Rossella Briancesco

Occurrence of Cryptosporidium oocysts in sewage effluents and correlation with microbial, chemical and physical water variables.

Contaminated water are recognized as a potential source of Cryptosporidium oocysts. In Italy studies on the environmentalspread of the parasite are still scarce even if a high frequencyof serological responses could suggest high rates of endemic Cryptosporidium infections. In this investigation theoccurrence of the parasite in water samples from a municipalwastewater treatment plant was monitored with the aim to evaluatepossible correlation between oocysts and bacterial indicators,pathogens and physico-chemical parameters using a multivariateanalysis. Data collected showed high numbers of oocysts, with ahigh percentage of positive samples and a significant correlationwith pH, redox potential and total organic carbon. No correlationwas found between Cryptosporidium concentration and that of the other microrganisms. The results, through a probing statistical analysis, show that none of the selected microrganisms was a reliable predictor of the presence of theparasite.

Non-tuberculous mycobacteria and microbial populations in drinking water distribution systems

Data on the occurrence of non-tuberculous mycobacteria (NTM), in parallel with those obtained for bacterial indicators and amoebae, are presented with the aim to collect information on the spread of NTM in drinking water distribution systems in Italy. Samples were collected from taps of hospitals and households in Central and Southern Italy. The concentration values obtained for the more traditional microbial parameters complied with the mandatory requirements for drinking water. Conversely, moderate-to-high microbial loads (till 300 CFU/L) were observed for the NTM. Positive samples were obtained from 62% of the investigated water samples. Analogous results were observed for amoebae showing a higher percentage of positive samples (76%). In terms of public health, the presence of mycobacteria in water distribution systems may represent a potential risk especially for vulnerable people such as children, the elderly or immunocompromised individuals.

Occurrence of Giardia and Cryptosporidium in Italian water supplies

A total of 21 samples: raw water (RW) samples; water samples after coagulation with aluminium sulfate (clarified water: CW); and water after chlorination (treated water: TW) from a water purification plant that treats river surface water from the neighbourhood of Foggia (Italy), were analysed for the presence of Giardia cysts and Cryptosporidium oocysts. Bacteriological indicator of faecal contamination (total and faecal coliforms, faecal streptococci,), total bacterial count at 22 and 36°C and physicochemical parameters (turbidity, temperature, pH) were evaluated. Cryptosporidium oocysts were not found in any samples examined, while Giardia cysts were found only in RW samples, with the maximal concentration of 8 cysts/100 l. A positive correlation was found between the Giardia densities and quality parameters such as TC, FC and TBC at 22°C. Giardia levels in raw water samples correlated (p<0.05) with TC, FC and with temperature. No other water quality parameters was consistently correlated with cysts level.

Assessment of microbiological and parasitological quality of composted wastes: health implications and hygienic measures

Feedstock and compost samples were collected from twenty composting plants and analysed from the microbiological point of view. Faecal indicator organisms were determined in order to evaluate the efficacy of processes for the removal of pathogenic micro-organisms with similar survival characteristics and to verify their suitability as appropriate markers of microbial quality of composted products. In addition to the classical bacterial indicators, selected organisms, such as Salmonella, Giardia , Cryptosporidium, Clostridium spores and helminth ova, were investigated. Statistically significant differences in the removal of the different micro-organisms were observed with regard to both the different composting plants (P < 0.05) and feedstock composition (P < 0.05). In fact, compost obtained by feedstock containing sewage sludge was shown to have a better hygienic quality in comparison with compost containing green discards and municipal solid waste as raw matter. Giardia cysts, Cryptosporidium oocysts and helminth ova were not effective indicators of hygienic quality of compost, whereas Clostridium perfringens spores, because of their high resistance to treatments, could be considered as an additional model for assessing the composting process, especially with regard to more resistant pathogen reduction.

Occurrence of potential bacterial pathogens in coastal areas of the Adriatic Sea

A monitoring program was carried out in bathing waters along the sea-coast of the Adriatic Sea. The investigation was aimedat obtaining a quali-quantitative picture of microorganisms ofanthropic origin and of a more strictly autochthonous origin and at verifying the existence of possible reciprocal correlations and combinations of relationship between them. Results showed that the concentrations of indicators of faecal contamination, whether within or over the values established by legislation, are not always related to the presence and density of microorganisms of environmental origin but the regression modelsused can help to describe how these latter microorganisms can bein relation to levels of the other parameters. The difficultyis evident of the predictability of health effects swimming-associated; for this reason more complex models that are currently used should be taken into account for minimising the risk for bathers.

First detection of papillomaviruses and polyomaviruses in swimming pool waters: unrecognized recreational water-related pathogens?

Viral outbreaks associated with swimming pools have been described worldwide. The objective of this study was to examine the extent of viral contamination in indoor and outdoor swimming pools.

Analysis of Microorganisms in Hospital Environments and Potential Risks

This report provides information on indoor air quality and on associated potential risks in hospitals. Spread and persistence of microbial communities in hospital environments are of huge interest to public health. Hospitals are characterized by high infective risk, firstly cause of the compromised immunologic conditions of the patients that make them vulnerable to bacterial, viral, parasitological and fungal opportunistic infections. Evidence suggests that microbial agents spread through air, surfaces, aerosol and hands. If surfaces may act as a reservoir for some pathogens, hands are an important transmission route. Airborne and aerosolized waterborne microorganisms are taken into consideration, and their presence into the hospital environments is reviewed.

Zootechnical wastewater reuse: constructed wetland as a challenge for protozoan parasite removal

Samples of soil, well water, and wastewater from a zootechnical farm, water after phytodepuration and maize plants (Zea mays) grown on soils irrigated with these different kinds of water were analysed for indicator bacteria and the protozoa Giardia and Cryptosporidium. Protozoa and bacterial indicators, except coliforms, were not recovered from well water samples. In the effluent from the zootechnical farm, high parasitological concentrations were observed, whilst water after the phytodepuration process showed a concentration reduction of two orders of magnitude. The high numbers of Giardia and Cryptosporidium in the zootechnical effluent could represent a potential risk for the spread of the pathogens. Nevertheless the environmental spread is minimized when data on soils and plants are observed. From the study, it emerges that this water treatment system could represent an alternative option to other conventional wastewater treatments and an economic and environmental advantage.

Detection of heterotrophic and pigmented bacteria in well water

The heterotrophic plate count (HPC), at different temperatures, allows to recover mesophilic and psychrophilic bacteria, including some pigmented forms. Their densities were verified in well water ...