Fecal Microorganisms Research Articles

Reduction of bacterial indicators and bacteriophages infecting faecal bacteria in primary and secondary wastewater treatments.

To compare the suitability of various bacterial and viral indicators to assess the removal of faecal micro-organisms by primary and secondary wastewater treatment processes. The numbers of several bacterial indicators [faecal coliforms (FC), enterococci (ENT) and sulphite-reducing clostridia (SRC)] and bacteriophages (somatic coliphages, F-specific RNA phages and bacteriophages infecting Bacteroides fragilis strain RYC2056) were determined in incoming raw sewage and effluents from various primary and secondary wastewater treatment processes in several geographical areas. Reductions in the numbers of indicators were calculated as log10 reductions. Processes based on removal and mild disinfection, showed no significant differences in the elimination of any of the indicators tested or between geographical areas. In contrast, treatment processes that include strong microbial inactivation, such as lime-aided flocculation and lagooning, showed significant differences between the log10 reductions of the various micro-organisms studied, FC showing the highest reduction and spores of SRC and phages infecting B. fragilis the lowest. The microbial elimination performance of treatment processes based principally on removal and mild disinfection can be evaluated with a single indicator. In contrast, processes with additional disinfecting capabilities require more than one indicator for accurate evaluation of the treatment; bacteriophages are good candidates for use as second indicators. Bacteriophages provide additional information for the evaluation of microbial elimination in some treatment plants. The easy, fast and cheap methods available for phage determination are feasible both in industrialized and developing countries.

Simulating transport of E. coli derived from faeces of grazing livestock using the macro model

Abstract. Coliforms such as Escherichia coli and E. coli O157 are present in faeces deposited on the ground by grazing livestock, which gives rise to environmental concerns about the consequences of their transport in soil water draining to rivers, lakes, groundwater, water supplies and bathing waters. Following a similar study in relation to slurry spreading (Soil Use and Management 2003; 19, 321–330), a two‐stage approach was adopted to using the dual‐porosity contaminant transport model macroto simulate processes by which E. coli microorganisms from grazing livestock (sheep) pass through the soil to receiving waters via field drains. First, model parameter values were selected to reproduce experimental measurements showing rapid flows of the organisms by macropore flow without trapping in smaller pores. However, because of the large number of parameters and likely experimental errors, the set of values chosen, although plausible, is not necessarily unique and so any predictions should be considered provisional pending validation. Second, a series of predictive simulations was carried out to test the influence of soil and weather conditions on losses to field drains during grazing. These showed that E. coli losses were influenced almost entirely by the soil water content at the time of grazing, rising to a high level during grazing in wet conditions, but low or zero under dry conditions. In contrast, rainfall at the time of grazing had almost no consistent effect, other than large losses on the occasional days with over 20 mm of rain. Overall losses for a period of grazing were generally small during summer, but rose to a high level if grazing continued into autumn, due to the increase in soil water content. This demonstrates that there would probably be substantial reductions in the environmental risks of water pollution by E. coli and other faecal microorganisms if continuous grazing were stopped around early September and replaced by grazing on dry days only.

Human fecal metabolism of soyasaponin I.

The metabolism of soyasaponin I (3-O-[alpha-L-rhamnopyranosyl-beta-D-galactopyranosyl-beta-D-glucuronopyranosyl]olean-12-ene-3beta,22beta,24-triol) by human fecal microorganisms was investigated. Fresh feces were collected from 15 healthy women and incubated anaerobically with 10 mmol soyasaponin I/g feces at 37 degrees C for 48 h. The disappearance of soyasaponin I in this in vitro fermentation system displayed apparent first-order rate loss kinetics. Two distinct soyasaponin I degradation phenotypes were observed among the subjects: rapid soyasaponin degraders with a rate constant k = 0.24 +/- 0.04 h(-)(1) and slow degraders with a k = 0.07 +/- 0.02 h(-)(1). There were no significant differences in the body mass index, fecal moisture, gut transit time, and soy consumption frequency between the two soyasaponin degradation phenotypes. Two primary gut microbial metabolites of soyasaponin I were identified as soyasaponin III (3-O-[beta-D-galactopyranosyl-beta-D-glucuronopyranosyl]olean-12-ene-3beta,22beta,24-triol) and soyasapogenol B (olean-12-ene-3beta,22beta,24-triol) by NMR and electrospray ionized mass spectroscopy. Soyasaponin III appeared within the first 24 h and disappeared by 48 h. Soyasapogenol B seemed to be the final metabolic product during the 48 h anaerobic incubation. These results indicate that dietary soyasaponins can be metabolized by human gut microorganisms. The sugar moieties of soyasaponins seem to be hydrolyzed sequentially to yield smaller and more hydrophobic metabolites.

