We recently demonstrated that the major decapping activity in mammalian cells involves DcpS, a scavenger pyrophosphatase that hydrolyzes the residual cap structure following 3¢ to 5¢ decay of an mRNA. The association of DcpS with 3¢ to 5¢ exonuclease exosome components suggests that these two activities are linked and there is a coupled exonucleolytic decaydependent decapping pathway. We puri®ed DcpS from mammalian cells and identi®ed the cDNA encoding a novel 40 kDa protein possessing DcpS activity. Consistent with puri®ed DcpS, the recombinant protein speci®cally hydrolyzed methylated cap analog but did not hydrolyze unmethylated cap analog nor did it function on intact capped RNA. Sequence alignments of DcpS from different organisms revealed the presence of a conserved hexapeptide, containing a histidine triad (HIT) sequence with three histidines separated by hydrophobic residues. Mutagenesis analysis revealed that the central histidine within the DcpS HIT motif is critical for decapping activity and de®nes the HIT motif as a new mRNA decapping domain, making DcpS the ®rst member of the HIT family of proteins with a de®ned biological function.

Antimicrobial hand soaps provide a greater bacterial reduction than nonantimicrobial soaps. However, the link between greater bacterial reduction and a reduction of disease has not been definitively demonstrated. Confounding factors, such as compliance, soap volume, and wash time, may all influence the outcomes of studies. The aim of this work was to examine the effects of wash time and soap volume on the relative activities and the subsequent transfer of bacteria to inanimate objects for antimicrobial and nonantimicrobial soaps. Increasing the wash time from 15 to 30 seconds increased reduction of Shigella flexneri from 2.90 to 3.33 log 10 counts (P ‫؍‬ 0.086) for the antimicrobial soap, while nonantimicrobial soap achieved reductions of 1.72 and 1.67 log 10 counts (P > 0.6). Increasing soap volume increased bacterial reductions for both the antimicrobial and the nonantimicrobial soaps. When the soap volume was normalized based on weight (ϳ3 g), nonantimicrobial soap reduced Serratia marcescens by 1.08 log 10 counts, compared to the 3.83-log 10 reduction caused by the antimicrobial soap (P < 0.001). The transfer of Escherichia coli to plastic balls following a 15-second hand wash with antimicrobial soap resulted in a bacterial recovery of 2.49 log 10 counts, compared to the 4.22-log 10 (P < 0.001) bacterial recovery on balls handled by hands washed with nonantimicrobial soap. This indicates that nonantimicrobial soap was less active and that the effectiveness of antimicrobial soaps can be improved with longer wash time and greater soap volume. The transfer of bacteria to objects was significantly reduced due to greater reduction in bacteria following the use of antimicrobial soap.Hand washing has long been considered one of the easiest and simplest public health practices for preventing the spread of disease in clinical and nonclinical settings (2,10,12,14,25). Recommendations on wash times and the proper procedure for washing hands have been published by various public health organizations (6, 37). The transmission of transient bacteria by the hands plays a significant role in direct and indirect transmissions of disease. While experts agree that hand washing with soap and water is effective at reducing the spread of disease-causing bacteria, there still remain doubts on the benefit of antimicrobial hand washes over nonantimicrobial soap and water. Studies looking at the reduction of disease between groups using antimicrobial soap and those using nonantimicrobial soap continue to show conflicting results (1, 18, 30). The differences in findings may be due to confounding factors, such as soap volume, wash time, type of antimicrobial product, and lack of uniformity among these factors in the published studies.The effects of these variables on assessment of hand washing efficacy have also been studied. Larson et al. demonstrated that soap volume and wash time can have an effect on the numbers of resident bacteria remaining on the hands after multiple hand washes but not after a single hand wash (17). The effect o...

NCT00993759.

These studies evaluated the effectiveness of ethanol hand sanitizers with or without organic acids to remove detectable rhinovirus from the hands and prevent experimental rhinovirus infection. Ethanol hand sanitizers were significantly more effective than hand washing with soap and water. The addition of organic acids to the ethanol provided residual virucidal activity that persisted for at least 4 h. Whether these treatments will reduce rhinovirus infection in the natural setting remains to be determined.Direct hand-to-hand transmission of virus appears to play an important role in the spread of rhinovirus infections. The purpose of the studies described in this article was to compare the immediate and residual effectiveness of different hand treatments for removal of rhinovirus from the hands.Comparison of hand washing with hand disinfectant for removal of virus from hands. The fingers of 95 healthy volunteers were contaminated with 125 50% tissue culture infective doses (TCID 50 ) of rhinovirus, type 39, by placing the virus into a "cup" formed by the tip of the index finger, middle finger and thumb of the right hand. The contaminating virus was distributed over the tips of the index and middle fingers by rubbing with the thumb and then allowed to dry for 5 min. The volunteers were block randomized to one of six hand treatments. A control group had no hand treatment. A second group washed their hands by rubbing under running water for 15 s. A third group washed their hands with 2 ml of nonmedicated liquid soap by rubbing their hands together and then rinsing under running water for 15 s. Both of the groups who used a water rinse dried their hands by pat-drying with a paper towel. A fourth group had 1.5 ml of 65% ethanol hand sanitizer applied to the palm of the hand. This group of volunteers then rubbed the sanitizer over the hands until the material was evaporated. A fifth group of volunteers also applied 1.5 ml of 65% ethanol hand sanitizer, although this group repeated the process two times for a total application of 3 ml of the hand sanitizer. The final group applied 1.5 ml of an 83% ethanol hand sanitizer in the manner described above. The goal in all of the treatment groups was to mimic the natural use of hand washing or application of hand sanitizer; only the duration of the hand wash was controlled. After the hand treatment, all volunteers had the fingertips of the contaminated hand rinsed 10 times with 1.5 ml of viral collecting broth for detection of residual virus.The ethanol hand sanitizers removed detectable virus from at least 80% of hands. All ethanol treatments were significantly more effective than no treatment, water alone, or soap and water for removal of detectable rhinovirus from the hands (Table 1). Soap and water removed detectable virus from 5 (31%) of 16 hands (P ϭ 0.04 compared to the no-treatment control). There was no difference detected among the various hand sanitizer regimens.Assessment of residual activity against rhinovirus hand contamination and infection following organic ac...

The goals of this study were to evaluate the effectiveness of two hand wash regimens in reducing transient bacteria on the skin following a single hand wash and the subsequent transfer of the bacteria to a ready-to-eat food item, freshly cut cantaloupe melon. The number of bacteria recovered from hands and the quantity transferred to the melon were significantly less following the use of an antibacterial soap compared with plain soap. The antimicrobial soap achieved > 3-log reductions versus Escherichia coli and 3.31- and 2.83-log reductions versus Shigella flexneri. The plain soap failed to achieve a 2-log reduction against either organism. The bacteria recovered from the melon handled by hands treated with antimicrobial hand soap averaged 2 log. Melon handled following hand washing with plain soap had > 3 log bacteria in the experiments. Based on previously published feeding studies, an infection rate in the range of approximately 15 to 25% would be expected after ingesting melon containing 2 log CFU compared with ingesting greater than the 3 log transferred from hands washed with plain soap, which would result in a higher infection attack rate of 50 to 80%. The data thus demonstrate there is a greater potential to reduce the transmission and acquisition of disease through the use of an antimicrobial hand wash than through the use of plain soap.