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Microbial Contamination (microbial + contamination)

Distribution by Scientific Domains

Life Sciences	46%
Chemistry	33%

Selected Abstracts

Micro-organisms and dust exposure in an Italian grain mill

JOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2005
C. Dacarro
Abstract Aims:, In order to assess possible occupational risk for workers in a grain mill, we evaluated aerial microbiological contamination in different areas of the mill and at different points of the production line. We also measured the concentration of aerodispersed dust particles. Methods and Results:, An assessment of microbiological contamination levels based on a Global Index of Microbial Contamination per cubic metre (GIMC per m3), an Index of Mesophilic Bacterial Contamination, and an Amplification Index is proposed. The indices were obtained from total and fungal counts. The cleaning sector is the most contaminated area of the mill: the mean GIMC per m3 was 17 213·6. In this area, the average microbial contamination was 11·41 times higher than that in the external environment. The highest concentrations of aerodispersed dust (inhalable 2·763 mg m,3; respirable 1·400 mg m,3) were found in the cleaning area. Conclusions:, The proposed microbiological indices and the concentrations of aerodispersed dust particles show that the most hazardous section of the mill is the cleaning area. The large variation in the data does not depend on seasonal factors, but rather on not easily identifiable conditions of the internal environment which facilitate diffusion and/or proliferation of the micro-organisms. Significance and Impact of the Study:, The proposed microbiological contamination indices and the evaluation of the concentration of dust particles allow the identification of critical positions during the production cycle so that suitable measures to prevent the aerial contamination can be taken. [source]

In situ evaluation of the protein value of wheat grain corrected for ruminal microbial contamination

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 4 2009
José M Arroyo
Abstract BACKGROUND: Uncorrected and microbial corrected in situ estimates of ruminal effective degradability (RED) of dry matter (DM), organic matter (OM) and crude protein (CP) and intestinal effective digestibility (IED) of DM and CP of a wheat grain sample were obtained by a simplified method using a sample pooled from rumen-incubated residues representing rumen outflow of undegraded food. Uncorrected values of RED of DM and CP were also obtained by the usual mathematical integration method. The study was performed in three rumen and duodenum cannulated wethers. RESULTS: Uncorrected values of RED of CP were similar either for the mathematical integration or this simplified method (82.4% vs. 82.2%). Microbial contamination in the rumen led to small underestimations (P < 0.05) of RED of DM (87.9% vs. 88.1%) and CP (82.2% vs. 82.8%) and to small overestimations (P < 0.05) of IED for DM (66.5% vs. 66.1%) and CP (87.7% vs. 87.3%). Accumulative errors resulted in overestimations (P < 0.05) of the intestinal digested fractions of DM (1.8%) and CP (4.0%). CONCLUSION: Corrected values of intestinal digested CP show that the protein value of wheat is closely related to the microbial protein synthesis derived from its OM rumen fermentation. This synthesis and the content of intestinal digested undegraded protein may be respectively higher and lower than is usually assumed in feed tables. Copyright © 2009 Society of Chemical Industry [source]

Microbial contamination of contact lenses and lens care accessories of soft contact lens wearers (university students) in Hong Kong

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 1 2007
M. S. Yung
Abstract Purpose:, This study aimed to examine the rates of microbial contamination, and identify contaminants associated with contact lenses and lens care accessories used by a group of young contact lens wearers. Methods:, Collected contact lenses, lens cases, and lens care solutions were studied by bacterial culture. Contamination rates of these samples were recorded and compared with those reported in previous studies. Results:, Of the samples tested, 9% of lens extracts, 34% of case extracts and 11% of solution samples were contaminated with ocular pathogenic microorganisms. Serratia spp., Staphylococcus aureus and coagulase-negative staphylococci were the most common microorganisms isolated. Lens cases were the most frequently contaminated item. Lens cases also yielded the widest range of bacterial isolates. Contact lenses used by occasional wearers were associated with a higher contamination rate. Using either saline or multipurpose solution to rinse lenses before use appeared to be effective in reducing incidence of contamination. Conclusion:, Our findings demonstrate that contact lenses and lens care accessories are not well maintained by contact lens wearers. Regular reviews and reinforcement of lens care procedures for the usage and care of contact lenses and lens care accessories is therefore important and essential. [source]

