Systems toxicology meta-analysis of in vitro assessment studies: biological impact of a candidate modified-risk tobacco product aerosol compared with cigarette smoke on human organotypic cultures of the aerodigestive tract

Systems biology combines comprehensive molecular analyses with quantitative modeling to understand the characteristics of a biological system as a whole. Leveraging a similar approach, systems toxicology aims to decipher complex biological responses following exposures. This work reports a systems toxicology meta-analysis in the context of in vitro assessment of a candidate modified-risk tobacco product (MRTP) using three human organotypic cultures of the aerodigestive tract (buccal, bronchial, and nasal epithelia). Complementing a series of functional measures, a causal network enrichment analysis of transcriptomic data was used to compare quantitatively the biological impact of aerosol from the Tobacco Heating System (THS) 2.2, a candidate MRTP, with 3R4F cigarette smoke (CS) at similar nicotine concentrations. Lower toxicity was observed in all cultures following exposure to THS2.2 aerosol compared with 3R4F CS. Because of their morphological differences, a smaller exposure impact was observed in the buccal (stratified epithelium) compared with the bronchial and nasal (pseudostratified epithelium). However, the causal network enrichment approach supported a similar mechanistic impact of CS across the three cultures, including the impact on xenobiotic, oxidative stress, and inflammatory responses. At comparable nicotine concentrations, THS2.2 aerosol elicited reduced and more transient effects on these processes. To demonstrate the benefits of additional data modalities, we employed a newly established targeted mass-spectrometry marker panel to further confirm the reduced cellular stress responses elicited by THS2.2 aerosol compared with 3R4F CS in the nasal culture. Overall, this work demonstrates the applicability and robustness of the systems toxicology approach for in vitro inhalation toxicity assessment.

Control ofLegionella pneumophilaContamination in a Respiratory Hydrotherapy System With Sulfurous Spa Water

Objective.

To evaluate the effectiveness of different disinfection treatments in a spa water system contaminated byLegionella pneumophilaand associated with a case ofLegionellapneumonia.

Design.

During an 18-month period, the spa water was analyzed by taking samples from the well, the recirculation line, and the final distribution devices (nebulizers and nasal irrigators). Various attempts were made to eradicateLegionellaorganisms by chemical and thermal shock. The final protocol consisted of heat shock treatment at 70°C-75°C for 3 hours, 2 nights per week, followed by a lowering of the water temperature to 30°C ± 1°C for use in the plant. In addition, 3 times a week superheated steam (at a pressure of 1 atmosphere) was introduced for 1 hour into the nebulization machines.

Setting.

A spa at which sulfurous water was used for hydrotherapy by means of aerosol and nasal irrigation.

Patient.

A 74-year-old woman with legionnaires disease.

Results.

After the case of infection occurred,L. pneumophilawas isolated from the recirculation line at a concentration of 400,000 cfu/L and from the nebulizers and nasal irrigators at levels ranging from 3,300 to 1,800,000 cfu/L. The colonizing organisms consisted of a mixture ofL. pneumophilaserogroup 1 (12%) and serogroup 5 (88%). The shock treatment with chlorine dioxide and peracetic acid resulted in the eradication ofLegionellaorganisms from the recirculation line but not from the water generated from the final distribution devices. After the restructuring of the plant and the application of thermal shock protocol, an evaluation after 12 months revealed no evidence ofLegionellacontamination.

Conclusion.

To preventLegionellacolonization, disinfection treatment is effective if associated with carefully selected materials, good circuit design, and good maintenance practices.

Controlling Legionella and Pseudomonas aeruginosa re-growth in therapeutic spas: implementation of physical disinfection treatments, including UV/ultrafiltration, in a respiratory hydrotherapy system

The study aimed to assess the efficacy of an integrated water safety plan (WSP) in controlling Legionella re-growth in a respiratory hydrotherapy system located in a spa centre, supplied with sulphurous water, which was initially colonized by Legionella pneumophila. Heterotrophic plate counts, Pseudomonas aeruginosa, Legionella spp. were detected in water samples taken 6-monthly from the hydrotherapy equipment (main circuit, entry to benches, final outlets). On the basis of the results obtained by the continuous monitoring and the changes in conditions, the original WSP, including physical treatments of water and waterlines, environmental surveillance and microbiological monitoring, was integrated introducing a UV/ultrafiltration system. The integrated treatment applied to the sulphurous water (microfiltration/UV irradiation/ultrafiltration), waterlines (superheated stream) and distal outlets (descaling/disinfection of nebulizers and nasal irrigators), ensured the removal of Legionella spp. and P. aeruginosa and a satisfactory microbiological quality over time. The environmental surveillance was successful in evaluating the hazard and identifying the most suitable preventive strategies to avoid Legionella re-growth. Ultrafiltration is a technology to take into account in the control of microbial contamination of therapeutic spas, since it does not modify the chemical composition of the water, thus allowing it to retain its therapeutic properties.

Microbial quality of drinking water from microfiltered water dispensers

A comparison was made between the microbial quality of drinking water obtained from Microfiltered Water Dispensers (MWDs) and that of municipal tap water. A total of 233 water samples were analyzed. Escherichia coli (EC), enterococci (ENT), total coliforms (TC), Staphylococcus aureus, Pseudomonas aeruginosa and heterotrophic plate count (HPC) at 22 °C and 37 °C were enumerated. In addition, information was collected about the principal structural and functional characteristics of each MWD in order to study the various factors that might influence the microbial quality of the water. EC and ENT were not detected in any of the samples. TC were never detected in the tap water but were found in 5 samples taken from 5 different MWDs. S. aureus was found in a single sample of microfiltered water. P. aeruginosa was found more frequently and at higher concentrations in the samples collected from MWDs. The mean HPCs at 22 °C and 37 °C were significantly higher in microfiltered water samples compared to those of the tap water. In conclusion, the use of MWDs may increase the number of bacteria originally present in tap water. It is therefore important to monitor the quality of the dispensed water over time, especially if it is destined for vulnerable users.

