Treatment of Platelet Products with Riboflavin and UV Light: Effectiveness Against High Titer Bacterial Contamination

Contamination of platelet units by bacteria has long been acknowledged as a significant transfusion risk due to their post-donation storage conditions. Products are routinely stored at 22 °C on an agitating shaker, a condition that can promote bacterial growth. Although the total number of bacteria believed to be introduced into a platelet product is extremely low, these bacteria can multiply to a very high titer prior to transfusion, potentially resulting in serious adverse events. The aim of this study was to evaluate a riboflavin based pathogen reduction process against a panel of bacteria that have been identified as common contaminants of platelet products. This panel included the following organisms: S. epidermidis, S. aureus, S. mitis, S. pyogenes, S. marcescens, Y. enterocolitica, B. neotomae, B. cereus, E. coli, P. aeruginosa and K. pneumoniae. Each platelet unit was inoculated with a high bacterial load and samples were removed both before and after treatment. A colony forming assay, using an end point dilution scheme, was used to determine the pre-treatment and post-treatment bacterial titers. Log reduction was calculated by subtracting the post-treatment titer from the pre-treatment titer. The following log reductions were observed: S. epidermidis 4.7 log (99.998%), S. aureus 4.8 log (99.998%), S. mitis 3.7 log (99.98%), S. pyogenes 2.6 log (99.7%), S. marcescens 4.0 log (99.99%), Y. enterocolitica 3.3 log (99.95%), B. neotomae 5.4 log (99.9996%), B. cereus 2.6 log (99.7%), E. coli ≥5.4 log (99.9996%), P. aeruginosa 4.7 log (99.998%) and K. pneumoniae 2.8 log (99.8%). The results from this study suggest the process could help to lower the risk of severe adverse transfusion events associated with bacterial contamination.     

Response of Antarctic Soil Bacterial Assemblages to Contamination by Diesel Fuel and Crude Oil

Abstract The effects of diesel fuel and ``Arabian light' crude oil addition on Antarctic bacterial assemblages were studied in four contaminated soils during 1 year in the Terre Adelie land area. Monthly sampling allowed a regular survey of the bacterial changes occurring in the contaminated soils. All samples were analyzed for total bacteria, heterotrophic culturable microbiota, and hydrocarbon-utilizing microbiota. Crude oil contamination induced an initial increase of all bacterial parameters in all contaminated soils. Diesel oil contamination had a more complex effect. Hydrocarbon degrading bacterial abundance increases occurred after diesel oil addition. In contrast, general heterotrophic bacterial abundance could significantly decrease in the same conditions. In all cases the stimulatory effects of oil addition disappeared after several months of contamination. Received: 13 April 1999; Accepted: 24 February 2000; Online Publication: 29 May 2000     

Rationale and Procedures for Using the Tissue-Residue Approach for Toxicity Assessment and Determination of Tissue,Water, and Sediment Quality Guidelines for Aquatic Organisms

This article describes a set of procedures for developing tissue, water, and sediment quality guidelines for the protection of aquatic life by using the tissue-residue approach (TRA) for toxicity assessment. The TRA, which includes aspects of the Critical Body Residue (CBR) approach, associates tissue concentrations of chemicals with adverse biological effects in a dose-response fashion that can be used to determine CBRs. These CBRs can then be used to develop tissue quality guidelines (TQGs), which may be translated into water or sediment guidelines with bioaccumulation factors. Not all toxicants are amenable to this type of analysis; however, some appear to exhibit relatively consistent results that can likely be applied in a regulatory framework. By examining tissue residues, variations in toxicokinetics (temporal aspects of accumulation, biotransformation, and internal distribution) are greatly reduced allowing a greater focus on toxicodynamics (action and potency) of the toxicants. The strongest feature of this approach is causality; hence, guidelines based on tissue concentrations are based on data demonstrating a causal relationship between the acquired dose and the biological effect. Because the TRA has utility for assessing the toxicity of contaminant mixtures, an approach is presented here using toxic unit values that can be used to assess the likelihood of observing toxic effects based on tissue residues.     

