Coliform Group Bacteria Research Articles

전북지역 과수원의 토양특성이 미생물 분포에 미치는 영향

This study was conducted to investigate impacts of soil properties on microbial distribution in Jeonbuk orchard fields. Soil samples were collected from 110 sites cultivated with different fruit plants. The population of aerobic bacteria and fungi and the content of soil microbial biomass carbon (C) were found to increase with increasing silt content in the soils. Different activity of dehydrogenase was not observed among the different textures of soil. Microbial distribution, amount of microbial biomass C, and dehydrogenase activity in the soils were not significantly different among the topographic sites. However, in pear and grape fruit plant fields, coliform group of bacteria was found in relatively higher population, 133.0x10 3 CFU g -1 and 107.4x10 3 CFU g -1 , respectively. Microbial groups were simplified and their density was reduced with increasing the cultivation periods of fruit plants. The soil microbial distribution was proportionally correlated with some of soil properties such as soil pH, soil organic matter (SOM) content, and exchangeable Mg content; in particular, the population of Bacillus sp. was proportionally correlated with soil pH and exchangeable Mg content. The amounts of microbial biomass C and the dehydrogenase activity in the soils were significantly correlated with the contents of SOM and exchangeable Ca ion (p<0.01).

Effects of ultraviolet light and ultrasound on microbial quality and aroma‐active components of milk

Heat treatment is the most common way to extend the shelf life of milk. However, alternative technologies such as ultraviolet (UV) light and ultrasound (US), which are non-thermal methods for processing milk, have been developed to replace heat treatment. These technologies do not have any adverse effects on the quality of milk. The major purpose of this study was to investigate the effects of UV and US on different micro-organism groups and aroma compounds in milk. Heat pasteurisation at 65 °C for 30 min was used as thermal control treatment. The growth of total coliform group bacteria, Escherichia coli and Staphylococcus spp. was completely reduced by UV treatment. Application of US was not sufficient to reduce the numbers of yeasts and moulds. In neutral/basic fractions, 3-methylthiophene (plastic), hexanal (grass) and 1-hexen-3-one (floral) were major volatiles in milk samples. UV had a major effect on total coliforms, E. coli and Staphylococcus spp., but US was not as effective as UV and heat treatment in reducing certain groups of micro-organisms. No major differences were observed in terms of aroma-active compounds and flavour of milk following the different treatments. However, some new volatiles and change in rheological properties were generated by UV and US treatments.

Assesment of some microbiological and chemical properties of pismaniye sweet

The objective of this research was to determine some microbiological and chemical properties of pismaniye sweet. A total of 47 plain and with cacao pismaniye samples were purchased from retail markets in the Marmara region, Turkey. Mean moisture, ash, fat and total sugar contents were found as 3.16 to 3.31, 0.18 to 0.23, 11.67 to 11.87 and 37.10 to 35.72%, for plain and with cacao, respectively. The microbial counts were in the range of 3.05 to 3.12 log cfu g -1 for total mesophilic aerobic bacteria (TMAB). 2.19 to 2.51 log cfu g -1 for yeast and mould, 0.17 to 0.59 log cfu g -1 for total Coliform group bacteria. It was observed that 51.06% of samples were contaminated by Staphylococcus types, 42.55% by Salmonella-Shigella and 10.64% by Escherichia coli. The microbiological findings showed the presence of high counts of microorganisms depending on poor sanitary practices due to empiric traditional manufacturing procedures.