Control of Penicillium roqueforti (Thom) infection in cultures of Drosophila melanogaster (Meigen) (Diptera: Drosophilidae)

AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 2 2008
Clare E Holleley
Abstract, Microbial contamination of artificial insect food media can jeopardise the viability, productivity and survival of many insect cultures, including Drosophila melanogaster. Here we investigated and improved upon control methods for one common contaminant, Penicillium roqueforti. We found that the combined effect of methyl p -hydroxybenzoate (23.7 mM), propionic acid (67.5 mM) and sorbic acid (8.9 mM) (PSNPS treatment) was the most effective of the four candidate treatments, at inhibiting the growth of P. roqueforti. PSNPS treatment inhibited 100% of visible P. roqueforti growth for 21 days (a complete D. melanogaster life cycle) and thus reduced the risk of transmitting infection to the next generation. Although the PSNPS treatment negatively affected the two D. melanogaster fitness components, survivorship (number of adults) and biomass (live weight), it did not prevent successful reproduction and is suitable for short-term treatment of P. roqueforti infections. [source]

Micro-organisms and dust exposure in an Italian grain mill

Peracetic acid as an alternative wastewater disinfectant to chlorine dioxide

JOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2002
S. Stampi
Aims: The aim of this study was to compare the efficiency of peracetic acid with that of chlorine dioxide in the disinfection of wastewater from a sewage treatment plant (serving about 650 000 inhabitants) that has been using peracetic acid as a disinfectant since 1998. Methods and Results: A total of 23 samplings were made, each consisting of three samples: from secondary effluent, effluent disinfected with 2 mg l,1 of peracetic acid and effluent disinfected with 2·2 mg l,1 of chlorine dioxide (contact time 20 min). For each sample, measurements were made of the heterotrophic plate count at 36°C, total and faecal coliforms, Escherichia coli, enterococci, pH, suspended solids and chemical oxygen demand (COD). During the first phase of the experiment the peracetic acid was seen to be less efficient than chlorine dioxide. To improve the disinfectant action a system of mechanical agitation was added which led to a greater efficiency in the inactivation of bacteria of faecal origin. Conclusions: Both products were found to be influenced by the level of microbial contamination, the amount of suspended solids and COD but not by the pH of the effluent before disinfection. The immediate mixing of the wastewater and disinfectant caused a greater reduction in enterococci. Significance and Impact of the Study: Since peracetic acid was seen to produce a high abatement of micro-organisms, it can be considered as a valid alternative to chlorine dioxide in the disinfection of wastewaters. [source]

Hygiene measures considering actual distributions of microorganisms in Japanese households

JOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2002
M. Ojima
Aims: Effective household hygiene measures require that sources of bacterial contamination and the places to which contamination spreads be carefully identified. Therefore, a study was performed to examine the distribution of microorganisms throughout ordinary households in Japan, which has its own unique customs of daily life and food preparation. Methods and Results: Using the stamping method, samples were taken from 100 different places and items in each of 86 households. This study found kitchens/dining rooms to have the greatest level of microbial contamination and bathrooms, the next highest level. Toilets (water closets) were found to have an unexpectedly low level of bacterial contamination. The largest bacterial counts were found on items such as drain traps, dish-washing sponges, counter towels, sinks, dish-washing tubs, and bathroom sponges. Conclusions: It is necessary to carefully identify both the items that can become instruments for spreading bacterial contamination and the places that easily become subject to secondary contamination, and then to take timely and effective disinfection/sanitizing measures. Significance and Impact of the Study: The data gathered in this study will be very valuable for anticipating the pathways over which bacteria are transported and prioritizing disinfection targets, to make effective disinfection possible. [source]