Assessment of Blood Contamination in Biological Fluids Using MALDI-TOF MS

Biological fluid sample collection often includes the risk of blood contamination that may alter the proteomic profile of biological fluid. In proteomics studies, exclusion of contaminated samples is usually based on visual inspection and counting of red blood cells in the sample; analysis of specific blood derived proteins is less used. To fill the gap, we developed a fast and sensitive method for ascertainment of blood contamination in crude biological fluids, based on specific blood-derived protein, hemoglobin detection by MALDI-TOF MS. The MALDI-TOF MS based method allows detection of trace hemoglobin with the detection limit of 0.12 nM. UV-spectrometry, which was used as reference method, was found to be less sensitive. The main advantages of the presented method are that it is fast, effective, sensitive, requires very small sample amount and can be applied for detection of blood contamination in various biological fluids collected for proteomics studies. Method applicability was tested on human cerebrospinal and follicular fluid, which proteomes generally do not contain hemoglobin, however, which possess high risk for blood contamination. Present method successfully detected the blood contamination in 12 % of cerebrospinal fluid and 24 % of follicular fluid samples. High percentage of contaminated samples accentuates the need for initial inspection of proteomic samples to avoid incorrect results from blood proteome overlap.     

Effects of Spilled Oil on Bacterial Communities of Mediterranean Coastal Anoxic Sediments Chronically Subjected to Oil Hydrocarbon Contamination

The effects of spilled oil on sedimentary bacterial communities were examined in situ at 20 m water depth in a Mediterranean coastal area. Sediment collected at an experimental site chronically subjected to hydrocarbon inputs was reworked into PVC cores with or without a massive addition of crude Arabian light oil (∼20 g kg⁻¹ dry weight). Cores were reinserted into the sediment and incubated in situ at the sampling site (20 m water depth) for 135 and 503 days. The massive oil contamination induced significant shifts in the structure of the indigenous bacterial communities as shown by ribosomal intergenic spacer analysis (RISA). The vertical heterogeneity of the bacterial communities within the sediment was more pronounced in the oiled sediments particularly after 503 days of incubation. Response to oil of the deeper depth communities (8–10 cm) was slower than that of superficial depth communities (0–1 and 2–4 cm). Analysis of the oil composition by gas chromatography revealed a typical microbial alteration of n-alkanes during the experiment. Predominant RISA bands in oiled sediments were affiliated to hydrocarbonoclastic bacteria sequences. In particular, a 395-bp RISA band, which was the dominant band in all the oiled sediments for both incubation times, was closely related to hydrocarbonoclastic sulfate-reducing bacteria (SRB). These bacteria may have contributed to the main fingerprint changes and to the observed biodegradation of n-alkanes. This study provides useful information on bacterial dynamics in anoxic contaminated infralittoral sediments and highlights the need to assess more precisely the contribution of SRB to bioremediation in oil anoxic contaminated areas.     

Comprehensive Assessment of Germline Chemical Toxicity Using the Nematode Caenorhabditis elegans

Identifying the reproductive toxicity of the thousands of chemicals present in our environment has been one of the most tantalizing challenges in the field of environmental health. This is due in part to the paucity of model systems that can (1) accurately recapitulate keys features of reproductive processes and (2) do so in a medium- to high-throughput fashion, without the need for a high number of vertebrate animals.We describe here an assay in the nematode C. elegans that allows the rapid identification of germline toxicants by monitoring the induction of aneuploid embryos. By making use of a GFP reporter line, errors in chromosome segregation resulting from germline disruption are easily visualized and quantified by automated fluorescence microscopy. Thus the screening of a particular set of compounds for its toxicity can be performed in a 96- to 384-well plate format in a matter of days. Secondary analysis of positive hits can be performed to determine whether the chromosome abnormalities originated from meiotic disruption or from early embryonic chromosome segregation errors. Altogether, this assay represents a fast first-pass strategy for the rapid assessment of germline dysfunction following chemical exposure.     