Simulation of transport through soil of E. coli derived from livestock slurry using the macro model

Abstract. Leaching of faecal coliforms to rivers, lakes and groundwater following the spreading of animal slurry on land is of environmental and public health concern. A two‐stage approach was adopted to modelling the transport processes by which Escherichia coli passes through the soil to receiving waters via field drains. First, parameter values were selected for the dual‐porosity contaminant transport model macro to simulate through‐soil flows, sorption and die‐off of E. coli. These simulations reproduced experimental measurements showing rapid flows of the microorganisms to field drains after slurry spreading, which could be explained in terms of macropore flow in which trapping of colloids such as E. coli does not take place. Second, a series of predictive simulations was carried out to test the influence of soil and weather conditions on E. coli losses. These showed that losses are strongly influenced by soil wetness conditions at the time of spreading, and to a lesser degree by rainfall occurring soon after spreading. Selection of spreading ‘workdays’ with particular weather and soil wetness conditions is beneficial, which indicates opportunities for substantial reductions in the environmental risks of water pollution by E. coli and other faecal microorganisms.

Influence of seasonal environmental variables on the distribution of presumptive fecal Coliforms around an Antarctic research station.

Factors affecting fecal microorganism survival and distribution in the Antarctic marine environment include solar radiation, water salinity, temperature, sea ice conditions, and fecal input by humans and local wildlife populations. This study assessed the influence of these factors on the distribution of presumptive fecal coliforms around Rothera Point, Adelaide Island, Antarctic Peninsula during the austral summer and winter of February 1999 to September 1999. Each factor had a different degree of influence depending on the time of year. In summer (February), although the station population was high, presumptive fecal coliform concentrations were low, probably due to the biologically damaging effects of solar radiation. However, summer algal blooms reduced penetration of solar radiation into the water column. By early winter (April), fecal coliform concentrations were high, due to increased fecal input by migrant wildlife, while solar radiation doses were low. By late winter (September), fecal coliform concentrations were high near the station sewage outfall, as sea ice formation limited solar radiation penetration into the sea and prevented wind-driven water circulation near the outfall. During this study, environmental factors masked the effect of station population numbers on sewage plume size. If sewage production increases throughout the Antarctic, environmental factors may become less significant and effective sewage waste management will become increasingly important. These findings highlight the need for year-round monitoring of fecal coliform distribution in Antarctic waters near research stations to produce realistic evaluations of sewage pollution persistence and dispersal.

Sources and Persistence of Fecal Coliform Bacteria in a Rural Watershed

Abstract Water quality within the Thomas Brook watershed, which is a small catchment located in the headwaters of the Cornwallis River drainage basin, was assessed through an integrated monitoring program. The Thomas Brook watershed is approximately 1000 ha and is characterized by both agricultural and residential land uses. Fecal coliform concentrations and stream flow were monitored at several points throughout the watershed during an eight-month period (May to December, 2001). Thomas Brook was seriously degraded with respect to microbial water quality. Fecal coliform levels frequently exceeded recreational water quality guidelines. At the watershed outlet, 94% of the collected samples exceeded the recreational water quality guideline during low flow conditions. Substantial bacterial loading was observed along stream reaches impacted by livestock operations. Bacterial loading was also observed along a stream reach that was not impacted by agricultural activities. A dense clustering of residences, using on-site septic systems, was the suspected source. Results from this study indicate the presence of a reservoir of fecal microorganisms within the stream sediments. The release of fecal microorganisms from the stream sediments to the water column during both low and high flow conditions could be a major source of bacterial loading.

