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L Toti

Publications and source records attributed to L Toti.

At least 19 recordsLinked to original sources
PubMed2007

Comparison of different biochemical and molecular methods for the identification of Vibrio parahaemolyticus.

AIMS: Multicentre evaluation of biochemical and molecular methods for the identification of Vibrio parahaemolyticus. METHODS AND RESULTS: For the biochemical identification methods, API 20E and API 20NE and Alsina's scheme were evaluated in intra- and interlaboratory tests in order to determine the accuracy and concordance of each method. Both in intra- and interlaboratory tests, the Alsina's scheme showed the highest sensitivity (86% of correct identifications in the interlaboratory test). False-positive results were obtained by all methods (specificity was 95% for API 20E, 73% for API 20NE and 84% for Alsina's scheme) and concordance varied from 65% of API 20NE to 84% of API 20E. For the molecular identifications, polymerase chain reaction (PCR) for the detection of toxR gene, tl gene and pR72H fragment were tested on 30 strains by two laboratories. The PCR for toxR showed the highest inclusivity (96%), exclusivity (100%) and concordance (97%). CONCLUSIONS: Among the biochemical identification methods tested, the Alsina's scheme gave more reliable results; however, in order to avoid false-positive results, all the biochemical identifications should be confirmed by means of molecular methods. SIGNIFICANCE AND IMPACT OF THE STUDY: Availability of an efficient identification method of Vibrio parahaemolyticus to use in official control of fisheries products.

Bacterial Proteins↗
PubMed2004

Marginal donors in liver transplantation.

Marginal liver donor criteria included the following: obesity (weight >100 Kg or BMI >27), age >50 years; macrovesicular steatosis >50%; intensive care unit stay >4 days; prolonged hypotensive episodes of >1 hour, and <60 mm Hg with high inotropic drug use (dopamine, [DPM] > 14 microg/kg per minute); cold ischemia time >14 hours, peak serum sodium >155 mEq/L; sepsis, viral infections, and alcoholism; high levels of bilirubin, ALT, and AST, or extrahepatic neoplasia. Between August 1992 and May 2003, we performed 251 liver transplants in 241 patients of whom 155 are presently alive. We used 124 (49.4%) standard donors and 127 (50.6%) marginal donors. Among the group that received a standard donor, 81 (65.3%) are still alive. Among recipients of organs from marginal donors. 81 (63.8%) are still alive. We also assessed the quality of donors according to the severity of recipient disease. For standard donors these outcomes were 61.5% for UNOS 1, 37.5% for UNOS 2A, 73.2% for UNOS 2B, and 80% for UNOS 3 for marginal donors they were 46.1% for UNOS 1, 53.6% for UNOS 2A, 70.7% for UNOS 2B, and 63.6% for UNOS 3. Among the patients who received a liver from a donor >60 years old, there were no survivors in UNOS 1 and 2A, but there were good results in groups 2B and 3. These results suggest there is no difference between marginal and standard donors, even in sick patients, with the exception of donor age.

Age Factors↗
PubMed2002

Effects of depuration of molluscs experimentally contaminated with Escherichia coli, Vibrio cholerae 01 and Vibrio parahaemolyticus.

AIMS: The aim of the present study was to investigate the behaviour of two pathogenic vibrios (Vibrio cholerae O1 and Vibrio parahaemolyticus) during depuration and to compare it with that of Escherichia coli, used as an indicator of suitability for consumption. METHODS AND RESULTS: Samples of Mytilus galloprovincialis were experimentally contaminated with E. coli, V. cholerae O1 and V. parahaemolyticus, depurated in a pilot plant using ozone and analysed at selected intervals. Numbers of E. coli and vibrios were estimated using an MPN method. The presence of vibrios was confirmed by the use of PCR. The target genes used were ctx for V. cholerae O1 and the restriction fragment pR72H for V. parahaemolyticus. There was a substantially smaller reduction in the numbers of both vibrios (approximately 1 log) during the depuration process than of E. coli (approximately 3 log). CONCLUSIONS: The results confirm the inadequacy of E. coli as an indicator that molluscs have been cleansed of other microbiological agents. SIGNIFICANCE AND IMPACT OF THE STUDY: The study confirms the risk associated with the consumption of mussels and the need to correctly conserve and cook them prior to consumption.

Animals↗
PubMed2001

Evaluation of rapid methods for the determination of okadaic acid in mussels.

AIMS: Two different screening methods, a Buffalo Green Monkey cytotoxicity test and a biosensor test, have been considered to replace the official mouse bioassay in monitoring for okadaic acid (OA) levels in mussels. METHODS AND RESULTS: Diarrhoetic shellfish poison-contaminated mussels from the Adriatic Sea were assayed in parallel by means of the mouse bioassay and both alternative methods. Both the cytotoxicity test and the biosensor test showed high sensitivity (OA 0.01 mg g-1 hepatopancreas and 0.002 mg g-1 hepatopancreas, respectively) and a high correlation with the mouse bioassay (r=0.932, P < 0.001 and r=- 0.850, P < 0.001, respectively). CONCLUSION: Both methods are efficacious, quick, inexpensive and provide data on the amount of toxin present in mussels. SIGNIFICANCE AND IMPACT OF THE STUDY: Both methods, besides allowing the simultaneous assay of a great number of samples, comply with the ethical need to reduce the use of animals in the laboratory.

