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Biomedical subjects

P Legnani

Publications and source records attributed to P Legnani.

At least 19 recordsLinked to original sources

Survival and growth of Pseudomonas aeruginosa in natural mineral water: a 5-year study.

A 5-year study was carried out on the growth curve of two strains of P. aeruginosa inoculated at a density of 10(2) cfu/ml into samples of natural mineral water with different levels of dissolved solids (TDS at 180 degrees C: 72.5 and 382 mg/l) and low organic content (TOC: 0.17 and 0.35 mg/l). The resulting growth curves were similar for both strains, with only slight differences depending on the different amounts of dissolved solids in the water. After 4-5 days counts were increased by 3 log units. This level was maintained until 70-100 days from inoculation, after which a slow decrease began, culminating in the death of one of the strains after 5 years. No difference in recovery was observed between the method using direct inoculation on Cetrimide Agar and the resuscitation technique (preincubation in Tryptone Soya Agar followed by inoculation on Cetrimide Agar) in the exponential phase of the growth curve. During the stationary and death phases, however, the enrichment technique gave statistically slightly higher counts than the selective technique, indicating the presence of damaged P. aeruginosa cells. The use of a resuscitation step when using Cetrimide Agar to assess bottled water quality is recommended.

Beverages↗

Risk of infection associated with microbiological quality of public swimming pools in Bologna, Italy.

Twelve public swimming pools in Bologna (Emilia-Romagna region, Italy) were investigated for the microbiological quality of water and surfaces of the pool edges, showers and changing rooms. At the same time a cross-sectional study was carried out on the health of 238 users (bathers) compared with 238 controls who practised sports other than swimming. Data regarding duration and frequency of exposure, behaviour and recent medical history were gathered by means of a questionnaire. All participants also underwent a medical examination. Compliance of the pool water to the microbiological standards set by Italian regulations was generally good; compliance was total when free chlorine residual was within the recommended limits. However, when analysis was extended to the various surfaces, potentially pathogenic bacteria such as P. aeruginosa and C. albicans were isolated. Eye burning and diarrhoea were the only declared symptoms and verrucas the only diagnosed disease showing statistically significant differences between bathers and controls. Verrucas tended to increase in proportion to exposure. Athlete's foot had a very high prevalence among both bathers (34 %) and controls (27.3%) and controls (27%). The environmental and epidemiological investigations both confirmed the risk of infection, mainly associated with the contamination of surfaces.

Bacterial Infections↗

Prevalence of mycobacteria in a swimming pool environment.

A study was performed to evaluate the prevalence of non-tubercular mycobacteria in swimming pool environments. The bacteria in question were found in 88.2% of pool water samples. The most frequent species were Mycobacterium gordonae (73.5% of samples; range 1-840 cfu 100 ml - 1), M. chelonei (38.2% 2-360 cfu 100 ml - 1) and M. fortuitum (35.3% 2-250 cfu 100 ml - 1). The same species were also recovered from the water at the different phases of the treatment cycle, with relative percentages similar to those of the pool water. Shower floors and pool edges also presented high concentrations of the mycobacteria (100% of samples) and M. marinum was isolated from the surfaces of pool edges on two occasions (4.5% of samples). The swimming pool environment provides a suitable habitat for the survival and reproduction of mycobacteria. Although mycobacteria are common in swimming pools, human mycobacterial disease associated with their use is rare. Apart from superficial infections with M. marinum, the risk of more serious diseases in subjects with weakened immune systems should not be underestimated, given the widespread presence of mycobacteria that are possible opportunistic pathogens and the direct contact bathers have with the water and aerosol.

Bacteriological Techniques↗

Use of gloves and prevalence of glove-related reactions in a sample of general dental practitioners in Italy.

OBJECTIVE: The purpose of this study was to evaluate the frequency of the use of gloves and to assess the prevalence of glove-related symptoms in a sample of Italian dentists with a high occupational exposure to latex gloves. METHOD AND MATERIALS: A 31-question instrument was mailed to all dentists (n = 550) practicing in the town of Bologna during 1994 to determine the type of procedures for which gloves were worn by dentists and the prevalence of self-reported glove-related symptoms. RESULTS: Of the dentists who replied to the items (n = 160), 94% reported that they usually wear nonsterile latex examination gloves; and 46% reported that they wear surgical gloves, even if not exclusively. About 98% reported changing gloves after contact with each patient, and 14% reported using disinfectants to treat examination gloves. Of the 106 respondents claiming to use examination gloves for surgical activities, 79 (74%) reported wearing them for extractions. Sterile surgical gloves were reported to be mostly worn for implant placement (47%) and periodontal surgery (42%). There were 46 (29%) responses indicating glove-related problems; of those subjects, 14 (30%) reported having other allergies. CONCLUSION: The use of gloves is common in the sample of Italian dentists, and the choice between nonsterile examination gloves and sterile surgical gloves seems to be made appropriately.

