Number Of Fecal Coliforms Research Articles

Quality and Possibilities of Use of Stabilized Sludge Compost Obtained by Inoculation with Geocell‐1 Consortium

AbstractAnaerobically stabilized sludge from wastewater treatment is always a challenge from the environmental aspect of management. The agrarian environmental surroundings present a possibility for swift and efficient utilization of compost from anaerobically stabilized sludge in order to increase the quality of the biological product. With intensification of the composting procedure by means of the microbiological consortium Geocell‐1 (Cellvibrio sp., Pseudomonas fluorescens with the addition of micro‐ and macro‐elements), the results show that the compost obtained from stabilized sludge after inoculation is significantly improved in terms of moisture reduction (39–43%), while in the control compost, this value is significantly higher with 61%. The results of the pathogenic effect show a significant reduction in the number of fecal coliform (<1 × 103) and Enterococcus bacteria (<1 × 104) in the inoculated (treated) compost. With a slight decrease in the concentration of limiting factors such as As, Cd, Cu, a quality biological product can be achieved, which can be safely deposited on soil. The phytotoxicological germination test with white mustard (Sinapis alba) shows a higher number of sprouting plants with a mixture of treated compost and standard soil for flowers 1:1 and 1:4 compared to the control group.

Water Quality Assessment of Ghezelozan River in Zanjan Province Using NSFWQI, IRWQI and Liou

Background: Unsustainable development of agriculture and aquaculture has reduced the water quality of rivers. The most important aim of this study is assessing of water quality in the Ghezel Özan basin in Zanjan province. Method: 18 sites were selected based on standard criteria including land use, geology, biodiversity points, accessibility and standard distributions. Content of Dissolved Oxygen, Temperature, Turbidity and Electrical Conductivity were measured in-situ while number of Fecal Coliform, amount of BOD, COD, Phosphate, Nitrate, Nitrite, Ammonia, Sulfate and Chlorine were measured at laboratory. Results: One-sample T.test showed a significant difference between the Coliform and its standard. Results have illustrated the remarkable impacts of agricultural and aquaculture activities on the river health. Also, among all quality parameters, Nitrate and Fecal Coliform show a significant difference in two regions, Tarom and Mahneshan. There is the best water quality in site 7 (upstream site) located far from human access. IRWQI index (Iranian water quality index for surface water) shows the best results because of more overlap with land-uses and the trend of variables. Conclusion: Olive cultivation and unsustainable aquaculture development in Tarom and Mahneshan, respectively, are main reasons for decreasing of water quality. So, integrated water resources management, training local people, assessing environmental impacts and determining the ecological potential are highly recommended to improve the water quality of the studied river.

Elucidation of the microbial diversity in rivers in south-west Victoria, Australia impacted by rural agricultural contamination (dairy farming)

We assessed the water quality of south-west Victorian rivers impacted by the dairy industry using traditional water quality assessment together with culture-dependent (colilert/enterolert) and also culture-independent (next generation sequencing) microbial methods. The aim of the study was to identify relationships/associations between dairy farming intensity and water contamination. Water samples with high total and faecal coliforms (>1000 MPN cfu/100 ml), and with high nitrogen levels (TN) were observed in zones with a high proportion of dairy farming. Members of the genus Nitrospira, Rhodobacter and Rhodoplanes were predominant in such high cattle density zones. Samples from sites in zones with lower dairy farming activities registered faecal coliform numbers within the permissible limits (<1000 MPN cfu/100 ml) and showed the presence of a wide variety of microorganisms. However, no bacterial pathogens were found in the river waters regardless of the proportion of cattle. The data suggests that using the spatially weighted proportion of land used for dairy farming is a useful way to target at-risk sub-catchments across south west Victoria; further work is required to confirm that this approach is applicable in other regions.

