Bacillus subtilis PaiA has been implicated in the negative control of sporulation as well as production of degradative enzymes. PaiA shares recognizable sequence homology with N-acetyltransferases, including those that can acetylate spermidine/spermine substrates. We have determined the crystal structure of PaiA in complex with CoA at 1.9 Å resolution and found that PaiA is a member of the N-acetyltransferase superfamily of enzymes. Unexpectedly, we observed the binding of an oxidized CoA dimer in the active site of PaiA, and the structural information suggests the substrates of the enzyme could be linear, positively charged compounds. Our biochemical characterization is also consistent with this possibility, since purified PaiA possesses N 1 -acetyltransferase activity toward polyamine substrates including spermidine and spermine. Further, conditional overexpression of PaiA in bacteria results in increased acetylation of endogenous spermidine pools. Thus, our structural and biochemical analyses indicate that PaiA is a novel N-acetyltransferase capable of acetylating both spermidine and spermine. In this way, the pai operon may function in regulating intracellular polyamine concentrations and/or binding capabilities. In addition to preventing toxicity due to polyamine excess, this function may also serve to regulate expression of certain bacterial gene products such as those involved in sporulation.In Bacillus subtilis, the pai operon is involved in negative control of sporulation as well as the production of extracellular and cell-associated proteases and other enzymes such as ␣-amylase and alkaline phosphatase (1). The pai operon contains two genes, paiA and paiB, encoding proteins of 172 (PaiA) and 207 (PaiB) amino acid residues, respectively.

BackgroundRefugees are at high risk for communicable diseases due to overcrowding and poor water, sanitation, and hygiene conditions. Handwashing with soap removes pathogens from hands and reduces disease risk. A hepatitis E outbreak in the refugee camps of Maban County, South Sudan in 2012 prompted increased hygiene promotion and improved provision of soap, handwashing stations, and latrines. We conducted a study 1 year after the outbreak to assess the knowledge, attitudes, and practices of the refugees in Maban County.MethodsWe conducted a cross sectional survey of female heads of households in three refugee camps in Maban County. We performed structured observations on a subset of households to directly observe their handwashing practices at times of possible pathogen transmission.ResultsOf the 600 households interviewed, nearly all had soap available and 91 % reported water was available “always” or “sometimes”. Exposure to handwashing promotion was reported by 85 % of the respondents. Rinsing hands with water alone was more commonly observed than handwashing with soap at critical handwashing times including “before eating” (80 % rinsing vs. 7 % washing with soap) and “before preparing/cooking food” (72.3 % vs 23 %). After toilet use, 46 % were observed to wash hands with soap and an additional 38 % rinsed with water alone.ConclusionsDespite intensive messaging regarding handwashing with soap and access to soap and water, rinsing hands with water alone rather than washing hands with soap remains more common among the refugees in Maban County. This practice puts them at continued risk for communicable disease transmission. Qualitative research into local beliefs and more effective messaging may help future programs tailor handwashing interventions.

Abstractobjective To evaluate household faecal contamination using children's toys among 100 rural Bangladeshi households categorised as 'cleaner' (toilet that reliably separates faeces from the environment and no human faeces in/around living space) or 'less clean' (no toilet or toilet that does not reliably separate faeces from the environment and human faeces in/around living space).methods We distributed toy balls to each household and rinsed each study toy and a toy already owned by the household in 200 ml of Ringer's solution. We enumerated faecal coliforms and faecal streptococci from each rinse using membrane filtration methods.results Study toys from 39 cleaner households had lower mean faecal coliform contamination than toys from 61 less clean households (2.4 log 10 colony-forming units (CFU)/200 ml vs. 3.2 log 10 CFU/ 200 ml, P = 0.03). However, wealth measures explained a portion of this relationship. Repeat measures were moderately variable [coefficient of variation (CV) = 6.5 between two toys in the household at the same time, CV = 37.6 between toys in the household at two different times 3-4 days apart]. Too few households owned a non-porous toy to compare groups without risk of bias.conclusion In rural Bangladesh, improved sanitation facilities and practices were associated with less environmental contamination. Whether this association is independent of household wealth and whether the difference in contamination improves child health merit further study. The variation found was typical for measures of environmental contamination, and requires large sample sizes to ascertain differences between groups with statistical significance.

Water, sanitation, and hygiene (WASH) interventions are key to reducing the burden of disease associated with outbreaks, and are commonly implemented in emergency response. However, there is a lack of summarized evidence on the efficacy and effectiveness of these interventions. We conducted a systematic review of published and grey literature by developing theory of change models, developing inclusion criteria, conducting the search, selecting evaluations for inclusion, assessing the quality of the evidence, and analysing the included evaluations. Overall, 15,026 documents were identified and 51 evaluations from 47 studies met inclusion criteria. Interventions from 19 countries were included, primarily in response to cholera (86 per cent). Most included evaluations (70 per cent) were at high risk of bias and nearly half were from grey literature (49 per cent). We found that WASH interventions consistently reduced both the risk of disease and the risk of transmission in outbreak contexts; however, programme design and beneficiary preferences were important considerations to ensure WASH intervention effectiveness. Critical programme design characteristics included simple interventions that were appropriately timed, community-driven, and had linkages between relief and development. Beneficiary preferences, barriers, and facilitators to WASH interventions in outbreak response were taste and smell of water treatment, communication methods, inaccurate perception of efficacy, and trust/fear. Research on commonly implemented but severely under-researched WASH interventions is recommended. It is also recommended that responders implement interventions that are: efficacious, simple, well-timed, community-driven, link relief and development, and address barriers and facilitators to use with communities.

Diarrhea and acute respiratory infections account for nearly 30% of deaths among children displaced by humanitarian emergencies. Handwashing with soap reduces the risk of diarrhea and acute respiratory infection in non-emergency settings. However, the practice and the effectiveness of handwashing promotion efforts and the health benefits are not well documented in emergency settings. We conducted key informant interviews with 12 experts working in water, sanitation, and hygiene and examined current approaches, challenges, and knowledge gaps in relation to handwashing promotion in emergency settings. We identified many constraints to implementing effective handwashing promotion efforts including a failure to define objectives and targets for improvements in handwashing rates, lack of technical expertise and attention to the development and implementation of effective behavior change communication approaches, and limited understanding of the appropriateness, use, and acceptability of different handwashing hardware. Respondents identified multiple knowledge gaps and research needs that could improve current efforts. Collaborations between response agencies and research institutions could generate high quality data and facilitate contextualized and potentially more effective and robust handwashing promotion strategies.