Comparison of decay rates of faecal indicator organisms in recreational coastal water and sediment

2002 ◽  
Vol 2 (3) ◽  
pp. 131-138 ◽  
Author(s):  
D.L. Craig ◽  
H.J. Fallowfield ◽  
N.J. Cromar
Keyword(s):  
Water Column ◽  
Coastal Water ◽  
Decay Rates ◽  
Organic Carbon Content ◽  
Indicator Organisms ◽  
Filtration Method ◽  
E Coli ◽  
Water And Sediment ◽  
Increased Risk ◽  
High Organic Carbon Content

A laboratory based microcosm study utilising intact non-sterile sediment cores was undertaken to determine the survival of the faecal indicator organisms Escherichia coli, Enterococcus faecium and somatic coliphage in both recreational coastal water and sediment. Overlying water was inoculated with the test organisms and incubated at 10°C, 20°C or 30°C. E. coli, enterococcus and coliphage were enumerated from the water column and sediment by the membrane filtration method, Enterolert (IDEXX Laboratories) and the double-agar overlay methods respectively on days 0, 1, 2, 7, 14 and 28 following inoculation. It was demonstrated that for all organisms, greater decay (k; d-1) occurred in the water column compared to sediment. Sediment characteristics were found to influence decay, with lowest decay rates observed in sediment consisting of high organic carbon content and small particle size. Decay of E. coli was significantly greater in both the water column and sediment compared with enterococcus and coliphage under all conditions. Decay of enterococcus was found to closely resemble that of coliphage decay. Survival of all organisms was inversely related to temperature, with greatest decay at 30°C. However, increased temperature had a less significant impact on survival of enterococcus and coliphage compared with E. coli. The importance of this study for estimating risk from recreational exposure is great if some pathogenic microorganisms behave similarly to the organisms tested in this study. In particular if survival rates of pathogens are similar to enterococcus and coliphage, then their ability to accumulate in coastal sediment may lead to an increased risk of exposure if these organisms are resuspended into the water column due to natural turbulence or human recreational activity.

Effectiveness of guideline faecal indicator organism values in estimation of exposure risk at recreational coastal sites

2003 ◽  
Vol 47 (3) ◽  
pp. 191-198 ◽  
Author(s):  
D.L. Craig ◽  
H.J. Fallowfield ◽  
N.J. Cromar
Keyword(s):  
Coastal Water ◽  
Poor Quality ◽  
Decay Rates ◽  
Sediment Layer ◽  
Quantitative Microbial Risk Assessment ◽  
High Concentration ◽  
Maximum Probability ◽  
Salmonella Spp ◽  
Overlying Water ◽  
Water And Sediment

Decay rates in coastal water and sediment for the bacterial pathogens Salmonella typhimurium and S. derby were compared in laboratory-based microcosms with results previously obtained for a number of faecal indicators. In general, the decay rates of Salmonella spp. were greater than either enterococci or coliphage in overlying water and sediment. Decay rates of E. coli were similar to Salmonella spp. in overlying water, although greater in sediment. Raised temperature resulted in an increased decay rate for all organisms in the overlying water (and to a lesser extent in the surface sediment layer). It was demonstrated that decay rates for both S. typhimurium and S. derby were greater in overlying water compared with sediment. This suggested that sediments may be acting as a reservoir for pathogenic microorganisms released into the coastal environment during recreational activity and should be considered when estimating environmental exposure. Using measured decay rates and available dose-response data, a quantitative microbial risk assessment (QMRA) utilising Monte Carlo simulation was undertaken to estimate the risk of infection to Salmonella spp. following exposure to recreational coastal water subject to a range of faecal contamination levels. In waters of extremely poor quality, subject to contamination by faecal coliforms (106 CFU/100 mL), the maximum probability of infection on the day of an accidental release was above 2.0 × 10−1 and remained above 1 × 10−3 for three days following the initial high concentration.

Campylobacter in waterborne epidemics in Finland

2004 ◽  
Vol 4 (2) ◽  
pp. 39-45 ◽  
Author(s):  
M.-L. Hänninen ◽  
R. Kärenlampi
Keyword(s):  
Campylobacter Jejuni ◽  
Causative Agent ◽  
Water Samples ◽  
Fecal Coliforms ◽  
Risk Level ◽  
Source Water ◽  
Indicator Organisms ◽  
Faecal Contamination ◽  
E Coli ◽  
July August September

The sources for drinking water in Finland are surface water, groundwater or artificially recharged groundwater. There are approximately 1400 groundwater plants in Finland that are microbiologically at a high risk level because in most cases they do not use any disinfection treatment. Campylobacter jejuni has caused waterborne epidemics in several countries. Since the middle of the 1980s, C. jejuni has been identified as the causative agent in several waterborne outbreaks in Finland. Between 1998 and 2001, C. jejuni or C. upsaliensis caused seven reported waterborne epidemics. In these epidemics approximately 4000 people acquired the illness. Most of the outbreaks occurred in July, August , September or October. In four of them source water and net water samples were analysed for total coliforms or fecal coliforms, E. coli and campylobacters. We showed that large volumes of water samples in studies of indicator organisms (up to 5000 ml) and campylobacters (4000–20,000 ml) increased the possibility to identify faecal contamination and to detect the causative agent from suspected sources.

