Intestinal parasite infections have been known to compromise the quality of human life since prehistoric times. Throughout the ages, human civilizations have fought against parasitism, including intestinal parasites. During the second half of the last century, the focus of disease-combating efforts moved to other imminent public health issues, under the notion that the fight against infectious diseases had been won. However, the disease incidence data indicate that these diseases continue to wreak havoc on human productivity across the globe. Lately, chemotherapeutic intervention has been stressed for the control of intestinal parasitic infections. In this paper we evaluate the need for a holistic approach to address this issue and make recommendations for this cause.

Four methods, fast titration, salt addition, mass titration, and ζ potentiometry, were employed to determine the point of zero charge (PZC) and isoelectric point (IEP) of NiO. However, this work mainly focuses on the fast titration method because it limits the release of Ni from the substrate. Furthermore, the fast titration is simple, rapid, and accurate and requires a small quantity of substrate as compared to the salt addition and mass titration techniques. The similarity between the PZC and IEP values rules out the specific adsorption of the bulk electrolyte onto the NiO surface. However, the PZC values shift downward with the increase in Cd ion concentration, which indicates the specific adsorption of Cd onto the NiO. In addition, temperature has a mild effect on the deprotonation constants and PZC of NiO. It was also observed that the thermodynamic parameters favor the deprotonation of NiO. ' MATERIALS AND METHODSMaterials. Analytical grade reagents were used in this study. All glassware and polyethylene bottles were rinsed with 10%

A human breast cancer cell line (MCF-7) was used to investigate the cumulative estrogenicity profiles elicited during the oxidation of three estrogenic compounds [bisphenol A (BPA), 17beta-estradiol (E2), and 17alpha-ethynyl estradiol (EE2)]. High-performance liquid chromatography (HPLC) with a method detection limit (MDL) of approximately 1 nM was used to measure the initial and final concentrations of test compounds during oxidation. Both chlorination and ozonation removed from 75% to >99% of the test compounds in distilled water. Increasing contact time and chlorination dose improved compound removal. Chlorination byproducts of BPA, E2, and EE2 elicited low levels of estrogenicity over an extended period of time. For equivalent molar oxidant dosages, ozone and chlorine had comparable residual proliferative effect values and >99% loss of the parent compounds. For oxidation studies of estrogenic chemicals, ammonium chloride was found to adequately quench residual chlorine without interfering with cell culture assay. Oxidation of test compounds with chlorine and ozone resulted in a similar estrogenicity trend, with a relative higher level of estrogenicity elicited during the early phases of oxidation, which gradually dissipated over the extended exposure time to a stable point. Oxidation with ozone resulted in the rapid transformation of test compounds, reaching a stabilized estrogenic level in 10 min, whereas for chlorination it took more than 120 min for elicited estrogenicity to stabilize.

Biosolids contain a wide variety of organic contaminants that are known for their ability to inhibit PCR. During sample processing, these contaminants are coconcentrated with microorganisms. Elevated concentrations of these compounds in concentrates render samples unsuitable for molecular applications. Glycine-based elution and recovery methods have been shown to generate samples with fewer PCR inhibitory compounds than the current U.S. EPA-recommended method for pathogen recovery from biosolids. Even with glycine-based methods, PCR inhibitors still persist in concentrations that may interfere with nucleic acid amplification. This results in considerable loss of time and resources and increases the probability of false negatives. A method to estimate the degree of inhibition prior to application of molecular methods is desirable. Here we report fluorescence excitation-emission matrix (EEM) profiling as a tool for predicting levels of molecular inhibition in sample concentrates of biosolids.

The objective of this study was to find out the impact of environmental conditions on the survival of intestinal parasites on environmental surfaces commonly implicated in the transmission of these parasites. The study was performed by incubating Cryptosporidium and Giardia (oo)cysts on environmentally relevant surfaces such as brushed stainless steel, formica, ceramic, fabric, and skin. Parallel experiments were conducted using clean and soiled coupons incubated under three temperatures. The die-off coefficient rates (K) were calculated using first-order exponential formula. For both parasites, the fastest die-off was recorded on fabric, followed by ceramic, formica, skin, and steel. Die-off rates were directly correlated to the incubation temperatures and surface porosity. The presence of organic matter enhanced the survivability of the resting stages of test parasites. The decay rates calculated in this study can be used in models for public health decision-making process and highlights the mitigation role of hand hygiene agents in their prevention and control.