Genetic characterization of a pigeon paramyxovirus type 1 isolated from Columba livia in Uruguay

SUMMARY. The isolation and molecular characterization of pigeon paramyxovirus type 1 (PPMV-1) from a sick racing pigeon in Uruguay is reported for the first time. Hemagglutination inhibition (HI) tests were performed to detect antibodies against avian paramyxovirus serotype 1 (APMV-1), and a HI titer of 1/32 was obtained. Tracheal and cloacal swabs were processed by real-time reverse transcription-polymerase chain reaction (rRT-PCR) with the use of the National Veterinary Services Laboratory-U.S. Department of Agriculture validated matrix (M) gene assay and were positive for APMV-1. Viral isolation in embryonated chicken eggs confirmed the molecular detection of the isolate. A fragment corresponding to the 3' region of the fusion (F) protein gene was amplified by RT-PCR, and subsequently sequenced. The deduced amino acid sequence at the F protein cleavage site displayed the motif 112RRQKR/F117. Phylogenetic analysis of this part of the genome allowed the isolated virus to be grouped in the lineage VIb/ 4b, which suggests that it shares the same ecologic niche with other PPMV-1 that were found in the region, and it is not imported as other European or North American viruses.

[Prospective observational study of pneumonia in an Italian hospital]

A prospective observational study was conducted during a two-year period to evaluate the prevalence of hospitalized pneumonia in six hospital units of the Bologna S.Orsola-Malpighi hospital (Italy). The selected units were: general surgery, general medicine, internal medicine, geriatrics, respiratory physiopathology and pneumology, with a total of 205 beds and around 4,800 admissions per year. Data were collected from the clinical cards and cases of pneumonia were distinguished by origin (community-acquired or hospital-acquired according to CDC definition), individual and clinical characteristics, and aetiology. The study involved 486 cases of pneumonia: 75 hospital-acquired and 411 community-acquired (84.6%). Patients affected by hospital-acquired pneumonia were older (average age 77 years) compared to community-acquired cases (74 years) and show a more homogeneous gender distribution (males: 48.0% vs 59.4%). Hospital stays (42 vs 21 days) and mortality rates (24.0% vs 11.7%) were significantly higher in hospital-acquired pneumonia. The incidence rate of nosocomial pneumonia was 7.4 per 1000 hospitalized patients and increased to 17-23 per 1000 in the pneumology and respiratory physiopathology units. Only 16.9% of cases had an aetiological diagnosis (14.1% community-acquired; 31.8% hospital-acquired); the most common isolates were S. aureus and P. aeruginosa. The hospital-acquired cases were caused by Gram-negative bacilli more often than the community-acquired cases, and infections were more frequently polymicrobial (37.5% vs 3.4%). In order to reduce morbidity and mortality due to pneumonia it is important to implement prevention measures in the community (i.e. specific vaccination campaigns), improve clinical protocols for aetiological diagnosis in hospitalised patients and increase epidemiological surveillance of hospital-acquired infections.

Disinfection efficiency of peracetic acid (PAA): inactivation of coliphages and bacterial indicators in a municipal wastewater plant

The aim of the study was to assess the efficiency of low doses of peracetic acid against viral and bacterial indicators in wastewater and to evaluate if the treatment allows regulatory requirements to be satisfied. A total of 31 samplings were carried out, each involving the collection of secondary effluent and of effluent disinfected with 1.2 or 1.5 mg l(-1) of peracetic acid (contact time 20 minutes). In each sample were measured: somatic coliphages, F-specific RNA bacteriophages, Escherichia coli, total and faecal coliforms, enterococci. Peracetic acid disinfection showed significant differences between the reductions of the microorganisms tested: E. coli showed the highest reduction (1.78 and 2.43 Log respectively with 1.2 and 1.5 mg l(-1) of peracetic acid) and phages the lowest (ranging between 0.52 and 0.60 Log). Only a concentration of 1.5 mg l(-1) of peracetic acid would enable the effluent to be discharged into surface waters in compliance with Italian regulations. The variability of microbial resistance against the peracetic acid disinfection treatment, underlines the importance of assessing disinfection efficiency by using more than one indicator microorganism. The detection of E. coli could be usefully accompanied by tests for more resistant microorganisms such as enterococci or coliphages. In conclusion, peracetic acid can be used for the disinfection of effluents even at low doses, with the advantage of reducing costs and preventing the formation of significant amounts of genotoxic by-products.

