Effect of effluent from a nitrogen fertilizer factory and a pulp mill on the distribution and abundance of Aeromonas hydrophila in Albemarle Sound, North Carolina.

The density of Aeromonas hydrophila, standard count bacteria, fecal coliform bacteria, and 18 physical and chemical parameters were measured simultaneously at six sites for 12 months in Albemarle Sound, N.C. One site was above and two sites were below the discharge plume of a Kraft pulping process paper mill. The fourth site was above and the remaining two sites were below the discharge point of a nitrogen fertilizer factory. The impact of the pulp mill on water quality was acute, whereas that of the nitrogen fertilizer factory was chronic and much more subtle. Diffusion chamber studies indicated that A. hydrophila survival is increased by pulp mill effluent and decreased by nitrogen fertilizer factory effluent. From correlation and regression analysis, A. hydrophila was found to be directly affected by phytoplankton density and, thus, indirectly by concentrations of phosphate, nitrate, and total organic carbon. These two point sources are suspect as indirect causes of red-sore disease epizootics, a disease of fish caused by A. hydrophila.     

Effect of effluent from a nitrogen fertilizer factory and a pulp mill on the distribution and abundance of Aeromonas hydrophila in Albemarle Sound, North Carolina

The density of Aeromonas hydrophila, standard count bacteria, fecal coliform bacteria, and 18 physical and chemical parameters were measured simultaneously at six sites for 12 months in Albemarle Sound, N.C. One site was above and two sites were below the discharge plume of a Kraft pulping process paper mill. The fourth site was above and the remaining two sites were below the discharge point of a nitrogen fertilizer factory. The impact of the pulp mill on water quality was acute, whereas that of the nitrogen fertilizer factory was chronic and much more subtle. Diffusion chamber studies indicated that A. hydrophila survival is increased by pulp mill effluent and decreased by nitrogen fertilizer factory effluent. From correlation and regression analysis, A. hydrophila was found to be directly affected by phytoplankton density and, thus, indirectly by concentrations of phosphate, nitrate, and total organic carbon. These two point sources are suspect as indirect causes of red-sore disease epizootics, a disease of fish caused by A. hydrophila.     

Comparison of Gelman and Millipore Membrane Filters for Enumerating Fecal Coliform Bacteria

Tests of two leading brands of membrane filters used for enumerating fecal coliform bacteria showed that Gelman GN-6 filters recovered statistically more colonies of bacteria than did Millipore HAWG 047SO filters from pure cultures incubated at either 35 C (the optimal growth temperature) or 44.5 C (the standard temperature for the fecal coliform test). Standard membrane filter procedures with M-FC broth base were used to enumerate the organisms. Densities of colonies incubated on Gelman filters at 44.5 C averaged 2.3 times greater than those on Millipore filters. Plate counts of the bacteria at both temperatures indicated that incubation at 44.5 C did not inhibit propagation of fecal coliform bacteria. For the pour plates, M-FC broth base plus 1.5% agar was used. This modified medium compared favorably to plate count agar for enumerating Escherichia coli. At 35 and 44.5 C, colony counts on Gelman filters agreed closely with plate counts prepared concurrently, but Millipore counts were consistently lower than plate counts, especially at 44.5 C. Comparative analyses of river water for fecal coliform bacteria by the membrane filter technique gave results comparable to those for the pure cultures.     

Ecology ofAeromonas hydrophila in a South Carolina cooling reservoir

Densities ofAeromonas hydrophila were determined monthly from December 1975 to December 1977 in a South Carolina cooling reservoir which receives heated effluent from a single nuclear production reactor. Selected water quality parameters and prevalence of red-sore disease among largemouth bass were monitored simultaneously.Higher densities ofA. hydrophila were observed in areas of the reservoir receiving effluent from the reactor. Densities ofA. hydrophila generally were heterogeneous in the water column. The sediments had lower densities ofA. hydrophila than water immediately above.A. hydrophila could not be isolated from sediments greater than 1 cm from the water interface. Temperature, redox potential, pH, and conductivity were all significantly correlated with densities ofA. hydrophila in the water column. The temporal and spatial distribution and abundance ofA. hydrophila in water were not related to total organic carbon, dissolved organic carbon, particulate organic carbon, inorganic carbon, or dissolved oxygen. High densities ofA. hydrophila were observed in mats of decomposingMyriophyllum spicatum and, enterically, in largemouth bass, several other species of fish, turtles, alligators, and snails. The greatest densities ofA. hydrophila in water occurred during March and June with a second peak in October. The mean monthly densities ofA. hydrophila were positively correlated with the incidence of infection in largemouth bass. Largemouth bass from thermally altered parts of the reservoir had a significantly higher incidence of infection. It is concluded that thermal effluent significantly affects the ecology ofA. hydrophila and the epizootiology of red-sore disease within Par Pond.     