Acid Phosphatase↗
PubMed2001

Detection of Vibrionaceae in mussels and in their seawater growing area.

AIMS: The seasonal trend and frequency of detection of Vibrionaceae in seawater samples and in molluscs collected in the Adriatic Sea was measured. METHODS AND RESULTS: Over a 2-year period, 726 bacterial strains were isolated, of which 46.9% belonged to the Vibrio genus, 29.8% to the Aeromonas genus and the remaining 23.3% was made up of the Pseudomonas, Flavobacterium, Pasteurella, Agrobacterium and Ochrobacterium genera. Many of the isolated strains were shown to produce toxins. CONCLUSION: The Vibrio genus, which was isolated more often than the other genera, was particularly prevalent in summer (54.4% of the total number of bacteria isolated during this season), while it was scarce in the winter months.

Aeromonas↗
PubMed2001

Detecting the presence of infectious hepatitis A virus in molluscs positive to RT-nested-PCR.

AIMS: The objective of this study was to determine the presence of infectious hepatitis A virus (HAV) in molluscs naturally contaminated with viral HAV-RNA. METHODS AND RESULTS: One hundred and forty-two mollusc samples were analysed for the presence of viral HAV-RNA using RT-nested-PCR; positive samples were then analysed with an integrated method, cell-culture RT-PCR, to detect infectious virus. Viral HAV-RNA was detected in 34.5% of the samples while 12.7% of the total samples were positive for the presence of infectious virus. CONCLUSIONS: The results demonstrate the validity of the screening method (RT-nested-PCR) and the necessity of applying a method that is capable of detecting the presence of infectious HAV. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrates that in any case, to determine the safety for human consumption, the results of RT-nested-PCR must be confirmed with an integrated cell-culture PCR method.

Animals↗
PubMed2001

Behavior of aeromonas hydrophila in bottled mineral waters.

The growth and survival of Aeromonas hydrophila in three types of natural mineral waters were investigated. Mineral waters with different levels of mineral content (low, medium, and high) were experimentally contaminated with A. hydrophila, stored at different temperatures (10 degrees C and 20 degrees C), and analyzed at intervals over a 60-day period. Water samples that were not experimentally contaminated were investigated for indigenous A. hydrophila. The results confirmed that A. hydrophila may occur naturally in mineral waters and showed that the level of mineral content, temperature, length of storage, and, in some cases, the type of container used may favor the growth of A. hydrophila. The greatest proliferation was observed in water with a low mineral content stored in PET bottles at 10 degrees C, in which A. hydrophila peaked at day 28 (4.47 +/- 0.01 log CFU/100 ml). At 20 degrees C, the same load was observed at day 60. The presence of high densities of A. hydrophila in bottled mineral water can constitute a risk for some groups of consumers, such as elderly and immunocompromised persons.

Aeromonas hydrophila↗
PubMed1999

Detection of hepatitis A virus in shellfish by nested reverse transcription-PCR.

A method for the detection of HAV in shellfish, based on the use of guanidinium isothiocyanate-containing solution for RNA extraction and purification steps, followed by nested PCR, is hereby proposed. Tests were carried out on mollusc samples spiked with HAV strain FG. Results showed that in samples subjected only to one round of PCR it was possible to detect HAV at concentrations of 10(3)-10(4) TCID50/10 g of mollusc. The use of the nested PCR renders the system more sensitive and specific enabling the identification of HAV concentrations as low as 1 TCID50/10 g of mollusc. Furthermore thus method, in addition to allowing the avoidance of confirming tests, such as hybridization, proved to be inexpensive and simple to perform.

Animals↗
PubMed1999

Inactivation of hepatitis A virus in heat-treated mussels.

Hepatitis A is a widespread infectious disease world-wide. In Italy, shellfish consumption was shown to be a major risk factor for hepatitis A infection, especially when these products are eaten raw or slightly cooked. The aim of the present study was to evaluate Hepatitis A virus (HAV) resistance in experimentally contaminated mussels treated at different temperatures (60, 80 and 100 degrees C) for various times. The presence of HAV was evaluated by cell culture infection and reverse transcriptase-polymerase chain reaction confirmation. The experiments, carried out on HAV suspension and contaminated mussel homogenate both containing about 10(5) 50% tissue culture infectious dose ml-1, showed that, under our experimental conditions, the treatments at 60 degrees C for 30 min, 80 degrees C for 10 min and an immersion at 100 degrees C for 1 min were not sufficient to inactivate all the viruses; it was necessary to prolong the treatment at 100 degrees C for 2 min to completely inactivate the virus. Thus it is advisable to eat only cooked shellfish, paying particular attention to the times and temperatures used in the cooking process, since evidence suggests that the shellfish body may protect the virus from the heat effect.

