ABSTRACT
Nanotechnologies have been advantageous in many sectors and gaining much concern due to the unique physical, chemical and biological properties of nanomaterials (NMs). We have surveyed peer-reviewed publications related to "nanotechnology", "NMs", "NMs water treatment", "NMs air treatment", and "NMs environmental risk" in the last 23 years. We found that most of the research work is focused on developing novel applications for NMs and new products with peculiar features. In contrast, there are relatively few of publications concerning NMs as environmental contaminants relative to that for NMs applications. Thus, we devoted this review for NMs as emerging environmental contaminants. The definition and classification of NMs will be presented first to demonstrate the importance of unifying the NMs definition. The information provided here should facilitate the detection, control, and regulation of NMs contaminants in the environment. The high surface-area-to-volume ratio and the reactivity of NMs contaminants cause the prediction of the chemical properties and potential toxicities of NPs to be extremely difficult; therefore, we found that there are marked knowledge gaps in the fate, impact, toxicity, and risk of NMs. Consequently, developing and modifying extraction methods, detection tools, and characterization technologies are essential for complete risk assessment of NMs contaminants in the environment. This will help also in setting regulations and standards for releasing and handling NMs as there are no specific regulations. Finally, the integrated treatment technologies are necessary for the removal of NMs contaminants in water. Also, membrane technology is recommended for NMs remediation in air.
ABSTRACT
BACKGROUND: Human bocavirus (HBoV) is globally distributed and associated with respiratory and enteric infections. Limited data are available about the incidence of HBoV in Egyptian children. We aimed to investigate the association of HBoV genotypes in children with diarrheal disease and also to determine the possibility of HBoV co-infections with other human enteric pathogens. METHODS: A total of 102 stool samples were collected from children under five years old with diarrhea. Samples were analyzed for the presence of HBoV by real-time PCR. HBoV positive samples were tested for adenovirus (AdV), rotavirus (RoV), parasitic helminths, and enteric protozoa. RESULTS: HBoV was detected in 58% of examined cases. HBoV-3 was the most prevalent genotype observed (44%; 45 of 102), followed by HBoV-2/4 (33%; 34 of 102) and HBoV-1 (30%; 31 of 102). Although the incidence of HBoV was higher in males (66.6%; 34 of 51) than females (49%; 25 of 51), the analysis showed no significant difference for HBoV between genders. The average HBoV concentrations were 5.3 × 104 GC/g in males and 1.03 × 105 GC/g in females. Among the HBoV-positive samples, the single infection of HBoV was 52.5% (31/59), while the co-infections with multiple viruses were found in 1.7% (1/59) for HBoV and AdV, 33.9% (20/59) for HBoV and RoV, and 11.9% (7/59) for HBoV, and RoV and AdV. No co-infection with parasitic helminths or enteric protozoa was found. CONCLUSIONS: The single infection of HBoV in some children suffering from acute gastroenteritis indicated that HBoV could be the main etiologic agent of the disease. The study highlights the high incidence of HBoVs genotypes with remarkable multiple co-infections in the pre-school children in Egypt.
ABSTRACT
Real time PCR (qPCR) is increasingly being used for viral detection in aquatic environments because it enables high specificity and sensitivity of detection. However, the limited number of fluorescent reporter dyes restricts its multiplex application. In this study, a multiplex Luminex assay was established for the simultaneous detection of human adenovirus (HAdV), human polyomavirus (HPyV), enterovirus (EV), rotavirus (RoV), norovirus GI (NoVGI) and norovirus GII (NoVGII). Different river water and wastewater samples were tested for the viruses using both qPCR and the multiplex Luminex xMAP assay. HAdV and HPyV were the most abundant in all environmental samples. HAdV was detected in all river water and wastewater samples, and HPyV was detected in 79% of river water and 95.8% of wastewater samples. The multiplex xMAP assay revealed high specificity and no cross-reactivity. Using the multiplex Luminex assay, the viral detection rates in river water samples were lower than the rates obtained by qPCR for all viruses. Conversely, in wastewater samples, the viral detection rates were the same for both methods. In addition, the analytical sensitivity of the monoplex Luminex assay was comparable to or lower than qPCR. Results suggest that the multiplex Luminex assay could be a reliable method for the simultaneous detection of viral pathogens in wastewater.
