Evidence that tropical soil environment can support the growth of Escherichia coli

1998 ◽  
Vol 38 (12) ◽  
pp. 171-174 ◽  
Author(s):  
M. N Byappanahalli ◽  
R. S. Fujioka

Concentrations of faecal coliforms and Escherichia coli in environmental waters have historically been used to establish recreational water quality standards. When these bacteria are used as indices of water quality, it is assumed that there are no significant environmental sources of these bacteria which are unrelated to direct faecal contamination. However, we have previously reported that in tropical island environments such as in Hawaii, these faecal indicators are consistently found at high concentrations in all streams and the source of these faecal bacteria is the soil. To become so well established in soil we hypothesized that these faecal bacteria must have the ability to multiply in the natural soil environment at ambient temperature (23–25°C). Three lines of evidence support this hypothesis: (1) E. coli was shown to grow on 10% soil extract agar, (2) populations of faecal coliforms and E. coli from sewage were shown to immediately increase by about three logs when simple nutrients (glucose and salts) were added to natural soil and (3) faecal coliforms and E. coli increased by two logs within 24 h when a minimal amount of sewage was added to cobalt-irradiated soil. These results indicate that tropical soil environments provide sufficient means to support the growth of faecal coliforms and E. coli. However, under natural soil conditions, indigenous soil microorganisms are much more efficient in obtaining nutrients and we hypothesize that faecal bacteria grow sporadically in response to available nutrients.

1982 ◽  
Vol 88 (2) ◽  
pp. 265-273 ◽  
Author(s):  
R. C. Wright

SummaryA selective membrane filtration medium is described for use in the rapid assessment of water quality in tropical countries where the incidence of faecal coliforms other than E. coli presents problems in the interpretation of results. The medium gives comparable results to MPN values obtained in the multiple tube dilution test using modified Gray's glutamate medium, and to membrane filtration counts obtained using M-FC broth and membrane-enriched Teepol broth, whilst differentiation of E. coli is enhanced.


1993 ◽  
Vol 27 (3-4) ◽  
pp. 267-270 ◽  
Author(s):  
M. T. Augoustinos ◽  
N. A. Grabow ◽  
B. Genthe ◽  
R. Kfir

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.


2004 ◽  
Vol 2 (2) ◽  
pp. 103-114 ◽  
Author(s):  
Julie Kinzelman ◽  
Sandra L. McLellan ◽  
Annette D. Daniels ◽  
Susan Cashin ◽  
Ajaib Singh ◽  
...  

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.


2011 ◽  
Vol 9 (4) ◽  
pp. 708-717 ◽  
Author(s):  
Andrew S. Ferguson ◽  
Brian J. Mailloux ◽  
Kazi M. Ahmed ◽  
Alexander van Geen ◽  
Larry D. McKay ◽  
...  

The retention and release of total coliforms and Escherichia coli was investigated in hand-pumps removed from tubewells tapping a faecally contaminated aquifer in Matlab, Bangladesh, and from a new hand-pump deliberately spiked with E. coli. All hand-pumps were connected to reservoirs of sterile water and flushed. Faecal coliforms were observed in the discharge from all three of the previously used hand-pumps, at concentrations comparable to levels measured in discharge when they were attached to the tubewells. During daily flushing of one of the previously used hand-pumps, the concentration of total coliforms in the discharge remained relatively constant (≈103 MPN/100 mL). Concentrations of E. coli in the pump discharge declined over time, but E. coli was still detectable up to 29 days after the start of flushing. In the deliberately spiked hand-pump, E. coli was observed in the discharge over 125 days (t50 = 8 days) and found to attach preferentially to elastomeric materials within the hand-pump. Attempts to disinfect both the village and new hand-pumps using shock chlorination were shown to be unsuccessful. These results demonstrate that hand-pumps can act as persistent reservoirs for microbial indicator bacteria. This could potentially influence drinking water quality and bias testing of water quality.


Author(s):  
Nada Hanna ◽  
Manju Purohit ◽  
Vishal Diwan ◽  
Salesh P. Chandran ◽  
Emilia Riggi ◽  
...  

The emergence of antibiotic resistance is a major global and environmental health issue, yet the presence of antibiotic residues and resistance in the water and sediment of a river subjected to excessive anthropogenic activities and their relationship with water quality of the river are not well studied. The objectives of the present study were a) to investigate the occurrence of antibiotic residues and antibiotic-resistant Escherichia coli (E. coli) in the water and sediment of the Kshipra river in India at seven selected sites during different seasons of the years 2014, 2015, and 2016 and b) to investigate the association between antibiotic residues and antibiotic-resistant E. coli in water and sediment and measured water quality parameters of the river. Antibiotic residues and resistant E. coli were present in the water and sediment and were associated with the measured water quality parameters. Sulfamethoxazole was the most frequently detected antibiotic in water at the highest concentration of 4.66 µg/L and was positively correlated with the water quality parameters. Significant (p < 0.05) seasonal and spatial variations of antibiotic-resistant E. coli in water and sediment were found. The resistance of E. coli to antibiotics (e.g., sulfamethiazole, norfloxacin, ciprofloxacine, cefotaxime, co-trimoxazole, ceftazidime, meropenem, ampicillin, amikacin, metronidazole, tetracycline, and tigecycline) had varying associations with the measured water and sediment quality parameters. Based on the results of this study, it is suggested that regular monitoring and surveillance of water quality, including antibiotic residues and antibiotic resistance, of all rivers should be taken up as a key priority, in national and Global Action Plans as these can have implications for the buildup of antibiotic resistance.


