scholarly journals High-Throughput and Quantitative Procedure for Determining Sources of Escherichia coli in Waterways by Using Host-Specific DNA Marker Genes

2006 ◽  
Vol 73 (3) ◽  
pp. 890-896 ◽  
Author(s):  
Tao Yan ◽  
Matthew J. Hamilton ◽  
Michael J. Sadowsky
Keyword(s):  
Escherichia Coli ◽  
Water Sample ◽  
High Throughput ◽  
Lake Water ◽  
Water Samples ◽  
Great Promise ◽  
Fecal Bacteria ◽  
E Coli ◽  
Gene Probes ◽  
Macroarray Hybridization

ABSTRACT Escherichia coli is currently used as an indicator of fecal pollution and to assess water quality. While several genotypic techniques have been used to determine potential sources of fecal bacteria impacting waterways and beaches, they do not allow for the rapid analysis of a large number of samples in a relatively short period of time. Here we report that gene probes identified by Hamilton and colleagues (M. J. Hamilton, T. Yan, and M. J. Sadowsky, Appl. Environ. Microbiol. 72:4012-4019, 2006) were useful for the development of a high-throughput and quantitative macroarray hybridization system to determine numbers of E. coli bacteria originating from geese/ducks. The procedure we developed, using a QBot robot for picking and arraying of colonies, allowed us to simultaneously analyze up to 20,736 E. coli colonies from water samples, with minimal time and human input. Statistically significant results were obtained by analyzing 700 E. coli colonies per water sample, allowing for the analysis of approximately 30 sites per macroarray. Macroarray hybridization studies done on E. coli collected from water samples obtained from two urban Minnesota lakes and one rural South Carolina lake indicated that geese/ducks contributed up to 51% of the fecal bacteria in the urban lake water samples, and the level was below the detection limit in the rural lake water sample. This technique, coupled with the use of other host source-specific gene probes, holds great promise as a new quantitative microbial source tracking tool to rapidly determine the origins of E. coli in waterways and on beaches.

Antimicrobial Activity of Silver Nanoparticles Prepared Under an Ultrasonic Field

2011 ◽  
Vol 4 (3) ◽  
pp. 1491-1496
Author(s):  
Umadevi M ◽  
Rani T ◽  
Balakrishnan T ◽  
Ramanibai R
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Reduction Method ◽  
Therapeutic Potential ◽  
Chemical Reduction ◽  
Ultrasonic Field ◽  
Great Promise ◽  
Chemical Reduction Method ◽  
E Coli

Nanotechnology has great promise for improving the therapeutic potential of medicinal molecules and related agents. In this study, silver nanoparticles of different sizes were synthesized in an ultrasonic field using the chemical reduction method with sodium borohydride as a reducing agent. The size effect of silver nanoparticles on antimicrobial activity were tested against the microorganisms Staphylococcus aureus (MTCC No. 96), Bacillus subtilis (MTCC No. 441), Streptococcus mutans (MTCC No. 497), Escherichia coli (MTCC No. 739) and Pseudomonas aeruginosa (MTCC No. 1934). The results shows that B. subtilis, and E. coli were more sensitive to silver nanoparticles and its size, indicating the superior antimicrobial efficacy of silver nanoparticles. 

An Improved Membrane Filtration Method for Enumeration of Faecal Coliforms and E. Coli by a Fluorogenic β-Glucuronidase Assay

1993 ◽  
Vol 27 (3-4) ◽  
pp. 267-270 ◽  
Author(s):  
M. T. Augoustinos ◽  
N. A. Grabow ◽  
B. Genthe ◽  
R. Kfir
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Membrane Filtration ◽  
Faecal Coliforms ◽  
Environmental Waters ◽  
Filtration Method ◽  
E Coli ◽  
Wide Range ◽  
Pure Cultures ◽  
Glucuronidase Assay

A fluorogenic β-glucuronidase assay comprising membrane filtration followed by selective enumeration on m-FC agar at 44.5°C and further confirmation using tlie 4-metliylumbelliferyl-β-D-glucuronide (MUG) containing medium was evaluated for the detection of Escherichia coli in water. A total of 200 typical blue and non-typical blue colonies were isolated from sea and fresh water samples using initial selective enumeration on m-FC agar. Pure cultures of the selected colonies were further tested using the MUG assay and identified using the API 20E method. Of the colonies tested which were shown to be positive using the MUG assay 99.4% were Escherichia coli. The results of this study indicate the combination of the m-FC method followed by the MUG assay to be highly efficient for the selection and confirmation of E. coli from a wide range of environmental waters.

