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A study was conducted to investigate the influence of starvation on physiological activity and chlorine disinfection resistance in Escherichia coli O157:H7 using fluorogenic strains and probes. Results indicated that starvation supported the development of an injury-resistant membrane structure against deoxycholate susceptibility during the absence of disinfection. Findings also showed that intracellular mechanisms accommodate disinfection resistance.

A study was conducted to characterize the microbial associates of Lophelia pertusa in the northeastern Gulf of Mexico that are known to benefit the corals by cycling carbon, fixing nitrogen, chelating iron, and producing antibiotics that protect the coral from other microbes. The studies identified several new bacterial associates and two Lophelia-specific groups, a group of Mycoplasma spp. and a cluster of symbiont-like thiotrophs and offered insight into the effects of environmental gradients on the microbial diversity of samples.

A study is conducted to address the occurrence of microbial indicators and clostridium perfringens in the untreated wastewater, watercolumn and sediments of the impacted area and drinking water treatment facility and distribution system at McMurdo Station. A wastewater treatment facility at McMurdo station has started operation and the data provides a baseline data set for monitoring the recovery of the impacted area.

The traditional epifluorescent microscopy (EFM) techniques for counting fluorescently labeled bead and bacteria are compared to the solid-phase cytometry (SPC) method to establish the minimum number of cells needed per filter for reliable total-direct-count data. The results indicate that when the numbers of bacterial cells per filter are reduced below 10(super 5), the microscopic methods increasingly overestimated the true bacterial abundance.

A liquid culture enrichment-polymerase chain reaction (E-PCR) assay was investigated as a potential tool to overcome inhibition by chemical component, debris, and background biological impurities in soil that were affecting detection assay performance for soil samples containing Bacillus atrophaeus subsp. globigii (a surrogate for B. anthracis). To evaluate this assay, 9 g of matched sets of three different soil types (loamy sand [sand], sandy loam [loam] and clay) was spiked with 0, ~4.5, 45, 225, 675 and 1350 endospores. One matched set was evaluated using a previously published endospore concentration and colony-forming unit spreadplate (CFU-S) assay and the other matched set was evaluated using an E-PCR assay to investigate differences in limits of detection between the two assays. Data illustrated that detection using the CFU-S assay at the 45-endospore spike level started to become sporadic whereas the E-PCR assay produced repeatable detection at the ~4.5-endospore spike concentration. The E-PCR produced an ~2-log increase in sensitivity and required slightly less time to complete than the CFU-S assay. This study also investigated differences in recovery among pure and blended sand and clay soils and found potential activation of B. anthracis in predominately clay-based soils. [ABSTRACT FROM AUTHOR]