Assessment of Anthropogenic Influence on Heavy Metals Contamination in the Aquatic Ecosystem Components: Water,Sediment, and Fish

Heavy metals (Pb, Cd, Ni, Cr, Cu, Zn, Mn, and As) concentration was investigated in the industrial effluents, water, sediment, and fish samples collected around the Dhaka Export Processing Zone, Savar, Bangladesh, to evaluate the level of contamination. The metals concentration in the industrial effluents of DEPZ and in the water samples of Dhalaibeel (lowland cum lake) and Bangshi River were significantly higher compared to the guideline values for industrial effluents and for drinking water (WHO and USEPA), respectively. The sedimentary metal concentrations were found to be lower than the respective probable effect concentrations (PECs) following the sediment quality guidelines. Furthermore, in comparison with the fish standards, the studied fish species were not found to be contaminated by heavy metals. Principal component analysis and cluster analysis demonstrated that the wastewater from the numerous industries and the domestic sewages around the DEPZ might have a possible impact on heavy metals contamination in the study area. The Pearson correlation analysis showed significant correlations (p < 0.01 and p < 0.05) between most of the metals in the samples of effluents, water, sediments, and fish muscles. The percentage enrichment factor (EF%) and geo-accumulation index () were followed to evaluate metal contamination in the sediment samples. Dhalaibeel sediment was maximally enriched for Cr (53.55%) and Bangshi River sediment for Zn (54.37%). The geo-accumulation index values for the sediment samples were less than zero, indicating that the sediment samples were free from contamination. This study could be used as a model study to assess the impact of anthropogenic activities on heavy metals contamination in aquatic ecosystems.     

Assessment of the Toxicity of CuO Nanoparticles by Using Saccharomyces cerevisiae Mutants with Multiple Genes Deleted

To develop applicable and susceptible models to evaluate the toxicity of nanoparticles, the antimicrobial effects of CuO nanoparticles (CuO-NPs) on various Saccharomyces cerevisiae (S. cerevisiae) strains (wild type, single-gene-deleted mutants, and multiple-gene-deleted mutants) were determined and compared. Further experiments were also conducted to analyze the mechanisms associated with toxicity using copper salt, bulk CuO (bCuO), carbon-shelled copper nanoparticles (C/Cu-NPs), and carbon nanoparticles (C-NPs) for comparisons. The results indicated that the growth inhibition rates of CuO-NPs for the wild-type and the single-gene-deleted strains were comparable, while for the multiple-gene deletion mutant, significantly higher toxicity was observed (P < 0.05). When the toxicity of the CuO-NPs to yeast cells was compared with the toxicities of copper salt and bCuO, we concluded that the toxicity of CuO-NPs should be attributed to soluble copper rather than to the nanoparticles. The striking difference in adverse effects of C-NPs and C/Cu-NPs with equivalent surface areas also proved this. A toxicity assay revealed that the multiple-gene-deleted mutant was significantly more sensitive to CuO-NPs than the wild type. Specifically, compared with the wild-type strain, copper was readily taken up by mutant strains when cell permeability genes were knocked out, and the mutants with deletions of genes regulated under oxidative stress (OS) were likely producing more reactive oxygen species (ROS). Hence, as mechanism-based gene inactivation could increase the susceptibility of yeast, the multiple-gene-deleted mutants should be improved model organisms to investigate the toxicity of nanoparticles.     

Assessing the Chronic Aquatic Toxicity of Phthalate Ester Plasticizers

Phthalic acid esters (PAE) are a class of chemicals varying greatly in terms of uses, properties, and toxicity. C1 to C4 PAE are used in non-vinyl commercial products and pharmaceuticals. C8 to C10 PAE are additives imparting flexibility to vinyl resins. The purpose of the present study is to assess chronic effects of PAE on aquatic organisms. Studies show that populations of fish and invertebrates may be adversely affected by exposure to C1 to C4 PAE, but are not adversely affected by exposure to C8 or higher PAE. Secondary endpoints, including molecular, biochemical, and/or histological responses to chemical exposure, do not appear to predict effects related to primary endpoints of survival, growth and development, or reproductive fitness. A previously published risk assessment for C1 to C4 PAE demonstrated low risks in North American and Western European surface waters. Risk assessments conducted by authorities in Europe with di-2-ethylhexyl-, di-isononyl-, and di-isodecyl phthalates have concluded no risks to aquatic organisms due to aqueous solubility constraints, low expected surface water concentrations, and metabolic biotransformation capabilities of aquatic organisms. The present review of chronic aquatic toxicity data, which includes data from studies performed subsequent to the risk assessments, confirms these earlier conclusions.     

