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Faecal Indicator Bacteria (faecal + indicator_bacteria)
Selected AbstractsHuman enteric viruses in groundwater indicate offshore transport of human sewage to coral reefs of the Upper Florida KeysENVIRONMENTAL MICROBIOLOGY, Issue 4 2010J. Carrie Futch Summary To address the issue of human sewage reaching corals along the main reef of the Florida Keys, samples were collected from surface water, groundwater and coral [surface mucopolysaccharide layers (SML)] along a 10 km transect near Key Largo, FL. Samples were collected semi-annually between July 2003 and September 2005 and processed for faecal indicator bacteria (faecal coliform bacteria, enterococci and Clostridium perfringens) and human-specific enteric viruses (enterovirus RNA and adenovirus DNA) by (RT)-nested polymerase chain reaction. Faecal indicator bacteria concentrations were generally higher nearshore and in the coral SML. Enteric viruses were evenly distributed across the transect stations. Adenoviruses were detected in 37 of 75 samples collected (49.3%) whereas enteroviruses were only found in 8 of 75 samples (10.7%). Both viruses were detected twice as frequently in coral compared with surface water or groundwater. Offshore, viruses were most likely to be found in groundwater, especially during the wet summer season. These data suggest that polluted groundwater may be moving to the outer reef environment in the Florida Keys. [source] Covalently linked immunomagnetic separation/adenosine triphosphate technique (Cov-IMS/ATP) enables rapid, in-field detection and quantification of Escherichia coli and Enterococcus spp. in freshwater and marine environmentsJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2010C.M. Lee Abstract Aims:, Developing a rapid method for detection of faecal pollution is among the critical goals set forth by the Environmental Protection Agency in its revision of water quality criteria. The purpose of this study is to devise and test covalently linked antibody,bead complexes for faecal indicator bacteria (FIB), specifically Escherichia coli or Enterococcus spp., in measuring water quality in freshwater and marine systems. Methods and Results:, Covalently linked complexes were 58,89% more robust than antibody,bead complexes used in previous studies. Freshwater and marine water samples analysed using covalently linked immunomagnetic separation/adenosine triphosphate quantification technique (Cov-IMS/ATP) and culture-based methods yielded good correlations for E. coli (R = 0·87) and Enterococcus spp. (R = 0·94), with method detection limits below EPA recreational water quality health standards for single standard exceedances (E. coli, 38 cells per 100 ml; Enterococcus spp. , 25 cells per 100 ml). Cov-IMS/ATP correctly classified 87% of E. coli and 94% of Enterococcus spp. samples based on these water quality standards. Cov-IMS/ATP was also used as a field method to rapidly distinguish differential loading of E. coli between two stream channels to their confluence. Conclusions:, Cov-IMS/ATP is a robust, in-field detection method for determining water quality of both fresh and marine water systems as well as differential loading of FIB from two converging channels. Significance and Impact of the Study:, To our knowledge, this is the first work to present a viable rapid, in-field assay for measuring FIB concentrations in marine water environments. Cov-IMS/ATP is a potential alternative detection method, particularly in areas with limited laboratory support and resources, because of its increased economy and portability. [source] Evaluation of novel fluorogenic substrates for the detection of glycosidases in Escherichia coli and enterococciJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2006J.D. Perry Abstract Aims:, Enzyme substrates based on 4-methylumbelliferone are widely used for the detection of Escherichia coli and enterococci in water, by detection of , -glucuronidase and , -glucosidase activity respectively. This study aimed to synthesize and evaluate novel umbelliferone-based substrates with improved sensitivity for these two enzymes. Methods and Results:, A novel , -glucuronide derivative based on 6-chloro-4-methylumbelliferone (CMUG) was synthesized and compared with 4-methylumbelliferyl- , - d -glucuronide (MUG) using 42 strains of E. coli in a modified membrane lauryl sulfate broth. Over 7 h of incubation, the fluorescence generated from the hydrolysis of CMUG by E. coli was over twice that from MUG, and all of the 38 glucuronidase-positive strains generated a higher fluorescence with CMUG compared with MUG. Neither substrate caused inhibition of bacterial growth in any of the tested strains. Four , -glucosidase substrates were also synthesized and evaluated in comparison with 4-methylumbelliferyl- , - d -glucoside (MU-GLU) using 42 strains of enterococci in glucose azide broth. The four substrates comprised , -glucoside derivatives of umbelliferone-3-carboxylic acid and its methyl, ethyl and benzyl esters. Glucosides of the methyl, ethyl and benzyl esters of umbelliferone-3-carboxylic acid, were found to be superior to MU-GLU for the detection of enterococci, especially after 18 h of incubation, while umbelliferone-3-carboxylic acid- , - d -glucoside was inferior. However, the variability in detectable , -glucosidase activity among the different strains of enterococci in short-term assays using the three carboxylate esters (7 h incubation) may compromise their use for rapid detection and enumeration of these faecal indicator bacteria. Conclusions:, The , -glucuronidase substrate CMUG appears to be a more promising detection system than the various , -glucosidase substrates tested. Significance and Impact of the Study:, The novel substrate CMUG showed enhanced sensitivity for the detection of , -glucuronidase-producing bacteria such as E. coli, with a clear potential for application in rapid assays for the detection of this indicator organism in natural water and other environmental samples. [source] Microbial and nutrient pollution in the coastal bathing waters of Dar es SalaamAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2009Thomas J. Lyimo Abstract 1.The objective of the present study was to assess the microbial and nutrient quality of coastal beach waters used for bathing in the city of Dar es Salaam, Tanzania. Concentrations of traditional and alternative microbial indicators of faecal pollution and nutrients were assessed over a 1 year period (August 2005 to August 2006) using standard methods and the results were compared with the WHO water quality guidelines. 2.Faecal indicator bacteria values varied in a consistent fashion and correlated significantly with eachother, reflecting the presumed human faecal pollution. 3.The maximum counts (MPN per 100,mL) were observed on the site close to the city centre (Ocean Road) throughout the sampling period where values ranged from 1700 to>240 000 total coliform (TC), 200 to 92000 faecal coliform (FC) and 11 to 4900 enterococci (ENT). Other sites showed less predictable results with a range of values from 0,920, 0,540 and 0,46 for TC, FC and ENT, respectively. Furthermore, the faecal indicator bacteria concentration varied significantly with sampling time (P<0.05) and between sampling points (P<0.05). 4.Similarly, nutrients were significantly higher (P<0.05) at Ocean Road where concentration (µmolL,1) ranges were 0.2,54 (NO3), 0.0,20 (NO2) and 0.3,45 (PO4). 5.The levels of faecal indicator bacteria and nutrients were higher during the rainy seasons than the dry seasons, showing the inclusion of rain run-off as a source of contamination. The faecal indicator bacteria correlated positively with nutrients in both 1 year and daily data sets (P<0.01). Positive relationships were also observed among faecal indicators. This strongly suggests that an important role is played by sewage contamination in the extent of microbial pollution at the studied urbanized coastal beaches. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||