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Roberto Cauda

Publications and source records attributed to Roberto Cauda.

At least 19 recordsLinked to original sources
PubMed2007

Metallo-beta-lactamases as emerging resistance determinants in Gram-negative pathogens: open issues.

The rapid spread of acquired metallo-beta-lactamases (MBLs) among major Gram-negative pathogens is a matter of particular concern worldwide and primarily in Europe, one of first continents where the emergence of acquired MBLs has been reported and possibly the geographical area where the increasing diversity of these enzymes and the number of bacterial species affected are most impressive. This spread has not been paralleled by accuracy/standardisation of detection methods, completeness of epidemiological knowledge or a clear understanding of what MBL production entails in terms of clinical impact, hospital infection control and antimicrobial chemotherapy. A number of European experts in the field met to review the current knowledge on this phenomenon, to point out open issues and to reinforce and relate to one another the existing activities set forth by research institutes, scientific societies and European Union-driven networks.

Anti-Bacterial Agents↗
PubMed2006

Partial protective effect of CCR5-Delta 32 heterozygosity in a cohort of heterosexual Italian HIV-1 exposed uninfected individuals.

Despite multiple sexual exposure to HIV-1 virus, some individuals remain HIV-1 seronegative (exposed seronegative, ESN). The mechanisms underlying this resistance remain still unclear, although a multifactorial pathogenesis can be hypothesised. Although several genetic factors have been related to HIV-1 resistance, the homozigosity for a mutation in CCR5 gene (the 32 bp deletion, i.e. CCR5-Delta32 allele) is presently considered the most relevant one. In the present study we analysed the genotype at CCR5 locus of 30 Italian ESN individuals (case group) who referred multiple unprotected heterosexual intercourse with HIV-1 seropositive partner(s), for at least two years. One hundred and twenty HIV-1 infected patients and 120 individuals representative of the general population were included as control groups. Twenty percent of ESN individuals had heterozygous CCR5-Delta 32 genotype, compared to 7.5% of HIV-1 seropositive and 10% of individuals from the general population, respectively. None of the analysed individuals had CCR5-Delta 32 homozygous genotype. Sequence analysis of the entire open reading frame of CCR5 was performed in all ESN subjects and no polymorphisms or mutations were identified. Moreover, we determined the distribution of C77G variant in CD45 gene, which has been previously related to HIV-1 infection susceptibility. The frequency of the C77G variant showed no significant difference between ESN subjects and the two control groups. In conclusion, our data show a significantly higher frequency of CCR5-Delta 32 heterozygous genotype (p = 0.04) among the Italian heterosexual ESN individuals compared to HIV-1 seropositive patients, suggesting a partial protective role of CCR5-Delta 32 heterozygosity in this cohort.

Journal Article↗
PubMed2006

Improving empirical antibiotic treatment using TREAT, a computerized decision support system: cluster randomized trial.

BACKGROUND: Appropriate antibiotic treatment decreases mortality, while superfluous treatment is associated with antibiotic resistance. We built a computerized decision support system for antibiotic treatment (TREAT) targeting these outcomes. METHODS: Prospective cohort study comparing TREAT's advice to physician's treatment followed by a cluster randomized trial comparing wards using TREAT (intervention) versus antibiotic monitoring without TREAT (control). We included patients suspected of harbouring bacterial infections in three hospitals (Israel, Germany and Italy). The primary outcome, appropriate antibiotic treatment, was assessed among patients with microbiologically documented infections (MDI). Length of hospital stay, adverse events, mortality (interventional trial) and antibiotic costs (both studies), including costs related to future antibiotic resistance, were compared among all included patients. RESULTS: Among 1203 patients included in the cohort study (350 with MDI), TREAT prescribed appropriate empirical antibiotic treatment significantly more frequently than physicians (70% versus 57%, P < 0.001) using less broad-spectrum antibiotics at half physicians' antibiotic costs. The randomized trial included 2326 patients, 570 with MDI. The rate of appropriate empirical antibiotic treatment was higher in intervention versus control wards [73% versus 64%, odds ratio (OR): 1.48, 95% confidence interval (CI): 0.95-2.29, intention to treat, adjusted for location and clustering]. For patients treated according to TREAT's advice in intervention wards, the difference with controls was highly significant (OR: 3.40, 95% CI: 2.25-5.14). Length of hospital stay, costs related to future resistance and total antibiotic costs were lower in intervention versus control wards. CONCLUSIONS: TREAT improved the rate of appropriate empirical antibiotic treatment while reducing antibiotic costs and the use of broad-spectrum antibiotic treatment.