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 ◽  
...  

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.


1967 ◽  
Vol 13 (11) ◽  
pp. 1461-1470 ◽  
Author(s):  
D. A. Klein ◽  
L. E. Casida Jr.

Addition of a small portion of autoclaved soil to normal soil provided some degree of protection against die-out for Escherichia coli cells also introduced into this soil. This protection was associated with organic carbon (glucose) availability, but not with nitrogen (ammonium nitrate) availability. An E. coli population was stabilized, at least temporarily, in soil by glucose feeding, and the protective effect of glucose was temperature dependent. Indigenous micro-organisms also multiplied in the glucose-amended soil, and, therefore, colonizing space and microbial production of compounds toxic to E. coli were not considered to be major controlling factors in E. coli die-out in soil. E. coli cells recovered after residence in this soil demonstrated an initial decreased growth rate which was less pronounced in cells recovered from glucose-amended soil and which disappeared for both cell types on subculture. It was concluded that a major factor in E. coli die-out from natural soil is its inability to step down its metabolic rate to meet the low availability of usable organic carbon in soil.


2014 ◽  
Vol 80 (16) ◽  
pp. 4814-4820 ◽  
Author(s):  
Lisa A. Jones ◽  
Randy W. Worobo ◽  
Christine D. Smart

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.


2013 ◽  
Vol 76 (6) ◽  
pp. 959-966 ◽  
Author(s):  
GAYEON WON ◽  
PAMELA J. SCHLEGEL ◽  
JENNIFER M. SCHROCK ◽  
JEFFREY T. LeJEUNE

Irrigation water is considered a potential source of preharvest pathogen contamination of vegetables. Hence, several organizations have recommended microbiological standards for water used to irrigate edible plants. The purpose of this study was to determine the strength of association between microbial quality indicators (coliforms and Escherichia coli) in irrigation water and on irrigated vegetables. Data analyzed included original results from a cross-sectional study conducted in the Midwestern United States during summer 2009 and information presented in two previously published studies performed in France and Portugal to investigate microbial quality of irrigation water and watered produce. In the cross-sectional study, repetitive PCR (rep-PCR) was used to characterize genetic relatedness of E. coli isolates from water and vegetables. No significant correlations were found between fecal indicators on leafy greens (lettuce and parsley, n = 91) or fruit (tomatoes and green peppers, n = 22) and those found in irrigation water used in the cross-sectional study (P &gt; 0.40) or in the previously published data sets (data set 1: lettuce and waste irrigation water, n = 15, P &gt; 0.40; data set 2: lettuce and irrigation water, n = 32, P = 0.06). Rep-PCR banding patterns of E. coli strains were all distinguishable among the pairs of E. coli isolates recovered from produce and irrigation water on the same farm. From the available data, the concentration of indicator organisms based on a single measure of irrigation water quality was not associated with the presence of these indicators on produce. In the absence of additional information, the use of a single microbial water quality parameter as an indicator of produce safety is of limited value for predicting the safety of the produce.


2021 ◽  
Author(s):  
M. M. Majedul Islam ◽  
Md. Atikul Islam

Abstract Faecal contamination of surface water sources is an important water quality issue worldwide. Although quite a few studies exist on surface water faecal contamination and variability of indicator bacteria, most of the studies have been based on larger river basins and in temperate region. The variability is relatively unknown in local scale and in tropical developing countries. In this study we assess how anthropogenic and environmental factors affect faecal contamination and physicochemical parameters in Rupsha and Bhairab rivers around Khulna city, Bangladesh. Water samples were collected from six locations of the rivers during a wet and dry period in 2018 to measure Escherichia coli (E. coli) concentrations. Water physicochemical parameters—temperature, turbidity, pH, dissolved oxygen, biochemical oxygen demand and chemical oxygen demand were also measured. Higher concentrations of E. coli were found in the sampling sites located near the densely populated urban area compared to the downstream site, which receives fewer amounts of discharges from sewer drains. All the E. coli samples violated bathing water quality standards. E. coli concentrations were found to be correlated positively with precipitation and turbidity. A linear regression model was applied, that explains large part of the variation in E. coli concentration (R2 = 0.42). Water quality index assessment was also ranked the water quality as ‘poor’ category; indicate that the water is unsuitable for uses in domestic and recreational purposes and high health risks involved with the water use. The study findings highlight the problem of untreated sewage discharge into the rivers. Implementation of sewage treatment plant with adequate capacity is highly recommended.


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