Composting of sewage sludge with mole cricket: stability, maturity and sanitation aspects

The composting of sewage sludge is constrained by structural insufficiencies such as high water retention, reduced free air space and limited compaction. To overcome these hindrances, this study investigates application of bioconversion method to compost sewage sludge. The bioconversion method uses insect mole cricket that provides benefits such as improved aeration by 32%, enhanced organic matter transformation, stability and maturity of the end product. Bioconversion method was compared with vermicomposting and conventional aerated composting methods. Comparison of the results among the three methods showed that the end product was mature with germination index (GI) > 80%, humification index (E4/E6) < 8, dissolved organic carbon < 10 mg kg−1 and C/N < 15. However, the end product of the bioconversion method had the highest GI of 140, cation exchange capacity of 91.7 and the lowest C/N ratio of 14 indicating that this compost was relatively more stable than the composts produced by the other two methods. The number of faecal coliforms in mature compost samples was 210, 230 and 750 CFU g−1 for the bioconversion, vermicomposting and conventional composting methods, respectively. The results highlight that bioconversion method produces a non-phytotoxic and microbiologically safe compost that can be considered as a reliable alternative for composting of sewage sludge.

Assessment of Microbial Quality of Vegetables Irrigated with Polluted Waters in Dar es Salaam City, Tanzania

This study was undertaken to assess microbial quality of fresh vegetables irrigated with polluted waters from Msimbazi River in Dar es Salaam City. Samples of river water were taken from seven sampling stations along Msimbazi River stretching 20.4 km from Pugu to Jangwani and its tributary (Ubungo River) at Mabibo. Vegetable samples of 5 different species were taken from two different vegetable gardens in different locations along Msimbazi river valley and its tributary (Ubungo river), and from six markets including one super market. The examination of samples was carried out in accordance with the standard methods. Results revealed that water from the Msimbazi River contains high concentration of salts and pathogenic organisms. Fecal coliforms were found in all river water samples with a maximum count of 2.1x106 cfu/100ml. Pollution of the river was increasing downstream and varies seasonally with wet season having poorer water quality than dry season. Vegetables from all the markets including super market were highly contaminated with fecal coliforms of up to 108 Cfu/kg-wet vegetables. Pathogenic organisms were detected on vegetables and all river water samples examined had Ascaris Lumbricoides except for the sample collected at Pugu station. Fresh vegetables were contaminated with pathogenic organisms such as Escherichia coli, Citrobacter ssp, Proteus ssp, Klebsiella ssp, Salmonella spp and Basillus spp. Vegetable samples collected from the markets were more contaminated than those collected from the gardens. High number of fecal coliforms in the markets was due to poor handling of these vegetable by contaminated hands and sprinkling of vegetables with polluted water to keep vegetables moist. It was concluded that water used for irrigating vegetables along river Msimbazi was highly polluted and vegetables from gardens and markets are not safe for consumption.

Avaliação de indicadores higiênico-sanitários em leite in natura comercializado em Caruaru, Brasil

Esse estudo objetivou avaliar o leite in natura comercializado em Caruaru, localizada no Nordeste do Brasil, através de ensaios físico-químicos e bacteriológicos. Os testes físico-químicos foram baseados e interpretados de acordo com a Instrução Normativa 69/2006 e a comparação dos resultados foram realizadas de acordo com a Instrução Normativa 62/2011 do Ministério da Agricultura, Pecuária e Abastecimento. A investigação bacteriológica incluiu a pesquisa e estimativa do número mais provável de coliformes totais e fecais, Pseudomonas aeruginosa, e contagem de Staphylococcus aureus. A presença de sangue foi evidenciada em 6,7% das amostras e 70% apresentaram positividade para a presença de exsudato inflamatório. A presença de coliformes totais foi reportada em todas as amostras e 96,6% apresentaram positividade para coliformes fecais. Um total de 70% das amostras apresentou-se inapropriado para o processo de pasteurização e todas foram positivas para a presença de S. aureus, cuja contagem variou de 7 x 103 a 1,8 x 106 UFC/ml. As amostras analisadas foram também positivas para P. aeruginosa, das quais 90% destas apresentaram NMP/100ml&gt;110. O leite in natura comercializado em Caruaru possui baixa qualidade sanitária e apresenta-se inapropriado para consumo humano. A facilidade de aquisição do produto demonstra a necessidade de maior vigilância pelas agências específicas.