Water quality relative to end use

Without a safe water supply, large urban populations are at risk of microbial infection. The sewage from urban living must be treated so that the load of faecal microorganisms is removed before it is discharged. Ideally, catchments should be closed to reduce contamination, but if this is not feasible, storage, filtration, disinfection, closed distribution, regular maintenance and monitoring can provide a safe supply. A Risk Management Framework has been developed to assist this process. Wastewater carries a heavy microbial load including organisms causing gastroenteritis. Appropriate treatment and disinfection can control the bacterial pathogens, but the oocysts of of Cryptosporidium and some viruses are resistant to chlorine. Recycling of wastewater therefore requires considerable expertise and is better adopted by centralized developments based on greenfield sites with a professional operator in control. Stormwater from the roof can be used safely from small tanks to supply toilets, hot water service and outdoor activities. Stormwater from roads must be treated at least through reed beds, wetlands and ponds or connected to a conventional plant.

A microbiota da carcaça e da carne ovina tratada com ácido acético, embalada a vácuo e maturada por 48 dias

Foi avaliada a carga de bacterias mesofilas e coliformes totais e fecais na superficie da carcaca ovina apos 12 horas do abate. Posteriormente, a carne foi cortada em fatias de aproximadamente 3cm de espessura, imersas por um minuto em acido acetico 1% ou em agua, embaladas individualmente a vacuo e armazenadas a 1°C. Nos dias 3,13, 23, 33 e 48 de maturacao as carnes foram analisadas para bacterias mesofilas e psicrotroficas, mofos e leveduras, coliformes totais e fecais, salmonela e clostridios sulfito-redutores. As contagens de bacterias mesofilas e psicrotroficas foram menores (p<0,05) nas carnes tratadas com acido acetico que nas nao tratadas nos dias 13 e 23 e nos dias 3 e 13 de maturacao, respectivamente. A contagem de mofos e leveduras foi menor (p<0,05), nas carnes tratadas em relacao as nao tratadas, apenas nos dias 13 e 23 de maturacao. Apos 3 dias de maturacao as carnes tratadas mostraram menores (p<0,05) contagens de coliformes fecais e totais que as nao tratadas. As carnes apresentaram presenca de salmonela com 3, 13 e 23 dias de maturacao mais nao com 33 e 48. Nao foi detectada presenca de clostridios sulfito-redutores durante todo o periodo de maturacao. Pode-se concluir que o tratamento com acido e as condicoes de maturacao utilizadas neste experimento mantem baixas contagens de microrganismos mesofilos, psicrotroficos, mofos e leveduras e coliformes por 13 dias. Durante este periodo, porem, inibicao do crescimento de salmonelas somente foi detectada apos 33 dias de maturacao da carne ovina.

Characteristic profile of intestinal microflora in Kawasaki disease

To investigate whether the ecology of the intestinal microflora may change in the acute phase of Kawasaki disease (KD), the distribution pattern was studied of common micro‐organisms in feces from 20 patients with KD, 20 patients with acute febrile diseases (disease control) and 20 healthy children. KD patients had a significantly lower (p &gt; 0.001) incidence of Lactobacillus (2/20, 10%) than disease control patients (16/20, 80%) and healthy children (14/20,70%). KD patients had no significant incidences of other microbial genera, compared with both disease control and healthy children. Conclusion: The results suggest that a lack or loss of the beneficial Lactobacillus genus in the enteric microflora may occur during the acute phase of KD.

Characteristic profile of intestinal microflora in Kawasaki disease.

To investigate whether the ecology of the intestinal microflora may change in the acute phase of Kawasaki disease (KD), the distribution pattern was studied of common micro-organisms in feces from 20 patients with KD, 20 patients with acute febrile diseases (disease control) and 20 healthy children. KD patients had a significantly lower (p < 0.001) incidence of Lactobacillus (2/20, 10%) than disease control patients (16/20, 80%) and healthy children (14/20, 70%). KD patients had no significant incidences of other microbial genera, compared with both disease control and healthy children. The results suggest that a lack or loss of the beneficial Lactobacillus genus in the enteric microflora may occur during the acute phase of KD.