Animals↗
PubMed1997

A rapid tissue culture assay for the detection of okadaic acid and related compounds in mussels.

Okadaic acid, the main toxin of the diarrhoetic shellfish poisoning (DSP) group, shows high cytotoxicity to Buffalo green monkey (BGM) kidney cell cultures after different times according to concentration. A rapid method of detecting the presence of okadaic acid and related compounds in contaminated mussels by means of a cytotoxicity test is presented. The method is based on direct microscopic observation of toxin-induced morphological changes in BGM cell cultures. A high correlation (r = 0.950; P < 0.001) was found between the official mouse bioassay and the cytotoxicity test conducted on naturally contaminated samples of Mytilus galloprovincialis.

Animals↗
PubMed1995

Influence of the extraction procedure on recovery of okadaic acid from experimentally contaminated mussels.

Hepatopancreas samples from mussels (Mytilus galloprovincialis) experimentally contaminated with okadaic acid were analysed with Yasumoto's mouse bioassay and HPLC. A likely effect of some components of the hepatopancreas on the results (matrix effect) was evaluated, and a possible loss of toxin during the extraction phase was quantified. Experiments were conducted by comparing two different extraction procedures. Under our experimental conditions, the results obtained from mouse bioassay showed no matrix effect with either procedure. A certain quantity of the actual amount of okadaic acid contained in the sample was found to be lost after the extraction, i.e. 10.2-17.0% in samples extracted with acetone alone and 9.8-18.5% in samples extracted with acetone and ether.

Acetone↗
PubMed1994

Diarrhetic shellfish poison in mussels: comparison of methods of detection and determination of the effectiveness of depuration.

The lack of specificity of the Yasumoto mouse bioassay for Diarrhetic Shellfish Poisoning (DSP) toxin and the possibility of obtaining false positive results, prompted a search for a suitable method to confirm doubtful results. The mouse bioassay, an enzyme-linked immunoassay (ELISA) and a tissue culture bioassay were compared; in addition the efficiency of depuration of toxic mussels in ozonized water was evaluated. DSP assay using tissue cultures was found suitable for confirming results obtained using the mouse bioassay, particularly where interpretation was difficult. The ELISA kit gave satisfactory results, but it responded only to okadaic acid and dinophysistoxin 1. Depuration reduced toxicity in some cases after 3 days of treatment.

Animals↗
PubMed1992

Ecology, metabolite production, and substrate utilization in endophytic fungi.

Endophytic fungi are a taxonomically and ecologically heterogenous group of organisms, mainly belonging to the Ascomycotina and Deuteromycotina. The isolation methods affect the species composition of the endophyte assemblage in a given host. The number of endophyte taxa isolated from a host species is usually large; however, only few, normally host specific species or strains are dominant. Endophyte assemblages are specific at the host species level, but species composition and frequencies are significantly affected by site-specific conditions. Moreover, the relative importance and number of endophytic species vary among individuals within sites. In some cases, each individual could be considered a separate ecosystem. In general, however, 40 individuals with 30 to 40 sampling units per organ and individual should be enough to detect 80% of taxa present in a given host at one site. Endophytes usually produce the enzymes necessary for the colonization of plant tissues. Substrate utilization studies and isozyme analysis have demonstrated that most endophytes are able to utilize most plant cell components. The production of growth promoting factors and of metabolites useful in the pharmaceutical and agricultural industry is widespread among endophytic fungi. The usefulness of endophytes in agricultural and pharmaceutical research is briefly discussed.

Ecology↗
PubMed1991

Meningococcal meningitis in Italy: 1887-1986.

In Italy three epidemic peaks of meningococcal meningitis have occurred reflecting pandemic recrudescence of the disease. The seasonal distribution of the disease is similar in the epidemic or non-epidemic periods. There is no significant difference in the regional distribution of the disease. The disease is more prevalent among young males. The prevalent serogroup of Neisseria meningitidis is C. There has been a decrease in resistance to sulphonamides and an increase to rifampin among the isolated strains.

Adolescent↗
PubMed1990

Depuration of Mytilus galloprovincialis experimentally contaminated with hepatitis A virus.

Mussels (Mytilus galloprovincialis) were contaminated with known amounts of laboratory strains of hepatitis A virus and Poliovirus 1 and the effectiveness of a self-cleansing mechanism was studied using a pilot depuration system. Both viruses were rapidly bioaccumulated by mussels and the maximal concentration of about 10(4) TCID50/ml was reached within 1.5 hours. Depuration was carried out up to 24 h; infectivity titer decreased to 10(2) TCID50/ml and 10(3.2) TCID50/ml within 6 h in hepatitis A virus and Poliovirus 1 contaminated mussels, respectively, but only a very slight further decrease was obtained after 24 h. E. coli was used as a control; within 24 h the concentration decreased from 40 to 2 bacteria/ml of mussel (MPN). The elimination of bacteria is not a reliable parameter to control the effectiveness of viral depuration.

Animals↗