scholarly journals Impact of Metazooplankton Filter Feeding on Escherichia coli under Variable Environmental Conditions

2019 ◽  
Vol 85 (23) ◽  
Author(s):  
Niveen S. Ismail ◽  
Brittney M. Blokker ◽  
Tyler R. Feeney ◽  
Ruby H. Kohn ◽  
Jingyi Liu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
Surface Waters ◽  
Environmental Variables ◽  
Bacterial Species ◽  
Clearance Rates ◽  
Filter Feeding ◽  
Fecal Indicator ◽  
Content Type ◽  
E Coli

ABSTRACT The fecal indicator bacterial species Escherichia coli is an important measure of water quality and a leading cause of impaired surface waters. We investigated the impact of the filter-feeding metazooplankton Daphnia magna on the inactivation of E. coli. The E. coli clearance rates of these daphnids were calculated from a series of batch experiments conducted under variable environmental conditions. Batch system experiments of 24 to 48 h in duration were completed to test the impacts of bacterial concentration, organism density, temperature, and water type. The maximum clearance rate for adult D. magna organisms was 2 ml h−1 organism−1. Less than 5% of E. coli removed from water by daphnids was recoverable from excretions. Sorption of E. coli on daphnid carapaces was not observed. As a comparison, the clearance rates of the freshwater rotifer Branchionus calyciflorus were also calculated for select conditions. The maximum clearance rate for B. calyciflorus was 6 × 10−4 ml h−1 organism−1. This research furthers our understanding of the impacts of metazooplankton predation on E. coli inactivation and the effects of environmental variables on filter feeding. Based on our results, metazooplankton can play an important role in the reduction of E. coli in natural treatment systems under environmentally relevant conditions. IMPORTANCE Escherichia coli is a fecal indicator bacterial species monitored by the U.S. Environmental Protection Agency to assess microbial water quality. Due to the potential human health implications linked to high levels of E. coli, it is important to understand the inactivation or reduction mechanisms in surface waters. Our research examines the capacities of two types of widespread filter-feeding freshwater metazooplankton, Daphnia magna and Brachionus calyciflorus, to reduce E. coli concentrations. We examine the impacts of different environmentally relevant conditions on the clearance rates. Our results contribute to a better understanding of the importance of metazooplankton in controlling E. coli concentrations and what conditions will reduce or increase grazing. These results provide baseline data to support future efforts to develop a quantitative model relating zooplankton uptake rates to relevant environmental variables.

scholarly journals Non-point source pollution: Determination of replication versus persistence of Escherichia coli in surface water and sediments with correlation of levels to readily measurable environmental parameters

2004 ◽  
Vol 2 (2) ◽  
pp. 103-114 ◽  
Author(s):  
Julie Kinzelman ◽  
Sandra L. McLellan ◽  
Annette D. Daniels ◽  
Susan Cashin ◽  
Ajaib Singh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
Point Source ◽  
Wave Height ◽  
Surface Waters ◽  
Lake Michigan ◽  
Recreational Water ◽  
Point Source Pollution ◽  
E Coli ◽  
Non Point Source Pollution

Racine, Wisconsin, located on Lake Michigan, experiences frequent recreational water quality advisories in the absence of any identifiable point source of pollution. This research examines the environmental distribution of Escherichia coli in conjunction with the assessment of additional parameters (rainfall, turbidity, wave height, wind direction, wind speed and algal presence) in order to determine the most probable factors that influence E. coli levels in surface waters. Densities of E. coli were highest in core samples taken from foreshore sands, often exceeding an order of magnitude greater than those collected from submerged sands and water. Simple regression and multivariate analyses conducted on supplementary environmental data indicate that the previous day's E. coli concentration in conjunction with wave height is significantly predictive for present-time E. coli concentration. Genetic fingerprinting using repetitive element anchored PCR and cellular fatty acid analysis were employed to assess the presence of clonal isolates which indicate replication from a common parent cell. There were relatively few occurrences of clonal patterns in isolates collected from water, foreshore and submerged sands, suggesting that accumulation of E. coli, rather than environmental replication, was occurring in this system. Non-point source pollution, namely transport of accumulated E. coli from foreshore sands to surface waters via wave action, was found to be a major contributor to poor recreational water quality at the Lake Michigan beaches involved in this study.

