat Burn Dressing for management of microbial contamination in cultured skin substitutes grafted to athymic mice.

Cultured skin substitutes (CSS) have become a useful adjunctive treatment for closure of burn wounds, but CSS are avascular and remain susceptible to microbial destruction longer than split-thickness skin grafts. Irrigation of CSS grafted to burn wounds with a topical antimicrobial solution (TAS) has been shown to promote engraftment of CSS, but TAS usage has potential limitations. Acticoat Burn Dressing (Acticoat; Westaim Biomedical, Exeter, NH) is a silver-coated barrier dressing reported to exhibit antimicrobial activity and to reduce infection in partial-thickness and full-thickness wounds. This study evaluated the cytotoxicity of Acticoat with CSS and the efficacy of Acticoat for the management of microbial contamination in CSS grafted to full-thickness wounds in athymic mice. The cytotoxicity of Acticoat was assessed in preliminary studies after 1 week of exposure to CSS during in vitro maturation or healing on wounds in athymic mice. Histologies were analyzed and cellular viability in the CSS was determined by MTT conversion on days 0, 1, and 7 of Acticoat exposure. At 1, 2, 3, and 4 weeks after grafting, wounds were traced, and areas of healing CSS were calculated by image analysis. At 4 weeks, wound biopsies were evaluated and scored for engraftment of human cells. In a subsequent study, wounds were inoculated with strain SBI-N of Pseudomonas aeruginosa at 1 x 10(5) cfu/wound before the application of CSS or inoculated onto the surface of Acticoat. At 4 weeks, swab cultures were collected from the surface of CSS and scored for the presence of SBI-N. Statistical significance was accepted at the 95% confidence level (P <.05). The data show that exposure in vitro of CSS to Acticoat was cytotoxic within 1 day, but 1 week of exposure in vivo did not injure CSS or inhibit wound healing. Contaminated wounds treated with Acticoat healed similarly to control treatments, with comparable rates of engraftment, and detection of SBI-N on the surface of only one graft. No SBI-N was detected on CSS after inoculation onto the surface of Acticoat. These results suggest that Acticoat may be suitable as a protective dressing to reduce environmental contamination of CSS, if used in conjunction with additional antimicrobials to control organisms present in the wound.

Animals↗

PubMed1978

[Determination of the microbial contamination of tablets of tetracycline series antibiotics].

The experiments showed that the method of direct plating of tetracycline tablet suspensions on solid nutrient media containing magnesium sulfate may be used for determination of microbial contamination. The method provided determination of both the antibiotic resistant and the antibiotic sensitive organisms which may be present in the drug. Dilution of the basic suspensions increased the probability of the microbe detection in the tablets.

Dose-Response Relationship, Drug↗

PubMed2003

Microbial contamination in dental unit waterlines.

The quality of water in a dental unit is of considerable importance because patients and dental staff are regularly exposed to water and aerosol generated from the dental unit. The aim of this study was to evaluate the occurrence of microbial contamination in dental unit waterlines. Water samples were collected aseptically from the waterlines (reservoir, triple-syringe, high-speed) of 15 dental units. After serial dilution to 1:10(6) in APHA, the samples were seeded by the pour-plate technique and cultured in plate count agar (Difco) for 48 h at 32 degrees C. Analysis was based on the number of colony forming units (CFU). The Wilcoxon non-parametric test indicated that the levels of water contamination were highest in the triple-syringe (13 of 15) and in the high-speed (11 of 15); both levels were higher than those of the water reservoir. There was no significant statistical difference between the level of contamination in the triple-syringe and the high-speed as determined by the Mann-Whitney test [p(H0) = 40.98%; Z = - 0.2281]. Because biofilm forms on solid surfaces constantly bathed by liquid where microorganisms are present, these results indicate that the water in the dental unit may be contaminated by biofilm that forms in these tubules.

Bacteria↗

PubMed1995

Microbial contamination of harvested bone marrow and peripheral blood.