Water Quality of Swimming Pools in Jerusalem

1993 ◽  
Vol 27 (7-8) ◽  
pp. 287-294 ◽  
Author(s):  
S. Lerman ◽  
O. Lev ◽  
A. Adin ◽  
E. Katzenelson
Keyword(s):  
Water Quality ◽  
Fecal Coliforms ◽  
Pathogenic Microorganisms ◽  
Swimming Pools ◽  
Indicator Organisms ◽  
Indicator Microorganisms ◽  
E Coli ◽  
Safe Water ◽  
Indirect Information

The Israel Ministry of Health is now revising its regulations for the assurance of safe water quality in public swimming pools. Since it is not possible to monitor each of the pathogenic microorganisms, it is often recommended to monitor indicator bacteria which provide indirect information on the water quality in the swimming pool. Three indicator microorganisms are often recommended: coliform counts (total coliforms, fecal coliforms or E. Coli), staphylococcus aureus and pseudomonas aeruginosa. A four year survey of the water quality of swimming pools in the Jerusalem District was conducted in order to determine whether the monitoring of all three indicators is necessary to assure safe water quality or is it sufficient to monitor only a single microorganism. A statistical analysis, conducted by using several different statistical techniques, reveals that the populations of the three indicator organisms are significantly interdependent but the correlations between each pair of these indicators are not sufficient to base a prediction of any of the organisms based on the measurements of the others. Therefore, it is concluded that monitoring of all three indicators should be recommended in order to provide an adequate picture of the water quality in swimming pools.

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.

The Effect of Mianserin on Lifespan of Caenorhabditis elegans is Abolished by Glucose

2021 ◽  
Vol 13 ◽  
Author(s):  
Abdullah Almotayri ◽  
Jency Thomas ◽  
Mihiri Munasinghe ◽  
Markandeya Jois
Keyword(s):  
Caenorhabditis Elegans ◽  
Scaffolding Protein ◽  
Lifespan Extension ◽  
Wild Type ◽  
E Coli ◽  
C Elegans ◽  
Risk Of Death ◽  
Increased Risk ◽  
Antidepressant Use ◽  
Extension Effect

Background: The antidepressant mianserin has been shown to extend the lifespan of Caenorhabditis elegans (C. elegans), a well-established model organism used in aging research. The extension of lifespan in C. elegans was shown to be dependent on increased expression of the scaffolding protein (ANK3/unc-44). In contrast, antidepressant use in humans is associated with an increased risk of death. The C. elegans in the laboratory are fed Escherichia coli (E. coli), a diet high in protein and low in carbohydrate, whereas a typical human diet is high in carbohydrates. We hypothesized that dietary carbohydrates might mitigate the lifespan-extension effect of mianserin. Objective: To investigate the effect of glucose added to the diet of C. elegans on the lifespan-extension effect of mianserin. Methods: Wild-type Bristol N2 and ANK3/unc-44 inactivating mutants were cultured on agar plates containing nematode growth medium and fed E. coli. Treatment groups included (C) control, (M50) 50 μM mianserin, (G) 73 mM glucose, and (M50G) 50 μM mianserin and 73 mM glucose. Lifespan was determined by monitoring the worms until they died. Statistical analysis was performed using the Kaplan-Meier version of the log-rank test. Results: Mianserin treatment resulted in a 12% increase in lifespan (P<0.05) of wild-type Bristol N2 worms but reduced lifespan by 6% in ANK3/unc-44 mutants, consistent with previous research. The addition of glucose to the diet reduced the lifespan of both strains of worms and abolished the lifespan-extension by mianserin. Conclusion: The addition of glucose to the diet of C. elegans abolishes the lifespan-extension effects of mianserin.

scholarly journals Risk Factors for and Mechanisms of COlistin Resistance Among Enterobacterales: Getting at the CORE of the Issue