Phosphorus and carbohydrate limitation of fecal coliform and fecal enterococcus within tidal creek sediments

Aquatic sediments can be a significant reservoir of bacterial indicators of fecal contamination at levels higher than the waters above them. Several environmental factors have been identified that can enhance the role of sediments as a reservoir for enteric pathogens, including carbon and/or phosphorus availability. In order to investigate the influence of these and other environmental factors on sediment fecal bacteria populations, sediment samples were collected from a coastal watershed in southeastern North Carolina and analyzed for fecal coliform and fecal enterococcus using a modified membrane filtration technique. Measurements of sediment phosphorus, sediment carbohydrate, and environmental factors were made and relationships with bacteria concentrations were assessed. These observations were accompanied by an experimental laboratory manipulation of phosphorus and carbohydrate and their effects on sediment-associated fecal coliform and enterococcus. Field results suggested that sediment-associated indicator bacteria were not limited by sediment phosphorus or carbohydrate. Experimental results suggested that sediment-associated fecal bacteria were more frequently limited by bioavailable carbohydrate. Sediment phosphorus was limiting for fecal enterococcus only where sediment P was initially low (<31 μg P g⁻¹). A strong positive response by sediment fecal coliform concentrations to recent (24 h) precipitation was evidence that stormwater runoff delivers fecal bacteria loadings that are only partly measurable by conventional water sampling schemes, and by driving sediment and sediment P-loading plays a significant role in enhancing aquatic sediments as reservoirs for fecal microbes.     

Distribution and in situ survival and activity ofKlebsiella pneumoniae andEscherichia coli in a tropical rain forest watershed

For a period of 7 months water samples were analyzed for the presence ofKlebsiella pneumoniae and fecal coliforms at 11 sites in a cloud rain forest watershed in Puerto Rico. Diffusion chamber studies were conducted at two sites which were found to contain low numbers of naturally occurringK. pneumoniae and fecal coliforms. These studies indicated that bothK. pneumoniae andEscherichia coli may be capable of surviving environmental conditions for extended periods of time. The presence of both bacteria in pristine natural waters is indicative of their being autochtonous to tropical environments. Thus, as a result, the use of coliform and even fecal coliform bacteria as indicators of fecal pollution may be misleading when applied to countries with a tropical climate.     

Isolation of faecal coliform bacteria from the American alligator (Alligator mississippiensis)

Aims: To determine whether American alligators (Alligator mississippiensis) are an unrecognized poikilothermic source of faecal coliform and/or potential pathogenic bacteria in South Carolina’s coastal waters. Methods and Results: Bacteria from the cloaca of American alligators, as well as bacteria from surface water samples from their aquatic habitat, were isolated and identified. The predominant enteric bacteria identified from alligator samples using biochemical tests included Aeromonas hydrophila, Citrobacter braakii, Edwardsiella tarda, Escherichia coli, Enterobacter cloacae, Plesiomonas shigelloides and putative Salmonella, and these were similar to bacteria isolated from the surface waters in which the alligators inhabited. Based on most‐probable‐number enumeration estimates from captive alligator faeces, faecal coliform bacteria numbered 8·0 × 10⁹ g^?1 (wet weight) of alligator faecal material, a much higher concentration than many other documented endothermic animal sources. Conclusions: A prevalence of enteric bacteria, both faecal coliforms and potential pathogens, was observed in American alligators. The high faecal coliform bacterial density of alligator faeces may suggest that alligators are a potential source of bacterial contamination in South Carolina coastal waters. Significance and Impact of the Study: These findings help to increase our understanding of faecal coliform and potential pathogenic bacteria from poikilothermic reptilian sources, as there is the potential for these sources to raise bacterial water quality levels above regulatory thresholds.     