Dentistry↗

The occurrence of Aeromonas species in drinking water supplies of an area of the Dolomite Mountains, Italy.

A study was made of the occurrence of Aeromonas spp. in drinking water supplies in a mountain area in northeast Italy (the Dolomites). On account of its location, the water in question is exposed to a low level of pollution and systematic chemical disinfection is not necessary. Out of 7395 water samples analysed over a 3 year period, 1623 (21 x 95%) were found to be positive for Aeromonas, with levels ranging from 1 to 240 cfu 100 ml-1; 72 x 4% of the strains were identified as Aer. hydrophila, 14 x 7% as Aer. caviae and 12 x 9% as Aer. sobria. The percentage of recovery from surface water (approximately 40%) was found to be higher than that of ground water (springs: 24 x 9%; wells : 28x 6%). Aeromonas spp. were isolated from 21 x 7% of samples from the distribution network and showed no significant variations compared with water from reservoirs. There was no evidence, therefore, of after-growth in the distribution system. No correlation was found between the concentration of Aeromonas spp. and faecal indicator organisms. As the distribution of Aeromonas spp. was unrelated to anthropic pollution, it is believed that the search for these micro-organisms should be adopted as a further indicator of drinking water quality, especially in waters such as those in the present investigation not undergoing systematic purification treatment.

Aeromonas↗

Distribution of indicator bacteria and bacteriophages in shellfish and shellfish-growing waters.

Shellfish (mussels and clams) and shellfish-growing waters were examined for indicator bacteria according to the EC regulations, Salmonella spp., coliphages and anti-Salmonella phages. Samples were collected both from natural-growing areas along the coast and from authorized shellfish-harvesting beds. The coastal area was affected by organic pollution and extensive faecal contamination and, according to the legal requirements, was unsuitable for shellfish farming. The shellfish collected along the coast also showed faecal contamination at levels which did not conform to legal standards. No significant differences were observed between the frequency of isolation of somatic coliphages and indicator bacteria from sea water. In contrast, both the authorized and wild coastal shellfish were contaminated by coliphages at a significantly higher level than the corresponding bacterial indicators for faecal contamination (chi 2 test, P < 0.01). Coliphage concentrations were significantly correlated with faecal indicators in marine waters (P < 0.001) and sediments (P < 0.05), but no correlation was found in shellfish, thus showing their low specificity as indicators of faecal pollution of human origin in shellfish of economic importance.

Analysis of Variance↗

Atmospheric contamination during dental procedures.

The aim of this study was to evaluate the level of aerosol pollution following dental procedures performed in 15 sessions with an ultrasound scaler and a bicarbonate cleaner. The air contamination was measured by means of the Surface Air System method and the "plate" method (Air Microbial Index). Each colony-forming unit per cubic meter of air was allotted a unit value for statistical analysis. The data were then compared with the hygienic assessments made in previous studies. The results showed that the initial environmental conditions in a dental office initiated at the level of mediocre, then became very bad during dental procedures, and fell between mediocre and very bad at the end of the procedures.

Aerosols↗

[Food poisoning with marine animal toxins of invertebrate origin].

The consumption of seafood is increasing and hence the risk of poisoning. For this reason, the study of food poisoning caused by zootoxins from marine invertebrates has become of signal importance. These toxins come from bivalve molluscs and other species. Depending on the type of toxin concerned, poisoning attributable to molluscs may give rise to paralysis, caused by saxitossin, neurotoxic effects (gimbretoxin), or haemolysis (venerupin). Poisoning caused by coelenterates, echinoderms, cephalopods, Neptunea, abalone, crabs and lobsters is less common, and its clinical pictures and pathogenesis have not been fully established. In some instances, toxins presented in the phytoplankton ingested by these animals appear to be responsible, whereas in others its would seem that they themselves elaborate the active principles directly.

Animals↗

[Synthesis and in vitro antibacterial activity of N-methylnitrone and nitrovinyl derivatives of some N-substituted 2-chloroindol-3-carboxaldehydes].

N-methylnitrones and nitrovinyl derivatives from 1-substituted-2-chloroindol-3-carboxaldehydes were synthesized and evaluated for their in vitro antibacterial activity. Some nitrovinyl derivatives displayed good in vitro activity against Gram-positive bacteria; the compound (II e), 1-(o-chlorobenzyl)-2-chloro-3-(2-nitroethenyl)indole, was more active than nitrofurantoin against Staphylococcus aureus and Streptococcus pyogenes. Some structure-activity relationships are discussed.

Anti-Bacterial Agents↗