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Biomedical subjects

A Pantosti

Publications and source records attributed to A Pantosti.

54 records · Page 3Linked to original sources
PubMed1985

Clostridium difficile colitis in leukemia patients.

Leukemia patients with diarrhea or other abdominal symptoms have been investigated for the presence of Clostridium difficile and its cytotoxin in stools. Of the patients studied 19% had C. difficile, in most cases together with cytotoxin. All patients but one had received antibiotics, while one had been treated with cytotoxic agents only. Symptoms of colitis were most often abdominal pain and distension rather than diarrhea. Owing to the not infrequent fatal evolution, it is recommended that routine search for C. difficile in leukemia patients with abdominal symptoms be performed and appropriate therapy started immediately.

Adolescent↗
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

[Evaluation of various methods of preserving samples for the study of intestinal microflora].

Intestinal microflora changes in ten adult and healthy subjects after storage of specimen with different modalities, temperatures and times were evaluated quantitatively and qualitatively. Aerobic components (Enterobacteriaceae, Enterococcus, Staphylococcus and Bacillus spp.) did not show considerable variations of concentration in all maintenance conditions. Anaerobic components showed different capacity of survival for every researched genus: Clostridia and Lactobacilli, even kept frozen for one month in glycerol broth at -70 degrees C, maintained a stable viable count; Bacteroides, Fusobacteria, Veillonellae and Peptostreptococci were found stable after one week, while after one month showed a loss of concentration superior to 4 Log; Eubacteria were found remarkably reduced after seven days and completely lost after one month.

Adult↗
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 activity of several cytostatic drugs against aerobic and anaerobic intestinal bacteria].

The human normal intestinal flora prevents the colonization of exogenous bacteria, maintaining a constant microecology: this property is called "colonization resistance". In leukemia patients antibiotics used for prevention and/or therapy of infectious episodes can alter the intestinal microecology, so that the gut can represent the trigger zone for generalized septicemia. Moreover cytotoxic drugs used in these patients can favour intestinal disturbances. In our study we evaluated the in vitro activity of three commonly used antineoplastic drugs (Daunorubicin, Cytosine arabinoside, Methotrexate) against aerobic and anaerobic intestinal bacteria and Clostridium difficile that is the aetiological agent of pseudomembranous colitis. Daunorubicin proved to be the most active inhibiting, in concentration ranging from 16 to 128 micrograms/ml, 50% of Bacteroides strains and 90% of Clostridium difficile and Enterococci strains tested. Methotrexate showed activity only against some Bacteroides strains, while Cytosine arabinoside had no activity at all. We conclude that in these patients the use of these drugs may represent another factor of risk altering the intestinal flora and so lowering the colonization resistance.

Bacteria, Aerobic↗
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↗
PubMed1983

Pyruvate dehydrogenase activity and metronidazole susceptibility in Bacteroides fragilis.

Pyruvate dehydrogenase activity was present and comparable (giving a colour change of 202-673 od units/min/g protein in our assay system) in two clinical strains of Bacteroides fragilis exhibiting reduced sensitivity to metronidazole (MIC 2-8 mg/l at 48 h) in a resistant strain (Ingham's) of Bact. fragilis (MIC 64/mg/l) and in two sensitive strains of Bact. fragilis (MIC 0.5 mg/l). Pyruvate dehydrogenase activity was not detected in a capnocytophaga strain (sensitive to 50 micrograms disc of metronidazole), in Escherichia coli or in 'Bact. fragilis' strain (Britz) AM24s (MIC greater than 64 mg/l). Further testing of AM24s strain indicated that it was not Bact. fragilis but a facultatively anaerobic Gram-negative rod. Pyruvate dehydrogenase activity therefore, is similar in sensitive and resistant strains of Bact. fragilis and is unlikely to be related to the mechanism of resistance to metronidazole.

Bacteroides fragilis↗
PubMed1983

Norfloxacin (MK-0366) treatment of urinary tract infections in hospitalized patients.

Norfloxacin (MK-0366) is a new antibacterial agent, closely related to nalidixic acid, with broad spectrum activity against Gram-positive and Gram-negative organisms, including Pseudomonas aeruginosa. A clinical study was conducted on forty hospitalized patients with bacteriologically proven urinary tract infections; 20 patients were given norfloxacin and 20 co-trimoxazole. Clinical results were excellent in both groups; norfloxacin was effective in infections due to Ps. aeruginosa and other multi-resistant pathogens. No side effects were reported.

Adolescent↗
PubMed1982

Comparison of antisera in the fluorescent antibody test for detection of Bacteroides spp in clinical specimens.