채소 및 주방기구에 대한 강산성전해수의 살균효과

The properties and bactericidal activities of strongly acidic electrolyzed water (SEW) against food-borne pathogenic bacteria, vegetables and kitchen apparatuses were investigated. The available chlorine concentration, pH and oxidation reduction potential (ORP) of SEW were 35±1.2 ppm, 2.3±0.2, and 1,140±20.4 ㎷, respectively. Five strains of food-borne bacteria with initial cell number of 7.00 ? CFU/㎖ were not detected except Bacillus cereus after treatment with SEW for 60 sec. The numbers of Bacillus cereus were reduced to 2.08±1.00 ? CFU/㎖ at the same condition. In vegetables, SEW treatment after washing strongly in alkalic electrolyzed water (AEW) showed better bactericidal effects than SEW only. The viable cell on stainless steel bowl (3.86±2.49 ? CFU/100 ㎠) and cup for water (2.40±1.80 ? CFU/100 ㎠) were not detected by SEW treatment (35 ppm of available chlorine concentration) for 30 sec, but survival of more than 1.00 ? CFU/100 ㎠ of viable cell was shown by washing of sodium hypochlorite solution at the same condition. On the other hand, the coliform group bacteria (5.08±4.00 CFU/100 ㎠) were detected on rubber globe only, and more than 2.00 ? CFU/100 ㎠ of viable cell and coliform group bacteria on it survived, though it was washed with flowing SEW for 30 sec.

Determination of microbiological characteristics of Turkish Karin Kaymagi cheeses packaged in different materials

The aim of this study is to transport to dairy plants the making technique of Karin Kaymagi cheese and to make them hygienic cheese. Also, the effects of different packaging materials (artificial case, barrel and tripe) on microorganism counts in the cheese samples were determined. In this research, four different Karin Kaymagi cheese samples were prepared from white cheese, civil cheese, whey cheese, pasteurized cream and concentrated yoghurt mixes. These mixes were put in three different packaging materials (artificial case, barrel and tripe) and ripened at 12°C for 2, 15, 30 and 60 days. The means of total aerobic mesophilic (TAMB), lactic acid (LAB), coliforms, proteolytic, lipolytic, psychrotrophic, spore forming bacteria and yeast-moulds in the cheese samples were determined as 7.08, 6.11, 1.18, 5.13, 4.82, 5.30, 1.30 and 4.83 log cfu/g, respectively. As the LAB counts and the yeast-mould counts of samples increased, the coliform group bacteria counts decreased during ripening periods. The yeast-moulds counts of cheese samples packaged in barrel were lower than that of tripe and artificial case. Key words: Karin Kaymagi cheese, microbiological characteristics, packaging materials.

ASSESSMENT OF JAJROOD RIVER WATERSHED MICROBIAL POLLUTION: SOURCES AND FATES

The Jajrood River watershed is one of the main drinking water resources of Tehran, the capital city of Iran. In addition it provides many recreational usages. However, a variety of microbial pollutions is commonly perceived in the Jajrood River, among them a high concentration of coliform group bacteria that has caused strong concerns. In this article, different aspects of microbial pollution as well as the main microbial pollution sources in the region are discussed. Coliform group bacterial die-off rates have been evaluated as the key parameters that govern bacterial fate in the watershed and were estimated using both laboratory and field data investigations. The high values of the bacterial die-off rates cause significant reduction in the bacteria population naturally. According to the first order decay equation, around 74% of the microbial pollution from domestic wastewater of the 3 main cities in the study area would be attenuated naturally before arrivals to the watershed outlet. In addition, around 98.1% of the microbial population of the animal excretion in the surface area would be decayed naturally. By investigating both sources and fates in the Jajrood River watershed, our knowledge about coliform group bacteria dynamics in this watershed would be enhanced. Therefore, microbial pollution can be managed in a sustainable way by evaluation and use of natural capacity of bacteria die-off in the environment. The derived values for bacterial die-off rates can be a useful reference in microbial studies and modeling attempts.

Provável surto de toxinfecção alimentar em funcionários de uma empresa no litoral da região sudeste do Brasil