Adolescent↗
PubMed2006

The importance of addressing multidrug resistance and not assuming single-drug resistance in case-control studies.

BACKGROUND: Case-control studies analyzing antibiotic exposure as a risk factor for antimicrobial resistance usually assume single-drug resistance in the bacteria under study, even though resistance to multiple antimicrobials may be present. Since antibiotic selection pressures differ depending on the susceptibility profile of the antimicrobial-resistant bacteria, an accurate assessment of whether exposure to an individual antimicrobial is a risk factor for the emergence of resistance should distinguish between single-drug-resistant and multidrug-resistant bacteria. OBJECTIVE: To determine whether the exposures to individual antibiotics that were identified as independent risk factors in case-control studies differed depending on whether single-drug-resistant or multidrug-resistant bacteria were evaluated. DESIGN: Two retrospective case-control studies were performed with data on patients harboring Pseudomonas aeruginosa strains resistant only to ciprofloxacin (CRPA) and patients harboring P. aeruginosa strains resistant to ciprofloxacin and other antibiotics (multidrug-resistant P. aeruginosa [MDR-PA]). These 2 groups were compared with patients not harboring P. aeruginosa. SETTING: Two tertiary care hospitals. RESULTS: A total of 41 patients harboring CRPA and 151 patients harboring MDR-PA were identified and matched to 192 control subjects. By conditional logistic regression, independent risk factors associated with presence of CRPA were nonambulatory status (OR, 5.6 [95% confidence interval {CI}, 1.4-23]; P=.02) and prior ciprofloxacin exposure (OR, 5.0 [95% CI, 1.2-21]; P=.03). Independent risk factors for presence of MDR-PA were a Charlson score greater than 2 (OR, 3.3 [95% CI 1.8-6.0]; P<.001) and exposure to quinolones (OR, 2.8 [95% CI, 1.2-5.0]; P=.001), third- and fourth-generation cephalosporins (OR, 3.5 [95% CI, 1.7-7.1]; P<.001), imipenem (OR, 3.8 [95% CI, 1.2-12.1]; P=.02), and/or aminoglycosides (OR, 2.3 [95% CI, 1.04-5.1]; P=.04). CONCLUSION: There were substantial differences in exposure to individual antimicrobials between patients harboring CRPA and patients harboring MDR-PA. Future case-control studies addressing risk factors for single-drug-resistant bacteria should consider the complete susceptibility profile of the bacteria under investigation.

Case-Control Studies↗
PubMed2006

A comparison between abacavir and efavirenz as the third drug used in combination with a background therapy regimen of 2 nucleoside reverse-transcriptase inhibitors in patients with initially suppressed viral loads.

BACKGROUND: Our objective was to compare the rate of viral rebound and therapy failure in patients receiving abacavir or efavirenz as the third drug (in addition to 2 non-abacavir nucleosides) in combination antiretroviral therapy (cART) and to compare the rate of metabolic alteration associated with these regimens. METHODS: We conducted a multicohort prospective observational study of human immunodeficiency virus-infected patients who had attained viral loads < or = 80 copies/mL while receiving cART, without having previously received antiretrovirals. The rates of virological rebound, therapy failure, and lipid-level alteration during follow-up were calculated as the number of events divided by person-years of follow-up (PYFU). A multivariable analysis was performed using a Poisson regression model. RESULTS: We studied a total of 744 patients; the median age was 37 years, 27% of the patients were female, and 41% were heterosexual. There was a total of 854 PYFU spent receiving efavirenz and 285 spent receiving abacavir. The nucleoside reverse-transcriptase inhibitor pairs most frequently used were zidovudine/lamivudine (66% of PYFU), stavudine/lamivudine (17.6%), and stavudine/didanosine (5.4%). The adjusted relative rates of virological failure and therapy failure for abacavir, compared with those for efavirenz, were 2.17 (95% confidence interval [CI], 1.12-4.18; P = .02) and 1.41 (95% CI, 1.01-2.01; P = .05), respectively. CONCLUSIONS: Patients with virological suppression while receiving regimens containing abacavir appear more likely to experience virological and therapy failure than those receiving efavirenz as their third drug. Although this is a selected group of adherent patients, bias cannot be ruled out, because this is a nonrandomized comparison.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Benefit of appropriate empirical antibiotic treatment: thirty-day mortality and duration of hospital stay.

