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Objectives: To investigate the epidemiological and clinical findings of extended-spectrum β-lactamase (ESBL)-producing Providencia stuartii infections in a large Italian university hospital. Patients and methods: All consecutive episodes of P. stuartii infection that occurred during 1999-2002 were included in the study. For each patient, we recorded the area of hospitalization and drug susceptibility of the P. stuartii strains. Patients with ESBL-producing P. stuartii infection were considered cases and those with non-ESBL-producing P. stuartii infection were used as controls. Results: One hundred and sixteen (52%) out of 223 P. stuartii strains collected during the study period were found to be ESBL-producing. On the basis of PCR and DNA sequencing experiments, TEM-52 was identified in 87% of isolates and TEM-72 in 13%. All ESBL-producing P. stuartii infections were nosocomially acquired. The prevalence increased from 31% of P. stuartii infections in 1999 to 62% in 2002 (P = 0.04). All 116 strains were classified as ESBL-producing multidrug-resistant P. stuartii, since 88% of the isolates were cross-resistant to ciprofloxacin and amikacin and the other 12% were cross-resistant to ciprofloxacin and gentamicin. At logistic regression analysis, advanced age (P < 0.001), previous hospitalization (P < 0.01), neoplastic disease (P < 0.001) and previous antibiotic therapy (P < 0.001) were independent risk factors for the development of ESBL-producing infections. Conclusions: This 4 year surveillance of Providencia complaints clearly indicates that infections caused by ESBL-producing multidrug-resistant P. stuartii are an emerging problem. [ABSTRACT FROM AUTHOR]

: Background The role of Candida glabrata in fungaemia is attributed in part to its reduced susceptibility to azoles, usually due to altered expression of genes encoding drug efflux pumps. The aims of this study were to identify risk factors for fungaemia due to C. glabrata isolates with decreased susceptibility to fluconazole and to analyse the response to antifungal treatment and the clinical outcome of C. glabrata infections in hospitalized patients. : Methods A retrospective case–case–control study was conducted at a university hospital from 2000 to 2006. Three patient groups were studied: 14 patients infected by a fluconazole-less-susceptible isolate [susceptible-dose-dependent (SDD) or resistant]; 21 patients infected by a fluconazole-susceptible (FS) isolate; and 70 uninfected controls. We measured expression of the drug efflux pump-encoding CgCDR1 and CgCDR2 genes in isolates of the two infected groups using quantitative real-time PCR. : Results Multivariable analysis found that patients with prior fluconazole use [odds ratio (OR) 12.24, 95% confidence intervals (CIs) 1.77–84.39, P = 0.01], diabetes (OR 10.47, 95% CI 1.96–55.96, P = 0.006) and a central venous catheter (CVC) (OR 8.48, 95% CI 1.82–39.36, P = 0.006) were more likely to develop fungaemia due to a less-susceptible isolate. Previous surgery (OR 7.73, 95% CI 2.18–27.41, P = 0.002) was an independent risk factor for fungaemia due to a susceptible isolate, in addition to the presence of a CVC (OR 5.48, 95% CI 1.69–17.72, P = 0.004). The crude 30 day mortality rate was high for both case groups. Seven patients received inadequate antifungal treatment, including five infected by a fluconazole-resistant isolate but empirically treated with fluconazole; six of these seven patients died. Expression of the CgCDR genes was up-regulated in all fluconazole-resistant and, to a lesser extent, SDD isolates, but not in the FS isolates. : Conclusions Our data suggest that when candidaemia is suspected or detected, a more broad-spectrum antifungal drug (i.e. echinocandins or amphotericin B) should be considered as initial treatment for patients with prior azole exposure. [ABSTRACT FROM AUTHOR]

: Background Current evidence does not provide a clear definition of the association between methicillin-resistant Staphylococcus aureus (MRSA) isolation and previous antibiotic use. A systematic review was performed to determine whether antibiotic exposure is a risk factor for the isolation of MRSA. : Methods MEDLINE and EMBASE databases were searched to identify studies published between 1976 and 2007 on the role of antibiotics as a risk factor for MRSA isolation in adult patients. The outcome of interest was MRSA isolation. Summary statistics were risk ratios (RR) comparing MRSA-positive patients to those without S. aureus isolation or with methicillin-susceptible S. aureus isolation. : Results Seventy-six studies, including a total of 24 230 patients, met the inclusion criteria. Antibiotic exposure was determined in the 126 ± 184 (mean ± SD) days preceding MRSA isolation. The risk of acquiring MRSA was increased by 1.8-fold [95% confidence interval (CI), 1.7–1.9; P < 0.001] in patients who had taken antibiotics. The RR for single classes of antibiotics was 3 (95% CI, 2.5–3.5) for quinolones, 2.9 (95% CI, 2.4–3.5) for glycopeptides, 2.2 (95% CI, 1.7–2.9) for cephalosporins and 1.9 (95% CI, 1.7–2.2) for other β-lactams. Significant heterogeneity was detected among studies. A regression analysis revealed that the heterogeneity was linked to the length of time in which antibiotic exposure was detected before MRSA isolation (more or less than 180 days). : Conclusions This meta-analysis shows a clear association between exposure to antibiotics and MRSA isolation. This information may be useful for researchers in designing future studies and for policy decision-making on the appropriate management of antibiotic therapies. [ABSTRACT FROM AUTHOR]

: Background Prediction of bacterial infections and their pathogens allows for early, directed investigation and treatment. We assessed the ability of TREAT, a computerized decision support system, to predict specific pathogens. : Methods TREAT uses data available within the first few hours of infection presentation in a causal probabilistic network to predict sites of infection and specific pathogens. We included 3529 patients (920 with microbiologically documented infections) participating in the observational and interventional trials of the TREAT system in Israel, Germany and Italy. Discriminatory performance of TREAT to predict individual pathogens was expressed by the AUC with 95% confidence intervals. Calibration was assessed using the Hosmer–Lemeshow goodness-of-fit statistic. : Results The AUCs for Gram-negative bacteria, including Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella spp. and Escherichia coli, ranged between 0.70 and 0.80 (all significant). Adequate calibration was demonstrated for any Gram-negative infection and individual bacteria, except for E. coli. Discrimination and calibration were acceptable for Enterococcus spp. (AUC 0.71, 0.65–0.78), but not for Staphylococcus aureus (AUC 0.63, 0.55–0.71). The few infections caused by Candida spp. and Clostridium difficile were well predicted (AUCs 0.74, 0.54–0.95; and 0.94, 0.88–1.00, respectively). The coverage with TREATs recommendation exceeded that observed with physicians treatment for all pathogens, except Candida spp. : Conclusions TREAT predicted individual pathogens causing infection well. Prediction of S. aureus was inferior to that observed with other pathogens. TREAT can be used to triage patients by the risk for specific pathogens. The systems predictions enable it to prescribe appropriate antibiotic treatment prior to pathogen identification. [ABSTRACT FROM AUTHOR]