The incidence and clinical consequences of microbiological contamination of autologous bone marrow and peripheral blood progenitor cells are not well documented. We therefore retrospectively analysed our experience with bacterial or fungal contamination of harvested bone marrow and/or peripheral blood. From January 1987 to the end of January 1994, 499 patients were harvested or which 301 were transplanted. A total of 3910 specimens obtained during three stages in the processing were assessed for microbial contamination: (1) in the operating room immediately after harvesting (1662 bags) with 2.1% culture positivity, (2) after processing for cryopreservation (1039 bags) with a further 1.1% cultures positive, and (3) after thawing at the time of reinfusion (1209 bags) of which 2.2% were culture positive. There were no culture positive specimens obtained from any peripheral blood progenitor cell products. The vast majority of the 85 culture positive specimens obtained from marrow were skin flora (89%) and 35% of all positive harvest specimens remained positive following processing and freezing. At least 36% of culture positive specimens were thought to have arisen as a result of exogenous contamination of blood culture bottles. Potentially pathogenic enteric organisms were present in nine (0.2%) specimens and infusion of these organisms occurred in four cases. A further seven patients were reinfused with marrow culture positive for skin organisms. No adverse clinical sequelae were noted following infusion of any contaminated products. However, clinical decision making continues to be influenced by culture results and multistage microbial culture continues to be of value in the management of our marrow recipients.

Bone Marrow↗

PubMedDate not supplied

[Microbial contamination of the bile and its effects on the course of the surgical wound after cholecystectomy].

From a series of 58 cholecystectomies for chronic cholecystitis or for asymptomatic cholelithiasis, the authors have retrieved: 1) gall microbial contamination in 15,5% of the samples under study; 2) a complicated evolution--according to criteria defined for this research--of the operative wounds in 37,5% of the cases with positive gall cultures, and in 11% when the gall was sterile. It is the authors' opinion that cholecystectomy shows an actual septic risk, even in a non-acute clinical stage.

Adult↗

PubMed2004

Total viable counts, ATP, and endotoxin levels as potential markers of microbial contamination of dental unit water systems.

OBJECTIVES: To determine if either ATP or endotoxin concentrations in water supplied by dental unit water systems (DUWS) correlated with total viable counts (TVC), and therefore could be used as a rapid, chairside measure of levels of microbial contamination. DESIGN: A prospective trial. METHOD: Fifty-seven water samples were taken from the 'triple spray', air rotor and source water supplies from 25 dental units in eight practices. The samples were assayed for endotoxin concentration, total ATP and TVC. A pilot study was performed to assess the relationship between TVC and total cell counts, as determined by flow cytometry. RESULTS: ATP concentrations ranged from 22 to 958 relative light units (RLU) and free endotoxin ranged from 25 to 600 EU ml(-1). TVC varied from not detected to 2.16 x 10(4) CFU ml(-1). The ATP method proved to be a simple and rapid method that could be used at the chairside. However, there was no correlation between ATP or endotoxin concentrations and TVC in DUWS. TVC generally underestimated the total cell count by 50 to 500 fold. CONCLUSION: Half of the water samples from DUWS exceeded recommended levels of TVC. However, ATP and endotoxin concentrations in DUWS water samples did not correlate with these TVC data and therefore could not be recommended as an alternative assay to TVC for measuring bacterial contamination or for monitoring water treatment efficacy.

Adenosine Triphosphate↗

PubMedDate not supplied

Microbial contamination of enteral feeding solutions in a community hospital.

Seven related studies were done to estimate the type and amount of contamination that occurred in nutrient feeding solution when administered according to procedure in a community hospital. The initial study was done in a simulated nonclinical setting with select technicians monitoring for gavage systems delivering a commercially prepared nutrient feeding solution. The solution remained sterile over 48 hr. In the second study, various nurses maintained the enteral feeding simulations unaware of the objective of study. Significant contamination was found, but a decrease occurred when the study was duplicated and the nurses were made aware that contamination was the issue being studied. The subsequent study had all gavage equipment in clinical use in the hospital on a given day cultured for microbial contamination. Significant contamination was present and did not decrease when the study was duplicated following inservice training. Suggestions for standards of care are made.

