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A Deplano

Publications and source records attributed to A Deplano.

At least 37 records · Page 2Linked to original sources
PubMed1999

Portohepatic gradient and portal hemodynamics in patients with cirrhosis due to hepatitis C virus infection.

We evaluated the agreement between wedged hepatic vein pressure (WHVP), portal vein pressure (PVP), and its relationship with portal hemodynamics in 21 patients with HCV-related cirrhosis with esophageal varices. Direct measurements of the portohepatic gradient (HVPG) were obtained by ultrasound-guided fine needle puncture of the right hepatic and the portal veins. In five cases PVP was 6.4-10.4 mm Hg higher than WHVP. In 12 cases measurements were similar (WHVP - PVP < or = 3 mm Hg). In the remaining four cases WHVP was 3.6-9.6 mm Hg higher than PVP. WHVP and PVP agreement was not related to HVPG mean value, Child-Pugh score, or grading of esophageal varices. By contrast, the difference between WHVP and PVP was inversely related to the portal flow velocity (P = 0.053) and directly related to the portal vascular resistance (P = 0.02). Whereas the portal branches were visualized in patients with WHVP lower or similar to PVP, a predominant left portosystemic collateral flow was observed in patients with WHVP > PVP. Our data point out that, in patients with cirrhosis due to hepatitis C virus infection, discrepant HVPG values reflect true hemodynamic differences.

Adult↗
PubMed1998

Central venous catheter-related bacteraemia in critically ill neonates: risk factors and impact of a prevention programme.

Risk factors for central venous catheter (CVC)-related bacteraemia among infants admitted to a neonatal intensive care unit (NICU) were analysed and the impact of surveillance and continuing education on the incidence of this complication investigated. Among patients admitted to a NICU, CVC-related bacteraemia increased from 1/15 (7%) in 1987 to 11/26 (42%) in 1988 (P = 0.01). Coagulase-negative staphylococci isolated from bacteraemia patients showed clonal diversity by plasmid and chromosomal fingerprinting. A review of CVC care procedures suggested breaches in aseptic techniques. Catheter-care technique was revised to ensure maximal aseptic precautions, including the use of sterile gloves, gown and drapes. The new policy was promoted by a continuing education programme and regular feed-back of CVC-related bacteraemia incidence to NICU staff. In the four-year follow-up period, the attack-rate of CVC-related bacteraemia decreased to 18/156 (12%) patients [relative risk (RR): 0.27, 95% confidence interval (CI); 0.15-0.51; P < 0.001 vs the previous period]. By using the Cox's model proportional hazards, very low birthweight and the period before use of strict aseptic CVC care were found to be predictors of increased risk of catheter-related bacteraemia after adjustment for duration of catheterization. These data provide further evidence that strict aseptic precautions during the maintenance and utilization of CVC can contribute to lower the risk of catheter infection in critically ill neonates. Regular feedback of surveillance data was associated with a progressive decrease in incidence of infection, suggesting that it improved staff compliance with aseptic precautions.

Bacteremia↗
PubMed1998

Comparative and library epidemiological typing systems: outbreak investigations versus surveillance systems.

A number of high-resolution molecular typing systems have been developed in recent years. Their availability raises the new issues of selecting the method (s) best suited for a particular purpose and interpreting and communicating typing results. Most of the currently available methods are comparative only: they allow testing of a sample of isolates for delineation of those closely related from those markedly different in genomic backgrounds. This approach is adequate for outbreak investigation, allowing determination of clonal spread in a microenvironment and identification of the source of infection. Comparative methods with sufficient resolution for most pathogens include restriction fragment-length polymorphism (RFLP), pulsed-field gel electrophoresis (PFGE), and arbitrarily primed and randomly amplified polymorphic DNA-polymerase chain reaction (PCR) analysis. For surveillance systems, monitoring clonal spread and prevalence in populations over extended periods of time requires library typing systems. These must be standardized, must have a high throughput, and must use a uniform nomenclature. Promising or validated methods include serotyping, insertion sequence fingerprinting, ribotyping, PFGE, amplified fragment-length polymorphism (AFLP), infrequent-restriction-site amplification PCR, interrepetitive element PCR typing (rep-PCR) and PCR-RFLP of polymorphic loci. PCR methods generating arrays of size-specific amplicons (AFLP, rep-PCR) can be more reproducibly analyzed by using denaturing polyacrylamide gel or capillary electrophoresis with automated laser detection. Binary probe typing systems appear optimal and should be enhanced further through use of DNA chip technology. In these systems, amplification of polymorphic regions is followed by solid-phase hybridization with a reference panel of sequence-variant specific probes. The resulting binary type results allow determination of reproducible, numeric profiles. However, interpretation and nomenclature of typing results for large-scale surveillance purposes still require a better understanding of population structure and microevolution of most microbial pathogens.