PURPOSE: We evaluated the effect of inappropriate antibiotic treatment on mortality and duration of hospital stay in medical inpatients with bacterial infections. SUBJECTS AND METHODS: Two cohorts of febrile adult patients (excluding patients with acquired immune deficiency syndrome and organ transplant recipients), hospitalized in three medical centers in Israel, Italy, and Germany, were included. Patients' data were collected prospectively. Initial empirical treatment was defined as appropriate if an antibiotic prescribed within 24 hours of the first encounter with the patient matched the in vitro susceptibility of a pathogen deemed to be the likely cause of infection. The results of cultures and serologic or direct tests, and data on outcomes were collected 30 days after initiation of empirical treatment. RESULTS: A total of 920 patients (26% of 3529 included patients) had microbiologically documented infections, and mortality data were available for 895 patients (97%). Inappropriate initial antibiotic treatment was prescribed in 36% of patients (N=319). All-cause 30-day mortality rates were 20.1% (N=64) and 11.8% (N=68) in patients who received inappropriate and appropriate treatment, respectively (odds ratio=1.88, 95% confidence interval [CI], 1.29-2.72, P=.001). When adjustment was made for medical center and other variables, the association between inappropriate with mortality was significant (odds ratio=1.58, 95% CI, 0.99-2.54, P=.058). In all 3 medical centers, the mean duration of hospital stay was at least 2 days longer for patients who were prescribed inappropriate antibiotic treatment (overall P=.002). This association was consistent after adjusting for other variables (P=.006). CONCLUSION: Appropriate empirical antibiotic treatment is associated with a better survival and shortened duration of hospital stay in medical patients with bacterial infections.

Adult↗
PubMed2006

Granulocyte colony-stimulating factor enhances the in vitro cytotoxicity of gemtuzumab ozogamicin against acute myeloid leukemia cell lines and primary blast cells.

OBJECTIVE: To evaluate the effects of granulocyte colony-stimulating factor (G-CSF) on the in vitro sensitivity of acute myeloid leukemia (AML) cell lines and primary AML blast cells to gemtuzumab ozogamicin (GO). MATERIALS AND METHODS: AML cell lines and primary blasts from 10 patients with AML were first incubated for 72 hours in the presence of G-CSF (5 or 100 ng/mL) and then exposed to increasing concentrations of GO (1-1,000 ng/mL) for an additional 72 hours. RESULTS: Pretreatment with G-CSF translated into significant enhancement of GO-induced cytotoxicity in the GO-sensitive HL-60 and NB-4 cells. Conversely, the response of GO-insensitive KG-1a, TF-1, and K562 cells was unaffected by in vitro priming with G-CSF. In vitro exposure to G-CSF augmented GO-induced apoptosis in 7 of 10 primary AML samples and rendered blast cells from three refractory patients sensitive to killing effect of GO. The G-CSF-induced increase of the cytocidal activity of GO was independent of effects on the cell cycle and on the expression levels of CD33 antigen. Of potential interest, G-CSF induced dose-dependent inhibition of P-glycoprotein (P-gp/ABCB1) function in the GO-sensitive HL-60 and NB-4 cells and in blasts from three patients with AML that we tested. CONCLUSION: Collectively, our findings point to G-CSF as a potential sensitizing agent that can be exploited therapeutically to improve the clinical efficacy of GO.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2006

Lower hemoglobin levels in human immunodeficiency virus-infected patients with a positive direct antiglobulin test (DAT): relationship with DAT strength and clinical stages.