ZAP-70 expression, as detected by immunohistochemistry on bone marrow biopsies from early-phase CLL patients, is a strong adverse prognostic factor

Zeta-associated protein-70 (ZAP-70), mostly assessed by flow-cytometry (FC), recently emerged as reliable prognostic factor in chronic lymphocytic leukaemia (CLL) at presentation. We evaluated ZAP-70 expression in 156 CLL patients by immunohistochemistry (IHC) on formalin-fixed bone marrow (BM) biopsies at diagnosis. At presentation, 117 patients (75%) were with Binet stage A, 27 (17%) stage B and 12 (8%) stage C. Median follow-up was 61 months (range 6-242). ZAP-70 was expressed in neoplastic lymphocytes of 69 patients (44%). Concordance between ZAP-70 by IHC and ZAP-70 by FC, immunoglobulin heavy chain variable genes (IGHV) mutational status and CD38 expression was found in 41/46 (89%), 41/49 (80%) and in 60/88 (68%) tested cases, respectively. ZAP-70 expression significantly correlated with advanced Binet stage (B-C), diffuse BM infiltration, increased lactate dehydrogenase (LDH) and beta2-microglobulin serum levels and lymphocyte doubling time <12 months. ZAP-70 positivity was significantly related to poorer time to progression (median 16 months vs 158 of ZAP-70-negative cases) (P<0.0001) and overall survival (median 106 months vs not reached) (P=0.0002); this correlation was confirmed at multivariate analysis. ZAP-70 expression correlated with poorer outcome also when evaluated only in the 117 stage A patients. In conclusion, immunohistological detection of ZAP-70 on formalin-fixed BM biopsies at diagnosis appears a useful methodological approach to identify patients with poor prognosis in CLL.

Exopolysaccharides produced by clinical strains belonging to the Burkholderia cepacia complex

BACKGROUND

In the frame of a research line dedicated to better clarify the role of exopolysaccharides (EPS) in bacterial virulence, EPS produced by species of the Burkholderia cepacia complex (Bcc), namely Burkholderia multivorans, Burkholderia cenocepacia, and a Bcc member of undetermined genomovar, all isolated at the Cystic Fibrosis Regional Centre of Florence (Italy), were investigated for they structural properties.

METHODS

Three strains of B. multivorans, three of B. cenocepacia and one of a Bcc member of undetermined genomovar were isolated from CF patients. The reference strains C1576 and J2315, for genomovar II and III, respectively, were included in the study. The bacteria were grown on solid media, the exopolysaccharides produced were purified, and their structures were determined. In addition, sugar analysis of sputum samples was accomplished to search for EPS produced in vivo.

RESULTS

Six strains out of seven produced the exopolysaccharide cepacian, while one strain of B. multivorans produced a completely different polymer, previously known in the literature as PS1. Two strains synthesised very small amounts of EPS. No definitive evidence for the presence of cepacian in sputum samples was found.

CONCLUSIONS

Most strains examined produced abundant amounts of polysaccharides. Cepacian was the most common EPS isolated and its production was not associated to a particular genomovar.

[Purification of lake water using a combined ozonization, filtration and chlorine dioxide treatments. Experience with the water of Garda lake]

The hygienic characteristics of the freshwater from Garda Lake used for the water supply of Sirmione were evaluated before and during the various phases of treatment. The samples were taken at the moment of entry, after ozonization, after filtration and after the addition of chlorine dioxide. The coliforms and Escherichia coli, occasionally detected in the incoming water, were reduced by ozone and eliminated by filtration. Enterococci were always absent. The overall reduction in the total bacteria count was satifactory, considering the low initial levels (96.0% and 83.0% respectively for the Heterotrophic plate count at 22 degrees and the Heterotrophic plate count at 36 degrees). The chemical and physical indicators that underwent the greatest reductions were the sulphates, iron, manganese, ammonia and the turbidity. Several species of unicellular algae belonging to Chlorophyta, Cyanophyta and Bacillariophyta were identified in the water at entry and after ozonization, but were completely eliminated during the subsequent phase of filtration. deliver of high quality services.

[Monitoring and control of opportunistic bacteria in a spa water used for aerosol hydrotherapy]

A bicarbonate-sulphate-calcic water of a therapeutic spa was monitored for the presence of Legionella, Pseudomonas and Mycobacteria. The water was analysed by taking samples from the well, the feed tank and from the final aerosol generating devices of two different water lines, the former at 21-23 degrees, the second at 36-38 degrees. The bacteria in question were always absent from the well. Legionellae were found in the water of aerosol equipment: Legionella micdadei was isolated from 75% of samples, L. bozemanii from 75% and 50% (respectively 36-38 degrees and 21-22 degrees water lines) and other species of environmental Legionellae from 25% of samples. The water of aerosol equipment presented high total bacterial counts (10(3)-10(4) cfu/ml) and exspecially high concentrations of Pseudomonadaceae (10(2)-10(3) cfu/100 ml). These bacteria, unlike the Legionellae, were also isolated from the feed tank at mean concentrations of about 10(2) cfu/100 ml. Mycobacteria were found in 75 and 50% of samples collected from final devices, respectively from the heated and not heated water lines. The isolates were M. gordonae (85% of isolates) and M. fortuitum (15%), but at concentrations very low. Both treatments with sodium hypochlorite (20 ppm of residual chlorine) and peracetic acid (20 ppm) resulted in the reduction of total bacterial counts and elimination of Pseudomonas from the water in the tank, but not in elimination of Pseudomonas and Legionellae from the nebulizers. The disinfectants were evidently not able to efficiently reach all the points where Pseudomonas and Legionella had settled and grown. In order to obtain total abatement it was necessary to carry out a radical restructuring of the plant, involving the replacement of the old nebulizer benches with new aerosol equipment that could be subjected to a new system of programmed thermal shock.

Legionella waterline colonization: detection of Legionella species in domestic, hotel and hospital hot water systems

AIMS

An evaluation was made of the prevalence of Legionella species in hot water distribution systems in the city of Bologna (Italy) and their possible association with bacterial contamination (total counts and Pseudomonadaceae) and the chemical characteristics of the water (pH, Ca, Mg, Fe, Mn, Cu, Zn and Total Organic Carbon, TOC).

