Survey of US wastewater for carbapenem-resistant Enterobacteriaceae.

A survey for antibiotic-resistant (AR) Escherichia coli in wastewater was undertaken by collecting samples from primary clarifiers and secondary effluents from seven geographically dispersed US wastewater treatment plants (WWTPs). Samples were collected at each WWTP in cool and summer months and cultured using selective media. The resulting isolates were characterized for resistance to imipenem, ciprofloxacin, cefotaxime, and ceftazidime, presence of carbapenemase and extended-spectrum beta-lactamase (ESBL) genes, and phylogroups and sequence types (STs).

Characterization of the cell surface properties of drinking water pathogens by microbial adhesion to hydrocarbon and electrophoretic mobility measurements.

The surface characteristics of microbial cells directly influence their mobility and behavior within aqueous environments. The cell surface hydrophobicity (CSH) and electrophoretic mobility (EPM) of microbial cells impact a number of interactions and processes including aggregation, adhesion to surfaces, and stability of the cells within the aqueous environments. These cell characteristics are unique to the bacterial species and are a reflection of the large diversity of surface structures, proteins, and appendages of microorganisms.

Fate of pentabrominated diphenyl ethers in soil: abiotic sorption, plant uptake, and the impact of interspecific plant interactions.

Polybrominated diphenyl ethers (PBDEs) are potentially harmful and persistent environmental pollutants. Despite evidence that soils are a major sink for PBDEs, little is known regarding their behavior in this medium. An environmentally relevant level of a commercial penta-BDE mixture (75 microg kg(-1)) was added to topsoil, and the extractability of three congeners (BDE-47, -99, and -100) was monitored over 10 weeks in planted and unplanted treatments.

Use of SEC-ICP-MS with a collision cell for determining the interaction of chromium with DNA extracted from metal-contaminated soils.

The potential of chromium to bind to DNA isolated directly from soil microbial communities was investigated in this study. An analytical scheme was developed to distinguish between chromium bound to DNA and its fragments or chromium contained elsewhere in an environmental DNA extract. DNA was extracted from chromium-contaminated soils and purified using DNA clean-up resins.

Culture-based MEMS device to track Gordonia in activated sludge.

Previously, we reported on the use of microelectromechanical systems (MEMS) fabrication technologies to develop paraffin surfaces for miniaturization of culture-based detection and rapid quantification of Mycolata in environmental samples. In the current study, the novel culture-based biochip was calibrated with a broad range of pure cultures of Mycolata including Gordonia spp. isolated from activated sludge foam.

The widespread occurrence of the enterohemolysin gene ehlyA among environmental strains of Escherichia coli.

The putative virulence factor enterohemolysin, encoded by the ehlyA gene, has been closely associated with the pathogenic enterohemorrhagic Escherichia coli (EHEC) group. Escherichia coli isolates from effluents from seven geographically dispersed municipal wastewater treatment plants were screened for the presence of enterohemolysin. A total of 338 E.

In-situ enumeration and probing of pyrene-degrading soil bacteria.

Inferences about which microorganisms degrade polycyclic aromatic hydrocarbons in contaminated soils have largely been obtained using culture-based techniques, despite the low percentage of microorganisms in soil that are believed to be culturable. We used a substrate-responsive direct viable count method to identify and quantify potential polycyclic aromatic hydrocarbon-degrading bacteria in a soil containing petroleum wastes. Bacteria were extracted and their response to substrates determined in the presence of DNA gyrase inhibitors, which cause viable and active cells to elongate.

Developing rapid detection of mycobacteria using microwaves.

In this paper, we describe the development of a culture-based biochip device for rapid detection of mycobacteria in environmental samples. Individual biochips rely upon the unique paraffinophilic nature of mycobacteria to rapidly and selectively adhere to the surface of the device. We used prototype biochips to experimentally demonstrate the concept of rapid and selective detection of mycobacteria by testing pure cultures and using epifluorescence microscopy to visualize microorganisms on the surface.

High performance degradation of azo dye Acid Orange 7 and sulfanilic acid in a laboratory scale reactor after seeding with cultured bacterial strains.

Bacterial strains 1CX and SAD4i--previously isolated from the mixed liquor of a municipal sewage treatment plant--are capable of degrading the azo dye Acid Orange 7 (AO7) and sulfanilic acid, respectively. A rotating drum bioreactor (RDBR), operating under continuous flow and nutrient conditions designed to simulate the effluent from a dye manufacturing plant, was seeded with strains 1CX and SAD4i, forming a biofilm capable of degrading AO7 and sulfanilic acid. In addition, an RDBR containing a pre-existing biofilm capable of degrading AO7, but not sulfanilic acid, was seeded with strain SAD4i alone.

Degradation of acid orange 7 in an aerobic biofilm.

A stable microbial biofilm community capable of completely mineralizing the azo dye acid orange 7 (AO7) was established in a laboratory scale rotating drum bioreactor (RDBR) using waste liquor from a sewage treatment plant. A broad range of environmental conditions including pH (5.8-8.