BACKGROUND: There are conflicting opinions regarding the effect of positive direct antiglobulin test (DAT) on hemoglobin (Hb) levels in human immunodeficiency virus-infected (HIV+) patients. STUDY DESIGN AND METHODS: A total of 166 samples from HIV+ outpatients were studied. The DAT was performed with the tube test and column agglutination technology (CAT). RESULTS: The DAT was positive in 18.67 percent with the tube method and 33.73 percent with the CAT. Patients with DAT-positive results showed lower Hb levels than DAT-negative patients, 12.3 g per dL versus 14.3 g per dL (p = 0.0002). The univariate logistic regression enabled us to study the phenomenon better and fit the probability of having a DAT-positive result on the basis of the Hb levels. The relationship between the CAT and the tube test when washing the red blood cells (RBC) at 4 degrees C was stronger than when washing these at room temperature (phi = 0.8156; p = 0.000). The Hb levels were significantly lower in the positive DATs of Stage C (acquired immune deficiency syndrome [AIDS]) and Stage B (symptomatic non-AIDS patients), which showed decreasing Hb values for increasing agglutination strengths (p = 0.000). Anemia was related with the DAT results (odds ratio [OR], 8.005; p = 0.000) but not to the AIDS condition (OR, 1.741; p = 0.221). DISCUSSION: Our study indicates that the DAT-positive results may be specifically related to lower Hb levels in HIV+ patients. The immunologic RBC clearance could be part of the anemic multifactorial condition in HIV+ patients.

Anemia↗
PubMed2006

Bloodstream infections caused by extended-spectrum-beta-lactamase-producing Klebsiella pneumoniae: risk factors, molecular epidemiology, and clinical outcome.

Bloodstream infections caused by extended-spectrum-beta-lactamase (ESBL)-producing Klebsiella pneumoniae isolates are a major concern for clinicians, since they markedly increase the rates of treatment failure and death. One hundred forty-seven patients with K. pneumoniae bloodstream infections were identified over a 5-year period (January 1999 to December 2003). The production of ESBLs in bloodstream isolates was evaluated by molecular methods. A retrospective case-case-control study was conducted to identify risk factors for the isolation of ESBL-producing K. pneumoniae or non-ESBL-producing K. pneumoniae isolates in blood cultures. Forty-eight cases infected with ESBL-producing K. pneumoniae isolates and 99 cases infected with non-ESBL-producing K. pneumoniae isolates were compared to controls. Risk factors for isolation of ESBL-producing K. pneumoniae isolates were exposure to antibiotic therapy (odds ratio [OR], 11.81; 95% confidence interval [CI], 2.72 to 51.08), age (OR, 1.14; 95% CI, 1.08 to 1.21), and length of hospitalization (OR, 1.10; 95% CI, 1.04 to 1.16). Independent determinants for isolation of non-ESBL-producing K. pneumoniae were previous urinary tract infection (OR, 8.50; 95% CI, 3.69 to 19.54) and length of hospitalization (OR, 1.07; 95% CI, 1.04 to 1.10). When the initial response was assessed at 72 h after antimicrobial therapy, the treatment failure rate for the ESBL-producing K. pneumoniae-infected group was almost twice as high as that of the non-ESBL-producing K. pneumoniae-infected group (31% versus 17%; OR, 2.19; 95% CI, 0.98 to 4.89). The 21-day mortality rate for all patients was 37% (54 of 147); it was 52% (25 of 48) for patients with ESBL-producing K. pneumoniae bloodstream infections and 29% (29 of 99) for patients with non-ESBL-producing K. pneumoniae bloodstream infections (OR, 2.62; 95% CI, 1.28 to 5.35). In summary, this investigation identifies epidemiological characteristics that distinguish ESBL-producing K. pneumoniae infections from non-ESBL-producing K. pneumoniae ESBL bloodstream infections.