This paper reports a presumptive outbreak of food-borne disease occurred in September 2009 to 10 employees working for a company in Guaruja, Sao Paulo, Brazil. The food-supplying company was requested to send the suspected food, fruit juice and water samples in order to be investigated at Instituto Adolfo Lutz – Regional Laboratory of Santos. The collected foods samples were analyzed by means of conventional methods, following the Compendium of Methods for Microbiological Examination of Foods (2001) and the guidelines of the Standard Methods (2005). The results were analyzed according to the Brazilian Ministry of Health legislation ANVISA RDC 12/2001 and Decree 518/2004. The coliform group bacteria were isolated from the water samples, and fecal coliforms were isolated from lettuce and cheese salad served at the firm restaurant (N.M.P. 1,1x103/g). No coagulase-positive Staphylococcus, Bacillus cereus, Salmonella spp. and sulfite reductor Clostridium were detected. By associating the results based on laboratory findings to the gastroenteritis symptoms in employees, there may be presumed that an outbreak of food-borne disease has occurred. The municipal health surveillance service has not been notified by the food company, which is mandatory according to the legislation in effect. The present report evidences the remarkable task performed by a Public Health laboratory elucidating an outbreak of food-borne diseases.

Assessment of Groundwater and Surface Water Pollution at Mitm Area, Ibb City, Yemen

Groundwater and surface water samples were collected from Mitm area to study the possible impact of wastewater treatment percolation into the groundwater and surface water. The objective of the study is to assess the groundwater and surface water pollution due to wastewater treatment at Mitm area of Ibb city, in the Republic of Yemen. The concentrations of various physiochemical parameters include heavy metals (Pb, Zn, Ni, Cr, Cd, Cu) pH, temperature, Electrical Conductivity (EC), Total Dissolved Solids (TDS), and Dissolved Oxygen (DO), anions and nutrients (F-, Cl-, SO4-2, NO2, NO3-,NH3-N), major cations (Fe, Na, K, Ca, Mg) and parameters (COD, BOD5, and coliform group bacteria) were measured from the groundwater samples. The results show that three out of five boreholes are contaminated, where the concentration of physic-chemical parameters are above the standard acceptable levels which required for drinking water adapted by Yemen's Ministry of Water and Environment (YMWE, 1999). On the other hand, surface water is affected by the discharge of untreated wastewater. The concentrations of physiochemical parameters are above the standard acceptable levels which required for irrigation purpose adopted by Yemen's Ministry of Water and Environment (YMWE, 1999). Boreholes 1 and 2 are suitable for drinking water, whereas boreholes 3, 4 and 5 are not suitable for drinking water. Therefore, urgency for wastewater treatment at this site is recommended to prevent further contamination to surface and groundwater.

The Characteristics of Leachate and Groundwater Pollution at Municipal Solid Waste Landfill of Ibb City, Yemen

Problem statement: Yemen one of the developing country suffering from water pollution. Landfill is one of the source of water pollution. There are several boreholes located close to Ibb landfill used for drinking water. A study of composition of landfill leachate and groundwater pollution was conducted at Ibb landfill, which is located at Al-Sahool area, north of Ibb City, Yemen. Approach: The leachate was sampled at three different locations of the landfill, at the landfill itself and 15 and 20 m downstream of this landfill. Groundwater samples collected from 5 boreholes to study possible impact of leachate percolation into groundwater. Leachate and groundwater samples were collected during dry season only, due to the excessive generation of leachate during this season. Objective of this study was significant to assess degree of groundwater pollution due to Ibb landfill leachate at Al-Sahool area. The leachate and groundwater were physically and chemically characterized by using spectrophotometer HACH, BOD Trak HACH, flame photometer (PFP 7) and Inductively Coupled Plasma of Optical Emission Spectrometry (ICP-OES) model Vista MPX. Parameters measured were pH, temperature, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Dissolved Oxygen (DO), Fluoride (F), Chloride (Cl), Sulphate (SO4), Nitrites (NO2), Nitrates (NO3), ammonia-N (NH3-N), heavy metals (Pb, Zn, Ni, Cr, Cd, Cu), major cations (Na, Mg, Ca, K, Fe) and biological parameters (COD, BOD5 and coliform group bacteria). Results: The results showed that, leachate at landfill most likely in methanogenic phase, based on the alkaline pH value recorded (pH = 8.46). The results also showed that 4 out of 5 boreholes were contaminated, where concentration of physico-chemical parameters are above the standard acceptable levels which required for drinking water adapted by Yemen's ministry of water and environment and by word standard. Conclusion: Therefore, landfill is dangerous for environment so government should do sanitary landfill to prevent further contamination to surface water, groundwater as well as soil.

