Coli Load Research Articles

Evaluation of coliform (E. coli) load of the drinking water collected from Kosti and Rabak Cities, White Nile State, Sudan

Microbial drinking-water quality testing plays an essential role in measures to protect public health. However, such testing remains a significant challenge where resources are limited. The aim of this study was to evaluate the coliform load of drinking water from White Nile State. Samples of the drinking water were collected from Kosti and Rabak, White Nile State, Sudan, in clean disposable plastic bottles from random sites. The estimation of E. coli bacterium test was performed in Microbiology Laboratory, University of Gezira. The results showed that, Rabak samples had high mean number (92 + 22.27) of colonies/plate than Kosti samples (29.33 + 14.11), and this denotes a significant difference between them during (March, 2022), but those samples collected during (October 2022) and (March 2023) showed non-significant differences in microbial count, although Rabak samples showed high mean number of colonies/plate than Kosti samples. It was also noticed that, the contamination of the drinking water increased gradually throughout the study periods and sites. This reflect the increase in the organic waste and decrease in treatment of pollutants in both Kosti and Rabak cities during the study period.

Synergistic bactericidal activity of ultraviolet radiation, ozone, and liquid-thin-film technology against Escherichia coli in water

Abstract Providing effective and sustainable water disinfection methods, without harmful by-products, is essential to protect public health and safety. It is hypothesized that the application of liquid-thin-film (LTF) technology can enhance the bactericidal activity of both ultraviolet (UV) irradiation and ozone (O3) treatments. Therefore, this study aimed to examine the bactericidal activity and synergistic effect of the combined UV + O3 + LTF treatment against Escherichia coli in water processing. The results showed that LTF technology significantly increased the disinfection efficiency of UV and O3 in potable water production. Thus, the combined UV + LTF, O3 + LTF, and UV + O3 + LTF treatments were more effective than the individual treatments under identical conditions. Particularly, the combined double-UV (41.7 mJ cm−2) + O3 (100% O3) + LTF (65 L min−1) treatment exhibited the highest bactericidal activity, resulting in a 5.8-log decrease in the E. coli load within 30 min. Pearson's correlation analysis demonstrated a significant correlation between the synergistic effects of the combined treatments and UV dosage (r = 0.88, p < 0.0001) and aqueous O3 concentrations (r = 0.84, p < 0.0001). These findings suggest that combined UV + O3 + LTF treatment could be a viable alternative method for water disinfection.

Physicochemical parameters, organoleptic property, and Escherichia coli load of fresh turkey organs

Escherichia coli is a common microorganism of the digestive microflora of many warm-blooded animal species, including humans. The presence of E. coli in food is an indicator of faecal contamination and ultimately, possible contamination by pathogenic digestive microflora. The aim of the present work was to study the physicochemical parameters, organoleptic property, and E. coli load in turkey organs (thigh, upper thigh, breast, throat, liver, wing, and skin). A total of 224 samples were purchased from several markets, and subjected to different experiments. Results showed that the best overall scores for organoleptic property were recorded for breast (8.64 ± 0.43) and upper thigh (7.12 ± 0.72). The physicochemical parameter results varied across the studied organs. E. coli was isolated up to 100, 93.75, 90.62, 87.50, 62.5, 56.25, and 40.62% in the skin, wing, throat, liver, thigh, breast, and upper thigh samples, respectively. The highest E. coli loads were recorded in the skin, throat, and wing at 3.89, 3.52, and 3.27 log10 CFU/g, respectively. The present work highlighted the physicochemical parameters, organoleptic property, and E. coli load of turkey organs purchased from several districts of Kenitra city, and discussed a number of practices to improve turkey meat quality and protect consumer health from coliform contamination.

