Browsing by Author "Broadaway, Susan C."

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Bacteria associated with granular activated carbon particles in drinking water
(1986-09) Camper, Anne K.; LeChevallier, Mark W.; Broadaway, Susan C.; McFeters, Gordon A.
A sampling protocol was developed to examine particles released from granular activated carbon filter beds. A gauze filter/Swinnex procedure was used to collect carbon fines from 201 granular activated carbon-treated drinking water samples over 12 months. Application of a homogenization procedure (developed previously) indicated that 41.4% of the water samples had heterotrophic plate count bacteria attached to carbon particles. With the enumeration procedures described, heterotrophic plate count bacteria were recovered at an average rate of 8.6 times higher than by conventional analyses. Over 17% of the samples contained carbon particles colonized with coliform bacteria as enumerated with modified most-probable-number and membrane filter techniques. In some instances coliform recoveries were 122 to 1,194 times higher than by standard procedures. Nearly 28% of the coliforms attached to these particles in drinking water exhibited the fecal biotype. Scanning electron micrographs of carbon fines from treated drinking water showed microcolonies of bacteria on particle surfaces. These data indicate that bacteria attached to carbon fines may be an important mechanism by which microorganisms penetrate treatment barries and enter potable water supplies.
Community-based participatory research in Indian country: Improving health through water quality research and awareness
(2010-07) Cummins, C.; Doyle, John T.; Kindness, L.; Lefthand, M. J.; Bear Don't Walk, U. J.; Bends, Ada L.; Broadaway, Susan C.; Camper, Anne K.; Fitch, R.; Ford, Tim E.; Hamner, Steve; Morrison, A. R.; Richards, Crystal L.; Young, Sara L.; Eggers, Margaret J.
Water has always been held in high respect by the Apsaalooke (Crow) people of Montana. Tribal members questioned the health of the rivers and well water because of visible water quality deterioration and potential connections to illnesses in the community. Community members initiated collaboration among local organizations, the tribe, and academic partners, resulting in genuine community-based participatory research. The article shares what we have learned as tribal members and researchers about working together to examine surface and groundwater contaminants, assess routes of exposure, and use our data to bring about improved health of our people and our waters.
Detection and source tracking of Escherichia coli, harboring intimin and Shiga toxin genes, isolated from the Little Bighorn River, Montana
(2014-09) Hamner, Steve; Broadaway, Susan C.; Berg, Ethan; Stettner, Sean; Pyle, Barry H.; Big Man, N.; Old Elk, J.; Eggers, Margaret J.; Doyle, John T.; Kindness, L.; Good Luck, B.; Ford, Tim E.; Camper, Anne K.
The Little Bighorn River flows through the Crow Indian Reservation in Montana. In 2008, Escherichia coli concentrations as high as 7,179 MPN/100 ml were detected in the river at the Crow Agency Water Treatment Plant intake site. During 2008, 2009, and 2012, 10 different serotypes of E. coli, including O157:H7, harboring both intimin and Shiga toxin genes were isolated from a popular swim site of the Little Bighorn River in Crow Agency. As part of a microbial source tracking study, E. coli strains were isolated from river samples as well as from manure collected from a large cattle feeding operation in the upper Little Bighorn River watershed; 23% of 167 isolates of E. coli obtained from the manure tested positive for the intimin gene. Among these manure isolates, 19 were identified as O156:H8, matching the serotype of an isolate collected from a river sampling site close to the cattle feeding area.
Detection of Pathogenic and Non-pathogenic Bacteria in Drinking Water and Associated Biofilms on the Crow Reservation, Montana, USA
(2018-07) Richards, Crystal L.; Broadaway, Susan C.; Eggers, Margaret J.; Doyle, John T.; Pyle, Barry H.; Camper, Anne K.; Ford, Tim E.
