Structure and function of radical SAM enzymes

'Radical SAM' enzymes juxtapose a [4Fe-4S] cluster and S-adenosyl-l-methionine (SAM) to generate catalytic 5'-deoxyadenosyl radicals. The crystal structures of oxygen-independent coproporphyrinogen III oxidase HemN and biotin synthase reveal the positioning of both cofactors with respect to each other and relative to the surrounding protein environment. Each is found in an unprecedented coordination environment including the direct ligation of the [4Fe-4S] cluster by the amino nitrogen and one carboxylate oxygen of the methionine moiety of SAM, as observed for other members of the Radical SAM family by ENDOR. The availability of two protein structures supported by biochemical and biophysical data underscores common features, anticipating the structural elements of other family members. Remaining differences emphasize the plasticity of the protein scaffold in functionally accommodating 600 family members.     

Oral care training in the basic education of care professionals

doi:10.1111/j.1741‐2358.2009.00304.x
Oral care training in the basic education of care professionals Objective: To investigate the quantity and quality of oral care training in the basic education of future long‐term care (LTC) professionals in Norway. Background: The level of oral hygiene has often proved inadequate in LTC facilities. It has been maintained that this could be due to insufficient knowledge of oral care among care professionals. Materials and methods: A self‐administered questionnaire was sent to all 270 schools in Norway which offered basic education of LTC personnel in 2004/05. Information on theoretical and practical oral care training, scope of oral care in teaching material and curriculum, educational background of the teaching staff and schools opinion regarding adequacy of their training programme was collected. Results: Of the 203 respondents (75% response rate), 188 (participants) included oral care in their educational programme. Approximately two‐thirds of the participating schools provided 3 h or more of oral care training and many of the important themes were presented in the textbooks that were recommended. Moreover, the practical exercises performed in practice placement supplemented the knowledge. Conclusion: The results could not confirm that LTC professional’s basic education concerning oral care was inadequate. There may therefore be other explanations for the poor oral hygiene in many LTC facilities.     

Expression of virulence factors by classical and El Tor Vibrio cholerae in vivo and in vitro

Abstract We examined the production of virulence factors of Vibrio cholerae O1 bacteria, and especially compared expression in vitro under near optimal growth conditions with that in vivo during experimental cholera infection. The results show that the in vitro formation of cholera toxin (CT), soluble hemagglutinin (SHA), colonizing pilus TCP, and the biotype associated hemagglutinins FSHA and MSHA, as well as of various cell envelope antigens often rather poorly reflected expression in vivo. For instance, production of CT by vibrios of classical biotype and of TCP by the El Tor biotype were enhanced in vivo, while production of SHA was instead suppressed. Likewise significant differences in cell envelope antigen composition were found between bacteria grown in vivo and in vitro. A more precise definition of the role of different postulated virulence factors in the processes of infection and immunity should include in vivo studies as outlined by this study.     

Starvation survival of the fish pathogenic bacteria Vibrio anguillarum and Vibrio salmonicida in marine environments

Abstract The possible fate in sea water of the two fish pathogenic bacteria Vibrio anguillarum and Vibrio salmonicida is discussed on the basis of microcosm experiments with these and other copiotrophic bacteria. Recent articles dealing with the survival of fish pathogens are reviewed, and the reported survival capacities are discussed in relation to ecological mechanisms, such as death, and predation, leading to the removal of bacteria from the water column.