Locally produced lactic acid bacteria for pathogen inactivation and odor control in fecal sludge.

Providing safe fecal sludge (FS) sanitation has remained an important goal of global communities because of the high risks imposed on human health of the exposure to un-sanitized FS. This study used lactic acid fermentation as a pre-treatment technology to evaluate the sanitization effect of lactic acid bacteria (LAB) on FS. A combination of fermented rice flour and brown sugar was used as the medium to prepare LAB, and fecal coliforms were used as the indicator organisms. The addition of a LAB suspension grown in fermented rice flour and brown sugar to FS was studied to evaluate the survival of fecal coliforms. The pH decreased during ongoing lactic acid fermentation after the addition of the LAB suspension. The results revealed that fecal coliforms in reactors containing 1:1 and 2:1 w/w of FS and LAB suspension decreased to half of the initial concentration within seven days of the treatment process in comparison with that of the control reactor. Viable plate counts of 0.6 × 108, 0.9 × 108, and 2.4 × 108 CFU/100 mL were recorded from reactors 1:1, 2:1, and the control, respectively. The total elimination of the fecal coliforms below the detection limit (<3 log 10 CFU/100 mL) was observed in both reactors after 15–17 days, whereas the number of fecal coliforms remained at 2.3 × 108 CFU/100 mL in the control reactor. The fecal coliforms were eliminated because of the acidification caused by the LAB during the incubation time. The final pH in the treatment reactors 1:1 and 2:1 was 3.7 and 3.9. While the final pH in the control reactor was 7.91. The results revealed that the bacterial pathogens in FS can be completely eliminated through a low-cost technique and a simple lactic acid fermentation process.

Antibacterial activity of the white lily Moringa oleifera seed extract and its use in water treatment

White lily Moringa oleifera seed powder acts as a natural coagulant promoting the reduction of water turbidity by the coagulation and sedimentation of the suspended particles, also eliminating the microorganisms by sedimentation. The aqueous extract of M. oleifera presented an inhibitory capacity for the growth of Staphylococcus aureus, whereas the hydroalcoholic extract inhibited S. aureus, Salmonella typhimurium and Vibrio cholerae, using the agar diffusion test. Standard strains of Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis were resistant to the extracts. The water treatment through the aqueous extract of M. oleifera seeds at 0.02% and 0.01% concentrations was evaluated with the water samples collected in the Sinibu River, Paraíba State, Brazil, using the jar test. The water samples analyzed in this work were characterized by low turbidity (2.8-3.0 NTU), and pH and alkalinity between 5.8-7.3 and 10-30 mg CaCO3/L, respectively. After water treatment with M. oleifera aqueous extract, it was observed that pH, turbidity and alkalinity did not change significantly. Total heterotrophic bacteria counts in the crude water samples were between 1.9 x 10^5 UFC/100 mL and 1.1 x 10^6 CFU/100 mL, while the number of fecal coliforms was between 2.3 x 10^2 NMP/100 mL and 2.4 x 10^3 NMP/100 mL. The counts of total bacteria and fecal coliforms in the water samples treated with aqueous white lily extract at both concentrations tested (0.02% and 0.01%) during the 1.5-hour period did not differ significantly when compared to the untreated water. The results obtained in this work indicate that low turbidity of water influenced the efficacy of M. oleifera extract in the removal of bacteria in the treated water, since the level of coagulation depends on water turbidity.