Private residences in rural areas with water systems that are not adequately regulated, monitored, and updated could have drinking water that poses a health risk. To investigate water quality on the Crow Reservation in Montana, water and biofilm samples were collected from 57 public buildings and private residences served by either treated municipal or individual groundwater well systems. Bacteriological quality was assessed including detection of fecal coliform bacteria and heterotrophic plate count (HPC) as well as three potentially pathogenic bacterial genera, Mycobacterium, Legionella, and Helicobacter. All three target genera were detected in drinking water systems on the Crow Reservation. Species detected included the opportunistic and frank pathogens Mycobacterium avium, Mycobacterium gordonae, Mycobacterium flavescens, Legionella pneumophila, and Helicobacter pylori. Additionally, there was an association between HPC bacteria and the presence of Mycobacterium and Legionella but not the presence of Helicobacter. This research has shown that groundwater and municipal drinking water systems on the Crow Reservation can harbor potential bacterial pathogens.
Evaluation of portability and cost of a fluorescent PCR ribotyping protocol for Clostridium difficile epidemiology
(2015-01) Martinson, Jonathan N.V.; Broadaway, Susan C.; Lohman, Egan J.; Johnson, Christina; Alam, M. Jahangir; Khaleduzzaman, Mohammed; Garey, Kevin W.; Schlackman, Jessica; Young, Vincent B.; Santhosh, Kavitha; Rao, Krishna; Lyons, Robert H. Jr; Walk, Seth T.
Clostridium difficile is the most commonly identified pathogen among health care-associated infections in the United States. There is a need for accurate and low-cost typing tools that produce comparable data across studies (i.e., portable data) to help characterize isolates during epidemiologic investigations of C. difficile outbreaks and sporadic cases of disease. The most popular C. difficile-typing technique is PCR ribotyping, and we previously developed methods using fluorescent PCR primers and amplicon sizing on a Sanger-style sequencer to generate fluorescent PCR ribotyping data. This technique has been used to characterize tens of thousands of C. difficile isolates from cases of disease. Here, we present validation of a protocol for the cost-effective generation of fluorescent PCR ribotyping data. A key component of this protocol is the ability to accurately identify PCR ribotypes against an online database (http://walklab.rcg.montana.edu) at no cost. We present results from a blinded multicenter study to address data portability across four different laboratories and three different sequencing centers. Our standardized protocol and centralized database for typing of C. difficile pathogens will increase comparability between studies so that important epidemiologic linkages between cases of disease and patterns of emergence can be rapidly identified.
Factors affecting the determination of respiratory activity on the basis of cyanoditolyl tetrazolium chloride reduction with membrane filtration
(1995-12) Pyle, Barry H.; Broadaway, Susan C.; McFeters, Gordon A.
Growth and persistence of pathogens on granular activated carbon filters
(1985-07) Camper, Anne K.; LeChevallier, Mark W.; Broadaway, Susan C.; McFeters, Gordon A.
Three enteric pathogens Yersinia enterocolitica 0:8, Salmonella typhimurium, and enterotoxigenic Escherichia coli, were examined for their ability to colonize granular activated carbon (GAC) in pure cultures and in the presence of autochthonous river water organisms. All three organisms readily colonized sterile GAC and maintained populations of ca. 105 to 107 CFUg-1 for 14 days when suspended in sterile river water. Exposure of pathogen biofilms on GAC to unsterile river water resulted in a gradual decline in pathogens on the carbon (0.08 to 0.14 log day-1). When pathogens were introduced to sterile GAC in the presence of heterotrophic plate count organisms, they attached at levels similar to those in the pure cultures and then decreased (0.10 to 0.22 log day-1). When added with heterotrophic plate count bacteria to GAC supporting a mature biofilm of native river water bacteria, they attached at a lower level (1.0 x 104 to 4.6 x 104 CFUg-1) and decreased at a more rapid rate (0.11 to 0.70 log day-1).
Isolation of potentially pathogenic Escherichia coli O157:h7 from the Ganges River
(2007-02) Hamner, Steve; Broadaway, Susan C.; Mishra, Veer B.; Tripathi, Anshuman; Mishra, Rajesh K.; Pulcini, Elinor D.; Pyle, Barry H.; Ford, Tim E.