Enteral Nutrition↗

PubMedDate not supplied

Rumen effective degradability of amino acids from soybean meal corrected for microbial contamination.

Rumen degradation kinetics and effective degradability of individual amino acids, total analysed amino acids (TAA) and crude protein (CP) of soybean meal were measured on four rumen-cannulated wethers using the nylon bag technique. Microbial contamination of the incubated residues was corrected using a continuous 15N intraruminal infusion and isolated solid associated bacteria as a reference sample. TAA showed a lower soluble fraction (14.9 vs. 20.8%; P < 0.01), a similar insoluble-degradable fraction (79.0 vs. 79.2%) and a higher degradation rate (11.5 vs. 8.4% x h(-1); P < 0.05) than CP. As a consequence, effective degradability was similar for TAA and CP (74.7 vs. 75.7%). Degradability values of individual amino acids varied moderately (range: +/-6% of TAA degradability). Valine, isoleucine, leucine, alanine, aspartic acid and tyrosine showed significantly lower degradability than TAA, while the opposite effect was observed for histidine, threonine and glutamic acid. Degradability of individual amino acids was related to their soluble fraction (r = 0.877; P<0.001).

Amino Acids↗

PubMed1984

[Epidemiological assessment of the microbial contamination of the breast milk of healthy women].

The qualitative and quantitative composition of the microflora of human milk has been studied. The dynamics of the occurrence of different microorganisms constituting the microflora at different periods of lactation has been established. The connection between the appearance of septic purulent infections in infants and the microbial contamination of milk has been revealed. The presence of Staphylococcus aureus in human milk in an amount of 500 microbial cells/ml has been found to constitute no menace to healthy infants.

Breast Feeding↗

PubMed2006

Microbial contamination of preservative free eye drops in multiple application containers.

BACKGROUND/AIMS: The majority of eye drops used in the United Kingdom contain preservatives and are bottled in plastic containers. Preservative free drops are used to avoid ocular irritation and allergies in certain individuals. The aim of this study was to investigate the incidence of microbial contamination of preservative free drops dispensed from multiusage containers. METHODS: Eye drop bottles were collected from patients attending the Tennent Institute of Ophthalmology outpatient and inpatient departments. The bottles were collected on day 3 (for inpatients) and day 7 (for outpatients) of use. The drops were inoculated onto different culture plates (chocolate agar, blood agar, fungal culture media, and enriched media) and the resulting microbial growth was identified using standard microbial identification techniques. RESULTS: 95 eye drop bottles were collected, containing a variety of 10 different eye drops. Significant bacterial growth was found in eight bottles. In total, seven different types of organism were identified from the eye drops. The organisms identified were Staphylococcus aureus, coagulase negative staphylococcus, Bacillus spp, Serattia spp, Klebsiella oxytoca, Enterobacter cloacae, and alpha streptococcus. Staph aureus was the commonest microbial organism. CONCLUSION: Preservative free eye drops in multiple application containers are at risk of contamination by potentially pathogenic micro-organisms.

Anti-Bacterial Agents↗

PubMed1985

Microbial contamination of non-sterile pharmaceutical products made in hospitals in the North East Thames Regional Health Authority.

Non-sterile pharmaceutical products made in nine hospitals in the North East Thames Regional Health Authority were examined for microbial contamination as part of a quality assurance programme. The incidence of contamination was found to vary between hospitals, but in all cases improvements were seen during the 3-year monitoring period in the microbiological quality of products made in individual hospitals. The most common isolates were aerobic spore bearers--usually less than 10(2) colony forming units/g or ml. Gram-negative isolates were found in at least one product from each hospital. Pseudomonas spp. were isolated from several samples of peppermint water.

Bacteria↗

PubMed1997

Microbial contamination of hydrogel contact lenses.