Microorganisms associated with production lots of the nucleopolyhedrosis virus of the gypsy moth,Lymantria dispar [Lep.: Lymantriidae]

Samples of a gypsy moth nucleopolyhedrosis virus product, Gypchek^®, were taken each day during a 100-day production run and monitored for the presence of pathogenic bacteria and fungi. The standard plate count/g of product was 5.97±1.51×10⁸ over the 100-day period, while the sporulating bacteria count was 3.81±1.21×10⁶/g. We did not detect obligate anaerobic or fecal coliform bacteria in any of the samples.Bacillus cereus, Staphylococcus epidermidis, B. licheniformis, Streptococcus faecalis, Serratia liquefaciens, andAspergillus niger were the most frequently isolated microorganisms. We did not detect primary pathogenic bacteria or fungi, but the presence of opportunistic pathogens indicated that assiduous monitoring of the virus production facility and rigorous quality control of production batches are necessary.     

Bacteria associated with granular activated carbon particles in drinking water

A sampling protocol was developed to examine particles released from granular activated carbon filter beds. A gauze filter/Swinnex procedure was used to collect carbon fines from 201 granular activated carbon-treated drinking water samples over 12 months. Application of a homogenization procedure (developed previously) indicated that 41.4% of the water samples had heterotrophic plate count bacteria attached to carbon particles. With the enumeration procedures described, heterotrophic plate count bacteria were recovered at an average rate of 8.6 times higher than by conventional analyses. Over 17% of the samples contained carbon particles colonized with coliform bacteria as enumerated with modified most-probable-number and membrane filter techniques. In some instances coliform recoveries were 122 to 1,194 times higher than by standard procedures. Nearly 28% of the coliforms attached to these particles in drinking water exhibited the fecal biotype. Scanning electron micrographs of carbon fines from treated drinking water showed microcolonies of bacteria on particle surfaces. These data indicate that bacteria attached to carbon fines may be an important mechanism by which microorganisms penetrate treatment barriers and enter potable water supplies.     

Bacteria associated with granular activated carbon particles in drinking water.

A sampling protocol was developed to examine particles released from granular activated carbon filter beds. A gauze filter/Swinnex procedure was used to collect carbon fines from 201 granular activated carbon-treated drinking water samples over 12 months. Application of a homogenization procedure (developed previously) indicated that 41.4% of the water samples had heterotrophic plate count bacteria attached to carbon particles. With the enumeration procedures described, heterotrophic plate count bacteria were recovered at an average rate of 8.6 times higher than by conventional analyses. Over 17% of the samples contained carbon particles colonized with coliform bacteria as enumerated with modified most-probable-number and membrane filter techniques. In some instances coliform recoveries were 122 to 1,194 times higher than by standard procedures. Nearly 28% of the coliforms attached to these particles in drinking water exhibited the fecal biotype. Scanning electron micrographs of carbon fines from treated drinking water showed microcolonies of bacteria on particle surfaces. These data indicate that bacteria attached to carbon fines may be an important mechanism by which microorganisms penetrate treatment barriers and enter potable water supplies.     

Influence of Physicochemical Parameters on the Abundance of Coliform Bacteria in an Industrial Site of the Hooghly River, India

Industrial effluents from jute, paper, pulp mills and sewage from households are regularly discharged into the Hooghly River. It generates a potential risk for both humans and animals of the area concerned. In the present study, water quality of the Hooghly River passing by the site of a growing township (Naihati, North 24 Parganas, West Bengal, India) was assessed throughout the year 2010 on the basis of the data collected on the physicochemical and microbiological parameters. The water samples collected on each month revealed the presence of higher amount of coliform bacteria, Streptococcus sp. and Escherichia coli, than the standard limit. Different physicochemical parameters like chemical oxygen demand, biological oxygen demand, dissolved oxygen (DO), total suspended solids, total dissolved solids (TDS), total hardness, alkalinity, chlorinity, nitrate and nitrite of the water at the sampling sites were found to be considerably higher than the levels standardized by WHO (2006). It was found that the relative abundance of Streptococcus and E. coli was influenced by two independent variables (water quality parameters), namely, DO and TDS. The abundance of coliform bacteria in the water sample warrants the adoption of proper measures to reduce the pollution level at the point source on way of scientific disposal of industrial effluents.     

Determination of the Viability of Aeromonas hydrophila in Different Types of Water by Flow Cytometry, and Comparison with Classical Methods

The presence of Aeromonas spp. in water can represent a risk for human health. Therefore, it is important to know the physiological status of these bacteria and their survival in the environment. We studied the behavior of a strain of Aeromonas hydrophila in river water, spring water, brackish water, mineral water, and chlorinated drinking water, which had different physical and chemical characteristics. The bacterial content was evaluated by spectrophotometric and plate count techniques. Flow cytometric determination of viability was carried out using a dual-staining technique that enabled us to distinguish viable bacteria from damaged and membrane-compromised bacteria. The traditional methods showed that the bacterial content was variable and dependent on the type of water. The results obtained from the plate count analysis correlated with the absorbance data. In contrast, the flow cytometric analysis results did not correlate with the results obtained by traditional methods; in fact, this technique showed that there were viable cells even when the optical density was low or no longer detectable and there was no plate count value. According to our results, flow cytometry is a suitable method for assessing the viability of bacteria in water samples. Furthermore, it permits fast detection of bacteria that are in a viable but nonculturable state, which are not detectable by conventional methods.     