Risk Analysis and Effective Factors of Pathogens on the Hands of Kindergarten Students in Istanbul - Turkey

Summary Persons are the primary performers for all food security systems and public health procedures, but humans do not have a standard configuration. The personal variables like age, gender, economic positions, psychological conditions, educations given by the family, life style and environment are the factors that determine main personal differences of humans. This situation can cause implementation differences for standard procedures as food security performances, educations related with food hygiene. Especially individual hygiene procedures must be taught to students are being educated in preschool programs very effectively and in entertaining ways. In this study, we aim to determine how the personal variables (age, gender, social and economic positions, hand washing habits etc) effect the microbiological load of the students’ hands according to the chosen microbiological parameters statsitically (plate count, total coliform group bacteria, Escherichia coli, Staphylococcus aureus, Salmonella spp.) who are registered preschool education (kindergarten) programs of different schools in Istanbul. For this purpose, 10 preschool education programs (kindergartens) were visited during 3 months (visits were monthly). From each school 20 students were sampled. The samples were analyzed for the chosen microbiological parameters and the correlations were determined among the microbiological parameters and the individual variables of the students.

Microbiota of radish plants, cultivated in closed and open ecological systems

It is common knowledge that microorganisms respond to environmental changes faster than other representatives of the living world. The major aim of this work was to examine and analyze the characteristics of the microbiota of radish culture, cultivated in the closed ecological system of human life-support Bios-3 and in an open system in different experiments. Microbial community of near-root, root zone and phyllosphere of radish were studied at the phases of seedlings, root formation, technical ripeness—by washing-off method—like microbiota of the substrate (expanded clay aggregate) and of the seeds of radish culture. Inoculation on appropriate media was made to count total quantity of anaerobic and aerobic bacteria, bacteria of coliform group, spore-forming, Proteus group, fluorescent, phytopathogenic bacteria, growing on Fermi medium, yeasts, microscopic fungi, Actinomyces. It was revealed that formation of the microbiota of radish plants depends on the age, plant cultivation technology and the specific conditions of the closed system. Composition of microbial conveyor-cultivated in phytotrons varied in quality and in quantity with plant growth phases—in the same manner as cultivation of even-aged soil and hydroponics monocultures which was determined by different qualitative and quantitative composition of root emissions in the course of plant vegetation. The higher plant component formed its own microbial complex different from that formed prior to closure. The microbial complex of vegetable polyculture is more diverse and stable than the monoculture of radish. We registered the changes in the species composition and microorganism quantity during plant cultivation in the closed system on a long-used solution. It was demonstrated that during the short-term (7 days) use of the nutrient solution in the experiments without system closing, the species composition of the microbiota of radish plants was more diverse in a multiple-aged vegetable polyculture (61 species of bacteria), than in an even-aged monoculture (32 species). Long-term use (120 days) of the solution for cultivation of multiple-aged vegetable polyculture from different radish parts in the experiment without system closing revealed 50 species, while in the experiment with the closed ecosystem only 39 species of bacteria were detected. It was found out that plant cultivation in a polyculture consisting of nine vegetable cultures is more preferable than in a monoculture, because the microbial complex is more stable, the functioning of elements is more accurate and the crop is higher.