scholarly journals Poikilothermic Animals as a Previously Unrecognized Source of Fecal Indicator Bacteria in a Backwater Ecosystem of a Large River

2018 ◽  
Vol 84 (16) ◽  
Author(s):  
Christina Frick ◽  
Julia Vierheilig ◽  
Rita Linke ◽  
Domenico Savio ◽  
Horst Zornig ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clostridium Perfringens ◽  
Fecal Indicator Bacteria ◽  
Indicator Bacteria ◽  
Primary Sources ◽  
Fecal Indicator ◽  
Content Type ◽  
E Coli ◽  
High Concentrations ◽  
Intestinal Enterococci

ABSTRACTQuantitative information regarding the presence ofEscherichia coli, intestinal enterococci, andClostridium perfringensin poikilotherms is notably scarce. Therefore, this study was designed to allow a systematic comparison of the occurrence of these standard fecal indicator bacteria (SFIB) in the excreta of wild homeothermic (ruminants, boars, carnivores, and birds) and poikilothermic (earthworms, gastropods, frogs, and fish) animals inhabiting an alluvial backwater area in eastern Austria. With the exception of earthworms, the average concentrations ofE. coliand enterococci in the excreta of poikilotherms were equal to or only slightly lower than those observed in homeothermic excreta and were 1 to 4 orders of magnitude higher than the levels observed in the ambient soils and sediments. Enterococci reached extraordinarily high concentrations in gastropods. Additional estimates of the daily excreted SFIB (E. coliand enterococcus) loads (DESL) further supported the importance of poikilotherms as potential pollution sources. The newly established DESL metric also allowed comparison to the standing stock of SFIB in the sediment and soil of the investigated area. In agreement with its biological characteristics, the highest concentrations ofC. perfringenswere observed in carnivores. In conclusion, the long-standing hypothesis that only humans and homeothermic animals are primary sources of SFIB is challenged by the results of this study. It may be necessary to extend the fecal indicator concept by additionally considering poikilotherms as potential important primary habitats of SFIB. Further studies in other geographical areas are needed to evaluate the general significance of our results. We hypothesize that the importance of poikilotherms as sources of SFIB is strongly correlated with the ambient temperature and would therefore be of increased significance in subtropical and tropical habitats and water resources.IMPORTANCEThe current fecal indicator concept is based on the assumption that the standard fecal indicator bacteria (SFIB)Escherichia coli, intestinal enterococci, andClostridium perfringensmultiply significantly only in the guts of humans and other homeothermic animals and can therefore indicate fecal pollution and the potential presence of pathogens from those groups. The findings of the present study showed that SFIB can also occur in high concentrations in poikilothermic animals (i.e., animals with body temperatures that vary with the ambient environmental temperature, such as fish, frogs, and snails) in an alluvial backwater area in a temperate region, indicating that a reconsideration of this long-standing indicator paradigm is needed. This study suggests that poikilotherms must be considered to be potential primary sources of SFIB in future studies.

scholarly journals Predictive Models for Escherichia coli Concentrations at Inland Lake Beaches and Relationship of Model Variables to Pathogen Detection

2013 ◽  
Vol 79 (5) ◽  
pp. 1676-1688 ◽  
Author(s):  
Donna S. Francy ◽  
Erin A. Stelzer ◽  
Joseph W. Duris ◽  
Amie M. G. Brady ◽  
John H. Harrison ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
Predictive Models ◽  
Pathogen Detection ◽  
Model Performance ◽  
Current Method ◽  
Content Type ◽  
E Coli ◽  
Predictive Variables ◽  
Inland Lake