Occurrences of Giardia cysts in beach water

1998 ◽  
Vol 38 (12) ◽  
pp. 73-76 ◽  
Author(s):  
B. S. W. Ho ◽  
T.-Y Tam
Keyword(s):  
Health Risk ◽  
Water Sample ◽  
Water Samples ◽  
High Concentration ◽  
Potential Health ◽  
Infectious Dose ◽  
Potential Health Risk ◽  
E Coli ◽  
Beach Water ◽  
Giardia Cysts

A total of 64 beach water samples with various bacteriological quality (Grades 1 to 4) were analysed for their bacteriological and parasitological contents (E coli and Giardia cysts respectively). Results indicated that Giardia cysts were detected in less than 10% of the Grade 1 beach water samples with E coli concentrations of <24/100mL. For Grades 2, 3 & 4 beach water samples, Giardia cysts were found, respectively, in 85, 50 and 64% of the samples. Except for one beach water sample which had an unusually high concentration of Giardia cysts (23 cysts/L), they were generally present at moderate concentrations (<10 cysts/L) in all other beach water samples. Despite moderate levels of Giardia cysts present in beach water of different grades, the potential health risk faced by swimmers bathing in local beach water needs to be carefully assessed as Giardia is known to have a low infectious dose.

scholarly journals A High-Throughput Approach To Identify Compounds That Impair Envelope Integrity in Escherichia coli

2016 ◽  
Vol 60 (10) ◽  
pp. 5995-6002 ◽  
Author(s):  
Kristin R. Baker ◽  
Bimal Jana ◽  
Henrik Franzyk ◽  
Luca Guardabassi
Keyword(s):  
Escherichia Coli ◽  
High Throughput ◽  
High Throughput Screening ◽  
Gram Negative Bacteria ◽  
Chromogenic Substrate ◽  
Intrinsic Resistance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Screening Platform

ABSTRACTThe envelope of Gram-negative bacteria constitutes an impenetrable barrier to numerous classes of antimicrobials. This intrinsic resistance, coupled with acquired multidrug resistance, has drastically limited the treatment options against Gram-negative pathogens. The aim of the present study was to develop and validate an assay for identifying compounds that increase envelope permeability, thereby conferring antimicrobial susceptibility by weakening of the cell envelope barrier in Gram-negative bacteria. A high-throughput whole-cell screening platform was developed to measureEscherichia colienvelope permeability to a β-galactosidase chromogenic substrate. The signal produced by cytoplasmic β-galactosidase-dependent cleavage of the chromogenic substrate was used to determine the degree of envelope permeabilization. The assay was optimized by using known envelope-permeabilizing compounds andE. coligene deletion mutants with impaired envelope integrity. As a proof of concept, a compound library comprising 36 peptides and 45 peptidomimetics was screened, leading to identification of two peptides that substantially increased envelope permeability. Compound 79 reduced significantly (from 8- to 125-fold) the MICs of erythromycin, fusidic acid, novobiocin and rifampin and displayed synergy (fractional inhibitory concentration index, <0.2) with these antibiotics by checkerboard assays in two genetically distinctE. colistrains, including the high-risk multidrug-resistant, CTX-M-15-producing sequence type 131 clone. Notably, in the presence of 0.25 μM of this peptide, both strains were susceptible to rifampin according to the resistance breakpoints (R> 0.5 μg/ml) for Gram-positive bacterial pathogens. The high-throughput screening platform developed in this study can be applied to accelerate the discovery of antimicrobial helper drug candidates and targets that enhance the delivery of existing antibiotics by impairing envelope integrity in Gram-negative bacteria.