Peracetic Acid Disinfection: A Feasible Alternative to Wastewater Chlorination

The paper summarizes the results of a bench-scale study to evaluate the feasibility of using peracetic acid (PAA) as a substitute for sodium hypochlorite both for discharge into surface water and for agricultural reuse. Trials were carried out with increasing doses (1, 2, 3, 5, 10, and 15 mg/L) and contact times (6, 12, 18, 36, 42, and 54 minutes) to study disinfectant decay and bacterial removal and regrowth, using fecal coliform and Escherichia coli (E. coli) as process efficiency indicators. Peracetic acid decay kinetics was evaluated in tap water and wastewater; in both cases, PAA decays according to first-order kinetics with respect to time, and a correlation was found between PAA oxidative initial consumption and wastewater characteristics. The PAA disinfection efficiency was correlated with operating parameters (active concentration and contact time), testing different kinetic models. Two data groups displaying a different behavior on the basis of initial active concentration ranges (1 to 2 mg/L and 5 to 15 mg/L, respectively) can be outlined. Both groups had a "tailing-off" inactivation curve with respect to time, but the second one showed a greater inactivation rate. Moreover, the effect of contact time was greater at the lower doses. Hom's model, used separately for the two data groups, was found to best fit experimental data, and the disinfectant active concentration appears to be the main factor affecting log-survival ratios. Moreover, the S-model better explains the initial resistance of E. coli, especially at low active concentrations (< 2 mg/L) and short contact times (< 12 minutes). Microbial counts, performed by both traditional methods and flow cytometry, immediately and 5 hours after sample collection (both with or without residual PAA inactivation), showed that no appreciable regrowth took place after 5 hours, neither for coliform group bacteria, nor for total heterotrophic bacteria.

Secondary Effluent Disinfection: PAA Long Term Efficiency

The paper summarizes the results of a bench-scale study to evaluate the long-term disinfection efficiency of peracetic acid (PAA). Bacterial counts were repeated 5, 24, and 29 h after the end of the disinfection test, to simulate real re-growth conditions (no residual quenching) and, for the 5 h interval, the potential re-growth (quenching of residual PAA). Fecal coliforms, Escherichia coli, and total heterotrophic bacteria (THB) were enumerated by traditional plate count technique; THB were also enumerated by cytometry. After disinfection, the residual PAA concentration became negligible in about 5 to 11 h, depending on the tested doses. Microbial counts showed that no appreciable re-growth took place after 29 h for coliform group bacteria. For THB, the previously cited enumeration techniques gave different results in re-growth tests, especially for the lowest PAA doses. Indeed plate count technique evaluates the ability to form colonies, while cytometry enumerates intact membrane cells. No regrowth took place, even when no residual disinfectant was present, suggesting that bacteria are unable, even at the lowest doses, to repair damage caused by the PAA disinfecting action. PAA was found to be an efficient disinfecting agent, not only as a bacteriostatic, but also as a bactericide.

Prevalence of aerobic and anaerobic uterine bacteria during peripartum period in normal and dystocia-affected buffaloes

Parturition complications predispose establishment of uterine infections, which in turn affect subsequent fertility. The aim of present study was to characterize and compare the type of bacterial flora prevalent within the uterine lumen of dystocia-affected buffaloes and compare them with the normally calving buffaloes. The study was conducted on 40 buffaloes; of which 10 calved normally (Group I) and 30 were treated for dystocia (Group II). Bacteriological examination was performed using uterine swabs, which were collected before delivery, immediately after delivery and day's 24–60 postpartum. A total of 30 uterine swabs from Group I and 79 swabs from Group II were collected, of which 19 (63.3%) and 71 (89.9%) yielded significant bacterial growth, respectively. A total of 205 isolates belonging to 10 different genera of bacteria were identified, 8 facultative anaerobes and 2 obligate anaerobes. In Group II, 91.6% of the bacteria positive swabs ( n = 71) yielded mixed cultures, whereas the remainder being pure cultures. In contrast, 89.5% of the bacteria positive swabs of Group I ( n = 19) yielded pure cultures. Mixed infections comprised mostly Arcanobacter (Actinomyces) pyogenes together with obligate anaerobes, Fusobacterium spp. and Bacteroides spp. In Group II, the frequency of incidental and coliform group bacteria was highest at the time of parturition, i.e., before and immediately after delivery, and decreased to nil during the 24–60-day postpartum period. However, in Group I, the incidental and coliform group of bacteria present at the time of parturition apparently persisted beyond the period when uterine involution is complete. The frequency of obligate anaerobes and A. pyogenes at the time of parturition was nil in the Group I while they predominated in dystocia-affected buffaloes (Group II). During the postpartum period of 24–60 days, the frequency of both obligate anaerobes and A. pyogenes increased significantly in Group II, whereas in Group I, only occasional isolates were obtained. To conclude, at the time of calving the prevalence of obligate anaerobes and A. pyogenes occurring in combination was highest in dystocia-affected buffaloes, and further increased in the postpartum period suggesting that these infections act synergistically.