Bacterial Infections↗
PubMed1997

Association of mutations in grlA and gyrA topoisomerase genes with resistance to ciprofloxacin in epidemic and sporadic isolates of methicillin-resistant Staphylococcus aureus.

The types of topoisomerase alterations in genomically diverse epidemic and sporadic strains of methicillin- and fluoroquinolone-resistant Staphylococcus aureus isolated from European hospitals between 1984 and 1994 were characterized. Convergent dual mutations in gyrA (codon 83, 84, or 88) and grlA (codon 79 and/or 80) were found in all strains exhibiting high-level resistance to ciprofloxacin (MIC, 16 to > or = 128 microg/ml). In some epidemic strains, the resistant phenotype and genotype appeared in the 1990s and persisted thereafter.

Anti-Infective Agents↗
PubMed1997

Typing of Staphylococcus aureus and Staphylococcus epidermidis strains by PCR analysis of inter-IS256 spacer length polymorphisms.

IS256 elements are present in multiple copies in the staphylococcal genome, either flanking the transposon Tn4001 or independent of it. PCR-based analysis of inter-IS256 spacer polymorphisms was developed for typing of methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis strains. Using SmaI macrorestriction analysis resolved by pulsed-field gel electrophoresis (PFGE) as the reference method for MRSA typing, excellent reproducibility (100%), discriminatory power (97%), and in vivo stability were observed. Good concordance of the results with those of other molecular typing methods was found for two MRSA collections. Inter-IS256 PCR analysis of a U.S. collection of MRSA strains (n = 36), previously characterized by 15 typing methods, showed more limited discrimination. Agreement was 78% with PFGE analysis and 83% with ribotyping (HindIII). Analysis of a second set of Belgian MRSA strains (n = 17), categorized into two widespread epidemic clones by PFGE analysis, showed 65% agreement. For typing of S. epidermidis strains (n = 26), inter-IS256 PCR showed complete typeability (100%) and good discriminatory power (85%). Inter-IS256 PCR analysis is proposed as an efficient molecular typing assay for epidemiological studies of MRSA or S. epidermidis isolates.

Bacterial Typing Techniques↗
PubMed1996

Inter-centre comparison of pulsed-field gel electrophoresis for the typing of methicillin-resistant Staphylococcus aureus.

The results of pulsed-field gel electrophoresis (PFGE) of chromosomal DNA of the same 12 methicillin-resistant S. aureus (MRSA) strains of diverse geographical origin, performed in three different laboratories were compared; one laboratory used field-inversion gel electrophoresis (FIGE), one used contour clamped homogenous electrophoresis (CHEF) and one used both (all manufactured by BioRad Laboratories Inc., Hercules, CA, USA). No single method produced the maximum number of chromosomal fragments from all isolates. In only four instances were the same number of fragments identified by any two techniques. Although there were similar trends in strain identification the results showed many discrepancies even with a three-band difference rule to discriminate between strains. Plasmids in seven of the isolates produced a fragment, but this did not affect discrimination of the study isolates. There is a great need to standardise methodology and produce a standard set of strains to assist in this process.

Bacterial Typing Techniques↗
PubMed1996

Comparison of pulsed-field gel electrophoresis and randomly amplified DNA polymorphism analysis for typing extended-spectrum-beta-lactamase-producing Klebsiella pneumoniae.