Interactions between heterotrophic plate count bacteria and coliform organisms

Studies were initiated to investigate the interactions between heterotrophic plate count bacteria and coliform organisms. We used spiked samples to show that heterotrophic plate count bacteria could reduce coliform densities by more than 3 logs within 8 days. Some heterotrophic plate count bacteria were able to cause injury to the coliform population. A significant correlation (r = 0.66; P less than 0.05) was observed between the initial level of heterotrophic plate count bacteria and the rate of coliform decline. Competition for limiting organic carbon was hypothesized to be responsible for the observed effects.     

Interactions between heterotrophic plate count bacteria and coliform organisms.

Studies were initiated to investigate the interactions between heterotrophic plate count bacteria and coliform organisms. We used spiked samples to show that heterotrophic plate count bacteria could reduce coliform densities by more than 3 logs within 8 days. Some heterotrophic plate count bacteria were able to cause injury to the coliform population. A significant correlation (r = 0.66; P less than 0.05) was observed between the initial level of heterotrophic plate count bacteria and the rate of coliform decline. Competition for limiting organic carbon was hypothesized to be responsible for the observed effects.     

Learamoeba waccamawensis, N. G., N. Sp. (Heterolobosea: Vahlkampfiidae), a New Temperature-Tolerant Cyst-Forming Soil Amoeba

Soil from a roadside ditch at Lake Waccamaw, North Carolina, was tested for cyst-forming free-living amoebae, and water from the same ditch was tested for fecal coliform bacteria. Soil samples incubated at room temperature (21-23° C) yielded Acanthamoeba polyphaga, Amoeba sp., Hyperamaeba sp., Mayorella penardi. Naegleria gruberi, Naegleria minor , and unidentified ciliates, testaceans and slime molds. Incubation at 37-39° C yielded Acanthamoeba jacobsi, Platyamoeba schaefferi , and a new amoeba to be described herein. Fecal contamination of the ditch was confirmed by a direct membrane filtration technique that yielded a mean of 1,410 + 134 bacteria/ ml. The new amoeba is assigned to the class Heterolobosea Page & Blanton, 1985 on the basis of promitotic nuclear division, and a flagellated stage with a cytostome as seen in the genus Tetramitus. Amoebae studied in hanging drop preparations were flattened and irregular as described for the genus Stachyamoeba in the family Gruberellidae but changed to a lobose cylindrical form as described for species of Vahlkampfia in the family Vahlkampfiidae. A new genus and species, Learamoeba waccamawensis , is proposed for the amoeba described herein.     

Microbial quality of common carp and pikeperch fingerlings cultured in a pond fed with treated wastewater

A pond with a surface area of 0.94 ha and a maximum depth of 1.6 m, situated on land owned by a wastewater treatment plant in Olsztynek (Poland), was filled with water from underground springs in the pond bottom. Twice during the production season, the pond was fed with sewage which had been biologically treated in sequencing batch reactors (SBR). No commercial feed or medicinal products were applied to the pond and natural feed in the pond was the only source of nutrition for the fish. After the production season, pikeperch and carp fingerlings (aged 0+), weighed 8.4 ± 1.2 g fish^?1 and 62.1 ± 13.6 g fish^?1, respectively.The microbiological examinations included tests of the pond water and the contents of the digestive tract, skin mucus and the muscles of the fingerlings. In the water the total cell count, heterotrophic bacteria count at a temperature of 22 °C and 37 °C (HPC 22 °C and 37 °C), coliforms, fecal coliforms, Streptococcus faecalis, Salmonella sp. and Aeromonas hydrophila, were recorded. The same groups of bacteria were noted in the analyzed fish tissue without the total cell count. In addition, the antibiotic sensitivity of A. hydrophila, isolated from all the examined environments, was tested.The low count of all examined groups of bacteria in the pond water was noted. The common carp tissues were more contaminated than the pikeperch tissues, but the microbial quality of both species was satisfactory. A. hydrophila strains proved to be highly sensitive to the tested antibiotics. The results of this study indicate that a high microbiological quality in the fingerlings was achieved thanks to the seasonal feeding of pond water by treated sewage.     

