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Biomedical subjects

I Luzzi

Publications and source records attributed to I Luzzi.

At least 55 records · Page 3Linked to original sources
PubMed1992

Hemolytic-uremic syndrome and Vero cytotoxin-producing Escherichia coli infection in Italy. The HUS Italian Study Group.

In a 3-year prospective study, 49 Italian children with the hemolytic-uremic syndrome (HUS) were examined for evidence of infection with Vero cytotoxin-producing Escherichia coli (VTEC). Diagnosis of infection was established in 37 patients (75.5%) by the combined use of stool examination for VTEC and for free fecal neutralizable Vero cytotoxin and serum analysis for antibodies to the Vero toxins and the lipopolysaccharides (LPS) of three major VTEC serogroups (O157, O26, O111). Anti-LPS antibodies were detected in sera from 30 patients: 25 had antibody to O157 LPS, 4 to O26, and 1 to O111. In as many as 27 patients (55.1%), diagnosis of infection relied only on serologic findings, and the presence of antibody to LPS was the sole evidence of VTEC infection in 20 patients (40.8%). The use of LPS from different E. coli serogroups provided evidence that in Italy O157 strains are the most prevalent VTEC involved in HUS.

Adolescent↗
PubMed1990

Isolation in Italy of a verotoxin-producing strain of Escherichia coli O157:H7 from a child with hemolytic-uraemic syndrome.

Verotoxin-producing Escherichia coli O157:H7 was isolated for the first time in Italy from a child with hemolytic-uremic syndrome and his asymptomatic sister. Both parents remained asymptomatic, and neither had evidence of this infection. The source of the infection was not identified, but the children had eaten ground beef during the 15 days prior to the onset of symptoms.

Bacterial Toxins↗
PubMed1988

Clostridium difficile in preterm neonates.

Stool specimens from premature neonates over the first month of life were examined for the presence of toxigenic Clostridium difficile and to evaluate a possible correlation between colonization and bowel disorders or prior antibiotic administration. Results showed a high isolation rate (63%) of Clostridium difficile with similar incidence in infants treated or not with antibiotics and with or without bowel disorders. Differentiation among strains according to SDS-PAGE, antibiotic susceptibility patterns and toxin production were useful to reveal cross-contamination. Both toxin-producing and non toxigenic strains were found in the infants' intestines. However, toxigenic strains were only present in infants suffering from bowel disorders and thus treated with oral antibiotics, suggesting that these factors may favour colonization by toxigenic strains.

Bacterial Proteins↗
PubMed1986

Detection of clostridial toxins in stools from children with diarrhoea.

A cell-culture assay was used to detect toxins directly in stools from sporadic cases of infantile diarrhoea. Cytotoxins were revealed in 11 out of 58 samples from children with diarrhoea, nine of whom had no common enteric pathogens in their stools. A preliminary characterisation of the cytotoxins was obtained by neutralisation tests with clostridial antitoxins.

Bacterial Proteins↗
PubMed1985

Comparison of the in vitro activities of teicoplanin and vancomycin against Clostridium difficile and their interactions with cholestyramine.

The in vitro activity of teicoplanin was compared with that of vancomycin against fecal isolates of Clostridium difficile. All strains were susceptible to both antibiotics, but teicoplanin was fourfold more active than vancomycin. Cholestyramine was found to bind teicoplanin almost completely, reducing its activity to nondetectable levels.

Anti-Bacterial Agents↗
PubMed1985

Evaluation of gas-liquid chromatography for the rapid diagnosis of Clostridium difficile associated disease.

Direct gas-liquid chromatography of faecal specimens with isocaproic acid as a marker was used for the rapid diagnosis of Clostridium difficile associated diarrhoeal diseases. Ninety stools were examined and results were compared with conventional culture on selective medium and cytotoxin assay in tissue culture. Using a combined analysis of isocaproic acid and butyric acid peak heights we defined three categories: positive, negative, and indeterminate. When the indeterminate group was excluded, the positive and negative predictive values of gas-liquid chromatography analysis were 86.9% and 85% respectively compared with culture and 71.4% and 95% respectively compared with cytotoxin assay.

Caproates↗
PubMed1985

Clostridium difficile isolation in leukemic children on maintenance cancer chemotherapy. A preliminary study.

Between December 1982 and November 1983, stool specimens from 15 children with acute lymphoblastic leukemia, who were on maintenance cancer chemotherapy, were examined weekly for the presence of Clostridium difficile and its toxin. Four out of 15 patients were positive for C. difficile: three patients had stool specimens that did not contain toxin, but cultures yielded growth of toxigenic C. difficile on only one occasion. The fourth patient, who had a recent history of hospitalization, particularly aggressive cancer chemotherapy, neutropenia, and antibiotic therapy, excreted both C. difficile and its toxin for at least 1 month. All children were asymptomatic at the time of positive cultures. This preliminary study reveals a low rate of C. difficile colonization in leukemic children on maintenance cancer chemotherapy.