Microbial Quality of three Imported Fresh Locally Produced Marine Fishes in Al-Faw City, Basrah, Iraq

The present study was conducted to determine microbial quality have been measured in gills and gut tissues in three imported fishes samples obtained from trawl fishing boats in Al-Faw city, Basrah, Iraq. In this study, tissues samples were collected from 80 fish samples of three fresh marine fish species: silver pomfret Pampus argenteus (Euphrasen, 1788); Oriental Sole Brachirus orientalis (Bloch & Schneider, 1801) and Yellowfin seabream, Acanthopagrus latus (Houttuyn,. 1782) were collected from trawl fishing boats of Al-Faw city during period from January 2017 to April 2017. Samples of three marine fish’s species were examined for the fecal coliforms. Level of fecal coliforms was higher on tissues samples of Pampus argenteus were total number of fecal coliform identified were in 18 samples (22.50%) and in Brachirus orientalis fecal coliforms bacteria species were found in 11 samples (13.75%), while the lowest level of fecal coliforms was found in tissues samples of Acanthopagrus latus 4 (5%). To find out pathogenic bacteria culturing technique was used followed by staining for identification of bacterial species. In this study determination of coliforms especially Escherichia coli, Pseudomonas aeruginosa and Salmonella sp., three fecal coliforms Bacteria species were found (E. coli, P. aeruginosa, and Salmonella sp.) in tissues of three fish species samples in this study, E. coli was mostly present specie and it was identified in 16 tissues samples of P. argenteus (20.00%) followed by tissues samples of B. orientalis in 14 samples (17.50%), while were found in 10 tissues samples of A. latus (12.50%).

Determination of Drinking Water Quality: A Case Study on Saline Prone South-West Coastal Belt of Bangladesh

This research integrates quantitative data of underground and sub-surface sources of drinking water from two coastal union Gabura and Munshiganj of Shyamnagur upazila of Satkhira district. Four drinking water sources have been selected and sampled during dry season when the salinity rate is generally high. A total of 22 water samples have been collected of which 6 from protected pond, 6 from tube well, 6 from rainwater and 4 from pond sand filter (PSF). The average pH of tube well water, protected pond water, pond sand filter water and rain water were 6.59 (±.05), 6.46 (±1.03), 6.60 (±.52), 5.95 (±.87), respectively. The average EC (μs cm-1) range of tube well water, protected pond water, pond sand filter water and rain water were 2059.16 (±49.43), 1756 (±14), 769 (±94.27), 64.33(±59.91) while the TDS (ppm) range were 1319.97 (±31.69), 1125.64 (±913.46), 492.94 (±60.43) and 15.38 (±118.59) respectively. The maximum concentration of salinity was found in tube well water which was 1.37 (±53) ppt. Most of the protected ponds were highly contaminated with sulphate and it ranges from 84.64 to 218.25 ppm. The average number of fecal Coliform in protected ponds were 1650 100 m l-1 of water while in PSF source pond 2350 100ml-1 and collection point 1.5 100ml-1.J. Environ. Sci. &amp; Natural Resources, 10(1): 101-108 2017

Assessing the seawater quality of a coastal city using fecal indicators and environmental variables (eastern Aegean Sea)

The presence of fecal bacteria in seawater is one of the most important bio-indicator parameters of fecal pollution. In this study, the Bay of İzmir (in the eastern Aegean Sea), which is a critical area because of its relationship with marine transportation and industrial and commercial activities, was evaluated for its microbiological and physicochemical parameters through a monitoring program. The data were obtained from seasonally assembled surface seawater samples from 2015 to 2017 at 23 sampling stations. Bacteriological investigations were performed by membrane filtration technique. During the monitoring period, for stations at the inner and middle-outer part, it was found that the inner part is exposed to more number of fecal coliforms (8.8×102cfu/100mL) and fecal streptococci (1.1×103cfu/100mL). The monitoring analysis performed in this study showed that there was negative correlation between physicochemical parameters and the level of fecal bacteria, but no significance was recorded by the Pearson correlation test. Fecal contamination parameters should be routinely monitored for improving the environmental conditions of coastal cities.

Evaluation of Autothermal Thermophilic Aerobic Digester Performance for the Stabilization of Municipal Wastewater Sludge.