Bacterial contamination of contact lenses (CLs) may contribute to CL-related corneal infection and inflammation. This study reports CL biota over time during daily and extended wear. Microbial contamination of a 58% water, ionic hydrogel CL and a 38% water, non-ionic hydrogel CL was evaluated in an Australian and an Indian population. Fifty wearers were repeatedly sampled over 18 months. Overnight CL use did not alter the frequency of positive cultures, nor the spectrum of organisms compared with daily CL wear. There were no differences in type and frequency of CL contamination between the CL types. Positive cultures were more frequently recovered from the Indian population compared with the Australian population. Streptococcus spp. and Propionibacterium spp. were more frequently isolated from the Australian population. Fungi and Bacillus spp. were more frequently isolated from the Indian population. Normal CL biota alone cannot explain the increased rate of infection and inflammation in extended wear.

Bacillus↗

PubMed1995

Risk of microbial contamination of iodinated contrast media on multiple use of large-volume bottles.

Large-volume bottles of iodinated contrast material (CM) offer advantages over single-dose vials in respect of handling, radiation protection of personnel, cost and waste. Because non-ionic CM are considered to be susceptible to microbial contamination, the probability of such contamination was investigated under practical conditions with reference to the duration of use. Under conditions identical to those in practice, contamination was found in only about 1% of bottles examined after a single piercing. Under worst-case conditions, a maximum of 9 microorganisms/bottle was found. No pathogen multiplication was observed within 24 h in microbial challenge tests; rather, the nosocomial pathogens examined died quickly in iopromide, the only exception being Pseudomonas aeruginosa. There was not a single case of bacterial multiplication on clinical use of 500-ml infusion bottles in patients undergoing routine computed tomography, using either injection by hand or an automatic infusion device. In conclusion, the microbial count rate did not differ from that of small-volume parenterals used up immediately after piercing. To ensure an adequate safety margin for the avoidance of septicemia or pyrogenic reactions, the CM should be used within 1 examination day.

Bacteria↗

PubMed1997

Microbial Contamination in Spodoptera littoralis Nuclear Polyhedrosis Virus Produced in Insects in Egypt

Spodoptera littoralis nuclear polyhedrosis virus produced in Egypt, for use in field trials for the control of S. littoralis on cotton, was subject to microbiological examination to quantify microbial contamination. Bacteria were found to be present at 10(6)-10(9) colony-forming units/ml in virus suspensions containing 2.1 x 10(9) polyhedral inclusion bodies/ml. Batches were found to contain between 2 and 11 different species of contaminant microbes. No primary human pathogens of medical importance were found. The dominant species were fecal Streptococci and two Bacillus species, B. cereus and B. sphaericus. The Streptococci were derived from the normal gut flora found in healthy insects; the Bacillus species were common opportunistic saprophytes which gained access to the product by colonizing dead larvae and diet waste. Purification methods based on centrifugation were found to be ineffective in removing bacteria and improved methods of hygiene and harvesting appeared to be of more value in reducing contamination.

Journal Article↗

PubMed1993

Denture adhesives: cytotoxicity, microbial contamination, and formaldehyde content.

Denture adhesives are extensively used to enhance retention of dentures. Denture adhesives and their leachable components are ingested, but reports on the biologic aspects of denture adhesives are scarce. This study investigated some biological properties of 19 commercially available denture adhesives. The adhesives were assessed by the agar overlay technique and analyzed for microbial contamination and formaldehyde content. In the agar overlay test, all of the materials caused severe cytotoxic effects. Sabouraud dextrose agar was used for cultivation of fungi and tryptone soya broth for cultivation of aerobes, including fungi. Most of the samples tested showed microbial growth. The formaldehyde test revealed the presence of substantial amounts in four products and minor amounts in two products.

Adhesives↗

PubMed2000

Microbial contamination of gum elastic bougies.

The gum elastic bougie is a simple device that is used to assist in the management of the difficult intubation. It is not uncommon for a bougie to be re-used many times. This study investigated the incidence of microbial contamination of the bougies in one hospital. Potentially pathogenic organisms were identified both on the bougies and in their storage containers. This has implications for their cleaning and maintenance, and raises the question as to whether we should replace them with single-use, disposable devices.

Bacteria↗