This paper summarizes the conclusions of two recently completed projects that examined the occurrence of the protozoan pathogen Cryptosporidium in wastewater streams, and the efficacy of ultraviolet (UV) light for treatment of wastewaters to control Cryptosporidium. A 15-month survey of Cryptosporidium oocyst occurrence was conducted at ten US wastewater treatment plants. Cryptosporidium oocyst...

Recent bioterrorism concerns have prompted renewed efforts towards understanding the biology of bacterial spore resistance to radiation with a special emphasis on the spores of Bacillus anthracis. A review of the literature revealed that B. anthracis Sterne spores may be three to four times more resistant to 254-nm-wavelength UV than are spores of commonly used indicator strains of Bacillus sub...

Aerosolized viruses were passed through a high-intensity ultraviolet (UV) cell. This cell consisted of a long cylindrical aluminum tube [diameter, 7 in. (17.7 cm); length, 36 in. (91.4 cm)] with a highly reflective inner surface and a longitudinally extending helical baffle system which directed airborne particles in close proximity to a centrally located UV lamp. After having been passed throu...

Replication forks face a variety of structurally diverse impediments that can prevent them from completing their task. The mechanism by which cells overcome these hurdles is likely to vary depending on the nature of the obstacle and the strand in which the impediment is encountered. Both UV-induced DNA damage and thermosensitive replication proteins have been used in model systems to inhibit DN...

ultraviolet radiation (uvr) has been accepted as an attractive alternative to chlorination for the disinfection of wastewater. in this study the effluent from sahebgaranieh treatment plant was subjected to changes in uv transmission and turbidity in order to correlate these commonly measured parameters with the performance of a submerged -uv- reactor employed in disinfecting the effluent. studi...

Fluorescent brighteners increase insect viral activity and provide protection against UV inactivation. The relative amount of viral UV protection has not previously been determined due to the dual nature of these compounds. In this study, two distinct viral–host systems, a nuclear polyhedrosis virus of the gypsy moth (Lymantria dispar) infecting its homologous host and a nuclear polyhedrosis vi...

AIM The present work deals with different methods for foot and mouth disease virus (FMDV) inactivation for serotypes O/pan Asia, A/Iran05, and SAT-2/2012 by heat, gamma radiation, and ultraviolet (UV) in comparison with the traditional methods and their effects on the antigenicity of viruses for production of inactivated vaccines. MATERIALS AND METHODS FMDV types O/pan Asia, A/Iran05, and SAT...

This study investigated UV-C light inactivation of Escherichia coli O157:H7 and Listeria monocytogenes on the surface of organic apples, pears, strawberries, red raspberries and cantaloupes. Fruit surfaces spot inoculated with cocktail strains of E. coli O157:H7 and L. monocytogenes were exposed to UV-C doses up to 11.9 kJ/m(2) at 23 °C. Fruit surface roughness, contact angle, and surface energ...

The aim of this investigation was to study the efficacy of the combined processes of UV light and mild temperatures for the inactivation of Salmonella enterica subsp. enterica and to explore the mechanism of inactivation. The doses to inactivate the 99.99% (4D) of the initial population ranged from 18.03 (Salmonella enterica serovar Typhimurium STCC 878) to 12.75 J ml(-1) (Salmonella enterica s...

UV light only penetrates liquid food surfaces to a very short depth, thereby limiting its industrial application in food pasteurization. One promising alternative is the combination of UV light with mild heat (UV-H), which has been demonstrated to produce a synergistic bactericidal effect. The aim of this article is to elucidate the mechanism of synergistic cellular inactivation resulting from ...