P678 Definition of a microbial signature as a predictor of post-surgical recurrence in patients with Crohn’s disease

Abstract Background Although there are several effective drugs for the treatment of Crohn’s disease (CD), almost 80% of patients will end up needing a surgical resection throughout their lives. This procedure is not always curative, as the disease often reappears in the intestine. Endoscopic recurrence occurs in 65%-90% of patients after one year from surgery. The aetiology of the recurrence is unknown; however, several studies have shown how the resident microbiota is modified after surgery. The aim of this study is to evaluate samples from patients with CD before and after an intestinal resection to determine if at baseline there are differences in the abundance of different microbial markers, which could be capable of predicting endoscopic recurrences. Methods In this observational study, a stool sample was obtained from 20 patients with CD before undergoing surgery, recruited at Hospital Universitari Dr. Josep Trueta, Hospital Universitari of Bellvitge, and the Hospital Universitari Germans Trias i Pujol. From each sample, DNA was purified and the relative abundance of the following microbial markers was quantified using qPCR: F. prausnitzii (Fpra) and its phylogroups (PHG-I and PHG-II), E. coli (Eco ), A. muciniphila (Akk), Ruminococcus sp. (Rum), Bacteroidetes (Bac), M. smithii (Msm), and total bacterial load (Eub). Results Individually, none of the biomarkers demonstrated the ability to differentiate patients who will develop post-surgical recurrence from those who will not. In contrast, the combination of 4 microbial markers (Eco, PHGI, Bac, and Eub) showed a high capacity of discrimination between the 2 groups. The algorithm that incorporates these three markers shows a sensitivity and specificity of 100% and 90.91%, respectively, and a positive and negative predictive value of 90.00% and 100%, respectively. Conclusion A microbial signature to determine patients who will have post-surgical recurrence has been identified. This tool can be very useful in daily clinical practice allowing to schedule a personalized therapy, enabling preventive treatment only in that subgroup of patients who really require it. A broader prospective study will be needed to validate these results.

Impact and consequences of intensive chemotherapy on intestinal barrier and microbiota in acute myeloid leukemia: the role of mucosal strengthening

ABSTRACT Induction chemotherapy (7 + 3 regimen) remains the gold standard for patients with acute myeloid leukemia (AML) but is responsible for gut damage leading to several complications such as bloodstream infection (BSI). We aimed to investigate the impact of induction chemotherapy on the intestinal barrier of patients with AML and in wild-type mice. Next, we assessed the potential benefit of strengthening the mucosal barrier in transgenic mice releasing a recombinant protein able to reinforce the mucus layer (Tg222). In patients, we observed a decrease of plasma citrulline, which is a marker of the functional enterocyte mass, of short-chain fatty acids and of fecal bacterial load, except for Escherichia coli and Enterococcus spp., which became dominant. Both the α and β-diversities of fecal microbiota decreased. In wild-type mice, citrulline levels decreased under chemotherapy along with an increase of E. coli and Enterococcus spp load associated with concomitant histologic impairment. By comparison with wild-type mice, Tg222 mice, 3 days after completing chemotherapy, had higher citrulline levels, a faster healing epithelium, and preserved α-diversity of their intestinal microbiota. This was associated with reduced bacterial translocations. Our results highlight the intestinal damage and the dysbiosis induced by the 7 + 3 regimen. As a proof of concept, our transgenic model suggests that strengthening the intestinal barrier is a promising approach to limit BSI and improve AML patients’ outcome.

ENHANCEMENT OF WATER DISINFECTION EFFICIENCY USING UV RADIATION WITH THE AID OF A LIQUID-FILM-FORMING DEVICE

This study presents results for the use of UV radiation and a liquid-film-forming device (LFFD) for disinfection of water. Escherichia coli was used as a model microorganism for examining the bactericidal performance of UV. Bacterial inactivation was conducted in a LFFD with various condition of UV dosages, air flow rates, and initial bacterial concentrations. Combined UV/LFFD treatments resulted in a greater inactivation efficiency than those for the UV treatment alone. Combined treatment with UV (UV dosage = 3.020×10-20 kJ/m2, initial bacterial concentration = 1.1×105 – 2.2×105 CFU/mL, and room temperature) and LFFD (air flow rate = 2400 L/min) caused 89% inactivation in terms of the bacterial load. In contrast, when the UV treatment was used, only 29% of the E. coli load was inactivated. These findings suggest that the combined UV/LFFD treatments could provide a promising method for water disinfection.