用污染指示菌评价城市水体污染的研究

选择湖南省常德市江北城区水体为代表开展本项研究。结果表明,水体中污染指示菌,总大肠菌群（ＴＣ）和粪大肠菌群（ＦＣ）密度同ＢＯＤ＿５负荷以及综合污染指数Ｐ呈高度正相关。所以,污染指示菌指标,特别是粪大肠菌群指标足综合评价城市污水,尤其是生活污水污染的一个必不可少的重要参数。对该城区水体细菌污染的评价结果是,生活污水排放愈集中的地区,细菌污染愈严重。其中护城河水的ＴＣ密度超出我国地面水Ⅲ级标准４个数量级;ＦＣ密度超过ＷＨＯ娱乐用水标准３个数量级。护城河是细菌污染最严重水体。包括滨湖公园内湖在内的接纳生活污水多或较多的水体,细菌污好也相当严重。只是远离城区的柳叮湖受污染程度较轻。     

Microbial contamination of vegetable crop and soil profile in arid regions under controlled application of domestic wastewater

Increasing lack of potable water in arid countries leads to the use of treated wastewater for crop production. However, the use of inappropriate irrigation practices could result in a serious contamination risk to plants, soils, and groundwater with sewage water. This research was initiated in view to the increasing danger of vegetable crops and groundwater contamination with pathogenic bacteria due to wastewater land application. The research was designed to study: (1) the effect of treated wastewater irrigation on the yield and microbial contamination of the radish plant under field conditions; (2) contamination of the agricultural soil profile with fecal coliform bacteria. Effluent from a domestic wastewater treatment plant (100%) in Jeddah city, Saudi Arabia, was diluted to 80% and 40% with the groundwater of the experimental site constituting three different water qualities plus groundwater as control. Radish plant was grown in two consecutive seasons under two drip irrigation systems and four irrigation water qualities. Upon harvesting, plant weight per ha, total bacterial, fecal coliform, fecal streptococci were detected per 100 g of dry matter and compared with the control. The soil profile was also sampled at an equal distance of 3 cm from soil surface for fecal coliform detection. The results indicated that the yield increased significantly under the subsurface irrigation system and the control water quality compared to surface irrigation system and other water qualities. There was a considerable drop in the count of all bacteria species under the subsurface irrigation system compared to surface irrigation. The bacterial count/g of the plant shoot system increased as the percentage of wastewater in the irrigation water increased. Most of the fecal coliform bacteria were deposited in the first few centimeters below the column inlet and the profile exponentially decreased with increasing depth.     

Significance and suitability of <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis> vs. fecal coliforms in assessing microbiological water quality

We examined the significance and suitability of Aeromonas hydrophila versus fecal coliforms in assessing microbiological water quality. For this, we used the membrane filtration method to simultaneously estimate the abundance level of A. hydrophila and fecal coliforms in waters from the Mfoundi river watershed at Yaoundé, and compared how fluctuations in A. hydrophila abundance matched those observed with fecal coliforms index as an indicator of water quality in the system under study. Our results revealed that waters were not safe according to the standards for water quality established by the Word Health Organization (WHO). They also indicated the prevalence of A. hydrophila as compared to fecal coliforms, and suggested that water from the Mfoundi River and its tributaries could be classified as hypereutrophic based on the density of Aeromonas. Moreover, the spatial distribution of fecal coliforms and A. hydrophila exhibited similar trends within the different water bodies investigated, suggesting that A. hydrophila can be used as indicator of water quality in highly polluted waters. We concluded that waters from the Mfoundi River watershed at Yaoundé represent a great potential risk of infection for users, and foresee that the next challenge will be to determine, among other factors, the physico-chemical factors influencing the observed spatial distribution.     

Isolation of Fecal Coliform Bacteria from the Diamondback Terrapin (Malaclemys terrapin centrata)

Total and fecal coliform bacteria were isolated from the cloaca and feces of the estuarine diamondback terrapin. The majority of samples contained fecal coliforms. Escherichia coli was the predominant fecal coliform species isolated, and members of the genus Salmonella were isolated from 2 of 39 terrapins. Fecal coliform numbers are used to regulate shellfish harvests, and diamondback terrapins inhabit the brackish-water habitats where oyster beds are found; therefore, these findings have implications for the efficacy of current regulatory parameters in shellfishing waters.