METHODS AND RESULTS

A total of 137 hot water samples were analysed: 59 from the same number of private apartments, 46 from 11 hotels and 32 from five hospitals, all using the same water supply. Legionella species were detected in 40.0% of the distribution systems, L. pneumophila in 33.3%. The highest colonization was found in the hot water systems of hospitals (93.7% of samples positive for L. pneumophila, geometric mean: 2.4 x 10(3) CFU l(-1)), followed by the hotels (60.9%, geometric mean: 127.3 CFU l(-1)) and the apartments with centralized heating (41.9%, geometric mean: 30.5 CFU l(-1)). The apartments with independent heating systems showed a lower level of colonization (3.6% for Legionella species), with no evidence of L. pneumophila. Correlation analysis suggests that copper exerts an inhibiting action, while the TOC tends to favour the development of L. pneumophila. No statistically significant association was seen with Pseudomonadaceae, which were found at lower water temperatures than legionellae and in individual distribution points rather than in the whole network.

CONCLUSIONS

The water recirculation system used by centralized boilers enhances the spreading of legionellae throughout the whole network, both in terms of the number of colonized sites and in terms of CFU count.

SIGNIFICANCE AND IMPACT OF THE STUDY

Differences in Legionella colonization between types of buildings are not due to a variation in water supply but to other factors. Besides the importance of water recirculation, the study demonstrates the inhibiting action of copper and the favourable action of TOC on the development of L. pneumophila.

Exopolysaccharides produced by Burkholderia cenocepacia recA lineages IIIA and IIIB

Clinical and environmental strains of Burkholderia cenocepacia belonging to the recA lineages IIIA and IIIB were examined for exopolysaccharide (EPS) production. The exopolysaccharides structure was determined using mainly gas chromatography coupled to mass spectrometry and NMR spectroscopy. All the strains produced Cepacian, a highly branched polysaccharide constituted of a heptasaccharide repeating unit, composed of one rhamnose, one glucose, one glucuronic acid, one mannose and three galactose residues. This polymer is the most common exopolysaccharide produced by strains of the Burkholderia cepacia (Bcc) complex. One clinical strain produced also another polysaccharide constituted of three galactose units and one 3-deoxy-D-manno-2-octulosonic acid residues, a polymer that was previously isolated from two strains of B. cepacia genomovar I and B. cenocepacia IIIA.

Decontamination of dental unit water systems with hydrogen peroxide

AIMS

Transmission of microbial pathogens to patients from water in dental units is a concern. To reduce this risk, the decontaminating efficiency of hydrogen peroxide was evaluated.

METHODS AND RESULTS

Three percent hydrogen peroxide diluted 1 : 4 in distilled water (contact time 15 min) was used daily to disinfect the waterlines of a pilot unit previously contaminated with Pseudomonas aeruginosa or Staphylococcus aureus. The behaviour of the test bacteria was seen to differ over time. Staph. aureus numbers slowly decreased until only low numbers were recovered, after which the levels remained stable. Ps. aeruginosa abatement was more rapid and the density of the bacteria reached a peak when the circuit was empty.

CONCLUSIONS

Staph. aureus and Ps. aeruginosa treated with hydrogen peroxide fell from 6 to 4 log.

SIGNIFICANCE AND IMPACT OF THE STUDY

Treatment of dental unit waterlines with hydrogen peroxide was seen to be able to keep the number of the bacteria under control, as long as the treatment was repeated daily.

[Tobacco smoking among nursing students: behaviour and knowledge of the correlated risks]

This study was designed to assess knowledge and consumption of tobacco, during the three years of the university course for nurses in Bologna. A questionnaire consisting of items about personal details, smoking habits, and one open question about knowledge of health risks linked to tobacco consumption 505 students. 43% of males and 33% of females were current smokers. The males were mostly medium and heavy smokers (>11 cigarettes/day) and the females light smokers (<10/day). As regards knowledge an increase in both number and accuracy of the answers given by the third year students was seen. Suggestions for educational programs are given considering that the population in question is part of an "example group" who are supposed to play a role in influencing the behavior of the general population.

[Environmental diffusion of Legionella spp and legionellosis frequency among patients with pneumonia: preliminary results of a multicentric Italian survey]

A multicentric Italian investigation on legionnaires' disease is in course to clarify host factors as well as pathogen associated characteristics involved in the infection/disease. The main goal of the research plan is to account for some critical aspects concerning identification and prevention of legionellosis. To improve knowledge on factors associated with Legionella spp colonisation in hot waters, to detect cases and to characterize risk factors in subjects which develop pneumonia are specific objectives of the research programme. Preliminary results show that hot waters of houses and hotels are frequently contaminated (22.6% and 54.6%, respectively), mainly by L. pneumophila. Microbial concentrations were low in domestic waters (<1.000 ufc/l), but higher in samples from the hotels (geom. mean 1.85 x 10(3) ufc/l). Warming system, age of the plant, type of building were risk factors significantly associated with Legionella spp positivity. The active surveillance on patients affected by pneumonia with search for Legionella urinary antigen allowed the identification of 34 cases, 3 of which of nosocomial origin, corresponding to 4.2% of the screened pneumonia. After informed consent, 26 subjects were recruited for a case-control-study to clarify risk factors for the disease.