Analysis of Effects of Physical, Chemical and Biological Properties in Domestic Waste Water (Slugde) on Environmental Health in Abia State, Nigeria

The study analyze the physical, chemical and Biological properties of sludge (Domestic waste water) in Umuda-Isingwu, Umuahia-Ibeku and Ihie-ndume in Umuahia north local government area of Abia state. Simple random sampling technique was adopted for the study. Data obtained from laboratory analysis of the water samples was analyzed using descriptive and inferential statistical techniques notably mean, F-LSD and F -test. The mean values of the physical and chemical parameters were compared with SON’s and WHO’s permissible limits. In the chemical properties COD had a mean range of 69.03 ± 0.06 to 80.03 ± 0.06 with all the means showing significant difference among each other (P ? 0.05). The highest TSS was observed in Ibeku at 921.03 ± 0.06. Nickel had a range of 7.42 ± 0.01 to 8.71 ± 0.01 Mg/l with all the means showing significant difference (P ? 0.05). PO4 had its highest concentration in Ihie Ndume community with a mean of 54.03 ± 0.06 Mg/l. None of the means of pH was seen to be above the WHO permissible limit of 8.5, as the mean range of pH was between 6.11 ± 0.01 to 7.76 ± 0.01. The E. coli load was high at Umuda Isingwu, followed by Ibeku and then Ihie Ndume. P. aeruginos and S. aereus was not observed in Ihie Ndume. The presence of fecal coliform bacteria is an indicator that a potential health hazard exists for individuals exposed to the source of water. Nickel was found to be slightly elevated at most of the sites above WHO. Trace metals have been implicated to be responsible for certain health disorders. The PO43- levels varied along the sampling community sites with some sites values having relatively higher values. In general the quality of these waste water cannot be guaranteed as most of the indicators were higher than the WHO and SON standards. This paper assumes that waste water evaluated pose huge treat to the immediate environment and should be investigated further in addition to epidemiological evaluation of the community to rule out occurrence of water-borne diseases.

Efficiency of constructed wetlands in treating E. coli bacteria present in livestock wastewater

Constructed wetlands are artificial wetland units, designed for adopting the principle of natural wetlands for purifying wastewater. Well-designed and well-constructed wetlands play an important role not only in reduction in organic compound/impurities, but also in coliform reduction in wastewater. The three small laboratory-scale units were control, Typha and plant species design based on USEPA procedure. The plant species are watered for a few days to promote their stable growth. Then, the three wetland units were seeded with livestock wastewater from a nearby cattle farm. Qualitative analysis by polymerase chain reaction and quantitative analysis are carried out by doing microbial culture in selective medium of MacConkey agar. The E. coli load is monitored before and after treatment in all the three units with different trials. It is found to be at a higher level in Typha unit after 24 h than in mixed and control units. The sample from the bottom of the constructed wetland unit is withdrawn and cultured for five days, and the bacterial load is found to be 9 × 104. Meanwhile, considerable reduction is observed in the Typha wetland unit after 5 days, and the bacterial load is 4 × 102. Mixed species wetland shows excellent treatment efficiency, and the bacterial load (E. coli) is very less after 5 days. It is evident from the study that constructed wetlands are effective in the treatment of E. coli bacteria wetland plants which are used for treatment.

Do reductions in agricultural field drainage during the growing season impact bacterial densities and loads in small tile-fed watersheds?

Predicting bacterial levels in watersheds in response to agricultural beneficial management practices (BMPs) requires understanding the germane processes at both the watershed and field scale. Controlling subsurface tile drainage (CTD) is a highly effective BMP at reducing nutrient losses from fields, and watersheds when employed en masse, but little work has been conducted on CTD effects on bacterial loads and densities in a watershed context. This study compared fecal indicator bacteria (FIB) [E. coli, Enterococcus, Fecal coliform, Total coliform, Clostridium perfringens] densities and unit area loads (UAL) from a pair of flat tile-drained watersheds (∼250–467 ha catchment areas) during the growing season over a 10−year monitoring period, using a before-after-control-impact (BACI) design (i.e., test CTD watershed vs. reference uncontrolled tile drainage (UCTD) watershed during a pre CTD intervention period and a CTD-intervention period where the test CTD watershed had CTD deployed on over 80% of the fields). With no tile drainage management, upstream tile drainage to ditches comprised ∼90% of total ditch discharge. We also examined FIB loads from a subset of tile drained fields to determine field load contributions to the watershed drainage ditches. Statistical evidence of a CTD effect on FIB UAL in the surface water systems was not strong; however, there was statistical evidence of increased FIB densities [pronounced when E. coli >200 most probable number (MPN) 100 mL−1] in the test CTD watershed during the CTD-intervention period. This was likely a result of reduced dilution/flushing in the test CTD watershed ditch due to CTD significantly decreasing the amount of tile drainage water entering the surface water system. Tile E. coli load contributions to the ditches were low; for example, during the 6-yr CTD-intervention period they amounted to on average only ∼3 and ∼9% of the ditch loads for the test CTD and reference UCTD watersheds, respectively. This suggests in-stream, or off-field FIB reservoirs and bacteria mobilization drivers, dominated ditch E. coli loads in the watersheds during the growing season. Overall, this study suggested that decision making regarding deployment of CTD en masse in tile-fed watersheds should consider drainage practice effects on bacterial densities and loads, as well as CTD's documented capacity to boost crop yields and reduce seasonal nutrient pollution.