The incidence and transmission patterns of extended-spectrum-beta-lactamase (ESBL)-producing Klebsiella pneumoniae in patients admitted to the intensive care unit (ICU) of a university hospital were investigated over a 3-year period. K. pneumoniae isolates were characterized by antibiotic susceptibility, capsular serotyping, plasmid profiles, and pulsed-field gel electrophoresis (PFGE) of genome macrorestriction patterns with XbaI, and the results were compared with those obtained by typing with the randomly amplified polymorphic DNA (RAPD) patterns. The discriminatory power of RAPD typing was evaluated for three primers. The incidence of isolation of ESBL-producing K. pneumoniae was 2.5 cases per 1,000 admissions to the ICU versus 0.35 cases per 1,000 admissions to other units (relative risk, 7.03; 95% confidence interval, 3.89 to 12.69). Infection developed in 53% of evaluable patients. Thirty-six percent of the cases were possibly acquired in other institutions. Isolates from ICU patients were subdivided into six capsular serotypes and into four clonal groups based on antibiotype, plasmid content, and PFGE and RAPD patterns. Two clones were associated with clusters of cross-infection, involving 5 and 12 patients, respectively. Following implementation of contact isolation precautions, the incidence of nosocomial acquisition of ESBL-producing K. pneumoniae decreased from 0.55 to 0.26 cases per 1,000 admissions (P = 0.03). PFGE and RAPD analysis showed concordant results and comparable discrimination for differentiation between groups of epidemiologically related strains of ESBL-producing K. pneumoniae. More subclonal variants were determined among epidemic clones by PFGE analysis than by RAPD analysis. Both methods are useful for typing K. pneumoniae strains in epidemiological investigations, although RAPD analysis is more efficient.

Bacterial Typing Techniques↗
PubMed1995

Evaluation of pulsed-field gel electrophoresis and rep-PCR for the epidemiological analysis of Ochrobactrum anthropi strains.

Pulsed-field gel electrophoresis and polymerase chain reaction genome fingerprinting based on repetitive chromosomal sequences (rep-PCR) were used for typing 14 strains of Ochrobactrum anthropi. Six strains isolated during an outbreak of bacteraemia in patients who had received a contaminated rabbit anti-thymocyte globulin gave identical patterns by both techniques. Different patterns were found in sporadic and reference strains, except for one clinical isolate received from another hospital that showed the same pattern as the epidemic clone. This patient had also received rabbit anti-thymocyte globulin from the same source at the time of the outbreak. This study illustrates the advantages of genetic typing methods in terms of high typeability and discriminating power, even for rare pathogens. Furthermore, it highlights the need for interhospital communication for effective identification of common sources of outbreaks related to intrinsic drug contamination.

Alcaligenes↗
PubMed1995

Comparison of arbitrarily primed PCR and macrorestriction (pulsed-field gel electrophoresis) typing of Pseudomonas aeruginosa strains from cystic fibrosis patients.

Arbitrarily primed PCR fingerprinting was carried out on 43 Pseudomonas aeruginosa isolates from cystic fibrosis (CF) patients. Seventeen major groups of strains that coincided with groups also distinguished by macrorestriction (pulsed-field gel electrophoresis) typing were identified. Our results illustrated that a CF patient can carry more than one strain and can carry a given strain for long periods of time and that strains can evolve by changes in drug resistance or other phenotypic traits during long-term colonization. The arbitrarily primed PCR method is recommended for first-pass screening of P. aeruginosa isolates from CF patients, especially when many strains are to be typed, because of its sensitivity and efficiency.

Bacterial Typing Techniques↗
PubMed1994

The role of pre-core hepatitis B virus mutants on the long-term outcome of chronic hepatitis B virus hepatitis. A longitudinal study.

To define the relationship between pre-core hepatitis B virus mutants and the long-term outcome of chronic hepatitis B virus infection, we monitored the type of circulating pre-core hepatitis B virus-DNA by polymerase chain reaction and sequencing in 41 selected chronic HBsAg carriers with extensive follow up. They included 12 HBeAg-positive patients with chronic hepatitis, who seroconverted to anti-HBe during follow up and 29 anti-HBe positive patients, 23 of whom had chronic hepatitis and six acute severe exacerbation occurring spontaneously (three cases) or during antitumor chemotherapy (three cases). In the presence of HBeAg, all showed prevalence of the pre-core wild type along with high levels of viral replication and elevated alanine aminotransferase. Anti-HBe seroconversion was accompanied by a dramatic reduction of hepatitis B virus replication and normalization of alanine aminotransferase in all, except one, and by the emergence of mutated strains with a pre-core stop codon (point mutation G to A at nt 1896) that replaced the wild type in seven of the 12. Of the seven who harboured the pre-core mutant, three continued to show normal alanine aminotransferase during subsequent follow up, three had mild alanine aminotransferase elevation and one had an acute short-lived reactivation after 4.4 years of normal alanine aminotransferase. The five cases who continued to show prevalence of wild type in spite of anti-HBe seroconversion all revealed persistently normal alanine aminotransferase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Pseudomonas aeruginosa and Enterobacteriaceae bacteremia after biliary endoscopy: an outbreak investigation using DNA macrorestriction analysis.

