A systematic review of outbreak and non-outbreak studies of extraintestinal pathogenic Escherichia coli causing community-acquired infections.

A systematic review of outbreak and non-outbreak studies of infections caused by extraintestinal pathogenic Escherichia coli (ExPEC) was conducted. This review examines the epidemiology, seasonality, source or mode of transmission, and temporal changes, based on E. coli serogroup, in ExPEC causing sporadic vs. outbreak-associated infections. Twelve outbreak and 28 non-outbreak studies were identified. The existence of ExPEC outbreaks was well supported. Three of four outbreak reports indicated peak periods during the winter months. Serogroups associated with outbreak infections ranged from 1% to 26% (average 11·4%) vs. (range 1-15%, average 3·5%) for serogroups associated with sporadic infections; the distribution of serogroups also differed for outbreak and non-outbreak infections. Study authors indicated that the outbreaks may have resulted from foodborne transmission, but direct evidence was unavailable. This review provides evidence that the epidemiology of endemic vs. epidemic ExPEC infections differs; however, study reporting quality limited epidemiological inferences.

Nitrogen, phosphorous, and organic carbon removal in simulated wetland treatment systems.

Effects of vegetation, wastewater drawdown, hydraulic retention time (HRT), and media depth on removal of nitrogen, phosphorous, and organic carbon in microcosms were investigated. Synthetic wastewater was added daily to 28 microcosms, and effluent was sampled every 12 days for 132 days. Effluent was analyzed for ammonium (NH(4)(+)-N), nitrate (NO(3)(-)-N), orthophosphate (PO(4)(3-)-P), and total organic carbon (TOC). Average percent removal of NH(4)(+)-N was significantly greater in microcosms containing plants (67%) than in those without plants (29%). Percent removal of PO(4)(3-)-P was also significantly greater in microcosms with plants (42%) than in microcosms without plants (20%), but no significant difference was found for TOC removal between microcosms with plants (67%) and those without plants (74%). Average removal was significantly lower in microcosms with wastewater drawdown than in those without wastewater fluctuation for both NH(4)(+)-N (51% versus 83%) and PO(4)(3-)-P (14% versus 71%). Percent NH(4)(+)-N removal was significantly greater in microcosms with a 6-day retention time (80%) than in those with a 2-day retention (53%), and PO(4)(3-)-P removal was also significantly greater with a 6-day retention time (55%) than a 2-day retention (29%). No differences were seen in TOC removal due to any of the treatments but HRT, where removal was greater microcosms with a 2-day HRT (76%) than in those with a 6-day HRT (60%). Media depth did not have a significant effect on nutrient removal. Results of this study demonstrate that required design parameters are different depending on the nutrient being removed in systems simulated by these microcosms.

Evaluation of cell lines and immunofluorescence and plaque assay procedures for quantifying reoviruses in sewage.

Twelve continuous cell lines were tested to determine their sensitivity to reovirus types 1, 2, and 3 isolated from sewage. Madin-Darby bovine kidney (MDBK), rhesus monkey kidney (LLC-MK2), and human embryonic intestinal (intestinal 407) cells were most sensitive, respectively. In a similar study, MDBK cells were more sensitive than LLC-MK2 and Buffalo green monkey kidney (BGM) cells to sewage-isolated, protamine-precipitated reoviruses which had not been serotyped and had no previous cell contact. Sewage-isolated, protamine-precipitated reoviruses were also used in conjunction with MDBK cells in a comparative evaluation of immunofluorescent cell count and plaque assay procedures. The immunofluorescence assay is more sensitive and more rapid than the plaque assay. Reoviruses in excess of 10(4)/liter of raw sewage were detected by the immunofluorescent cell count assay.