[Immigration and health: observational study concerning the foreign children attending the Bologna community pediatric service]

An analysis of the health situation of 2583 immigrant children examined by the Community Paediatric Service in the city of Bologna in 1999 and 2000 was made. The data were obtained from health records, from medical notes made in the districts or during school readmissions. Our investigation showed that: 68.8% of the children were of immigrant couples, 21.6% had at least one Italian parent, 6.0% had lost one or both parents and 3.6%, had been adopted by Italian couples; 68.8% were born in EU countries (1620 in Bologna and 133 in other regions). 99.6% of the children had received all compulsory vaccinations; 1853 subjects had also had one or more optional vaccinations: against whooping-cough 45.2%, measles 46.9% and mumps 33.8%. Only 38.5% of children had pathologies, and those most frequently encountered involved the respiratory and digestive systems. Diseases are more often infectious and allergic as in Italian population. Parasitic infections occurred more frequently than in Italian children; amoebiasis and cutaneous diseases were seen in 1.9% of the children (especially Indians). Cases of tuberculosis were limited. The children more often undergoing diagnostic investigations involving hospitalisation were from Asia and Africa. Only 10.1 of mothers and 7.6% of fathers reported medical problems; allergic pathologies were prevalent.

Immunomagnetic assay, classic culture method and fermentation tube test in the recovery of Escherichia coli O157 from sewage

The diffusion of E. coli O157 was studied in the effluents of a large sewage treatment plant. Three methods were used: the Culture Method, Immunomagnetic Separation (IMS) and Fermentation Tube Test. Vero cells assay and PCR were used to assess toxin production and the presence of virulence genes. E. coli O157 were only detected using IMS and the Fermentation Tubes Test: one strain in raw sewage and 2 in a sample of disinfected effluent. The latter resulted positive for the production of verocytotoxin and possessed genes coding for vt2 and type gamma intimin. The best results were obtained with SMAC-CT-BCIG medium. The use of various different recovery techniques confirmed the difficulty involved in isolating E. coli O157 from water samples.

Peracetic acid as an alternative wastewater disinfectant to chlorine dioxide

AIMS

The aim of this study was to compare the efficiency of peracetic acid with that of chlorine dioxide in the disinfection of wastewater from a sewage treatment plant (serving about 650 000 inhabitants) that has been using peracetic acid as a disinfectant since 1998.

METHODS AND RESULTS

A total of 23 samplings were made, each consisting of three samples: from secondary effluent, effluent disinfected with 2 mg l(-1) of peracetic acid and effluent disinfected with 2.2 mg l(-1) of chlorine dioxide (contact time 20 min). For each sample, measurements were made of the heterotrophic plate count at 36 degrees C, total and faecal coliforms, Escherichia coli, enterococci, pH, suspended solids and chemical oxygen demand (COD). During the first phase of the experiment the peracetic acid was seen to be less efficient than chlorine dioxide. To improve the disinfectant action a system of mechanical agitation was added which led to a greater efficiency in the inactivation of bacteria of faecal origin.

CONCLUSIONS

Both products were found to be influenced by the level of microbial contamination, the amount of suspended solids and COD but not by the pH of the effluent before disinfection. The immediate mixing of the wastewater and disinfectant caused a greater reduction in enterococci.

SIGNIFICANCE AND IMPACT OF THE STUDY

Since peracetic acid was seen to produce a high abatement of micro-organisms, it can be considered as a valid alternative to chlorine dioxide in the disinfection of wastewaters.

Polyalkylphenyl-sulphonic acid with acid groups of variable strength from compost

The insoluble organic fraction (humin-like material, HLM) from rice hull-dairy cattle compost is well converted into water soluble HLM-sulphonate by reaction in liquid SO3. Microanalytical, potentiometric, molecular weight, and NMR data are consistent with a highly homogeneous polymeric arylsulphonate having 4000 Da MW, 1.3 sulphonic groups per aromatic ring and significant content of carboxylic and phenolic groups. By comparison with structure-property relationships for commercial lignosulphonates derived from the pulp and paper industry, the above arylsulphonate is likely to be a candidate at a variety of applications in the chemical industry and in agriculture. Therefore, sulphonation is a means for upgrading composts HLM to the same uses as for commercial lignosulphonates.

Tobacco consumption and sports participation: a survey among university students in northern Italy

Social-demographic information of a total of 1249 students attending the University of Bologna was analyzed by means of an anonymous questionnaire containing 33 questions with particular reference to tobacco smoking and sports activity. Results revealed that 31.6% of the students practise some form of sports regularly (6 hours a week or more), 40.5% occasionally (at least an hour a week for 8 months in a year) and 27.9% do not take part in any kind of sport. Significant differences were seen between those that practise sports (60.4% are non-smokers and 33.5% are habitual smokers) and those that do not (52.9% are non-smokers and 40.1% smoke habitually). The smokers who are active in sports smoke a lower mean number of cigarettes a day than the inactive group and thus belong to the category of light smokers. They also smoke fewer cigarettes on days when they take part in sports activity. As far as knowledge of health risks is concerned, 21.1% of those who practise sports obtained a score between good and excellent compared to 15.9% of those who do not. Although on the whole the results appear to show a certain influence of sports on smoking habits, the kind of study we led and the differences in the number of smokers are not sufficient to consider sports practitioners as a group not at risk for behaviour harmful to the health. Further studies are necessary to verify the cause-effect relationship between sports activity and smoking habits.

Exopolysaccharide production by Streptococcus thermophilus SY: production and preliminary characterization of the polymer

AIMS

To evaluate the effect of yeast extract (YE) concentration, temperature and pH on growth and exopolysaccharide (EPS) production in a whey-based medium by Streptococcus thermophilus SY and to characterize the partially purified EPS.