ABSTRACTPredictive models, based on environmental and water quality variables, have been used to improve the timeliness and accuracy of recreational water quality assessments, but their effectiveness has not been studied in inland waters. Sampling at eight inland recreational lakes in Ohio was done in order to investigate using predictive models forEscherichia coliand to understand the links betweenE. coliconcentrations, predictive variables, and pathogens. Based upon results from 21 beach sites, models were developed for 13 sites, and the most predictive variables were rainfall, wind direction and speed, turbidity, and water temperature. Models were not developed at sites where theE. colistandard was seldom exceeded. Models were validated at nine sites during an independent year. At three sites, the model resulted in increased correct responses, sensitivities, and specificities compared to use of the previous day'sE. coliconcentration (the current method). Drought conditions during the validation year precluded being able to adequately assess model performance at most of the other sites.Cryptosporidium, adenovirus,eaeA(E. coli),ipaH(Shigella), andspvC(Salmonella) were found in at least 20% of samples collected for pathogens at five sites. The presence or absence of the three bacterial genes was related to some of the model variables but was not consistently related toE. coliconcentrations. Predictive models were not effective at all inland lake sites; however, their use at two lakes with high swimmer densities will provide better estimates of public health risk than current methods and will be a valuable resource for beach managers and the public.

scholarly journals Plant-Pathogenic Oomycetes, Escherichia coli Strains, and Salmonella spp. Frequently Found in Surface Water Used for Irrigation of Fruit and Vegetable Crops in New York State

2014 ◽  
Vol 80 (16) ◽  
pp. 4814-4820 ◽  
Author(s):  
Lisa A. Jones ◽  
Randy W. Worobo ◽  
Christine D. Smart
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
New York ◽  
Food Safety ◽  
Surface Water ◽  
New York State ◽  
Quality Parameters ◽  
Content Type ◽  
York State ◽  
E Coli

ABSTRACTIn the United States, surface water is commonly used to irrigate a variety of produce crops and can harbor pathogens responsible for food-borne illnesses and plant diseases. Understanding when pathogens infest water sources is valuable information for produce growers to improve the food safety and production of these crops. In this study, prevalence data along with regression tree analyses were used to correlate water quality parameters (pH, temperature, turbidity), irrigation site properties (source, the presence of livestock or fowl nearby), and precipitation data to the presence and concentrations ofEscherichia coli,Salmonellaspp., and hymexazol-insensitive (HIS) oomycetes (PhytophthoraandPythiumspp.) in New York State surface waters. A total of 123 samples from 18 sites across New York State were tested forE. coliandSalmonellaspp., of which 33% and 43% were positive, respectively. Additionally, 210 samples from 38 sites were tested for HIS oomycetes, and 88% were found to be positive, with 10 species ofPhytophthoraand 11 species ofPythiumbeing identified from the samples. Regression analysis found no strong correlations between water quality parameters, site factors, or precipitation to the presence or concentration ofE. coliin irrigation sources. ForSalmonella, precipitation (≤0.64 cm) 3 days before sampling was correlated to both presence and the highest counts. Analyses for oomycetes found creeks to have higher average counts than ponds, and higher turbidity levels were associated with higher oomycete counts. Overall, information gathered from this study can be used to better understand the food safety and plant pathogen risks of using surface water for irrigation.

scholarly journals Identification of Escherichia coli and Shigella Species from Whole-Genome Sequences

2016 ◽  
Vol 55 (2) ◽  
pp. 616-623 ◽  
Author(s):  
Marie A. Chattaway ◽  
Ulf Schaefer ◽  
Rediat Tewolde ◽  
Timothy J. Dallman ◽  
Claire Jenkins
Keyword(s):  
Escherichia Coli ◽  
Clonal Complex ◽  
Shigella Flexneri ◽  
Bacterial Species ◽  
Whole Genome ◽  
Content Type ◽  
E Coli ◽  
Shigella Species ◽  
Close Phylogenetic Relationship ◽  
Initial Identification