Secondary effluent disinfection by peracetic acid (PAA): microrganism inactivation and regrowth, preliminary results

The paper summarises - in terms of bacterial removal and re-growth - the results of a pilot scale study performed on a continuous flow pilot plant, using peracetic acid (PAA) as disinfecting agent. Trials were carried out with increasing doses and contact times (6, 12, 18, 36, 42, 54 min). The paper reports data deriving from the only doses (15 and 25 mg L-1) which were able to ensure the respect of the limits for agricultural re-use, according to Italian law. Disinfection efficiency was comparable for E. coli, TC and FC, and lower for total heterotrophic bacteria (THB), and clearly grew with increasing Cát values. The effect of contact time was greater at the lower doses. Microbial counts, performed by both traditional methods and flow cytometry, immediately and 6 hours after the sample collection (PAA was previously inactivated by sodium thiosulphate and bovine catalase), showed that no appreciable re-growth took place after 6 hours for coliform group bacteria. THB formed a slightly lower number of colonies immediately after collection than after 6 hours. The slight variations observed after 6 hours were the result of the recovered ability of forming colonies and of the lysis of some of the residual bacteria, as it was shown by flow cytometry.

A pilot solar water disinfecting system: performance analysis and testing

In most countries, contaminated water is the major cause of most water-borne diseases. Disinfection of water may be accomplished by a number of different physical–chemical treatments including direct application of thermal energy, chemical and filtration techniques. Solar energy also can be used effectively in this field because inactivation of microorganisms is done either by heating water to a disinfecting temperature or by exposing to ultraviolet solar radiation. A pilot solar system for disinfecting contaminated water is designed, constructed and tested. Investigations are carried out to evaluate the performance of a wooden hot box solar facility as a solar disinfectant. Experimental data show that solar energy is viable for the disinfection process. A solar radiation model is presented and compared with the experimental data. A mathematical model of the solar disinfectant is also presented. The governing equations are solved numerically via the fourth-order Runge–Kutta method. The effects of environmental conditions (ambient temperature, wind speed, solar radiation, etc.) on the performance of the solar disinfectant are examined. Results showed that the system is affected by ambient temperature, wind speed, ultraviolet solar radiation intensity, the turbidity of the water, the quantity of water exposed, the contact area between the transparent water container in the solar disinfectant and the absorber plate as well as the geometrical parameters of the system. It is pointed out that for partially cloudy conditions with a low ambient temperature and high wind speeds, the thermal efficiency of the solar disinfectant is at a minimum. The use of solar energy for the disinfection process will increase the productivity of the system while completely eliminating the coliform group bacteria at the same time.

Solar thermal desalination system with heat recovery

This work presents the energy and mass balance equations, the numerical simulation results for the production rate, and the experimental laboratory water tests for a thermal desalination unit with a heat recovery system. The system components are a solar collector and a desalination tower, although the system can be operated with other energy sources. The desalination tower is made of six stages and a water circulation system through the stages to avoid salt concentration. The numerical results calculated using ambient data show that the production rate can reach 25 L/m 2/d, which is by a factor of five times greater than the rate of a basin-type solar desalination unit. The water (polluted seawater and well water) laboratory tests results show that the desalination process eliminated the Coliform group bacteria and reduced the salt concentration to very low levels.