Sludge stabilization process in terms of operational, environmental and economic indexes is the most important stage of treatment and its disposal. This study was aimed to determine the performance of Autothermal Thermophilic Aerobic Digestion (ATAD) system as one of the low-cost and biocompatible methods of sludge treatment. This study has been done using a laboratory scale Autothermal Thermophilic Aerobic Digestion (ATAD). The reactor was consisted of two polyethylene tanks with a final capacity of 100 L for each tank. Both tanks with all fittings were installed on a metal frame. The variables of study were temperature, dissolved oxygen, pH, volatile organic compounds, total solids, COD and the number of Ascaris eggs and fecal coliforms per gram of dry matter of the sludge. The temperature was measured hourly and the pH and dissolved oxygen were measured and controlled twice per day. One-way ANNOVA was applied to analyze reasults. According to the results, the temperature of sludge increased from 11.7-61.2°C by biological reactions. Pathogen organisms were reduced from 80×106 to 503 in number during 72 h. After 6 days pathogen organisms and Ascaris eggs were removed completely. Volatile organic compounds and COD were reduced 42 and 38.3% respectively during the 6 days. It is concluded that the performance of ATAD in removing organic compounds from wastewater sludge were desirable. Resulted sludge from stabilization process were appropriate for use in agriculture as a soil supplement and met the indexes of class A sludge according to EPA's standards (CFR 40 Part 503).

Greenhouse Gas Emissions and Growth of Wheat Cultivated in Soil Amended with Digestate from Biogas Production

Digestate, the product obtained after anaerobic digestion of organic waste for biogas production, is rich in plant nutrients and might be used to fertilize crops. Wheat (Triticum spp. L.) was fertilized with digestate, urea, or left unfertilized and cultivated in the greenhouse for 120 d. Emissions of greenhouse gasses (carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)) were monitored and plant growth characteristics were determined at harvest. The digestate was characterized for heavy metals, pathogens, and C and N mineralization potential in an aerobic incubation experiment. No Salmonella spp., Shigella spp., or viable eggs of helminths were detected in the digested pig slurry, but the number of faecal coliforms was as high as 3.6 × 104 colony-forming units (CFU) g−1 dry digestate. The concentrations of heavy metals did not surpass the upper limits established by US Environmental Protection Agency (EPA). After 28 d, 17% of the organic C (436 g kg−1 dry digestate) and 8% of the organic N (6.92 g kg−1 dry digestate) were mineralized. Emissions of CO2 and CH4 were not significantly affected by fertilization in the wheat-cultivated soil, but digestate significantly increased the cumulative N2O emission by 5 times compared to the urea-amended soil and 63 times compared to the uncultivated unfertilized soil. It could be concluded that digestate was nutrient rich and low in heavy metals and pathogens, and did not affect emissions of CH4 and CO2 when applied to a soil cultivated with wheat, but increased emission of N2O.

Interaction between Thermotolerant Coliforms and Rhizobacteria in Soil Fertilized with Treated Domestic Wastewater

ABSTRACT Studies on the survival of pathogenic microorganisms in the soil after use of wastewater for fertilization of agricultural crops report the effects of moisture, pH, organic matter, and soil temperature on microorganisms. There are few studies that assess the survival of these microorganisms in the rhizosphere of plants fertilized with wastewater. Thus, the aim of this study was to quantify the number of fecal coliforms and rhizobacteria (fluorescent Pseudomonas spp., Bacillus spp,) in the rhizosphere of winter and summer [...]

QUALIDADE DA ÁGUA UTILIZADA NA LIMPEZA DOS TANQUES DE GRANELIZAÇÃO DE LEITE CRU: IMPLANTAÇÃO E AVALIAÇÃO DA CLORAÇÃO DA ÁGUA PARA GARANTIA DA QUALIDADE DO PRODUTO