METHODS AND RESULTS

Factorial experiments and empirical model building were used to optimize fermentation conditions and the chemical composition, average molecular weight (MW) and rheological properties of aqueous dispersions of the EPS were determined. Exopolysaccharide production was growth associated and was higher (152 mg l(-1)) at pH 6.4 and 36 degrees C with 4 g l(-1) YE. High performance size exclusion chromatography of the partially purified EPS showed two peaks, with a weight average MW of 2 x 10(6) and 5 x 10(4), respectively. The EPS was a heteropolysaccharide, with a glucose : galactose : rhamnose ratio of 2 : 4.5 : 1. Its water dispersions had a pseudoplastic behaviour and showed a higher viscosity of xanthan solutions.

SIGNIFICANCE AND IMPACT OF THE STUDY

The fermentation conditions and some properties of an EPS produced by Strep. thermophilus, a dairy starter organism, were described.

Mechanism of chiral recognition in the enantioseparation of 2-aryloxypropionic acids on new brush-type chiral stationary phases

New brush-type chiral stationary phases (CSP I-IV) comprising N-3,5,6-trichloro-2,4-dicyanophenyl-L-alpha-amino acids (1-4) were prepared by binding of chiral selectors 1-4 to gamma-aminopropyl silica gel. To check the role of excess free aminopropyl groups, CSP V was prepared by binding N-3,5,6-trichloro-2,4-dicyanophenyl-L-alanyl-(3-triethoxysilyl)propylamide to unmodified silica gel. The best separation of racemic 2-aryloxypropionic acids (TR-1-13) was obtained with CSP I; the -(-)-S enantiomer were regularly eluted first, as determined by a CD detector. The mechanism of chiral recognition implies a synergistic interaction of carboxylic acid analyte with the chiral selector and achiral free gamma-aminopropyl units on silica. In fact, CSP V, which is lacking an achiral aminopropyl spacer, shows a lower separation ability for 2-aryloxypropionic acids, but a similar enantioselective discrimination of esters TR-19-20, in comparison with CSP I. CSP I-IV retain unaltered separation ability after a few months of continuous work using a large number of various mobile phases.

Enantiomerization of 3-carbethoxy-l,4-benzodiazepin-2-one: combined chiral HPLC and spectroscopic study

Recently developed chiral HPLC columns CHIRIS AD1 and CHIRIS AD2 have been demonstrated to separate racemic, configurationally unstable ethyl-7-chloro-2-oxo-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepine-3-carboxylate (1) and its 3-methyl congener 2; fast on-column enantiomerization of configurationally unstable 1 was observed, however. Addition of 0.1% of AcOH to the eluting mixture inhibits enantiomerization, whereas the same percentage of Et(3)N completely precludes enantioseparation, suggesting base-catalysis by free beta-aminoethyl groups, present in low percentage in chiral stationary phase (CSP). When both CSPs were prepared under conditions of nonexhaustive acylation by N-DNB-alpha-aminoacids, no separation of 1 was observed. The rate of enantiomerization on CHIRIS AD2 was determined at 25 degrees C, the mechanism is discussed, and experimental results correlated with calculated relative stabilities of the tautomers la-c. Absolute (3S) configuration of (+) enantiomers of 1 and 2 was determined by comparison of their eluation profile to that of (+/-)-3 and (3S)-(+)-3, taking into account relative (psia or psie) configuration of the prevailing conformer in solution.

Airborne coagulase negative staphylococci produced by a sewage treatment plant

Since some coagulase-negative staphylococci species are involved in clinical and environmental situations, the authors carried out a study on the spread of these bacteria in the air of a sewage treatment plant. For these purposes a total of 196 samples were taken from 16 sampling stations, 11 during the day and 5 at night (only at 4 points), using the settle plate technique. Altogether 13 species of coagulase negative staphylococci were isolated: S. haemolyticus, S. xylosus and S. cohnii were particularly common. Station no. 2 (an area almost always kept closed containing the fine screens) was found to be the most contaminated. The presence of coagulase negative staphylococci was favoured by high temperatures and low humidity. No differences were found due to variations in wind speed and direction or between day and night.

Evaluation of the efficiency of peracetic acid in the disinfection of sewage effluents

AIMS

Evaluation of the efficiency of peracetic acid in the disinfection of wastewater in a large treatment plant.

METHODS AND RESULTS

Over a period of 18 months 30 sample collections were made, each consisting of three samples taken from: raw incoming sewage, secondary effluent (after 10-12 h) and secondary effluent disinfected with 1.5-2 mg l(-1) of peracetic acid (contact time: 20 min). Total coliforms and Escherichia coli declined from 10(7) MPN 100 ml(-1) in the raw sewage to 10(2) in the disinfected effluent and the enterococci fell from 10(6) MPN 100 ml(-1) to 702 MPN 100 ml(-1). The reduction of bacteria increased with the rise in temperature and decreased with the rise in BOD5.

CONCLUSIONS

Disinfection with peracetic acid reduced levels of faecal contamination by 97%, thus attaining the limit recommended by current Italian law (Escherichia coli <or= 5000 MPN 100 ml(-1)) for discharge into surface waters.

SIGNIFICANCE AND IMPACT OF THE STUDY

The process of disinfection with peracetic acid is easier to manage than other more common methods and the tests performed confirm that from the bacteriological point of view good results can be obtained for urban effluents.