ABSTRACTEscherichia coliandShigellaspecies are closely related and genetically constitute the same species. Differentiating between these two pathogens and accurately identifying the four species ofShigellaare therefore challenging. The organism-specific bioinformatics whole-genome sequencing (WGS) typing pipelines at Public Health England are dependent on the initial identification of the bacterial species by use of a kmer-based approach. Of the 1,982Escherichia coliandShigellasp. isolates analyzed in this study, 1,957 (98.4%) had concordant results by both traditional biochemistry and serology (TB&S) and the kmer identification (ID) derived from the WGS data. Of the 25 mismatches identified, 10 were enteroinvasiveE. coliisolates that were misidentified asShigella flexneriorS. boydiiby the kmer ID, and 8 wereS. flexneriisolates misidentified by TB&S asS. boydiidue to nonfunctionalS. flexneriO antigen biosynthesis genes. Analysis of the population structure based on multilocus sequence typing (MLST) data derived from the WGS data showed that the remaining discrepant results belonged to clonal complex 288 (CC288), comprising bothS. boydiiandS. dysenteriaestrains. Mismatches between the TB&S and kmer ID results were explained by the close phylogenetic relationship between the two species and were resolved with reference to the MLST data.Shigellacan be differentiated fromE. coliand accurately identified to the species level by use of kmer comparisons and MLST. Analysis of the WGS data provided explanations for the discordant results between TB&S and WGS data, revealed the true phylogenetic relationships between different species ofShigella, and identified emerging pathoadapted lineages.

scholarly journals Genotypic Diversity of Escherichia coli in the Water and Soil of Tropical Watersheds in Hawaii

2011 ◽  
Vol 77 (12) ◽  
pp. 3988-3997 ◽  
Author(s):  
Dustin K. Goto ◽  
Tao Yan
Keyword(s):  
Escherichia Coli ◽  
Genotypic Diversity ◽  
Tropical Soils ◽  
Water Quality Monitoring ◽  
Fecal Indicator ◽  
Content Type ◽  
E Coli ◽  
Tropical Watersheds ◽  
High Concentrations ◽  
Soil And Water

ABSTRACTHigh levels ofEscherichia coliwere frequently detected in tropical soils in Hawaii, which present important environmental sources ofE. colito water bodies. This study systematically examinedE. coliisolates from water and soil of several watersheds in Hawaii and observed high overall genotypic diversity (35.5% unique genotypes). In the Manoa watershed, fewer than 9.3% of the observedE. coligenotypes in water and 6.6% in soil were shared between different sampling sites, suggesting the lack of dominant fecal sources in the watershed. High temporal variability ofE. coligenotypes in soil was also observed, which suggests a dynamicE. colipopulation corresponding with the frequently observed high concentrations in tropical soils. WhenE. coligenotypes detected from the same sampling events were compared, limited sharing between the soil and water samples was observed in the majority of comparisons (73.5%). However, several comparisons reported up to 33.3% overlap ofE. coligenotypes between soil and water, illustrating the potential for soil-water interactions under favorable environmental conditions. In addition, genotype accumulation curves forE. colifrom water and soil indicated that the sampling efforts in the Manoa watershed could not exhaust the overall genotypic diversity. Comparisons ofE. coligenotypes from other watersheds on Oahu, Hawaii, identified no apparent grouping according to sampling locations. The results of the present study demonstrate the complexity of usingE. colias a fecal indicator bacterium in tropical watersheds and highlight the need to differentiate environmental sources ofE. colifrom fecal sources in water quality monitoring.

scholarly journals Tumble Suppression Is a Conserved Feature of Swarming Motility

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Jonathan D. Partridge ◽  
Nguyen T. Q. Nhu ◽  
Yann S. Dufour ◽  
Rasika M. Harshey
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Behavioral Adaptation ◽  
Diverse Group ◽  
Swarming Motility ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Surfactant Secretion ◽  
Motility Parameters