A água, além de servir como bebida para os animais, é utilizada em atividades relacionadas à ordenha e armazenamento do leite. Assim, objetivou-se avaliar a influência da cloração da água utilizada em 18 propriedades localizadas na Zona da Mata do estado de Minas Gerais, sobre a contagem de células somáticas (CCS) e de bactérias totais (CBT) do leite cru. Amostras de água e de leite cru foram coletadas para análise, sendo as amostras de água coletadas das mangueiras utilizadas para lavagem dos tanques individuais e coletivos e as amostras de leite cru diretamente dos tanques de expansão. A cloração da água não influenciou seus parâmetros físico-químicos. Amostras cloradas de água apresentaram resultados positivos quanto à redução do Número Mais Provável de coliformes totais e termotolerantes, entretanto, não foi observada redução significativa (p &gt; 0,05) do número de bactérias heterotróficas. A composição do leite não foi alterada pela cloração da água e não houve redução significativa (p &gt; 0,05) das contagens de CCS e CBT devido à cloração. Portanto, mesmo a água utilizada na limpeza dos tanques não apresentando boa qualidade, estando em desconformidade com a legislação, esta não influenciou a qualidade do leite cru refrigerado, que apresenta muitas fontes de contaminação na região estudada.

Effect of aeration rate on elimination of coliforms during composting of vegetable–fruit wastes

In waters and wastes, direct pathogen detection is difficult and time consuming. Therefore, coliforms are used as indicators to measure the presence of pathogens. Composts originated from extrements, sewage sludges and plant wastes those contact with manures may have potential health hazard to human. Therefore, the detection of coliforms both during composting and in the obtained composts is used to investigate the presence of pathogens for determination of the potential health risk. In this study, the effect of six different aeration rates on elimination of total and faecal coliform bacteria was investigated during in-vessel aerobic composting of vegetable–fruit wastes. Total coliform and faecal coliform numbers in the samples were measured by the most probable number method. Coliforms significantly increased before the thermophilic stage except the faecal coliforms in the reactor which operated with the lowest aeration. The coliforms suddenly decreased after thermophilic stage in all reactors. Total coliforms reduced within the range of 78.2–99.9 % while faecal coliforms reduced within the range of 72.5–99.9 % after the thermophilic stage. At the end of the composting period (day 18), total coliforms and faecal coliforms reduced within the range of 99.9–100 %. Although all the aeration rates used in the present study were effective for the elimination of coliforms, the lowest faecal coliform number was seen in the reactor that had the lowest aeration rate. At the end of the study, the faecal coliform numbers in all reactors confirmed some limits for the application activities of composts.

The INCA-Pathogens model: An application to the Loimijoki River basin in Finland

Good hygienic quality of surface waters is essential for drinking water production, irrigation of crops and recreation. Predictions of how and when microbes are transported by rivers are needed to protect downstream water users. In this study we tested the new process-based INCA-Pathogens model in the agricultural Loimijoki River basin (3138km2) in Finland, and we quantified ecosystem services of water purification and water provisioning for drinking and recreation purposes under different scenarios. INCA is a catchment scale process based model to calculate pollutant transfer from terrestrial environment and point sources to the catchment outlet. A clear gradient was observed in the numbers of faecal coliforms along the River Loimijoki. The highest bacterial counts were detected in the middle part of the main stream immediately after small industries and municipal sewage treatment plants. In terms of model performance, the INCA-Pathogen model was able to produce faecal coliform counts and seasonality both in the low pollution level sampling points and in the high pollution level sampling points. The model was sensitive to the parameters defining light decay in river water and in soil compartment, as well as to the amount of faecal coliforms in the manure spread on the fields. The modeling results showed that the number of faecal coliforms repeatedly exceeded 1000 bacteria 100ml−1. Moreover, results lead to the following conclusions: 1) Climate change does not cause a major threat to hygienic water quality as higher precipitation increases runoff and causes diluting effect in the river, 2) Intensification of agriculture is not a threat as long as animal density remains relatively low and environmental legislation is followed, 3) More intensive agriculture without environmental legislation causes a threat especially in tributaries with high field percentage and animal density, and 4) Hygienic water quality in the River Loimijoki can best be improved by improving sewage treatment. We conclude that this catchment scale model is a useful tool for addressing catchment management and water treatment planning issues.