Biological and molecular characterization of a pigeon paramyxovirus type-1 isolate found in Argentina

In this report, we describe the biological and molecular characterization of a paramyxovirus type-1 (PPMV-1) isolate found in wild pigeons in an urban habitat in Buenos Aires, Argentina. Of the nine pigeons captured, three were moribund, and the other six showed diarrhea, ataxia, tremor, torticolis, and wing paralysis. The intracerebral pathogenicity index was 1.29, and the amino acid (aa) sequence at the fusion protein cleavage site was 112GRQ KRF117. These characteristics correspond to a virulent Newcastle disease virus isolate. Nevertheless, it was not possible to reproduce the disease in chickens experimentally although the chickens exhibited seroconversion after inoculation. On the other hand, pigeons inoculated with the isolate became sick. These results provide further evidence about the unusual pathogenicity of PPMV-1 for chickens and show once more the need for more biological determinations in these cases to arrive at a final conclusion.

gamma-Linolenic acid production by solid-state fermentation of Mucorales strains on cereals

Oleaginous fungi of the genus Mucorales were screened for gamma-linolenic acid (GLA) production on solid substrates containing moistened cereals. Cunninghamella elegans CCF 1318 produced the highest yields of GLA when cultivated on barley. Substrate moisture and cultivation temperature proved critical for effective GLA production. Vegetable oil supplied to the cultures improved GLA production. Rotating bottles and plastic bags were used as cultivation vessels to reproduce the conditions found in rotating drums and tray bioreactors, respectively. After 11 days of cultivation at 21 degrees C, C. elegans produced 14.2 mg of GLA per gram of dry substrate, composed of a mixture of barley, spent malt grains (SMG) and peanut oil. GLA represented 15.6% of the total fatty acids in the lipid extract.

Tobacco smoking among high school students in Romagna (Italy) and evaluation of a prevention campaign

The aim of this study was to investigate the smoking habits of a sample of second year high school students in Romagna (Northern Italy) by means of an anonymous self-administered questionnaire and the efficiency of a previous health education campaign. A sample of 2,691 16-year-old pupils (74% of the school population of this age) was randomly selected. Of these, 863 (32.1%) had participated in a prevention campaign while attending middle school. 19.1% of the students who had taken part in the campaign were smokers compared to 23.2% of those who had not. The students' smoking habits were found to be influenced by the type of school and by the role models (parents, siblings, friends, teachers). The campaign appears to have had good results, especially in places where it was carried out on a wide scale. Suggestions are made for making such campaigns more efficient.

Recovery of Burkholderia pseudomallei and B. cepacia from drinking water

Samples of drinking water were examined in order to evaluate the occurrence of two gram-negative bacteria: Burkholderia pseudomallei and B. cepacia. A total of 85 samples were collected from public and private buildings in the province of Bologna (Italy). Other bacteriological indicators (heterotrophic plate count at 22 and 36 degrees C) were also examined, together with physical and chemical parameters (temperature, pH, residual chlorine, total hardness and chemical oxygen demand (COD)). High levels of B. pseudomallei were recovered (mean value = 578 cfu/100 ml) in about 7% of samples, while B. cepacia was recovered in 3.5% (mean value = < 1) of the samples. The two microorganisms were found to correlate positively with heterotrophic plate counts at 22 and 36 degrees C, but not with the physical and chemical parameters taken into consideration.

Water characteristics associated with the occurrence of Legionella pneumophila in dental units

This study evaluated the incidence of Legionella pneumophila in dental unit water samples and investigated how the occurrence of these bacteria may be related to some physical, chemical and bacteriological characteristics of the water. The samples were taken from the incoming tap water, oral rinsing cup, air-water syringe, ultrasonic scaler, and the turbine of 23 dental units of private and public institutions. Apart from L. pneumophila (serogroup 1 and 3) isolated in 22 out of the 101 (21.8%) water samples tested, two other species were found: L. bozemanii and L. dumoffii. The highest densities and frequency of L. pneumophila were observed in the water coming into the units and in the dental units of public institutions. A negative association between L. pneumophila and 36 degrees C and 22 degrees C heterotrophic total plate counts and other gram-negative bacteria was found. An inverse association between the concentration of L. pneumophila and water temperature was also observed. The values of pH and total hardness did not show any significant difference in the L. pneumophila-positive and -negative dental unit waters. Finally, the chemical oxygen demand (COD) and residual chlorine were found to correlate positively with L. pneumophila.

Occurrence and seasonal variation of airborne gram negative bacteria in a sewage treatment plant

A study was carried out to determine the microbial density and the seasonal variation of airborne Gram negative bacteria in a sewage treatment plant. Sampling was made at 16 sites and the settle plate technique was used. Of the 201 samples examined, 43.2% revealed fecal coliforms (mean value = 14 cfu/p/h), 53% Pseudomonas spp. (mean value = 11 cfu/p/h), 46.5% Shigella spp. (mean value = 13 cfu/p/h), 3% Legionella spp. (mean value = 2 cfu/p/h) and 2% Salmonella (mean value = < 1 cfu/p/h). 72% of the samples contained "other" Gram negative bacteria such as Aeromonas hydrophila, Serratia marcescens, Enterobacter cloacae and others. With the exception of Legionella spp. and Salmonella, all other bacteria were more frequent and numerous in the October-March period, when temperatures were lower and humidity higher. Although the oxidation tanks were covered overall contamination was nevertheless high, thus presenting a potential health risk for plant workers.