Soil Solarization: A Sustainable Agriculture Approach to Reduce Microorganisms in Chicken Manure-Treated Soil

ABSTRACT The common practice in many countries of using chicken manure in soil as a source of nutrients to plants is of paramount importance in sustainable agriculture. However, the application of non-composted manure on soil could contribute to contamination of the environment by fecal microorganisms. This creates a health hazard to humans, domestic animals, and to wildlife. The impact of soil solarization on reduction of microorganism-indicators of fecal contamination in chicken manure-treated soils has not been evaluated. In this study, 1.5 kg/m2 of chicken manure was applied to 40 cm deeply-ploughed clayish calcareous soils of four greenhouses. The soils of four other greenhouses were left as control-untreated with manure. Litter incorporation in the soil was performed by a harrow with 20 cm penetration depth. Irrigation was applied to soil of the eight greenhouses to obtain an average humidity at 40 cm-soil depth equivalent to 92.9%. Soil solarization of the chicken manure-treated soils with a 50 µm thick-polyethylene film for a period of six weeks resulted in an average 20 cm-soil depth temperature at 15 hr of 40°C in comparison to 28.3°C obtained in soil with no polyethylene film application. Solarization resulted in reduction in different microorganism-indicators per gram of chicken manure-treated soil collected at 20 cm depth in comparison to the count in the same soil before solarization. The percent reduction in counts in increasing order was: Staphylococcus aureus (26.3), total bacteria (45.5), fungi (71.3), Clostridium perfringes (81.8), fecal coliform (92.6), and non-lactose fermenting bacteria (100.0).

Numerical simulation of the microstructure and compression behavior of Eckernförde Bay sediments

Transmission electron microscope (TEM) studies conducted on sediments recovered using diver-collected cores and gravity cores from Eckernförde Bay in the Baltic Sea, Germany, reveal that the sediments consist of silt- to clay-sized sediment, both free and bound into fecal pellets, organic matter, biogenic materials, methane gas and microorganisms. The microstructure of the upper 2 m of the sediment is complex, with the clay particles arranged in a very open structure with variable inter- and intra-domain pore space. In an effort to understand the relationship between microscopic variables (e.g., microfabric) and macroscopic geotechnical properties (e.g., compressibility), a numerical study was performed using the discrete element method. The objective of this study was to develop an understanding of the micro- to macro-linkage of mechanical properties. Specifically, one-dimensional compression behavior of the sediment was numerically simulated and compared with experimental data. Compositional parameters of the sediment were obtained from specific tests conducted at the Naval Research Laboratory and from tests conducted by other researchers participating in the project. Image analysis was used to quantify the microfabric parameters from TEM images of the sediment. The effect of organic matter was simulated by introducing inter-particle contact cementation. Results indicate that inter-particle bonding due to inter-particle cementation and/or the van der Waals attractive force (1) contributes to the apparent overconsolidation observed in the laboratory and (2) holds the highly porous, unstable microstructure together until a threshold stress level is reached. Change in void ratio during compression is due to inter-, rather than intra-domain movement.

Runoff of faecal microorganisms and nutrients from perennial grass ley after application of slurry and mineral fertiliser

Perennial grass was fertilised with cattle slurry either surface-spread or injected into the soil. Slurry was spread once (early summer) in 1996 and 1997 and twice (both summer and autumn) in 1998 and 1999. The control was mineral fertilisation in summer. Faecal microbial numbers in surface runoff water were very high in late June 1998 soon after very heavy rains even though the last slurry application had been made almost one year earlier. There was no clear difference between slurry spreading methods. Autumn spreading of slurry lead to high microbial levels in runoff waters and water hygiene was protected better by slurry injection than by surface spreading. In spring, after snow melt, some faecal microorganisms were found in surface runoff water and the numbers of faecal microorganisms were less from plots with slurry surface spreading than those with slurry-injection. Losses of total phosphorus (TP) and total nitrogen (TN) in surface runoff were 2.7 and 7.7 kg/ha respectively from grass with surface-spread slurry in winter 1998-1999. The injection of slurry decreased TP and TN runoff by an average of 81% and 73% respectively. In 1999 there was little runoff because the summer was sunny and dry.