Respiratory phagocytes are implicated in enhanced colibacillosis in chickens co-infected with influenza virus H9N2 and Escherichia coli

ABSTRACT1. The aim of this study was to determine the most likely time interval after infection with influenza virus H9N2 for co-infection with Escherichia coli to cause colibacillosis, the importance of lung load of E. coli and the involvement of respiratory phagocytes.2. Specific pathogen free chickens were inoculated intranasally with 106EID50 of influenza virus or uninfected. After specified time intervals, 107 CFU E. coli or phosphate-buffered saline was inoculated. The presence of lesions, the number of respiratory phagocytes in the respiratory lavage fluid and the E. coli load in the lung were determined after different time intervals.3. Compared with the number of lesions in chickens receiving only E. coli inoculation, the number lesions in co-infected chickens were increased at 0- and 3-d time intervals, but reduced in the groups at 6- and 9-d intervals between co-infection.4. At 1–3 d after E. coli inoculation, the number of lesions chickens was correlated with the number of respiratory phagocytes harvested and related to the E. coli load in the lungs at 5 d.5. These results suggest that the lesions caused by E. coli in chickens were increased within a 0–3 d interval following H9N2 virus inoculation and that this effect is related to the number of respiratory phagocytes.

Evaluation Microbiologique Et Origines De La Contamination Des Produits De 4ème Gamme Vendus Sur Les Marchés D’abidjan, Cote D'ivoire

The sources and degree of microbial contamination of 4 th range products or ready-to-eat products made from traditional processes were evaluated in three markets in the city of Abidjan. This study initially consisted of searching for microorganisms such as Staphylococcus aureus, faecal coliforms, E. coli and Salmonella spp. Then, Ishikawa's method or diagram was used to determine potential sources of food contamination consisting of three (3) fruit and two (2) fruit vegetables and one (1) leafy vegetable, respectively, pineapple (Ananas comosus) papaya (Carica papaya), watermelon (Citrulus lanatus), onion (Allium cepa), tomato (Lycopersicum esculentum Mill.) and amaranthus (Amaranthus hybridus). Fecal coliform loads were very high at the fruit level (1.8 × 103 - 9.1 × 102 CFU / g), onion (1.3 × 104 CFU / g), tomato puree (1, 82 × 103 CFU / g) and an E. coli load at the tomato puree which is 9.1 × 102 CFU / g. The analysis using the Ishikawa diagram shows that contamination sources were the poor quality of water, raw material, lack of sanitation, illiteracy, unsafe traditional practices and sellers hygiene.

Quantifying faecal indicator organism hydrological transfer pathways and phases in agricultural catchments

Faecal indicator organisms (FIOs) can impact on water quality and pose a health and environmental risk. The transfer of FIOs, such as Escherichia coli (E. coli), from land to water is driven by hydrological connectivity and may follow the same flowpaths as nutrients, from agricultural and human sources. This study investigated E. coli transfer in two catchment areas with high source and transport pressures. These pressures were: organic phosphorus (P) loading; human settlement; conduits and fissures in a grassland karst area; and clay rich and impermeable soils in a mixed arable area. The occurrence of E. coli and its transport pathways, along with the pathways of nutrients, were studied using a combination of targeted FIO sampling, during different hydrological phases and events, and high resolution nutrient analysis. The quick flow component in both catchments was found to be a more potent vector for E. coli, and was coincident with the total P flowpaths using a P Loadograph Recession Analysis (LRA). The karst grassland catchment was found to be a transport limited system and the mixed arable catchment a source limited system. Hence, despite the grassland catchment being a potentially higher FIO source, the E. coli loads leaving the catchment were low compared to the mixed arable catchment. E. coli load whole-event comparisons also indicated that the grassland karst transfers tended to be much lower on falling phases of runoff, while the arable catchment, over greywacke and mudstone geology, showed little change between the phases. Furthermore, the arable catchment showed asymptotic decline of sustained E. coli loads towards low flows, which may be indicative of chronic point sources. These results indicate the dominance of transport mechanisms over source mechanisms for mass E. coli loads and also chronic loads during low flow. These will be important considerations for risk assessment and mitigation.