Adult↗
PubMed2006

Evaluation of the new VITEK 2 extended-spectrum beta-lactamase (ESBL) test for rapid detection of ESBL production in Enterobacteriaceae isolates.

Extended-spectrum beta-lactamases (ESBLs) are a large, rapidly evolving group of enzymes that confer resistance to oxyimino cephalosporins and monobactams and are inhibited by clavulanate. Rapid reliable detection of ESBL production is a prerequisite for successful infection management and for monitoring resistance trends and implementation of intervention strategies. We evaluated the performance of the new VITEK 2 ESBL test system (bioMérieux, Inc, Hazelwood, Mo.) in the identification of ESBL-producing Enterobacteriaceae isolates. We examined a total of 1,129 clinically relevant Enterobacteriaceae isolates (including 218 that had been previously characterized). The ESBL classification furnished by the VITEK 2 ESBL test system was concordant with that of the comparison method (molecular identification of beta-lactamase genes) for 1,121 (99.3%) of the 1,129 isolates evaluated. ESBL production was correctly detected in 306 of the 312 ESBL-producing organisms (sensitivity, 98.1%; positive predictive value, 99.3%). False-positive results emerged for 2 of the 817 ESBL-negative isolates (specificity, 99.7%; negative predictive value, 99.3%). VITEK 2 ESBL testing took 6 to 13 h (median, 7.5 h; mean +/- SD, 8.2 +/- 2.39 h). This automated short-incubation system appears to be a rapid and reliable tool for routine identification of ESBL-producing isolates of Enterobacteriaceae.

Anti-Bacterial Agents↗
PubMed2006

Three-year clinical outcomes of resistance genotyping and expert advice: extended follow-up of the Argenta trial.

OBJECTIVE: To investigate the influence of genotypic resistance-guided HIV-treatment decisions on long-term clinical and virological outcomes in patients failing antiretroviral therapy by a prospective 30-month observation following a 6-month randomized study (Argenta trial). METHODS: Patients (n=174) with virological failure on highly active antiretroviral therapy (HAART) were initially randomized (1:1) to receive empirical therapy or guidance by genotypic resistance results. After month 6, all patients with HIV RNA >1,000 copies/ml received genotypic resistance tests and expert advice. Predictors of virological and clinical outcomes were analysed by logistic regression and Cox's regression models. RESULTS: There was a gradual increase in the proportion of patients with HIV RNA <400 copies/ml with 29.3% at 36 months (intent-to-treat) without differences between initial randomization arms. Independent predictors of 36-month virological response were the use of a salvage therapy with less daily doses and a more pronounced 3-month viral load drop. At 36 months, 84% survived without new AIDS events/death. Independent predictors of new AIDS events/death were previous AIDS events, higher baseline viral load, less pronounced 3-month viral load drop and, in a separate model, baseline protease substitutions K20M/R and 184V. CONCLUSIONS: The virological benefit of genotype-guided treatment decisions was continuously appreciable over time. Short-term virological response and viral cross-resistance were independent predictors of long-term outcomes.

Adolescent↗
PubMed2006

Lopinavir/ritonavir or efavirenz plus two nucleoside analogues as first-line antiretroviral therapy: a non-randomized comparison.