VARIAÇÃO DA CONCENTRAÇÃO DE BACTÉRIAS INDICADORAS DE CONTAMINAÇÃO FECAL NAS DIVERSAS FASES DO PROCESSO DE TRATAMENTO DE ÁGUA DE ABASTECIMENTO PÚBLICO DA CIDADE DE ARARAQUARA - SÃO PAULO

O abastecimento de água de qualidade e em quantidade suficiente é de fundamental importância para a saúde da população. A potabilidade bacteriológica é determinada principalmente pela verificação da presença de bactérias do grupo coliforme (totais e fecais) indicadoras de poluição fecal, maior responsável pela transmissão de doenças infecciosas à população. O objetivo desta pesquisa foi verificar a eficácia dos processos de tratamento executados nas Estações de Tratamento de Água (ETA) de Araraquara, determinando as concentrações de bactérias coliformes totais e fecais, em&#x0D; cada etapa do processo de tratamento: água bruta, após floculação/decantação, filtração e cloração - relacionadas com a turbidez, avaliando se a água produzida está de acordo com os padrões do Ministério da Saúde e do Estado de São Paulo. O número mais provável (NMP/100mL) de bactérias coliformes totais e coliformes fecais foi determinado pela técnica das fermentações em tubos múltiplos, provas presuntiva e confirmatória. As análises foram realizadas mensalmente por um período de doze meses. Em todas as&#x0D; colheitas verificou-se que a água bruta apresentou grande quantidade de coliformes (NMP/100mL), daí a necessidade de tratamento e a importância fundamental que a fase de desinfecção tem para que a água chegue a população dentro dos padrões de qualidade. Concluíu-se que após a cloração ocorreu redução no número (NMP/100mL) de bactérias&#x0D; coliformes totais e fecais paralela à redução de turbidez e que a água produzida pelas ETAs atende aos padrões determinados pelo Ministério da Saúde e do Estado de São&#x0D; Paulo.

Possible impact of treated wastewater discharge on incidence of antibiotic resistant bacteria in river water

Escherichia coli and coliform group bacteria resistant to seven antibiotics were investigated in the Tama River, a typical urbanized river in Tokyo, Japan, and at a wastewater treatment plant located on the river. The percentages of antibiotic resistance in the wastewater effluent were, in most cases, higher than the percentages in the river water, which were observed increasing downstream. Since the possible increase in the percentages in the river was associated with treated wastewater discharges, it was concluded that the river, which is contaminated by treated wastewater with many kinds of pollutants, is also contaminated with antibiotic resistant coliform group bacteria and E. coli. The percentages of resistant bacteria in the wastewater treatment plant were mostly observed decreasing during the treatment process. It was also demonstrated that the percentages of resistance in raw sewage are significantly higher than those in the river water and that the wastewater treatment process investigated in this study works against most of resistant bacteria in sewage.

Chemical and bacteriological monitoring of drinking water from an urbanised water catchment drainage basin

The Linggi river drainage basin in Negeri Sembilan, Malaysia supplies water to the whole of Port Dickson district and meets 50% of the Seremban district needs. The Linggi River, the main tributary, passes through the highly urbanised and densely populated Seremban district while the water treatment plant is located 16 km downstream. In 1979 the USEPA declared the river unsuitable as a source of raw water whereas the WHO classified it as being heavily polluted requiring more extensive and effective treatment. In order to meet the WHO drinking water standards, an ozonation system was installed in the conventional water treatment plant. The objective of ozonation is for the control and removal of organic micropollutants and other deleterious matters. This study investigated the concentrations and distribution of organic micropollutants, heavy metals, and bacteriological counts in water samples collected from within the catchment and the treated water. The effectiveness of the ozonation system was also studied. The total level of phenolic water pollutants in the catchment was generally found to be very much higher than the maximum recommended level of 2.0 µgl-1. The extensive treatment process carried out at the plant was very effective in reducing the levels of total phenols in the treated water to less than 1.0 µgl-1. However the process was not efficient enough to reduce the levels of some heavy metals as required by the standards, for examples Cd and Pb were still three times higher than the standards of 5µgl-1 and 0.05 mgl-1 respectively. For bacteriological study, coliform group of bacteria, Salmonella, faecal streptococci and injured coliform were monitored in the raw and treated water. The raw water contained coliforms about 1000 times higher than the required standard for raw ater, but after the secondary treatment by ozonation coliform bacteria were absent, however a small number of Salmonella was still present occasionally. The study also showed that restructuring of the district and relocating of some commercial activities along the river banks to other areas carried out over the last five years has improved the general quality of the river water.