Wastewater treatment plants release large amounts of extended-spectrum β-lactamase-producing Escherichia coli into the environment.

The determinants of the spread of extended-spectrum β-lactamase-producing Escherichia coli (ESBLEC) in the community remain unclear. To evaluate its dissemination in the environment, we analyzed the ESBLEC population throughout an urban wastewater network. Samples were collected weekly, over a 10-week period, from 11 sites throughout the wastewater network of Besançon city (France). Total E. coli and ESBLEC loads were determined for each sample. As a control, we analyzed 51 clinical ESBLEC isolates collected at our hospital. We genotyped both environmental and clinical ESBLEC by pulsed-field gel electrophoresis and multilocus sequence typing and identified their blaESBL genes by sequencing. The E. coli load was higher in urban wastewater than in hospital wastewater (7.5 × 10(5) vs 3.5 × 10(5) CFU/mL, respectively). ESBLEC was recovered from almost all the environmental samples and accounted for 0.3% of total E. coli in the untreated water upstream from the wastewater treatment plant (WWTP). The ESBLEC load was higher in hospital wastewater than in community wastewater (27 × 10(3) vs 0.8 × 10(3) CFU/mL, respectively). Treatment by the WWTP eliminated 98% and 94% of total E. coli and ESBLEC, respectively. The genotyping revealed considerable diversity within both environmental and clinical ESBLEC and the overrepresentation of some clonal complexes. Most of the sequence types displayed by the clinical isolates were also found in the environment. CTX-M enzymes were the most common enzymes whatever the origin of the isolates. The treatment at the WWTP led to the relative enrichment of ESBLEC. We estimated that >600 billion of ESBLEC are released into the river Doubs daily and the sludge produced by the WWTP, used as fertilizer, contains 2.6 × 10(5) ESBLEC per gram.

Inhibitory effect of high-dosage zinc oxide dietary supplementation on Campylobacter coli excretion in weaned piglets

This study investigated the impact of zinc oxide (ZnO) on Campylobacter coli by in vivo and in vitro assays. By in vitro growth inhibition assays, a high susceptibility of Camp. coli against ZnO could be observed. At concentrations ≥ 2.6 mmol l(-1) ZnO, a decline in cell numbers occurred. Quantitative real-time PCR assays demonstrated an up-regulation of the main oxidative stress gene (katA) in response to ZnO treatment. The expression level of katA was increased by fivefold after ZnO treatment. An experiment was carried out in pigs to elucidate the impact of ZnO as feed supplement on Camp. coli faecal excretion. Feeding a high-dosage ZnO concentration (3100 mg kg(-1) ) to piglets significantly reduced the faecal excretion of Camp. coli by up to 1 log CFU g(-1) as compared to animals receiving a low (40 mg kg(-1) ) or medium (100 mg kg(-1) ) ZnO diet. In vitro assays showed a high susceptibility of Camp. coli against ZnO. Adding high levels of ZnO to the diet of weaned piglets reduced Camp. coli excretion significantly. There is evidence for the induction of an oxidative stress response by ZnO supplementation in Camp. coli. Supplementation of a high-dosage ZnO diet to piglets can reduce the Camp. coli load, potentially leading to a lower contamination risk of meat during slaughter.