2021 ◽  
Author(s):  
John P Mills ◽  
Laura J Rojas ◽  
Steve H Marshall ◽  
Susan D Rudin ◽  
Andrea M Hujer ◽  
...  
Keyword(s):  
Case Control Study ◽  
Clinical Isolates ◽  
Colistin Resistance ◽  
E Coli ◽  
The Core ◽  
Increased Risk ◽  
Recent Emergence ◽  
Enterobacter Species ◽  
Ann Arbor ◽  
Control Study

Abstract Background Despite the recent emergence of plasmid-mediated colistin resistance, the epidemiology and mechanisms of colistin-resistant Enterobacterales (CORE) infections remain poorly understood. Methods A case-case-control study was conducted utilizing routine clinical isolates obtained at a single tertiary health system in Ann Arbor, MI. Patients with CORE isolates from January 1st 2016 to March 31st 2017 were matched 1:1 with patients with colistin-susceptible Enterobacterales (COSE) and uninfected controls. Multivariable logistic regression was used to compare clinical and microbiologic features of patients with CORE and COSE to controls. A subset of available CORE isolates underwent whole genome sequencing to identify putative colistin resistance genes. Results Of 16,373 tested clinical isolates, 166 (0.99%) were colistin-resistant, representing 103 unique patients. Among 103 CORE isolates, 103 COSE isolates, and 102 uninfected controls, antibiotic exposure in the antecedent 90 days and age &gt; 55 years were predictors of both CORE and COSE. Of 33 isolates that underwent WGS, a large variety of mutations associated with colistin resistance were identified, including 4 mcr-1/mcr-1.1 genes and 4 pmrA/B mutations among 9 Escherichia coli isolates; 5 mgrB and 3 PmrA mutations among 8 Klebsiella pneumoniae isolates. Genetic mutations found in Enterobacter species were not associated with known phenotypic colistin resistance. Conclusions Increased age and prior antibiotic receipt were associated with increased risk for patients with CORE, and for patients with COSE. Mcr-1, pmrA/B, and mgrB were the predominant colistin resistance-associated mutations identified among E. coli and K. pneumoniae, respectively. Mechanisms of colistin resistance among Enterobacter species could not be determined.

Notable increases in nutrient concentrations in a shallow lake during seasonal ice growth

2016 ◽  
Vol 74 (12) ◽  
pp. 2773-2783 ◽  
Author(s):  
Yang Fang ◽  
Li Changyou ◽  
Matti Leppäranta ◽  
Shi Xiaonghong ◽  
Zhao Shengnan ◽  
...  
Keyword(s):  
Liquid Water ◽  
Shallow Lake ◽  
Water Environment ◽  
Open Water ◽  
Middle Layer ◽  
Nutrient Concentrations ◽  
Unfrozen Water ◽  
Total N ◽  
Water And Sediment ◽  
Increased Risk

Nutrients may be eliminated from ice when liquid water is freezing, resulting in enhanced concentrations in the unfrozen water. The nutrients diluted from the ice may contribute to accumulated concentrations in sediment during winter and an increased risk of algae blooms during the following spring and summer. The objective of this study was to evaluate the influence of ice cover on nitrogen (N) and phosphorus (P) concentrations in the water and sediment of a shallow lake, through an examination of Ulansuhai Lake, northern China, from the period of open water to ice season in 2011–2013. The N and P concentrations were between two and five times higher, and between two and eight times higher, than in unfrozen lakes, respectively. As the ice thickness grew, contents of total N and total P showed C-shaped profiles in the ice, and were lower in the middle layer and higher in the bottom and surface layers. Most of the nutrients were released from the ice to liquid water. The results confirm that ice can cause the nutrient concentrations in water and sediment during winter to increase dramatically, thereby significantly impacting on processes in the water environment of shallow lakes.

#92: What Is the Optimal Management of Patients Immunosuppressed with the Anti-compliment Monoclonal Antibody, Eculizumab? A Case Report and Review

2021 ◽  
Vol 10 (Supplement_1) ◽  
pp. S12-S12
Author(s):  
I Tinoco ◽  
A Jarrell ◽  
L Correa ◽  
J Bissler ◽  
J DeVincenzo ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Renal Failure ◽  
Antibiotic Prophylaxis ◽  
Neisseria Meningitidis ◽  
Paroxysmal Nocturnal Hemoglobinuria ◽  
Neisseria Species ◽  
E Coli ◽  
Increased Risk ◽  
Prescribing Information ◽  
Rabbit Complement