BACKGROUND: Although efavirenz (EFV) and lopinavir/ ritonavir (LPV/r) are both recommended antiretroviral agents for combination therapy in drug-naive HIV-infected patients, no randomized comparison of their efficacy and tolerability is available yet. A multi-cohort prospective observational comparative study was performed. METHODS: Efficacy was examined comparing time to virological failure, CD4 recovery and clinical progression. Tolerability was examined comparing time to treatment discontinuation for any reason and for toxicity and time to liver enzymes or lipid alterations. Survival analysis was conducted by an intent-to-treat principle using the Kaplan-Meier method, and standard and weighted Cox regression models. RESULTS: A total of 674 antiretroviral-naive patients starting a two nucleoside reverse transcriptase inhibitor regimen plus either EFV (n = 481) or LPV/r (n = 193) were examined. At baseline, patients starting LPV/r had higher HIV RNA and lower CD4+ T-cell counts. There was no difference in the adjusted hazards of virological failure (LPV/r versus EFV relative hazard [RH] 1.16, 95% confidence intervals [CI]: 0.58-2.32, P = 0.67), CD4 recovery (RH = 0.93, 95% CI: 0.66-1.30, P = 0.66), clinical progression (RH = 1.64, 95% CI: 0.70-3.84, P = 0.25), drug discontinuation for toxicity (RH = 0.92, 95% CI: 0.51-1.64, P = 0.76) and for any reason, and rates of liver enzyme and total/low density lipoprotein (LDL) cholesterol elevation. In contrast, the rate of triglycerides elevations (> 1 NCEP Adult Treatment Panel III category increase) was higher in the LPV/r group (RH = 1.69, 95% CI: 1.14-2.50; P = 0.01). Models weighted for the inverse of conditional probability of receiving either drug applied to the efficacy endpoints yielded similar results. CD4 recovery with both drugs was also similar in the lowest CD4 strata. CONCLUSIONS: Our analysis suggests similar efficacy and tolerability for EFV- or LPV/r-based first-line antiretroviral regimens. LPV/r was associated with higher rates of hypertriglyceridaemia.

Adult↗
PubMed2005

Role of lymphocyte multidrug resistance protein 1 in HIV infection: expression, function, and consequences of inhibition.

The multidrug resistance protein 1 (MRP1) is a drug transporter that protects cells from oxidative stress, which increases HIV-1 replication. The aim of this study was to characterize the expression, function, and role of lymphocyte MRP1 in HIV-1 infection and its modulation by antiretroviral drugs such as the protease inhibitors (PIs). Peripheral blood mononuclear cells (PBMCs) from HIV-positive individuals do not show significant alterations of MRP1 expression despite highly active antiretroviral therapy and HIV plasma viral load levels; however, they exhibit different intracellular MRP1 expression as compared with healthy subjects. By contrast, MRP efflux function is increased in subjects with primary HIV infection and becomes defective in later stages of the infection. PI- and probenecid (PBCD)-mediated inhibition of MRP lowers the in vitro stress-induced response of lymphoid cells by reducing the level of the specific reactive oxygen species superoxide anion and hydrogen peroxide. Finally, the blockade of MRP by PBCD and PIs down-modulates HIV-1 replication by a mechanism independent of inhibition of the HIV-1 protease. Our results are consistent with a model wherein HIV replication is favored by the MRP1-related oxidative stress and inhibition of MRP1 may contribute to the antiviral activity of PIs.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Economic evaluation of HIV treatments: the I.CO.N.A. cohort study.

OBJECTIVE: To describe the changes in costs of care for HIV-positive patients in Italy after the spread of antiretroviral combination therapies (HAART). METHODS: Five thousand four hundred and twenty-two patients from the I.CO.N.A. (Italian Cohort Naive Antiretrovirals) study were followed between 1997 and 2002. Costs included antiretroviral therapies (ART), hospital admissions, prophylaxis, and main laboratory examinations. The perspective was that of the National Health Service. RESULTS: Admission costs per person-year decreased from 2148 euro in 1997 to 256 in 2002, while the average annual costs of ART increased from 2145 to 3149 euro (1997 prices). From 1997 to 1999, ART costs increased from 42.3 to 85.9% of the total, while admission costs decreased from 42.3 to 7.0% and prophylaxis from 7.3 to 1.7%. The breakdown of ART costs shows how dual therapies decreased over time in favor of HAART, falling from 26.8% in 1997 to 5.9% in 2002. Patients with fewer than five treatment switches had the lowest costs distributions over the entire observation period. CONCLUSIONS: From 1997 to 2002 inpatient costs progressively decreased in favor of antiretroviral therapy. Annual average costs per patient decreased, while total direct costs increased over time: health resources, initially concentrated on hospitalized patients were then distributed over a growing number of subjects.

Antiretroviral Therapy, Highly Active↗