PURPOSE: An outbreak of gram-negative bacteremia in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) was investigated to determine the sources of infection and to control transmission. PATIENTS, METHODS, AND RESULTS: The incidence of post-ERCP bacteremia increased from 1.6% (60 of 3,696) procedures to 3.6% (53 of 1,454) procedures (relative risk 2.3, p < 0.0001) after endoscopes were processed in a new automated disinfector. Bacteremia involved nine species of Pseudomonas and Enterobacteriaceae, which were also isolated from processed endoscopes. Seven epidemic strains with highly related genomic macrorestriction profiles each infected 2 or more patients, accounting for 29 (55%) episodes of post-ERCP bacteremia. Strains recovered from endoscopes and from the disinfector were associated with 22 (42%) and 5 (9%) bacteremic episodes respectively. Effective endoscope disinfection was achieved by cleansing and disinfection of a blind channel not processed in the disinfector, additional isopropanol-air flush of all channels, and auto-disinfection of the disinfector. In the following period, the incidence of post-ERCP bacteremia returned to the pre-epidemic rate (1.7%, p = 0.0001). CONCLUSION: Bacterial genome fingerprinting by macrorestriction analysis enabled delineation of a multi-strain outbreak of post-ERCP bacteremia. Cross-contamination, and to a lesser extent, common-source contamination, appeared related to inadequate disinfection of endoscopes processed in an automated disinfector.

Bacteremia↗
PubMed1993

Changes of serum 2',5'-oligoadenylate synthetase activity during interferon treatment of chronic hepatitis C.

It was our aim to evaluate whether the baseline activity of 2-5 oligoadenylate synthetase (2-5 OAS) in serum and changes induced by the treatment with interferon are relevant factors in remission of chronic hepatitis C. Seventeen out of 30 adult patients with chronic hepatitis C were randomized to receive recombinant alpha-2b interferon at the dosage of 3 MU three times weekly. By the end of the third month, nine patients had normalized transaminase levels and continued to receive 3 MU of interferon for an additional 3 months, whereas in eight non-responders the dosage was increased to 6 MU for the same period of time. A single patient responded to the increased dosage. Baseline 2-5 OAS serum activity was significantly higher in patients with chronic hepatitis when compared with normal controls. Follow-up on the 13 untreated cases showed that 2-5 OAS elevation was stable and unrelated to concomitant infections. Comparison of responders and non-responders showed that the latter had higher baseline 2-5 OAS activity, tended to have an earlier and higher peak in the enzyme during the first 4 weeks of treatment, and maintained higher levels during the first 3 months of therapy. The increased dosage of interferon in this group led to an additional, although temporary, increase in 2-5 OAS. Our data suggest that HCV infection by itself induces elevated 2-5 OAS levels. The paradoxical increase in non-responders indicates that monitoring of the enzyme in serum does not predict the response to interferon. The role of the 2-5 OAS pathway in inducing the antiviral state in HCV infection should be further evaluated at tissue level.

2',5'-Oligoadenylate Synthetase↗
PubMed1993

Concordant clonal delineation of methicillin-resistant Staphylococcus aureus by macrorestriction analysis and polymerase chain reaction genome fingerprinting.

Pulsed-field gel electrophoresis of DNA macrorestriction fragments (macrorestriction analysis) allows epidemiologic typing and delineation of genetic relatedness of methicillin-resistant Staphylococcus aureus (MRSA) by indexing variations in the global chromosome architecture. Polymerase chain reaction (PCR)-mediated genome fingerprinting can also discriminate MRSA strains by detecting locally variable DNA motifs. To assess the correlation between these methods, 48 epidemic MRSA strains collected from 20 hospitals over a 10-year period were tested in a blind comparison by (i) macrorestriction analysis with SstII or SmaI endonuclease and (ii) PCR fingerprinting with four primer sets aimed at the mecA gene, enterobacterial repetitive intergenic consensus sequences, and arbitrary sequences. Isolates were discriminated into 22 macrorestriction patterns and 15 PCR fingerprints. MRSA strains belonging to 12 distinct clones by macrorestriction analysis showed 11 distinct PCR genotypes distinguished by multiple band differences. In contrast, 34 of 37 MRSA strains found to be clonally related by macrorestriction analysis clustered in two highly related PCR genotypes that differed by a single DNA fragment (P < 0.0001). These data demonstrate concordant clonal delineation of epidemic MRSA by macrorestriction analysis and PCR fingerprinting and thereby indicate that the rapid PCR assay may be an efficient epidemiologic typing system.