Quantitative risk assessment for Cryptosporidium oocysts and Giardia cysts was performed to determine the public health significance of non-potable use of tertiary treated reclaimed water. Seven reclaimed water treatment plants in the southwestern United States participated in this study. The average public exposure to oocysts and cysts was estimated, based on concentrations, recovery efficiency, viability and three exposure scenarios. The exponential dose-response model was chosen to determine the probability of infection from ingestion of various numbers of oocysts and cysts. The risks of infection for Giardia were approximately one or two orders of magnitude higher than those for Cryptosporidium. The combined risks of infection from oocysts and cysts at sites using a combination of chlorination and UV disinfection would meet the annual acceptable risk of 1.00E-04, whereas those at the other utilities using only chlorination indicated higher probability of infection than the 1.00E-04 resulting from accidental consumption of a small amount of non-potable reclaimed water.

The need for rapid, specific and sensitive assays that provide a detection of bacterial indicators are important for monitoring water quality. Rapid detection using biosensor is a novel approach for microbiological testing applications. Besides, validation of rapid methods is an obstacle in adoption of such new bio-sensing technologies. In this study, the strategy developed is based on using the compound 4-methylumbelliferyl glucuronide (MUG), which is hydrolyzed rapidly by the action of E. coli β-D-glucuronidase (GUD) enzyme to yield a fluorogenic product that can be quantified and directly related to the number of E. coli cells present in water samples.The detection time required for the biosensor response ranged from 30 to 120 minutes, depending on the number of bacteria. The specificity of the MUG based biosensor platform assay for the detection of E. coli was examined by pure cultures of non-target bacterial genera and also non-target substrates. GUD activity was found to be specific for E. coli and no such enzymatic activity was detected in other species. Moreover, the sensitivity of rapid enzymatic assays was investigated and repeatedly determined to be less than 10 E. coli cells per reaction vial concentrated from 100 mL of water samples.The applicability of the method was tested by performing fluorescence assays under pure and mixed bacterial flora in environmental samples. In addition, the procedural QA/QC for routine monitoring of drinking water samples have been validated by comparing the performance of the biosensor platform for the detection of E. coli and culture-based standard techniques such as Membrane Filtration (MF). The results of this study ii indicated that the fluorescence signals generated in samples using specific substrate molecules can be utilized to develop a bio-sensing platform for the detection of E. coli in drinking water. The procedural QA/QC of the biosensor will provide both industry and regulatory authorities a useful tool for near real-time monitoring of E. coli in drinking water samples. Furthermore, this system can be applied independently or in conjunction with other methods as a part of an array of biochemical assays in order to reliably detect E. coli in water.

Pilot-scale column experiments were conducted in this study using natural soil and river water from Ohio river to assess the removal of microbes of size ranging over 2 orders of magnitude, i.e., viruses (0.025-0.065 microm), bacteria (1-2 microm), and Cryptosporidium parvum oocysts (4-7 microm) under conditions representing normal operation and flood scour events. Among these different organisms, the bacterial indicators were transported over the longest distances and highest concentrations; whereas much greater retention was observed for smaller (i.e., viral indicators) and larger (i.e., Cryptosporidium parvum oocysts) microbes. These results are in qualitative agreement with colloid filtration theory (CFT) which predicts the least removal for micrometer size colloids, suggesting that the respective sizes of the organisms was a dominant control on their transport despite expected differences in their surface characteristics. Increased fluid velocity coupled with decreased ionic strength (representative of major flood events) decreased colloid retention, also in qualitative agreement with CFT. The retention of organisms occurred disproportionately near the source relative to the log-linear expectations of CFT, and this was true both in the presence and absence of a colmation zone, suggesting that microbial removal by the RBF system is not necessarily vulnerable to flood scour of the colmation zone.