Abstract Background Patients with deficiencies of terminal components of complement are at hundreds to thousands fold increased risk of severe and fatal Neisseria spp. infections compared with the general population. Eculizumab is a newly approved monoclonal antibody C5 complement inhibitor. It is indicated for the treatment of atypical hemolytic uremic syndrome (atypical HUS), myasthenia gravis, and paroxysmal nocturnal hemoglobinuria. Because of the complement-depleting effect of Eculizumab dosing (Soliris®, Alexion Pharmaceuticals, Munich, Germany), patients are immunosuppressed for specific infectious pathogens (including Neisseria species) against which protection partially relies on normal complement activity. Because Eculizumab treatment is associated with a dramatically increased risk of Neisseria species. infections, recommendations for Neisseria meningitidis vaccination and antibiotic prophylaxis are contained in Eculizumab prescribing information. However, the most appropriate prevention of infections after Eculizumab has yet to be determined. Methods Case report and literature review. Results A previously healthy 7-year-old male was diagnosed with atypical HUS which included renal failure progressing to dialysis, persistent thrombocytopenia, hemolytic anemia, and hemoglobinuria. Stool cultures and a stool multiplex PCR panel did not detect Shiga-like producing E. coli nor E. coli O157/H7. Eculizumab dosing was therefore planned and Infectious Diseases consultation was obtained for appropriate preventions. The FDA Prescribing Information recommends Neisseria meningitidis vaccination before starting Eculizumab or, if immediate Eculizumab is necessary, to use antibiotic prophylaxis until 2 weeks after vaccination. The accepted protective titer after meningococcal vaccination is population based and uses the serum bactericidal assay (SBA). An antibody titer of &gt;1:4 (human compliment) or 1:8 (rabbit complement) is considered protective. However, this “gold standard” assay incorporates the use of exogenous human or rabbit complement. The protective SBA titers in subjects with terminal complement component deficiencies may not be properly assessed using these same SBA titer protective thresholds. Furthermore, serious meningococcal infections have occurred after appropriate vaccination in patients receiving chronic Eculizumab treatments (ie for paroxysmal nocturnal hemoglobinuria). Finally, SBA protective levels after single Neisseria meningitidis vaccination have not been achieved in majorities of patients with renal failure receiving dialysis and or transplant immunosuppression. Conclusions The current Eculizumab prescribing information recommendations for vaccination and antimicrobial prophylaxis may be inadequate to prevent serious Neisseria infections. Repeated Neisseria meningitidis vaccination and extended antibiotic prophylaxis may afford better protection in patients chronically dosed with Eculizumab.

scholarly journals Decay of Fecal Indicator Bacterial Populations and Bovine-Associated Source-Tracking Markers in Freshly Deposited Cow Pats

2013 ◽  
Vol 80 (1) ◽  
pp. 110-118 ◽  
Author(s):  
Adelumola Oladeinde ◽  
Thomas Bohrmann ◽  
Kelvin Wong ◽  
S. T. Purucker ◽  
Ken Bradshaw ◽  
...  
Keyword(s):  
Decay Rate ◽  
Fecal Indicator Bacteria ◽  
Decay Rates ◽  
Indicator Bacteria ◽  
Source Tracking ◽  
Fecal Indicator ◽  
Bacterial Populations ◽  
Content Type ◽  
E Coli ◽  
Decay Dynamic

ABSTRACTUnderstanding the survival of fecal indicator bacteria (FIB) and microbial source-tracking (MST) markers is critical to developing pathogen fate and transport models. Although pathogen survival in water microcosms and manure-amended soils is well documented, little is known about their survival in intact cow pats deposited on pastures. We conducted a study to determine decay rates of fecal indicator bacteria (Escherichia coliand enterococci) and bovine-associated MST markers (CowM3, Rum-2-bac, and GenBac) in 18 freshly deposited cattle feces from three farms in northern Georgia. Samples were randomly assigned to shaded or unshaded treatment in order to determine the effects of sunlight, moisture, and temperature on decay rates. A general linear model (GLM) framework was used to determine decay rates. Shading significantly decreased the decay rate of theE. colipopulation (P< 0.0001), with a rate of −0.176 day−1for the shaded treatment and −0.297 day−1for the unshaded treatment. Shading had no significant effect on decay rates of enterococci, CowM3, Rum-2-bac, and GenBac (P> 0.05). In addition,E. colipopulations showed a significant growth rate (0.881 day−1) in the unshaded samples during the first 5 days after deposition. UV-B was the most important parameter explaining the decay rate ofE. colipopulations. A comparison of the decay behaviors among all markers indicated that enterococcus concentrations exhibit a better correlation with the MST markers thanE. coliconcentrations. Our results indicate that bovine-associated MST markers can survive in cow pats for at least 1 month after excretion, and although their decay dynamic differs from the decay dynamic ofE. colipopulations, they seem to be reliable markers to use in combination with enterococci to monitor fecal pollution from pasture lands.

Sign in / Sign up

Export Citation Format

Share Document