Environmental fecal pollution and concentration power of the clam Chamelea gallina

This study is aimed to verify hygienic conditions of a commercially-important clam: Chamelea (Venus) gallina, widely distributed along the Italian coasts. Five mussel beds have been simultaneously surveyed, collecting samples of water, sediment and molluscs. Total coliforms, fecal coliforms, and fecal streptococci have been analyzed. Results show that this shellfish does not seem to accumulate enteric bacteria in spite of the microbial contamination of water and sediment.     

Survey onYersinia Enterocolitica and related bacteria in shellfish

Results from examining shellfish collected from ‘safe’ (2–34Escherichia coli/100 mL) and ‘unsafe’ (> 34E. coli/100 mL) waters for the presence ofYersinia enterocolitica and related bacteria are reported. The recovery of these microorganisms was low in bivalve mollusks destined for food consumption, high in those derived from prohibited areas. No human pathogenic bio-serogroup f Yersinia was found during the entire survey.     

Fecal streptococci recoveries in different marine areas

The usual media and procedures were followed to measure the concentration of fecal streptococci (MPN on Azide Dextrose and Ethyl Violet Azide broths, membrane filtration on m-Enterococcus, KF and Pfizer Selective Enterococcus agars and according to the mE procedure) in samples collected along two different marine areas. The results were evaluated on the basis of three parameters: total concentrations, number of enterococci-like colonies (namely colonies gram positive, catalase negative, coccus shaped) and rate of strictly named fecal streptococci. From the results it appears that the various media and procedures employed gave different yields and their capacity to measure fecal streptococci varies according to the origin of samples. The accompanying bacterial flora may play an important role on the selectivity of each technique to measure the fecal streptococci.     

Behaviour in soil of polyethylene film and polyethylene film additivated with starch

Effective minesoil recovery requires spoils to be converted to soils of similar quality to those previously existing on that site. The developing minesoil should thus acquire three critical capacities, namely the capacities to a) support plant production, b) degrade organic matter and c) remove contaminants from water. The degree of development of these capacities provides a useful measure of soil quality and thus of the success of a given soil recovery technique. At the Meirama lignite mine in Galicia (northwest Spain), the possibility of using cattle slurry instead of the inorganic fertilizers currently used is being investigated. The results of a number of experiments suggest that cattle slurry is more effective (in terms of the above three critical capacities) than inorganic fertilizer. In slurry-fertilized spoils, rapid increases are observed in vegetation cover, in the relative abundance of self-seeded native plant species, in soil microbial activity and in those physical and chemical properties which affect infiltration and the capacity to remove contaminants from percolating water.     

Coliphages as indicators in a treatment plant

The potential use of coliphages as indicators of water pollution was investigated. Several strains ofE. coli hosts were used in order to detect the better marker. Analyses were carried out on a treatment plant for the convenience of phages recoveries. Results show the possibility that strains different fromE. coli 9484B can show better recoveries of PFU m1^?1.     

Enteric virus pollution of tyrrhenian areas

63 samples (53 seawater and 10 estuarine water samples) of 20 L were obtained during a bathing season from 47 seawater stations and from 1 estuarine station. To determine viral pollution, all samples were subjected to two different methods of viral concentration: tangential ultrafiltration and adsorption-elution with electropositive membranes. Detection of viruses was by cytopathic effect (CPE) in BGM and NA 104 cells. Isolates were identified by dot-blot hybridization and Polyacrylamide Gel Electrophoresis (PAGE). While estuarine water showed enterovirus and/or reovirus presence in 100% of samples, only 14 stations of 47 seawater station samples (30%) showed viral contamination: enteroviruses were isolated from 6 and reoviruses from 8 of the 14 stations. 28 unidentified viruses were detected from seawater in MA104 cells by CPE whereas these viruses were not detected in BGM cells. Enterovirus recovery seems to be better when water samples are concentrated by the tangential ultrafiltration than with absorption-elution with electropositive membranes. For reoviruses and the other viruses the two methods were almost equivalent. BGM cells seem to be more susceptible to enteroviruses, MA104 to reoviruses. Reoviruses failed to indicate enterovirus presence as most of enteroviruses were isolated in waters where reovirus was not observed. Isolated viral species distribution changed during bathing season.     

Water quality along the Neapolitan coast

Two kinds of surveys on marine environment quality were carried out along the Neapolitan Bay from the winter 1977 to 1980. The first was a general investigation along 60 km of coast, embracing several municipalities. Its purpose was to identify the most consistently polluted areas. The second one was a more limited but prolonged monitoring along about 12 km of coast entirely included in the municipality of Naples. At the beginning of this latter inspection two fecally contaiminated areas were found. These showed an increase in pollution during summer. However during the three years of surveillance a general improvement of the water quality was observed, perhaps due to the use of undersea pipes for the discharge of sewage far from the coast. As a consequence in the summer of 1980, 78% of the sampling points exihibited values ofEscherichia coli below limits prescribed in the Italian standard for bathing water (100E. coli/100 ml), while only 38% of the stations in the summer of 1978 could be considered suitable for bathing.