Microbial contamination of sand from major beaches in Fortaleza, Ceará State, Brazil

The presence of faecal contamination and pathogenic microorganisms in samples of dry and wet sand collected from three major beaches in Fortaleza, Ceara State, Brazil: (Praia do Mucuripe, Praia do Futuro and Praia do Caca e Pesca), during the period of May 1999 to January 2000 was evaluated. Praia do Caca e Pesca had the highest incidence of E. coli in dry sand (56%) followed by Praia do Mucuripe (28%) and Praia do Futuro (16%). In wet sand, results were 48%, 28% and 24% for Praia do Caca e Pesca, Praia do Futuro and Praia do Mucuripe, respectively. Only two samples from Praia do Futuro, one from dry sand and another one from wet sand, were positive for Salmonella. V. parahaemolyticus was isolated from four samples from Praia do Caca e Pesca (two from dry-sand samples and two from wet-sand), one from Praia do Futuro (wet sand), and three and four from Praia do Mucuripe (wet and dry sand, respectively). Yeasts belonged to the Candida genus. Dry-sand samples presented higher yeast contaminations level than wet-sand ones. Praia do Futuro had the highest level of yeast contamination (41%), followed by Praia do Caca e Pesca (33%) and Praia do Mucuripe (26%).

Effects of Sallropus androgynus (katuk) leaf extract on growth, fat accumulation and fecal microorganisms in broiler chickens

A study was conducted to determine the effects of Sauropus androgynus leaf extract on growth, carcass quality and the number of fecal microorganisms in broiler chickens. Forty-eight male Arbor Acres broiler chickens (21-d-old) obtained from a commercial hatchery were used in the present study. Experiment consisted of four treatment groups with four pen replicates of three broilers allotted randomly to each dietary treatment from day 21-42 old. One group was the control with no additional Sauropus androgynus leaf extract (SAE) (P0), and other three groups were given drinking water supplemented with 1.5 g (PI), 3.0 g (P2) or 4.5 g SAE/l water (P3). The diet used was a commercial mix (Crude protein: 19% and Metabolizable Energy 3200 kcal/kg). Feed intake significantly reduced in P2 or P3 as compared with the control (P<0.05). A decrease in feed conversion ratio was observed in treatment groups as compared with Po (P<0.05). Abdominal fat, neck fat and liver fat content were significantly reduced by SAE (P<0.05), while carcass fat content was not significantly different. Number of fecal Escherichia coli in P1 or P3 (P<0,01) and fecal Streptococcus sp and Salmonella sp. were significantly (P<0,01) reduced by SAE supplementation as compared with the control, while fecal Bacillus subtilis in P2 and Lactobacillus sp. in P1 (P<0,01) were significantly higher as compared with other groups. SAE (P2 or P3) also significantly improved meat taste, shank color but lowered meat color (P<0.05) as compared with the control group. It was found that the number of fecal Streptococcus sp was suitable to predict abdominal fat. In conclusion, the inclusion of SAE at 4.5 g/l drinking water resulted in the best performance and carcass quality. Key words : Sauropus androgynus leaf extract, fat accumulation, broilers

Linoleic Acid Conjugation by Human Intestinal Microorganisms Is Inhibited by Glucose and Other Substrates In Vitro and in Gnotobiotic Rats

The anticarcinogen conjugated linoleic acid (CLA) is a product of bacterial activity that isomerizes linoleic acid (LA) in the rumen of herbivores. Therefore, fatty dairy products in the human diet are enriched with CLA. Although bacteria capable of in vitro LA conjugation were detected in the human intestinal tract, CLA synthesis from dietary sunflower seed oil was not observed in gnotobiotic rats associated with these intestinal bacteria. The objective of the study was to investigate variables that affect LA conjugation. In vitro, LA conjugation was strongly inhibited by glucose and other substrates. Concentrations of 1.5 mmol glucose/L inhibited LA conjugation by 50%. Methyl-alpha-D-glucoside was a less effective inhibitor than glucose, and 2-deoxy-D-glucose did not inhibit LA conjugation at all. To analyze the concentration of carbohydrates in intestinal contents, the LA-conjugating bacterial mixed culture and human fecal microorganisms were introduced into germ-free rats. Samples of feces and cecum and colon contents of both groups exhibited in vitro LA-conjugating activity. Rats associated with human intestinal microorganisms contained 5.7 +/- 1. 3 mmol glucose/L in the cecal contents and 6.6 +/- 1.0 mmol glucose/L in the colonic contents. Rats associated with CLA-producing bacterial culture contained 3.4 +/- 1.3 mmol glucose/L in the cecal contents and 4.2 +/- 1.0 mmol glucose/L in the colonic contents. These values are within a range that may explain the observed inhibition of LA conjugation in vivo.