Twenty-two known strains of the Bacteroides fragilis group of organisms and 67 clinical specimens from a variety of sites were examined by fluorescent antibody test (IFA) using two different antisera fro the rapid detection of B fragilis group of organisms. A previously reported Barts' pooled antisera was compared with a commercially produced Fluoretec kit antisera and the findings were related to routine anaerobic culture and gas liquid chromatography for short chain fatty acids. The Barts' antisera was more sensitive (88%) but less specific (88%) than the kit (sensitivity 50%, specificity 98%). This indicates that Barts' antisera picks up more positive cultures than the kit. The predictive value of a positive test was 82% for Barts' antisera and 93% for the kit. There were higher numbers of false-negatives with the kit (13/26) than with the Barts' (3/26). The predictive value of a negative test was 92% for Barts' antisera and 75% for the kit, indicating that a negative IFA test with Barts' antisera is a reliable index of the absence of the B fragilis group of organisms from clinical specimens. The implications for the use of this test in a routine laboratory are discussed.

Bacteroides↗
PubMedDate not supplied

Cephalothin, cefoxitin, or metronidazole in elective colonic surgery? A single-blind randomized trial.

A randomized controlled trial aimed at comparing the individual efficacy of cephalothin, cefoxitin, and metronidazole in the prevention of postoperative wound infection was performed among 74 colorectal surgical patients. Of 28 patients on cephalothin, seven (25 per cent) developed a postoperative infection, but among 23 patients in each of the other two groups, only one (4 per cent) in each group became infected. These results confirm the primary importance of anaerobes in the causation of postoperative sepsis after colorectal surgery.

Adult↗
PubMedDate not supplied

[Antibiotic microbial resistance surveillance in invasive infections caused by Streptococcus pneumoniae and Staphylococcus aureus: the EARSS (European Antimicrobial Resistance Surveillance System) project in Italy (April 1999-April 2000)].

This paper presents the results of an Italian multicentric study conducted in the period April 1999-April 2000 in 64 clinical microbiology laboratories, aimed at collecting antimicrobial resistance data using a standard European protocol (EARSS Project, European Antimicrobial Surveillance System). A total of 1701 strains of Staphylococcus aureus were isolated from blood and 367 strains of Streptococcus pneumoniae were isolated from blood (72.7%) or from CSF (27.3%). Methicillin resistance in S. aureus was found to be 42.1%; it was significantly higher in adults (RR = 6.6, CI 95% 2.5-17.0), in hospitals of Centre and North of Italy (respectively RR = 1.45, CI 95% 1.1-2.0; RR = 1.6, CI 95% 1.1-2.2), and in intensive care and surgery units (respectively RR = 1.8, IC 95% 1.6-2.0 and RR = 1.7, CI 95% 1.4-1.9). Penicillin resistance in S. pneumoniae was found to be 12.1%; it was higher in South Italy (RR = 3.5, CI 95% 1.9-6.6, in meningitis compared to sepsis (RR = 2.5, CI 95% 1.4-2.5) and in intensive care units compared to other departments (RR = 2.2, CI 95% 1.0-4.8). The level of erythromycin resistance in S. pneumoniae was of 28.2%, reaching 56.4% in penicillin resistant strains. These results suggest that a continued surveillance and effective control measures are required.

Adolescent↗
PubMedDate not supplied

[Antibiotic-resistance in Italy: activity of the first year of the surveillance project AR-ISS].

The antibiotic resistance surveillance project AR-ISS, started in 2001, is based on a network of 62 sentinel microbiological laboratories throughout the country. The laboratories collect and transmit data to the Istituto Superiore di Sanità on the antibiotic susceptibility of bloodstream isolates of 7 species: Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis/faecium, Klebsiella pneumoniae/oxytoca ed Escherichia coli. They also send selected bacterial strains for further characterization. Results of the first year of surveillance are presented and are compared with data from the previous study EARSS-Italia and from other European countries. Oxacillin resistance in S. aureus appears to be stable, however, it remains one of the highest in Europe (41,5%). No strain with intermediate susceptibility or resistance to vancomycin has been isolated. In S. pneumoniae, the level of penicillin resistance is moderate (10,8%), but macrolide resistance has increased greatly (37,6% versus 28,6% of the previous study), following a tendency common to several European countries. Unexpectedly, vancomycin resistance in E. faecium was found to be 18%, the highest in Europe. Presumptive ESBL production in Gram-negative organisms can be estimated at 20% in Klebsiella and 1% in E. coli. Ampicillin and ciprofloxacin resistance in E. coli (respectively 50% and 18%) are among the highest in Europe. In conclusion, the rate of antibiotic resistance in the species studied is worrisome and requires continuing monitoring. Although some activities of AR-ISS need improvements, the surveillance has the potentiality to produce relevant and representative data about antibiotic resistance in Italy that can be used for comparison at the European level.

Adolescent↗