scholarly journals Foreshore Sand as a Source of Escherichia coli in Nearshore Water of a Lake Michigan Beach

2003 ◽  
Vol 69 (9) ◽  
pp. 5555-5562 ◽  
Author(s):  
Richard L. Whitman ◽  
Meredith B. Nevers
Keyword(s):  
Escherichia Coli ◽  
Lake Water ◽  
Lake Michigan ◽  
Beach Sand ◽  
Intensive Study ◽  
Concentration Gradients ◽  
Lake Water Quality ◽  
E Coli ◽  
Demographic Patterns ◽  
Hydrometeorological Conditions

ABSTRACT Swimming advisories due to excessive Escherichia coli concentrations are common at 63rd Street Beach, Chicago, Ill. An intensive study was undertaken to characterize the source and fate of E. coli in beach water and sand at the beach. From April through September 2000, water and sand samples were collected daily or twice daily at two depths on three consecutive days per week (water samples, n = 1,747; sand samples, n = 858); hydrometeorological conditions and bird and bather distributions were also recorded. E. coli concentrations in sand and water were significantly correlated, with the highest concentration being found in foreshore sand, followed by those in submerged sediment and water of increasing depth. Gull contributions to E. coli densities in sand and water were most apparent on the day following gull activity in a given area. E. coli recolonized newly placed foreshore sand within 2 weeks. Analysis of variance, correlation, cluster analyses, concentration gradients, temporal-spatial distribution, demographic patterns, and DNA fingerprinting suggest that E. coli may be able to sustain population density in temperate beach sand during summer months without external inputs. This research presents evidence that foreshore beach sand (i) plays a major role in bacterial lake water quality, (ii) is an important non-point source of E. coli to lake water rather than a net sink, (iii) may be environmentally, and perhaps hygienically, problematic, and (iv) is possibly capable of supporting an autochthonous, high density of indicator bacteria for sustained periods, independent of lake, human, or animal input.

scholarly journals Detection of antimicrobial resistance genes of carbapenem-resistant Enterobacteriaceae in Escherichia coli isolated from the water supply of smallholder dairy farms in Saraburi and Maha Sarakham, Thailand

2020 ◽  
Vol 6 (1) ◽  
pp. 1-5
Author(s):  
Natapol Pumipuntu ◽  
Sangkom Pumipuntu
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Water Samples ◽  
Dairy Farms ◽  
Drug Resistant ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Carbapenem Resistant Enterobacteriaceae ◽  
Smallholder Dairy Farms

Background and Aim: The problem of antimicrobial resistance of bacteria in both humans and animals is an important public health concern globally, which is likely to increase, including in Thailand, where carbapenem-resistant Enterobacteriaceae (CRE), such as Escherichia coli, are of particular concern. They are pathogens found in the gastrointestinal tract of humans and other animals as well as in the environment. They may cause opportunistic infection and are often resistant to antibiotics in various fields especially in animal husbandry, such as pets or livestock farms. This study aimed to investigate the occurrence of carbapenem-resistant E. coli from water samples of smallholder dairy farms in Saraburi and Maha Sarakham, Thailand. Materials and Methods: Sixty-four water samples were collected from 32 dairy farms in Kaeng Khoi district, Muak Lek district, and Wang Muang district of Saraburi Province, and Kantharawichai district and Mueang district of Maha Sarakham Province, Thailand. All samples were cultured and isolated for E. coli by biochemical tests. All E. coli isolates were tested for drug susceptibility using imipenem, meropenem, and drug resistance genes of carbapenemases such as blaNDM, blaIMP, and blaOXA48 of drug-resistant E. coli isolates detected by polymerase chain reaction (PCR) technique. Results: A total of 182 E. coli isolates were found (140 and 42 isolates from Saraburi and Maha Sarakham, respectively). Drug sensitivity tests found that two isolates of E. coli from water in Kaeng Khoi were resistant to imipenem; therefore, the incidence of E. coli resistance to carbapenem was 1.43% of Saraburi Province. On the other hand, there was no incidence of drug-resistant E. coli in Maha Sarakham. In addition, the detection of the drug-resistant gene of E. coli in both isolates by PCR showed the expression of blaNDM. Conclusion: This study reports E. coli resistance to antimicrobial drugs on livestock farms. It can be considered to be the first report of E. coli CRE detection in a dairy farm at Saraburi, which should be the subject of further extended study.