Catheterization and urinary tract infections: microbiology.

Patients with urinary catheters are a substantial proportion of the total patient population and catheter care is an important area of nursing practice. Urinary tract infection associated with catheterization is known to be the most common nosocomial (hospital-acquired) infection. Urinary tract infections can be caused by exogenous microorganisms or endogenous faecal or urethral microorganisms. The different microorganisms which are responsible for causing urinary tract infections have particular characteristics. Many microorganisms form a biofilm, a living layer of cells which stick to the surfaces of the catheter and the catheter bag. Biofilms not only lead to urinary tract infections, but also they are associated with encrustation and catheter blockage. The article considers the microorganisms implicated in catheter-associated urinary tract infections and aims to develop an increased awareness of the characteristics of different pathogens which could lead to enhanced nursing practice and improved patient care.

Information subsystem of the difference between anions sum and hardness of water and its influence on human health.

Underground and surface waters in Dalmatia (Southern Croatia) have relatively preserved their natural characteristics since the greatest agglomeration of population and industry is located along the coast. The danger of pollution with fecal microorganism and products of biological decomposition is the most immediate problem but can be efficiently eliminated by water chlorination. The ecological need to sum up the work on water quality examination and estimation of future water quality trends resulted in water quality monitoring, i.e. in human health monitoring. It is necessary for large number of analytical and ecological health data to organize them from the informatical aspect into databases, the relational database for chemical analysis studying (the difference between anions sum and hardness) as methodological base for studying the ecological factors that influence human health defined in this paper. Results used for the prototype implementation subsystem of the chemical water analysis control are based on the investigations of Water Examination Department of the Public Health Institute of the Split-Dalmatian County (Croatia). Over 3400 data are comprised what is the sufficient examination sample. The software used included Win '95, Mo '97, and Paradox 4,5, while the hardware used included Pentium II 300 MHz, floppy, 128 MB RAM HDD 4,3 GB, CD x 24, HP DeskJet 710C.

Kinetics of Fecal Coliform Removal in Constructed Wetlands

Major mechanisms influencing the removal of fecal microorganisms in constructed wetlands treating sewage in tropical regions include the effects of temperature, solar radiation, sedimentation, adsorption and filtration. This study aims to develop a model describing the kinetics of fecal coliform removal in free-water-surface (FWS) constructed wetlands. Separate model equations were proposed for removal rate coefficients for each of the major removal mechanisms. The model parameters were assessed from both literature and the performance data of laboratory-scale FWS constructed wetland units planted with cattails (Typha angustifolia). The model parameters and the kinetic model were validated with experimental data of two pilot-scale constructed wetlands. Statistical analyses of the calculated and observed performance data of the pilot-scale units revealed good correlation and were without significant practical difference, suggesting the kinetic model was feasible.

Inactivation of faecal indicator micro-organisms in waste stabilisation ponds: interactions of environmental factors with sunlight

Sunlight exposure is considered to be the most important cause of “natural” disinfection in waste stabilisation ponds (WSPs). We examined the influence of dissolved oxygen (DO), pH, and particulate and dissolved constituents in WSP effluent, on sunlight inactivation of faecal micro-organisms, using small reactors operated under controlled physico-chemical conditions. Inactivation of both enterococci and F-RNA phages increased strongly as DO was increased, and also depended on light-absorbing pondwater constituents, but pH was not influential over the range investigated (7.5 to 10). Inactivation of E. coli increased strongly when pH increased above 8.5, as well as being strongly dependent on DO. Inactivation of F-DNA phage was independent of the factors investigated. These results are consistent with the F-DNA phages being inactivated as a result of direct DNA damage by UVB in sunlight, whereas the other three microbiological indicators are inactivated as a result of photo-oxidative damage, although the target of damage is apparently different. Our findings of diverse influences of physico-chemical conditions suggest difficulties in interpreting data for a single micro-organism to indicate WSP effluent quality. However, sunlight remains the factor of over-riding importance, and disinfection in WSPs may be enhanced by increasing sunlight exposure.