Adolescent↗
PubMed1984

Cytotoxin and enterotoxin production by Clostridium difficile.

30 strains of Cl. difficile isolated from faeces of patients with pseudomembranous colitis (PMC), antibiotic associated diarrhoea (AAC) and other intestinal disorders and from faeces of asymptomatic carriers were studied for production of toxins. Tissue culture assay was used for the detection of cytotoxin (toxin B) and ileal loop test for enterotoxin (toxin A). All Cl. difficile isolates from patients with PMC and AAC were found to produce cytotoxin, whereas enterotoxin was demonstrated only in approximately 70% of strains.

Animals↗
PubMed1984

In vitro susceptibility of Clostridium difficile isolates to 12 antimicrobial agents.

The "in vitro" susceptibility of 48 strains of "Clostridium difficile" to 12 antimicrobial agents was determined by agar dilution method. All isolates were susceptible to ampicillin, metronidazole, piperacillin, vancomycin and N-formimidoylthienamycin, resistant or intermediate to the new cephalosporins: cefoxitin, cefotaxime and moxalactam. For clindamycin, the MIC distribution appeared to be bimodal with 41.7% of the strains susceptible to 8 micrograms/ml and 58.3% resistant to 128 micrograms/ml; 90% of these strains were also resistant to erythromycin, tetracycline and chloramphenicol. The percentage of resistant strains in the isolates from patients with pseudomembranous colitis is significantly higher than in the isolates from patients with antibiotic-associated colitis.

Anti-Bacterial Agents↗
PubMed1979

[Intestinal bacterial flora in normal adults].

In this preliminary study we have examined 12 healthy men aged between 20-60 years, by three specimens each. All the isolated could be assigned to genera by biochemical tests and gas-liquid chromatography. The results showed a 10(8)/g concentration of aerobe bacteria in faeces and a 10(10)/g concentration of anaerobe non sporing bacteria. The results of the count of Clostridia showed a variability among the examined individuals. The predominant groups of aerobes in the faeces were found to be E. coli and S. faecalis spp. and the predominant group of non sporing anaerobes were Bacteroides and Bificobacteria. These results were similar to the data obtained from foreign AA., showing the predominance of anaerobes in the faeces and particularly of Bacteroides.

Actinomycetaceae↗
PubMed1979

[Methods for collection, transport and culture media].

A crucial factor affecting the ultimate success of anaerobic cultures is a proper specimen collection, with care to avoid inclusion of normal flora often present on human mucosa. In general, material for anaerobic cultures is best obtained using a needle and syringe, from which the air must be expelled. Then the specimens should be placed immediately into an anaerobic transport broth and then in suitable culture pre-reduced media.

Anaerobiosis↗
PubMed1979

[Technics for isolation, incubation and preliminary identification tests].

In this report the AA. emphasize the fact that anaerobes are mostly isolated from mixed cultures in which several bacteria are present. Therefore they suggest to grow all the bacteria under the best conditions and consequently to select the anaerobes from the aerobes. Furthermore they describe the selecting techniques used at Istituto Superiore di Sanità and Clinica Medica III, to attain this aim and enumerate the best methods used for anaerobic incubation.

Actinomycetaceae↗
PubMed1979

[A definitive identification method: gas-liquid chromatography].

The definitive identification of many anaerobes requires the use of gas-liquid chromatography to detect alcohol and volatile acids end-products of their metabolism. In this study we have used the gas-liquid chromatography for the identification of 360 non sporing anaerobes isolated from faeces of healthy individuals. These analyses were performed on a Variant-Aerograph mod. 2700 gas chromatography fitted with a column without phosphoric acid. The results showed a good percentage of typing (83%).

Actinomycetaceae↗
PubMed1977

Heterogeneity of purified cholera toxin.

The heterogeneity of Vibrio cholerae toxin, obtained from culture filtrates in homogeneous form by gel filtration and preparative disc gel electrophoresis has been studied. By means of disc electrophoresis on polyacrylamide gel cholera toxin was separated into three forms designated I (5%), II (15%) and III (80%). The toxic activity, amino acid content and molecular weight of the three forms were similar. The difference so far observed between the various electrophoretic fractions is a difference in net charge. Incubation of either cholera toxin II or cholera toxin III at relatively high pH leads to the formation of the more acidic forms. These forms, generated in vitro by deamidation of asparagine and/or glutamine residues, are indistinguishable from the toxins of similar electrophoretic mobilities isolated from crude culture filtrates.

Bacterial Toxins↗