Assessment of Heavy Metal Contamination in the Sediments of the Shuangtaizi Estuary Using Multivariate Statistical Techniques

In order to assess heavy metal pollution of sediment samples collected from Shuangtaizi estuary, contamination factor (CF) and multivariate statistical analyses, including principal component analysis (PCA), cluster analysis (CA) and correlation analysis, are carried out in this paper. CF confirms that Pb, Cu and Hg concentrations are very low and all fall within the range of background, while Zn and Cd demonstrate moderate contamination (in A10, A13, A15, A16 and A17 sites) and very high contamination (in A10, A13, A15 and A17 sites), respectively. The PCA indicates that four significant principal components (PCs) are extracted, explaining 88.959% of total variance, which suggests that Pb, Cu and Zn are mainly associated with organic carbon (OC). The result from CA is consistent with that obtained from PCA, classifying that the heavy metals in two clusters derive from different sources. Correlation analysis supports the conclusions from PCA and CA, elucidating the relationships between heavy metals and particle sizes of the sediments.     

Using the PCR and Blood Agar in Diagnosis of Semen Bacterial Contamination of Fertile and Infertile Men

Background:One of the causes of male infertility is Genital tract infections (GTI). Considering the importance of GTI, widespread recognition of them seems necessary. we aimed to characterize and compare semen microbial populations in fertile and infertile men who referred to an infertility clinic in Yazd, Iran.Methods:Semen samples were collected from two groups of fertile (268) and infertile (210) men. Sperm analysis (concentration, morphology, viability and motility parameters) were performed according to the World Health Organization (WHO) 2010 guidelines laboratory manual. Bacterial isolation was performed in Sheep Blood Agar and Eosin Methylene Blue (EMB) agar plates. For PCR, samples were analyzed with genus specific primers.Results:All semen characteristics were poor in the infertile group compared to those in the fertile men (p-value< 0.05). Enterococcus spp. (18.7%, 17.1%; p= 0.814), E. coli (7.9%, 11.4%; p= 0.486), Staphylococcus aureus (6.4%, 2.9%; p= 0.398) and Proteus mirabilis (0%, 2.9%; p= 0.002) were the most common agents, respectively. Also, the results obtained from PCR were confirmed using culture-base method.Conclusion:Proteus mirabilis contamination was identified in the infertile group. While no significant association was observed between male infertility and semen microbial populations, p. mirabilis may be the leading cause of reproduction impairment in men.Key Words: Infertility, Microbial contamination, culture, PCR     

Uncertainty Analysis and Toxicity Classification in Life-Cycle Assessment Using the Case-study of Gas Purification Systems

This comprehensive thesis structures the decision-making process for making a choice of the most adequate gas purification system (GasPS). Various gas purification technologies (biofilter, activated carbon filter, catalytic oxidation, thermo-reactor) have been evaluated based on an industrial case-study for waste gas streams. The ecological performance was quantified using the life-cycle impact assessment methods Eco-Indicator 95 and Swiss Ecopoints (environmental scarcities). Both life-cycle impact assessment methods have been improved by a new classification method for volatile organic compounds (VOCs) which considers the environmental fate and exposure as well as the toxicity of these compounds. For life-cycle assessment, a detailed quantitative uncertainty analysis was carried out using Monte Carlo simulation. Based on the uncertainty analysis, developing statements about the significance of the results and of relative differences between various GasPS alternatives has been possible. The eco-efficiency of the investigated GasPSs was finally characterised based on four indicators: Net Ecological Benefit (NEB_N), Ecological Yield Efficiency (lgEYE), Net Present Value (NPV), and Ecological-Economic Efficiency (EEE).     