scholarly journals Isolation and Enumeration of Escherichia coli from Soil and Water

2020 ◽  
Vol 36 (2) ◽  
pp. 75-77
Author(s):  
Anindita Bhowmik ◽  
Sunjukta Ahsan
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Gas Production ◽  
Soil Samples ◽  
Most Probable Number ◽  
Biochemical Tests ◽  
Probable Number ◽  
E Coli ◽  
Dilution Series

Majority of the population of Bangladesh depend on tap or surface water as their source of water supply. This study was carried out to examine the microbial quality of both water and soil collected from different places using the multiple tube fermentation technique to determine coliform count by the most probable number (MPN) method in brilliant green lactose broth (BGLB) media.Inoculum from positive tubes of the presumptive test were further transferred on eosinemethylene blue (EMB) and MacConkey agar.The organisms isolated were further characterized using biochemical tests. Out of 93 water samples, 30 (32.26%) indicated the presence of lactose fermenter and gas producer in all 3 tubes of dilution series using inoculum quantities of 1.0, 0.1 and 0.01 ml, whereas out of 85 soil samples, 45 (52.94%) showed acid and gas production in all 3 tubes of dilution series.Among 85 soil samples, 40 samples that contained at least one positive in each dilution series and among 93 water samples, 31 samples that contained at least one positive in each dilution series were further re-identified with biochemical tests.This study showed 30.59% soil isolates and 26.88% water isolates were Escherichia coli which highlighted the fact that both water and soil act as a major reservoir of E.coli, which indicates possible fecal contamination as well as presence of potentially pathogenic E. coli. Bangladesh J Microbiol, Volume 36 Number 2 December 2019, pp 75-77

scholarly journals Incidence of Salmonella and Escherichia coli in fish farms and markets in Dinajpur, Bangladesh

2020 ◽  
Vol 55 (1) ◽  
pp. 65-72
Author(s):  
A Ava ◽  
M Faridullah ◽  
UJ Lithi ◽  
VC Roy
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Research Work ◽  
Fish Sample ◽  
Fish Farms ◽  
E Coli ◽  
Fish Samples

The research work was conducted to assess the incidence of Salmonella and Escherichia coli (E. coli) contamination in different fish farms and fish markets of Dinajpur district of Bangladesh. The level of incidence of Salmonella contamination was greater in scum samples (93.8%) and for E. coli the higher contamination found in water samples (81.3%). The study showed that, water and fish samples were also Salmonella positive and the percentage was 87.5% and 57.8% respectively and for E. coli contamination about 75% of scum and 75.6% of fish samples were E. coli positive among fish farms samples. In case of market, both basket and fish sample were tested Salmonella positive, the level of incidence of Salmonella contamination was higher for basket samples (100%) and lower in fish samples (48.9%). Meanwhile, E. coli contamination for fish, basket, and mat samples were 75.6%, 68.8% and 75% respectively. Therefore, the results are very much alarming. Bangladesh J. Sci. Ind. Res.55(1), 65-72, 2020

scholarly journals PSV-41 Antibacterial activity of ferulic acid and sodium chlorate against Escherichia coli F18 and K88 during incubations with porcine fecal bacteria

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 296-297 ◽  
Author(s):  
Claudio Arzola ◽  
Elizabeth Latham ◽  
Robin Anderson ◽  
Jaime Salinas-Chavira ◽  
Yamicela Castillo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ferulic Acid ◽  
Sodium Chlorate ◽  
Fecal Bacteria ◽  
Aerobic Incubation ◽  
E Coli ◽  
Mueller Hinton ◽  
Fecal Suspension ◽  
Porcine Feces ◽  
Mueller Hinton Broth