AQUEOUS GARLIC EXTRACT AND MICROBIOLOGICAL QUALITY OF REFRIGERATED POULTRY MEAT

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2005
KEILY ALVES DE MOURA OLIVEIRA
ABSTRACT The antibacterial effect of garlic extract (5, 10 and 15%) was investigated on poultry carcasses obtained from a slaughterhouse, stored under refrigeration, and evaluated at selected time intervals. The effect of the garlic extract on the microbial contaminants of the poultry carcass surface , Salmonella, strict and facultative aerobic, mesophilic, and total and fecal coliforms , was evaluated. The garlic extract exhibited a concentration-dependent reduction of microbial contamination. Garlic extract concentrations of 10 and 15% were the most effective. The bacteriostatic action of garlic extract against mesophilic microbiota can be observed until the third storage day. The count of total and fecal coliforms remained low during the storage period. Chicken feed was the apparent source of Salmonella contamination, and the aqueous garlic extract was not effective against Salmonella. [source]

IDENTIFICATION OF CRITICAL CONTROL POINTS IN THE TWO SELECTED HACCP-CERTIFIED PRAWN PROCESSING UNITS

JOURNAL OF FOOD QUALITY, Issue 2 2009
PADMAJA R. JONNALAGADDA
ABSTRACT A study on identification of critical control points in two export processing units indicated the contamination (cfu/g) of raw prawns with pathogenic fecal coliforms was <10,8 × 102 in Unit A, 1 × 101,1.3 × 102 in Unit B and 1 × 103,4 × 104 in pond to plate. The other microbial contaminants in Unit A and from Pond to Plate at different stages were Salmonella spp., 3 × 102,5.7 × 103 and 2 × 102,6 × 102; Staphylococcus aureus, 1.7 × 103,5.7 × 103 and 1 × 103 to 9 × 104; and Vibrio parahaemolyticus, 3 × 102,2 × 104 and 3 × 104,5 × 104, respectively. However, microbial contamination was significantly reduced to <10 after subjecting to household cooking process. PRACTICAL APPLICATIONS Implementation of hazard analysis critical control points (HACCPs) in the food industry is the most important approach to maintaining food safety. Identification of the critical control points in the HACCPs process will help the aquaculture industry to improve its production processes by applying good aquaculture and good hygienic practices at the production level. The study further provides clear insights into identifying critical control points both at the farm level and at the processing units that are important from farm to fork. [source]

Effect of High Pressure Pasteurization on Bacterial Load and Bioactivity of Echinacea Purpurea

JOURNAL OF FOOD SCIENCE, Issue 7 2010
Xiu-Min Chen
Abstract:, High hydrostatic pressure (HHP) technology was applied to organic Echinacea purpurea (E. purpurea) roots and flowers to determine the feasibility of using this technology for cold herb pasteurization, to produce microbiologically safe and shelf-stable products for the natural health products (NHPs) industry. HHP significantly (P < 0.01) reduced microbial contamination in both roots and flowers without affecting the phytochemical retention of chicoric and chlorogenic acids, and total alkamide contents. The antioxidant activity of E. purpurea methanol-derived extracts, evaluated in both chemical (2,2,-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) [ABTS] and oxygen radical absorption capacity [ORAC] assay) and in cell culture models (RAW264, 7 macrophage, H2O2 -induced intracellular oxidation, and lipopolysaccharide [LPS]-induced nitric oxide production), was not adversely affected by the application of HHP at both 2 and 5 min at 600 mPa. Furthermore, HHP did not affect the capacity of E. purpurea extracts to suppress nitric oxide production in LPS-activated macrophage cells. Therefore, our results show that HHP is an effective pasteurization process treatment to reduce microbial-contamination load while not adversely altering chemical and bioactive function of active constituents present in organic E. purpurea. Practical Application:, Our study reports for the first time, the effectiveness of using high hydrostatic pressure (HHP) technology pressure to pasteurize E. purpurea root and flower, and the comparative retention of bioactive phytochemicals. Therefore, this technique can be used in food and natural health product industries to produce high-quality, microbiologically safe, and shelf-stable products. [source]