Striatum adenosine A2 receptors are modified during seizure: effect of cyclopentyladenosine administration

Rat CNS adenosine A2A receptors were studied after administration of the convulsant drug 3-mercaptopropionic acid (MP) and the adenosine analogue cyclopentyladenosine (CPA) by means of a quantitative autoradiographic method. Specific binding was quantified in striatum only. The highest density was found in caudate-putamen (2.50 fmol/mm2), followed by nuclei accumbens (1.85 fmol/mm2) and the lowest values in the olfactory tubercle (1.26 fmol/mm2). These differences were statistically significant. MP administration (150 mg/kg) caused significant increases (12-18%) in caudate-putamen and nuclei accumbens in both stages: seizure and postseizure and no changes in the olfactory tubercle. CPA administration (2 mg/kg) originated a rise of 16% in nuclei accumbens but no change in the other two regions. When CPA was injected 30 minutes before MP, an increase (18 to 45%) in caudate-putamen and nuclei accumbens at seizure and postseizure stages was observed. Saturation results, in striatal membrane fraction, indicate that receptor sites increased their maximal binding capacity (Bmax) while the apparent dissociation constant (Kd) remained unchanged. These results suggest the involvement of the adenosine A2A receptors in convulsant activity and that CPA administration at the dose selected brings about a rise in neuronal excitability in this area.

Newcastle disease virus surveillance in Argentina: use of reverse transcription-polymerase chain reaction and sequencing for molecular typification

Newcastle disease virus (NDV) remains a major pathogen of poultry where highly virulent strains require reporting to the Office of International Epizootes. NDV is a paramyxovirus existing as different strains classified on the basis of severity of the disease they cause. The present study was conducted in Argentina to determine the prevalence of highly virulent velogenic NDV strains in commercial poultry farms. Tracheal and cloacal swabs from 693 flocks, representing 14% of the broiler production, were collected and pooled. A pool amplified twice in embryonated eggs presented a limited hemagglutination titer. We performed reverse transcription coupled to polymerase chain reaction to amplify fusion and matrix protein gene sequences of the isolate and the strain Trenque Lauquen, isolated in Argentina during an outbreak in 1970-71 and previously characterized as velogenic viscerotropic by biological methods. The amino acid sequences were deduced from nucleotide sequences of the amplification products and the pathotype predicted according to the sequences obtained. From the samples analyzed, we found only one type of NDV, being the isolate identified as lentogenic NDV. This strain is probably the one used in vaccination of flocks where that sample was obtained. These data have allowed us to consider a velogenic NDV-free status in Argentina's commercial poultry.

Effect of heat and acid decontamination treatments on the recovery of Legionella pneumophila from drinking water using two selective media

Two different decontamination systems, heat and acid, and two isolation media, GVPC and MWY agar were tested for the recovery of Legionella pneumophila from drinking water. The samples were concentrated by filtration through 0.2 micron polyamide filter and the membranes were resuspended in the original water samples. The suspension was divided into three parts: the first was placed in a 50 degrees C water bath, the second was acidified in HCl-KCl solution and the third did not undergo any treatment. The isolation was made by means of media containing charcoal, yeast extract and glycine with cycloeximide (GVPC) or vancomycin, polimixin B, anysomicin and dyes (MWY). Heating at 50 degrees C for 30 minutes was seen to be the best decontamination system above all when used with GVPC agar. Moreover, with this pretreatment higher counts were obtained both on MWY and GVPC agar. The MWY agar produced the highest isolatin percentages and the highest counts.

Comamonas acidovorans contamination of dental unit waters

A study was carried out to evaluate the extent of the colonization of dental water systems by Comamonas acidovorans and to investigate how the occurrence of these bacteria is related to certain water characteristics. The 152 water samples were collected from the oral rinsing cup, air-water syringe, turbine and supply lines to dental units. Comamonas acidovorans was found most frequently and in greatest quantities in samples taken from water entering the units and in samples with a lower total bacterial count at 22 degrees C, higher temperature, lower content of organic matter and, in general, higher concentrations of residual chlorine.

Occurrence, removal and seasonal variation of thermophilic campylobacters and Arcobacter in sewage sludge

The presence of thermophilic campylobacters and Arcobacter was investigated in four types of sewage sludge taken from the treatment plant in Bologna (Italy): primary, activated, thickened and anaerobically digested sludge. Campylobacter jejuni and Campylobacter coli were more numerous during the March-September period and were found only in primary sludge (22.7%) with mean counts of 278 MPN/g dry matter and 1403 MPN/g dry matter respectively. Arcobacter butzleri were found in all types of sludge with frequencies of 80% in activated and thickened sludges and 41% in digested sludges. They were more numerous in the spring/summer period with peaks in April, May, June and September. They were less sensitive to anerobic digestion than fecal bacteria, probably due to their microaerophilic growth properties. However, since they are found in anaerobically digested sludges at mean values of 7649 MPN/g dry matter the land application of digested sludges may cause high risks infection.

Relationship between low lead exposure and somatic growth in adolescents

The possible effects of moderate lead exposure on human growth and development are not well defined. This study was carried out in order to evaluate the relationship between somatic growth and lead exposure. 418 subjects (202 males and 216 females) aged 11-13 years in good health and living in an area of the northern region of Italy were submitted to the following determinations: blood lead levels (PbB), serum concentrations of gonadotropins (LH, FSH) and sex-steroid hormones (DHA-S, T, E2) and anthropometric measurements (stature and weight). The mean blood levels were 85.39 and 70.08 micrograms/1, respectively, for males and females. Significant and negative relationships were found between blood lead levels and stature in 13 years old males and 12 years old females (p = 0.009 and p = 0.006, respectively). Negative relationships between lead in blood and LH and FSH were found only in males with lead levels higher than 90 micrograms/1. Our findings seem to suggest that even for low lead exposure this metal may affect stature growth and gonadotropins levels.