Abstract The influence of ferulic acid (FA) and sodium chlorate (SC) was evaluated in two trials on the growth of Escherichia coli F18 and K88 (F18 and K88) incubated with porcine fecal bacteria. Treatments were 2 levels of FA (0 and 5 mg/mL) and 2 levels of SC (0 and 10 mM/mL). In trial one, ½-strength Mueller Hinton broth mixed with porcine feces (0.5% w/v) was inoculated with a novobiocin and naladixic acid resistant F18-strain. This fecal suspension was transferred to tubes (3/treatment) and anaerobically incubated at 39 oC for enumeration at 0, 6 and 24 h using MacConkey agar supplemented with novobiocin and naladixic acid with aerobic incubation at 37 oC. An interaction (FA x SC) at 6 and 24 h was observed (P &lt; 0.01). At 6 h of incubation, SC alone or combined with FA had the lowest counts (P &lt; 0.05); FA alone was lower than control but higher than SC or SC+FA (P &lt; 0.05). At 24 h, FA alone or combined with SC had the lowest counts (P &lt; 0.05); SC was lower than control but higher than FA or SC+FA (P &lt; 0.05). In trial 2 were used the same procedures of trial 1, except that K88 was used. There was an interaction at 6 h (P &lt; 0.01) where the lowest counts were in FA+SC (P &lt; 0.05). SC alone or FA alone were lower than control but higher than SC+FA (P &lt; 0.05). There was no interaction at 24 h (P = 0.16), where FA reduced the K88 counts (P &lt; 0.01), however it was not affected by SC (P = 0.12). In conclusion, SC reduced E. coli counts; however, at 24 h of incubation greater reductions were observed when FA alone or combined with SC was added into the incubation fluid with porcine feces.

scholarly journals PSV-40 Antibacterial activity of sodium chlorate and essential oils against Escherichia coli (F18 and K88) during incubations with porcine fecal bacteria

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 295-296
Author(s):  
Jaime Salinas-Chavira ◽  
Robin Anderson ◽  
Elizabeth Latham ◽  
Rafael Cabrera ◽  
Yamicela Castillo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Essential Oils ◽  
Pathogenic Bacteria ◽  
Sodium Chlorate ◽  
Fecal Bacteria ◽  
Cinnamon Oil ◽  
E Coli ◽  
Mueller Hinton ◽  
Fecal Suspension ◽  
Porcine Feces

Abstract In two trials was evaluated the influence of sodium chlorate (SC) and essential oils (EO) on the growth of Escherichia coli F18 and K88 (F18 and K88) incubated with porcine fecal bacteria. The treatments were 2 levels of SC (0 and 10 mM/mL) and 2 levels of Activo® (0 and 1.5%; vol/vol). Activo® (EW Nutrition, Des Moines, IA) is a blend of oregano oil and cinnamon oil (EO) with water and citric acid. In trial one, ½-strength Mueller Hinton broth mixed with porcine feces (0.5% w/vol) was inoculated with a novobiocin and naladixic acid resistant F18-strain. This fecal suspension was transferred to tubes (3/treatment) and anaerobically incubated at 39 oC for enumeration at 0, 6 and 24 h using MacConkey agar supplemented with novobiocin and naladixic acid with aerobic incubation at 37 oC. An interaction (EO x SC) at 6 and 24 was observed (P &lt; 0.01). At 6 and 24 h, EO alone or combined with SC had the lowest counts of F18 (P &lt; 0.05); SC alone had lower counts of F18 than control (P &lt; 0.05). In trial 2 were used the same procedures of trial 1, except that K88 was inoculated in the porcine fecal suspension. There was an interaction at 6 h (P &lt; 0.01) where EO had the lowest counts of K88. The control showed the highest counts of K88 (P &lt; 0.05). There was no interaction at 24 h (P = 0.14). The counts of K88 were reduced by EO (P &lt; 0.01), however the counts were not affected by SC (P = 0.14). It was concluded that SC reduced the counts of E. coli F18, but it had minimal effect on E. coli K88 in the challenged porcine feces; essential oils were effective to reduce the pathogenic bacteria in the porcine feces.

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