ABSTRACT Many bacteria use flagellum-driven motility to swarm or move collectively over a surface terrain. Bacterial adaptations for swarming can include cell elongation, hyperflagellation, recruitment of special stator proteins, and surfactant secretion, among others. We recently demonstrated another swarming adaptation in Escherichia coli, wherein the chemotaxis pathway is remodeled to decrease tumble bias (increase run durations), with running speeds increased as well. We show here that the modification of motility parameters during swarming is not unique to E. coli but is shared by a diverse group of bacteria we examined—Proteus mirabilis, Serratia marcescens, Salmonella enterica, Bacillus subtilis, and Pseudomonas aeruginosa—suggesting that increasing run durations and speeds are a cornerstone of swarming. IMPORTANCE Bacteria within a swarm move characteristically in packs, displaying an intricate swirling motion in which hundreds of dynamic rafts continuously form and dissociate as the swarm colonizes an increasing expanse of territory. The demonstrated property of E. coli to reduce its tumble bias and hence increase its run duration during swarming is expected to maintain and promote side-by-side alignment and cohesion within the bacterial packs. In this study, we observed a similar low tumble bias in five different bacterial species, both Gram positive and Gram negative, each inhabiting a unique habitat and posing unique problems to our health. The unanimous display of an altered run-tumble bias in swarms of all species examined in this investigation suggests that this behavioral adaptation is crucial for swarming.

scholarly journals Systematic Nomenclature for GGDEF and EAL Domain-Containing Cyclic Di-GMP Turnover Proteins of Escherichia coli: TABLE 1

2015 ◽  
Vol 198 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Regine Hengge ◽  
Michael Y. Galperin ◽  
Jean-Marc Ghigo ◽  
Mark Gomelsky ◽  
Jeffrey Green ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Bacterial Species ◽  
Content Type ◽  
E Coli ◽  
Diguanylate Cyclases ◽  
Genes Encoding ◽  
Systematic Nomenclature ◽  
K 12 ◽  
Encoding Genes

In recent years,Escherichia colihas served as one of a few model bacterial species for studying cyclic di-GMP (c-di-GMP) signaling. The widely usedE. coliK-12 laboratory strains possess 29 genes encoding proteins with GGDEF and/or EAL domains, which include 12 diguanylate cyclases (DGC), 13 c-di-GMP-specific phosphodiesterases (PDE), and 4 “degenerate” enzymatically inactive proteins. In addition, six new GGDEF and EAL (GGDEF/EAL) domain-encoding genes, which encode two DGCs and four PDEs, have recently been found in genomic analyses of commensal and pathogenicE. colistrains. As a group of researchers who have been studying the molecular mechanisms and the genomic basis of c-di-GMP signaling inE. coli, we now propose a general and systematicdgcandpdenomenclature for the enzymatically active GGDEF/EAL domain-encoding genes of this model species. This nomenclature is intuitive and easy to memorize, and it can also be applied to additional genes and proteins that might be discovered in various strains ofE. coliin future studies.

scholarly journals Lineage-Specific Distribution of Insertion Sequence Excision Enhancer in Enterotoxigenic Escherichia coli Isolated from Swine

2013 ◽  
Vol 80 (4) ◽  
pp. 1394-1402 ◽  
Author(s):  
Masahiro Kusumoto ◽  
Dai Fukamizu ◽  
Yoshitoshi Ogura ◽  
Eiji Yoshida ◽  
Fumiko Yamamoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Bacterial Genome ◽  
Enterotoxigenic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Genomic Deletions ◽  
Specific Distribution ◽  
Multiple Copies ◽  
Genomic Locations