A NEW LARVAL FISH BIOASSAY FOR TESTING THE PATHOGENICITY OF PFIESTERIA SPP. (DINOPHYCEAE),

JOURNAL OF PHYCOLOGY, Issue 3 2003
Vincent J. Lovko
Water quality, microbial contamination, prior fish health, and variable results have been major impediments to identifying the cause and mechanism of fish mortality in standard aquarium-format Pfiesteria bioassays. Therefore, we developed a sensitive 96-h larval fish bioassay for assessing Pfiesteria spp. pathogenicity using six-well tissue culture plates and 7-day-old larval cyprinodontid fish. We used the assay to test pathogenicity of several clonal lines of Pfiesteria piscicida Steidinger and Burkholder and P. shumwayae Glasgow and Burkholder that had been cultured with algal prey for 2 to 36 months. The P. shumwayae cultures exhibited 80%,100% cumulative mortality in less than 96 h at initial zoospore densities of approximately 1000 cells·mL,1. No fish mortalities occurred with P. piscicida at identical densities or in controls. In a dose-response assay, we demonstrated a strong positive correlation between dinospore density and fish mortality in a highly pathogenic culture of P. shumwayae, generating a 96-h LD50 of 108 zoospores·mL,1. Additionally, we applied the assay to evaluate a 38-L P. shumwayae bioassay that was actively killing fish and compared results with those from exposures of juvenile tilapia (Oreochromis niloticus) in a 500-mL assay system. Water from the fish-killing 38-L assay was filtered and centrifuged to produce fractions dominated by dinoflagellates, bacteria, or presumed ichthyotoxin (cell-free fraction). After 96 h, the larval fish assay exhibited 50%,100% cumulative mortality only in fractions containing dinoflagellates, with no mortalities occurring in the other fractions. The 500-mL bioassay with tilapia produced inconsistent results and demonstrated no clear correlation between mortality and treatment. The new larval fish bioassay was demonstrated as a highly effective method to verify and evaluate dinoflagellate pathogenicity. [source]

In situ evaluation of the protein value of wheat grain corrected for ruminal microbial contamination

Detection of Mollicutes in bioreactor samples by real-time transcription-mediated amplification

LETTERS IN APPLIED MICROBIOLOGY, Issue 6 2010
S. Laborde
Abstract Aim:, Contamination by Mollicutes is a significant challenge for research laboratories and biopharmaceutical industry. It leads to alteration of results or production quality as well as loss of time, materials and revenue. These organisms can czoriginate from mammalian, avian, insect, plant or fish cells. Culture-based methods may require 28 days to detect Mollicutes. Traditional microbiology could advantageously be replaced by nucleic acid testing for earlier detection. Methods and Results:, A membrane filtration-based concentration of the Mollicutes has been coupled to real-time transcription-mediated amplification (real-time TMA) to demonstrate these advantages. The eight species required by European Pharmacopoeia have been tested and were detected with sensitivity below 100 CFU per 20-ml sample. Co-culture experiments, in which Mollicutes are grown with CHO-S (suspension) or HEK 293 (adherent) cells, were also performed to respectively mimic a bioreactor or flask contamination. Despite the fact that Mollicutes can attach to or invade mammalian cells, they were consistently detected over multiple days. Conclusions:, the sample preparation and amplification method used in this study increases sensitivity and reduces time-to-result for detection of Mollicutes. Significance and Impact of the Study:, the described system allows real-time monitoring for microbial contamination of cell-based processes and products for the biopharmaceutical industry. [source]

Microbial contamination of contact lenses and lens care accessories of soft contact lens wearers (university students) in Hong Kong

Biofilm Formation and Control in Food Processing Facilities

COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2003
R.A.N. Chmielewski
ABSTRACT Microorganisms on wet surfaces have the ability to aggregate, grow into microcolonies, and produce biofilm. Growth of biofilms in food processing environments leads to increased opportunity for microbial contamination of the processed product. These biofilms may contain spoilage and pathogenic microorganisms. Microorganisms within biofilms are protected from sanitizers increasing the likelihood of survival and subsequent contamination of food. This increases the risk of reduced shelf life and disease transmission. Extracellular polymeric substances associated with biofilm that are not removed by cleaning provide attachment sites for microorganisms newly arrived to the cleaned system. Biofilm formation can also cause the impairment of heat transfer and corrosion to metal surfaces. Some of the methods used to control biofilm formation include mechanical and manual cleaning, chemical cleaning and sanitation, and application of hot water. [source]