Hydrodynamic modelling of the microbial water quality in a drinking water source as input for risk reduction management

To mitigate the faecal contamination of drinking water sources and, consequently, to prevent waterborne disease outbreaks, an estimation of the contribution from different sources to the total faecal contamination at the raw water intake of a drinking water treatment plant is needed. The aim of this article was to estimate how much different sources contributed to the faecal contamination at the water intake in a drinking water source, Lake Radasjon in Sweden. For this purpose, the fate and transport of faecal indicator Escherichia coli within Lake Radasjon were simulated by a three-dimensional hydrodynamic model. The calibrated hydrodynamic model described the measured data on vertical temperature distribution in the lake well (the Pearson correlation coefficient was 0.99). The data on the E. coli load from the identified contamination sources were gathered and the fate and transport of E. coli released from these sources within the lake were simulated using the developed hydrodynamic model, taking the decay of the E. coli into account. The obtained modelling results were compared to the observed E. coli concentrations at the water intake. The results illustrated that the sources that contributed the most to the faecal contamination at the water intake in Lake Radasjon were the discharges from the on-site sewers and the main inflow to the lake – the river Molndalsan. Based on the modelling results recommendations for water producers were formulated. The study demonstrated that this modelling approach is a useful tool for estimating the contribution from different sources to the faecal contamination at the water intake of a drinking water treatment plant and provided decision-support information for the reduction of risks posed to the drinking water source.

E. coli Transport through Surface-Connected Biopores Identified from Smoke Injection Tests

Macropores are the primary mechanism by which fecal bacteria from surface-applied manure can be transported into subsurface drains or shallow groundwater bypassing the soil matrix. Limited research has been performed investigating fecal bacteria transport through specific macropores identified in the field. The objective of this research was to better understand how fecal bacteria, using Escherichia coli (E. coli) as an indicator organism, are transported through naturally occurring macropores and potential interactions between the macropore and soil matrix domains in the field under controlled experimental conditions. Direct injection/infiltration tests were conducted in two naturally occurring, surface-connected macropores (biopores) that penetrated to the subsurface drain depth, as identified by smoke tests. Data included total drain flow rate (baseflow rate and biopore flow rate), biopore inflow rate, and Rhodamine WT and E. coli concentrations in the drains. Analysis techniques included determining increases in subsurface drain flow rates due to the infiltration tests and percentage of the injected concentration reaching the subsurface drains after dilution with the drain baseflow. In the absence of data for mechanistic models, empirically based rational polynomial models were compared to the more commonly utilized lognormal distribution for modeling the load rate breakthrough curves. Load estimates were derived from integrated forms of these empirical functions, and percent reductions were calculated for Rhodamine WT and E. coli. Peak total drain flow rates increased nearly two-fold due to direct injection into the biopores. Less than 25% of the initial concentrations injected into the biopores reached the drain after dilution with the baseflow in the drain. Lognormal distributions best fit the Rhodamine WT load rate breakthrough curves (R2 = 0.99 for both biopores) and the E. coli load rate data for one of the biopores (R2 = 0.98). A rational fractional polynomial model that tailed off more slowly best fit the E. coli load rate data for the other biopore (R2 = 0.98). Approximately one log reduction was estimated for E. coli loads due to interaction with the soil profile as water flowed through the tortuous path of the biopores; in other words, the soil surrounding the biopore filtered approximately 90% of the E. coli load that entered the biopore compared to approximately 75% for Rhodamine WT. Considering that applied animal manure can contain millions of bacteria per mL, high concentrations and loads are still possible in the subsurface drain flow if macropores are present.

The E. Coli Load In Self-Managed Rural Water In Australia

Access to clean drinking water is taken for granted in most developed nations where many think water quality is a third-world issue. However, for residents of rural Australia water quality is an emerging issue. Our research of drinking water quality, harvesting and management practices of rural NSW residents found that a substantial number of these consumers may be risking their health whenever they turn on their tap. More than half of the tank water sampled failed to meet the Australian Drinking Water Guidelines for safe drinking water. Levels of E. coli were up to 230x more than the acceptable levels proposed by the Australian Drinking Water Guidelines. Qualitative research found most consumers were unaware of the risks associated with drinking raw rainwater. Further, few took steps to minimise their risk through accepted water management practices.