ABSTRACTInsertion sequences (ISs) are the simplest transposable elements and are widely distributed in bacteria; however, they also play important roles in genome evolution. We recently identified a protein called IS excision enhancer (IEE) in enterohemorrhagicEscherichia coli(EHEC) O157. IEE promotes the excision of IS elements belonging to the IS3family, such as IS629, as well as several other families. IEE-mediated IS excision generates various genomic deletions that lead to the diversification of the bacterial genome. IEE has been found in a broad range of bacterial species; however, among sequencedE. colistrains, IEE is primarily found in EHEC isolates. In this study, we investigated non-EHEC pathogenicE. colistrains isolated from domestic animals and found that IEE is distributed in specific lineages of enterotoxigenicE. coli(ETEC) strains of serotypes O139 or O149 isolated from swine. Theieegene is located within integrative elements that are similar to SpLE1 of EHEC O157. Alliee-positive ETEC lineages also contained multiple copies of IS629, a preferred substrate of IEE, and their genomic locations varied significantly between strains, as observed in O157. These data suggest that IEE may have been transferred among EHEC and ETEC in swine via SpLE1 or SpLE1-like integrative elements. In addition, IS629is actively moving in the ETEC O139 and O149 genomes and, as in EHEC O157, is promoting the diversification of these genomes in combination with IEE.

scholarly journals Unexpected Diversity of Escherichia coli SialateO-Acetyl Esterase NanS

2016 ◽  
Vol 198 (20) ◽  
pp. 2803-2809 ◽  
Author(s):  
Ariel Rangel ◽  
Susan M. Steenbergen ◽  
Eric R. Vimr
Keyword(s):  
Escherichia Coli ◽  
Sialic Acid ◽  
Bacterial Species ◽  
Sialic Acids ◽  
Host Bacterium ◽  
Acetyl Esterase ◽  
Content Type ◽  
E Coli ◽  
Host Microbe Interactions ◽  
K 12

ABSTRACTThe sialic acids (N-acylneuraminates) are a group of nine-carbon keto-sugars existing mainly as terminal residues on animal glycoprotein and glycolipid carbohydrate chains. Bacterial commensals and pathogens exploit host sialic acids for nutrition, adhesion, or antirecognition, whereN-acetyl- orN-glycolylneuraminic acids are the two predominant chemical forms of sialic acids. Each form may be modified by acetyl esters at carbon position 4, 7, 8, or 9 and by a variety of less-common modifications. Modified sialic acids produce challenges for colonizing bacteria, because the chemical alterations toN-acetylneuraminic acid (Neu5Ac) confer increased resistance to sialidase and aldolase activities essential for the catabolism of host sialic acids. Bacteria withO-acetyl sialate esterase(s) utilize acetylated sialic acids for growth, thereby gaining a presumed metabolic advantage over competitors lacking this activity. Here, we demonstrate the esterase activity ofEscherichia coliNanS after purifying it as a C-terminal HaloTag fusion. Using a similar approach, we show thatE. colistrain O157:H7 Stx prophage or prophage remnants invariably include paralogs ofnanSoften located downstream of the Shiga-like toxin genes. These paralogs may include sequences encoding N- or C-terminal domains of unknown function where the NanS domains can act as sialateO-acetyl esterases, as shown by complementation of anE. colistrain K-12nanSmutant and the unimpaired growth of anE. coliO157nanSmutant onO-acetylated sialic acid. We further demonstrate thatnanShomologs inStreptococcusspp. also encode active esterase, demonstrating an unexpected diversity of bacterial sialateO-acetyl esterase.IMPORTANCEThe sialic acids are a family of over 40 naturally occurring 9-carbon keto-sugars that function in a variety of host-bacterium interactions. These sugars occur primarily as terminal carbohydrate residues on host glycoproteins and glycolipids. Available evidence indicates that diverse bacterial species use host sialic acids for adhesion or as sources of carbon and nitrogen. Our results show that the catabolism of the diacetylated form of host sialic acid requires a specialized esterase, NanS. Our results further show thatnanShomologs exist in bacteria other thanEscherichia coli, as well as part of toxigenicE. coliprophage. The unexpected diversity of these enzymes suggests new avenues for investigating host-bacterium interactions. Therefore, these original results extend our previous studies ofnanSto include mucosal pathogens, prophage, and prophage remnants. This expansion of thenanSsuperfamily suggests important, although as-yet-unknown, functions in host-microbe interactions.

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