细菌纤维素发酵培养基的优化及超微观结构分析

为了提高细菌纤维素的产量, 本研究对一株氧化葡糖杆菌菌株J2液体发酵生产细菌纤维素的培养基进行了优化, 并对其代谢的细菌纤维的超微观结构进行了观察。运用Plackett-Burman试验设计法对8个相关影响因素的效应进行了评价, 筛选出了有显著效应的3个因素: 酵母膏、ZnSO4、无水乙醇, 其他5个因素的影响未达到显著水平(P>0.05)。然后采用Box-Behnken的中心组合试验设计和响应面分析方法(RSM)确定了上述三个因素的最佳浓度, 并且以棉纤维为对照, 运用扫描电镜观察了细菌纤维素的超微观结构, 结果表明: 菌株J2利用优化后的发酵培养基生产细菌纤维素的产量为11.52 g/100 mL, 是优化前的1.35倍, 电镜照片显示细菌纤维素微纤维丝直径<0.1 mm, 比棉纤维细很多, NaOH处理可以除去纤维网络结构中的菌体。     

Sediment Toxicity Bioassays Using Ruditapes decussatus Embryos and Larvae to Assess the Contamination in Four Sites on the Coast of Tunisia

This paper aims to assess the marine sediment quality along the Tunisian coast using clam Ruditapes decussatus embryos and larval bioassays tests. Elutriate samples prepared with sediment from four sites (Monastir Lagoon, Chebba, Mahres, and Zarat) were used for chemical analysis and clam bioassays tests (embryogenesis, larval growth. and metamorphosis). For embryogenesis test, five elutriates concentrations (12%, 25%, 50%, 75%, and 100%) were prepared. Metal concentrations were highest at the Mahres and Monastir Lagoon sites. Clam embryogenesis success was significantly (p < 0.05) reduced in all elutriates preparations at concentrations up to 50% except Chebba, where inhibition was evident at only the highest concentration (100%). Compared to the control (9.4 μm day^?1), larval growth rate was significantly (p < 0.05) reduced only in two sites, Monastir Lagoon (6.8 μm day^?1) and Zarat (5.6 μm day^?1). However, larval survival was lower (42.9%) in elutriates prepared from Mahres sediment compared to other studied sites and control treatment. We did not note any significant (p > 0.05) effect of elutriate preparations on clam metamorphosis; conversely, survival in this stage was significantly affected in three sites (Monastir: 59.0 ± 6.7%; Zarat: 52.1 ± 6.3%, and Mahres: 64.1 ± 5.4%) compared to the control (83.2 ± 4.7%). This work shows that both clam embryos and larvae are sensitive to contaminants and can be used to evaluate sediment contamination and monitor pollution.     

Assessment and Interpretation of Bacterial Viability by Using the LIVE/DEAD BacLight Kit in Combination with Flow Cytometry

The commercially available LIVE/DEAD BacLight kit is enjoying increased popularity among researchers in various fields of microbiology. Its use in combination with flow cytometry brought up new questions about how to interpret LIVE/DEAD staining results. Intermediate states, normally difficult to detect with epifluorescence microscopy, are a common phenomenon when the assay is used in flow cytometry and still lack rationale. It is shown here that the application of propidium iodide in combination with a green fluorescent total nucleic acid stain on UVA-irradiated cells of Escherichia coli, Salmonella enterica serovar Typhimurium, Shigella flexneri, and a community of freshwater bacteria resulted in a clear and distinctive flow cytometric staining pattern. In the gram-negative bacterium E. coli as well as in the two enteric pathogens, the pattern can be related to the presence of intermediate cellular states characterized by the degree of damage afflicted specifically on the bacterial outer membrane. This hypothesis is supported by the fact that EDTA-treated nonirradiated cells exhibit the same staining properties. On the contrary, this pattern was not observed in gram-positive Enterococcus faecalis, which lacks an outer membrane. Our observations add a new aspect to the LIVE/DEAD stain, which so far was believed to be dependent only on cytoplasmic membrane permeability.     

Evaluation of Toxicity of <Emphasis Type="Italic">Cercospora piaropi</Emphasis> in a Mycoherbicide Formulation by Using Bacterial Bioluminescence and the Ames Mutagenicity Tests

An evaluation of the potential hazards associated with mutagenicity and acute toxicity of a mycoherbicide formulation based on the fungal pathogen Cercospora piaropi was performed. Neither the mycoherbicide nor any of its components were mutagenic to Salmonella typhimurium TA98 and TA100 with or without metabolic activation. Both the C. piaropi and the mycoherbicide formulation were shown to be moderately toxic with a bacterial bioluminescence assay. No acute toxicity was found in water samples taken from tanks after treatment of water hyacinth with the mycoherbicide.