Escherichia coli serotype O157:H7 was detected among bacteria collected from the Ganges River. O157:H7 isolates tested positive for stx1, stx2, and eae gene sequences. Identification of potentially pathogenic isolates from extensively used source water indicates that O157:H7 may be a significant but as yet underacknowledged public health concern in India.
Optimizing the growth of stressed Helicobacter pylori
(2011-02) Richards, Crystal L.; Buchholz, B. J.; Ford, Tim E.; Broadaway, Susan C.; Pyle, Barry H.; Camper, Anne K.
Helicobacter pylori is a gram-negative bacterium that colonizes the human stomach and is responsible for causing gastric ulcers. H. pylori is known to become stressed and nonculturable after exposure to unfavorable conditions. In this study, we enhanced previously published resuscitation procedures, characterized conditions under which stressed H. pylori can be recovered, and formulated a selective and differential resuscitation medium.Results showed that a specialized broth supplemented with trace minerals and lysed human erythrocytes and serum is required for the recovery of nonculturable H. pylori. The type of stress was an important factor in the efficacy of resuscitation, with cells exposed to atmospheric oxygen more readily resuscitated than nutrient-deprived cells. After resuscitation, culturable cells were recovered from previously nonculturable oxygen stressed cells (24 and 72 h of exposure) and nonculturable nutrient deprived cells (24 h of exposure). The length of time the cells were exposed to the stress was also an important factor in the recovery of stressed H. pylori. RNA levels were quantified and transcription of the cell division related gene, cdrA (HP0066), was assessed by qRT-PCR. The low levels of RNA detected in stressed cells, after resuscitation, support the idea that a small population of viable cells may be responsible for the colonies recovered on solid agar. The modification of the resuscitation broth into a selective and differential slant culture medium also allowed the recovery of stressed H. pylori. The methods presented here highlight the benefits and limitations of using human blood products for recovering nonculturable H. pylori.
Rapid direct methods for enumeration of specific, active bacteria in water and biofilms
(1998-12) McFeters, Gordon A.; Pyle, Barry H.; Lisle, John T.; Broadaway, Susan C.
Conventional methods for detecting indicator and pathogenic bacteria in water may underestimate the actual population due to sublethal environmental injury, inability of the target bacteria to take up nutrients and other physiological factors which reduce bacterial culturability. Rapid and direct methods are needed to more accurately detect and enumerate active bacteria. Such a methodological advance would provide greater sensitivity in assessing the microbiological safety of water and food. The principle goal of this presentation is to describe novel approaches we have formulated for the rapid and simultaneous detection of bacteria plus the determination of their physiological activity in water and other environmental samples. The present version of our method involves the concentration of organisms by membrane filtration or immunomagnetic separation and combines an intracellular fluorochrome (CTC) for assessment of respiratory activity plus fluorescent-labelled antibody detection of specific bacteria. This approach has also been successfully used to demonstrate spatial and temporal heterogeneities of physiological activities in biofilms when coupled with cryosectioning. Candidate physiological stains include those capable of determining respiratory activity, membrane potential, membrane integrity, growth rate and cellular enzymatic activities. Results obtained thus far indicate that immunomagnetic separation can provide a high degree of sensitivity in the recovery of seeded target bacteria (Escherichia coli O157:H7) in water and hamburger. The captured and stained target bacteria are then enumerated by either conventional fluorescence microscopy or ChemScank, a new instrument that is very sensitive and rapid. The ChemScanR laser scanning instrument (Chemunex, Paris, France) provides the detection of individual fluorescently labelled bacterial cells using three emission channels in less than 5 min. A high degree of correlation has been demonstrated between results obtained with the ChemScan and traditional plate counts of mixed natural bacterial populations in water. The continuing evolution of these methods will be valuable in the rapid and accurate analysis of environmental samples.