Supporting the implementation of drinking water management systems in New South Wales, Australia.

Since 2010, New South Wales (NSW) Health has assisted local water utilities to develop and implement risk-based drinking water management systems based on the Australian Drinking Water Guidelines Framework for Management of Drinking Water Quality. This support has benefited regional communities, and especially smaller utilities, by helping to identify and control risks. NSW Health's support projects have resulted in statistically significant improvements across many elements of drinking water management system implementation. Through this program of support, NSW Health has identified possible infrastructure and operational needs and assessed implementation of drinking water management systems. In parallel, NSW Health has worked to assess the risk from Cryptosporidium in drinking water supplies and to develop a formal audit program. Findings from the NSW Health support program informed the development of two NSW Government programs and the commitment of more than $1 billion to help local water utilities address public health and other critical needs. The introduction of risk-based drinking water management systems has driven incremental improvement in drinking water quality management across the state of NSW.

Investigation of the microbial communities colonizing prepainted steel used for roofing and walling.

Microbial colonization of prepainted steel, commonly used in roofing applications, impacts their aesthetics, durability, and functionality. Understanding the relevant organisms and the mechanisms by which colonization occurs would provide valuable information that can be subsequently used to design fouling prevention strategies. Here, next-generation sequencing and microbial community finger printing (T-RFLP) were used to study the community composition of microbes colonizing prepainted steel roofing materials at Burrawang, Australia and Kapar, Malaysia over a 52-week period. Community diversity was low and was dominated by Bacillus spp., cyanobacteria, actinobacteria, Cladosporium sp., Epicoccum nigrum, and Teratosphaeriaceae sp. Cultivation-based methods isolated approximately 20 different fungi and bacteria, some of which, such as E. nigrum and Cladosporium sp., were represented in the community sequence data. Fluorescence in situ hybridization imaging showed that fungi were the most dominant organisms present. Analysis of the sequence and T-RFLP data indicated that the microbial communities differed significantly between locations and changed significantly over time. The study demonstrates the utility of molecular ecology tools to identify and characterize microbial communities associated with the fouling of painted steel surfaces and ultimately can enable the targeted development of control strategies based on the dominant species responsible for fouling.

Glucose starvation-induced dispersal of Pseudomonas aeruginosa biofilms is cAMP and energy dependent.

Carbon starvation has been shown to induce a massive dispersal event in biofilms of the opportunistic pathogen Pseudomonas aeruginosa; however, the molecular pathways controlling this dispersal response remain unknown. We quantified changes in the proteome of P. aeruginosa PAO1 biofilm and planktonic cells during glucose starvation by differential peptide-fingerprint mass-spectrometry (iTRAQ). In addition, we monitored dispersal photometrically, as a decrease in turbidity/opacity of biofilms pre-grown and starved in continuous flow-cells, in order to evaluate treatments (e.g. inhibitors CCCP, arsenate, chloramphenicol, L-serine hydroxamate) and key mutants altered in biofilm development and dispersal (e.g. nirS, vfr, bdlA, rpoS, lasRrhlR, Pf4-bacteriophage and cyaA). In wild-type biofilms, dispersal started within five minutes of glucose starvation, was maximal after 2 h, and up to 60% of the original biomass had dispersed after 24 h of starvation. The changes in protein synthesis were generally not more than two fold and indicated that more than 100 proteins belonging to various classes, including carbon and energy metabolism, stress adaptation, and motility, were differentially expressed. For the different treatments, only the proton-ionophore CCCP or arsenate, an inhibitor of ATP synthesis, prevented dispersal of the biofilms. For the different mutants tested, only cyaA, the synthase of the intracellular second messenger cAMP, failed to disperse; complementation of the cyaA mutation restored the wild-type phenotype. Hence, the pathway for carbon starvation-induced biofilm dispersal in P. aeruginosa PAO1 involves ATP production via direct ATP synthesis and proton-motive force dependent step(s) and is mediated through cAMP, which is likely to control the activity of proteins involved in remodeling biofilm cells in preparation for planktonic survival.