English

Some Salmonella spp. are important pathogenic bacteria that can be transmitted to people via food and water and that can cause disease characterized by mild to severe enteric and systemic illness. In developing countries, infections caused by pathogenic antibiotic resistant Salmonella spp. are a major health challenge, particularly in children. Through the use of membrane filtration and Environmental Protection Agency (EPA) 1200 methods, the presence of fecal coliforms and antibiotic resistant Salmonella spp. in surface water sources was investigated, some of which had shared access for animals and people. Out of 100 water samples, 76 were positive for fecal coliforms and 63% of the positive samples contained &gt;100 CFU / 100 ml of water. We observed a significant positive correlation between the number of fecal coliforms and the presence of Salmonella spp. (r=0.46, n=100, P=0.01). Importantly, &gt;26% of the samples were positive for Salmonella spp. and 88% of these samples harbored isolates resistant to &ge;1 antibiotic. Moreover, we found that 26% of antibiotic resistant Salmonella spp. isolates were able to transfer their resistance traits to a recipient strain of Escherichia coli at the rate of 1-7 x 10-3 per donor cells. Microbiological contamination of water was clearly evident in open water sources from northern Tanzania, and the presence of Salmonella spp. poses an immediate risk to anyone who consumes these waters if untreated. Key words: Fecal bacteria, Salmonella, invA gene, polymerase chain reaction (PCR), water.

Potential microbiological threat to the Vistula waters by its tributaries in the vicinity of Kraków

The Vistula is the longest river in Poland. It stretches from the Silesian Beskids to the Gulf of Gdansk. Water from the Vistula is the source of drinking water for many cities and is used in industry, and therefore its quality and microbiological purity is an important issue. The quality of water in the Vistula depends, among others, on the quality of water in its basin. The aim of this study is to assess microbiological hazard to the Vistula waters from its tributaries in the vicinity of Krakow. The analyses were carried out on 10 tributaries of the Vistula: Prądnik, Dlubnia, Drwina Dluga, Drwinka, Raba, Uszewka, Szreniawa, Uszwica, Kisielina, and Dunajec. The examinations were carried out in four series, from May 2012 to March 2013. The numbers of coliforms, faecal coliforms, Enterococcus faecalis , and sulphate reducing Clostridium were determined using the membrane filtration method, while the serial dilutions method was used to determine the numbers of mesophilic and psychrophilic bacteria, Staphylococcus and Salmonella . There was a large variation in the number of microorganisms in the examined watercourses, however in most cases the water could be classified as clean, whereas waters of the Vistula in the vicinity of Krakow are microbiologically contaminated. Thus, the examined watercourses do not pose a serious threat to the quality of the Vistula. Among the analyzed tributaries, the waters of the Prądnik were characterized by the worst sanitary condition, while the best microbiological quality was observed in the Dunajec.

Occurrence of tetracycline-resistant fecal coliforms and their resistance genes in an urban river impacted by municipal wastewater treatment plant discharges

Antibiotic resistance of fecal coliforms in an urban river poses great threats to both human health and the environment. To investigate the occurrence and distribution of antibiotic resistant bacteria in an urban river, water samples were collected from the Chanhe River in Xi'an, China. After membrane filtration of water samples, the tetracycline resistance rate of fecal coliforms and their resistance genes were detected by plating and polymerase chain reaction (PCR), respectively. We found that fecal coliforms were generally resistant to tetracycline and saw average resistance rates of 44.7%. The genes tetA and tetB were widely detected, and their positive rate was 60%–100% and 40%–90%, respectively. We found few strains containing tetC, tetK, tetQ and tetX, and we did not identify any strains containing tetG, tetM or tetO. The prevalence of tetA and tetB over other genes indicated that the main mechanism for resistance to tetracycline is by changes to the efflux pump. Our analysis of the types and proportion of tetracycline resistance genes in the Chanhe River at locations upstream and downstream of the urban center suggests that the increased number of tetracycline-resistant fecal coliforms and spatial variation of tetracycline resistance genes diversity were related to municipal wastewater treatment plant discharge.