Base Sequence↗
PubMed1993

Genome macrorestriction analysis of diversity and variability of Pseudomonas aeruginosa strains infecting cystic fibrosis patients.

Genome macrorestriction fingerprinting with XbaI and DraI was used to analyze the relatedness of 166 Pseudomonas aeruginosa isolates collected from 31 cystic fibrosis patients over a 1- to 20-month period and to correlate their genotype with patterns of resistance to 14 antimicrobial agents. Quantitative comparison of intra- and interpatient similarities of P. aeruginosa macrorestriction patterns disclosed two discrete ranges that clearly discriminated subclonal variation (> 80% relatedness) and clonal diversity (10 to 70% relatedness). Cloning-derived mutants exhibited up to 20% divergence of genomic macrorestriction patterns during the course of chronic colonization of individual patients. Change of susceptibility to multiple antimicrobial agents developed in 50% of sequential pairs of isolates from individual patients. Only 19% of these susceptibility changes were attributable to strain substitution, while the majority (56%) of resistance changes were associated with minor genomic variations of a persistent strain. Sixty-six percent of patients harbored one strain, and 33% carried two strains. Three common strains colonized 5 (28%) of 18 patients attending a cystic fibrosis clinic, and another two strains colonized two patient pairs (31%) of 13 patients staying at a rehabilitation center, suggesting potential cross-infection in these settings. By indexing regional polymorphisms throughout the chromosome structure, macrorestriction analysis can monitor subclonal evolution of P. aeruginosa and identify isogenic resistance mutants. Quantitative macrorestriction fingerprinting enables discrimination between clonal variants and clones of distinct origins and should therefore provide a reliable tool for investigating the mode of acquisition of P. aeruginosa in cystic fibrosis patients.

Cross Infection↗
PubMed1993

Long-term follow-up of patients with chronic hepatitis C treated with different doses of interferon-alpha 2b.

Eighty patients with chronic hepatitis C who completed a previously reported randomized controlled trial on the efficacy of interferon-alpha 2b were followed up for at least 36 mo after therapy discontinuation. Seventeen patients (21.2%) maintained normal ALT values throughout the follow-up; 63 (78.8%) either did not normalize the levels of ALT or relapsed during the follow-up. A significantly greater proportion of patients treated with 3 million units of interferon three times a week subcutaneously for 48 wk were long-term responders compared with patients treated for 24 wk. Sex, age, hepatitis C virus antibody status, source of infection and pretreatment levels of ALT were not predictive of long-term response. Cirrhosis was found to be an unfavorable predictive factor. After 3 yr of follow-up, clearance of viremia was observed in 58.9% of the 17 long-term responders but in none of the non-responders (p = 0.002). E2-NS1 antibody tested negative in 88.2% of long-term responders and in 14.3% of nonresponders (p = 0.001). Fifty-nine percent of long-term responders tested negative for C100-NS4 antibody compared with 14.3% of nonresponders (p = 0.031). No significant change was observed in other antibodies. Four long-term responders underwent liver biopsy 2 yr after discontinuation of therapy. All four patients had normal liver histology compared with baseline assessment of chronic active hepatitis in three and chronic persistent hepatitis in the other. Three of the four were negative for serum hepatitis C virus RNA.

Adult↗
PubMed1992

Genotypic and phenotypic methods for the investigation of a nosocomial Legionella pneumophila outbreak and efficacy of control measures.

To determine the source of a nosocomial outbreak of Legionella pneumophila serogroup 1 infection and the efficacy of control measures, clinical and environmental isolates were characterized by molecular subtyping and disease surveillance was conducted. The outbreak involved 32 cases (relative risk, 4.0; P less than .001 vs. previous period). Water colonization with L. pneumophila serogroup 1 and patients' exposure to faucet use incriminated the water system as the environmental source. Monoclonal antibody typing showed that patient isolates belonged mainly to type Pontiac and water isolates mainly to type Bellingham (P less than .001). By four genotypic techniques, outbreak-related isolates from patients and the water system were found to be clonally related and distinct from control strains (P less than .001). Heat and UV light treatment of the water system showed a protective efficacy of 88% (95% confidence interval, 75%-94%). These findings indicate that phenotypic variation may interfere with monoclonal antibody typing of legionellae and that waterborne legionellosis can be controlled by physical disinfection.

Belgium↗