Stormflow dynamics and loads of Escherichia coli in a large mixed land use catchment

AbstractStorm events are major transporters of faecal microbial contaminants, but few studies have reported storm loads or concentration dynamics in relation to discharge or other pollutants, notably fine sediment. Episodically, high loads of faecal contamination during storm flows impact downstream uses of water bodies, particularly contact recreation and shellfish harvesting. We examined the storm dynamics of Escherichia coli, turbidity and discharge in the mixed land use Motueka catchment (2047 km2; 60% forest and 19% pasture) to gain insights into E. coli sources and transport. We also explored different approaches for calculating E. coli loads. Discharge and field turbidity were recorded continuously, and E. coli concentrations were sampled during events, over a 13‐month period near the mouth of the Motueka River. E. coli loads were estimated by interpolation, averaging estimators and by using linear regression with smearing correction of the log‐transformed variables: discharge, turbidity, and both turbidity and discharge. The annual E. coli load was dominated (∼98%) by export during events. Comparison of monthly monitoring with the intensive storm monitoring campaign suggests that simple stratification of the sampling into storm and baseflow would greatly improve export estimates. E. coli peak concentrations always preceded discharge and turbidity peaks (which had similar timing). Turbidity can be a useful surrogate for faecal microbes in smaller catchments, but in the Motueka turbidity was no better for predicting E. coli concentration than discharge. Runoff from grazed pasture and direct deposition from livestock are probably the ultimate E. coli sources in the Motueka catchment. However, in‐channel stores seem to dominate E. coli dynamics during events and account for the typical feature of bacterial concentrations peaking ahead of discharge and turbidity. This study demonstrates the importance of storm events to faecal microbial loads and shows that E. coli concentration dynamics may contrast with those of turbidity. Copyright © 2009 John Wiley & Sons, Ltd.

Effect of feeding intact brown seaweed Ascophyllum nodosum on some digestive parameters and on iodine content in edible tissues in pigs

AbstractBACKGROUND: Limited research suggests that brown seaweed (extracts) may be used in pig nutrition for improving gut health and performances and for iodine enrichment of tissues. One in vitro and two in vivo experiments with dried iodine‐rich intact marine seaweed (Ascophyllum nodosum) have been conducted with weaned piglets to further unravel the mechanisms.RESULTS: In vitro investigations revealed a statistically significant depressive effect of seaweed on pig gut flora, especially on Escherichia coli. In vivo, seaweed (10 g kg−1) had a reducing effect on the E. coli load in the stomach (P = 0.07) and small intestine (P < 0.05), while the lactobacilli/E. coli ratio was enhanced (P < 0.05) in the small intestine, indicating a beneficial shift in the microbial population. Statistically significant increases (P < 0.001) in iodine content were noted for several tissues in piglets on seaweed (20 g kg−1, corresponding to 10 mg iodine kg−1 feed) compared with the control diet (1 mg iodine kg−1 feed).CONCLUSION: Intact A. nodosum brown seaweed may be introduced in pig nutrition as a feed material with a double strategy: improvement of pig gut health and performances and iodine enrichment of porcine tissues. This feeding strategy may alleviate, but not solve, the actual iodine deficiency in Belgium. Copyright © 2009 Society of Chemical Industry

Direct and Indirect Hydrological Controls on E. coli Concentration and Loading in Midwestern Streams

This study investigates hydrological controls on E. coli concentration and loading in two artificially drained agricultural watersheds (58 and 23 km(2)) of the U.S. Midwest. Stream E. coli concentrations are significantly (p < 0.02) lower at base flow than high flow; however, E. coli load is significantly higher at high flow than at low flow (p < 0.001). Although E. coli concentrations are not significantly higher (p = 0.253) in summer/fall (3269 MPN/100 mL) than in the winter/spring (2411 MPN/100 mL), E. coli load is significantly higher (p < 0.05) in winter/spring (346 MPN/day) than in summer/fall season (75 MPN/day). Correlation analysis indicates that discharge and precipitation are the best indicators of E. coli concentration and 7-d antecedent precipitation (7dP), the best indicator of E. coli loading in the watersheds studied regardless of flow conditions and location. However, E. coli concentration and loading best correlate to 7dP and turbidity at base flow. A spatial dependency is also observed at base flow with E. coli concentration and load correlating better to 7dP in the headwaters and to turbidity in the lower reaches of the watersheds studied. For high flow conditions, E. coli concentration and loading are poorly correlated to most variables, except stream water temperature and 7-d antecedent discharge. These results are consistent with those reported in the literature and suggest that, at least during base flow conditions, turbidity and 7dP may be usable in artificially drained landscapes of the Midwest to identify potential hot spots of E. coli contamination.