Candidaemia in internal medicine departments: the burden of a rising problem.

Although internal medicine wards (IMWs) represent a significant reservoir of patients with candidemia, few investigators have specifically addressed the epidemiological aspects of candidaemia in this population. Of all patients hospitalized during the study period with candidaemia, 133/348 (38%) were admitted to IMWs. Variables associated with IMWs included: antibiotic therapy prior to hospitalization, urinary or central venous catheter, parenteral nutrition, tumour and age >75 years. Overall, 30-day mortality in IMWs was significantly higher than that in other wards (51.1% vs. 38.2%, p <0.02). Multiple logistic regression analysis identified the administration of antifungal treatment 48 h after having the first positive BC as an independent determinant of hospital mortality. Patients with candidaemia in IMWs account for a substantial proportion of patients with candidaemia and have higher mortality compared with patients in other wards.

Risk factors and mortality of healthcare-associated and community-acquired Staphylococcus aureus bacteraemia.

Staphylococcus aureus bacteraemia (SAB) is a leading cause of mortality and morbidity in both nosocomial and community settings. The objective of the study is to explore epidemiological characteristics and predisposing risk factors associated with healthcare-associated (HCA) and community-acquired (CA) SAB, and to evaluate any differences in mortality and efficacy of initial antimicrobial therapy on treatment outcome. We conducted a two-part analysis. First, a triple case-control study in which groups of HCA SAB with onset ≥ 48 h after hospital admission (HCA ≥ 48 h), HCA SAB with onset <48 h of hospital admission (HCA <48 h), and CA SAB were compared with controls. Second, a cohort study including all patients with SAB was performed to identify factors associated with in-hospital mortality. SAB was diagnosed in 165 patients over the study period (January 2007 to December 2007). Five variables were independently associated with HCA ≥ 48 h SAB: presence of central venous catheter, solid tumour, chronic renal failure, previous hospitalization and previous antibiotic therapy. Significant risk factors for HCA <48 h SAB were: Charlson Comorbidity Index ≥ 3, previous hospitalization, living in long-term care facilities and corticosteroid therapy. Factors independently associated with CA SAB were: diabetes mellitus, HIV infection and chronic live disease. Patients with HCA <48 h SAB were significantly more likely to receive initial inadequate antimicrobial treatment than patients with CA or HCA ≥ 48 h SAB (44.8% versus 33.3% and 31.5%, respectively). Logistic-regression analysis identified three variables as independent predictors of mortality: presentation with septic shock, infection with methicillin-resistant S. aureus, and initial inadequate antimicrobial treatment. More than half of patients with SAB have MRSA strains and presentation with septic shock, and inappropriate empirical therapy was associated with increased mortality.

Sequential outbreaks of multidrug-resistant Acinetobacter baumannii in intensive care units of a tertiary referral hospital in Italy: combined molecular approach for epidemiological investigation.

A laboratory-based surveillance study was conducted from January 2007 to May 2010 in San Martino Tertiary Referral Hospital in Genoa, Italy in which the molecular epidemiology of multidrug-resistant Acinetobacter baumannii was investigated in the five intensive care units (ICUs). A total of 53 A. baumannii strains were isolated from patients admitted to ICUs (69.8%) and to other epidemiologically linked hospital wards (30.2%) and were genotyped by repetitive extragenic palindromic polymerase chain reaction (REP-PCR), multilocus sequence typing (MLST) and adeB sequence typing. REP-PCR fingerprinting analysis, MLST and adeB typing results were well correlated and allowed us to classify strains causing epidemic events into three major epidemic clones: A (REP-I/ST4, adeB-STII genotype) isolated for the first time in May 2007, B (REP-IV/ST95, adeB-STI genotype) from November 2007 to May 2009 and C (REP-VII/ST118, adeB-STII genotype) from July 2008 to May 2010. MLST results demonstrated that epidemic clones A and C were related as they were members of the widespread clonal complex CC92. The genetic determinants of carbapenem resistance were investigated and resistance associated with the presence of the bla(OxA-58-like) gene with ISAba2 and ISAba3 elements flanking it in clone A, and with the bla(OxA-23-like) gene flanked by ISAba1 in clones B and C. A molecular approach allowed the prompt introduction of infection control measures and the evaluation of data in a global epidemiological context.

Multidrug-resistant Pseudomonas aeruginosa bloodstream infections: risk factors and mortality.

We retrospectively studied patients diagnosed with P. aeruginosa bloodstream infections (BSIs) in two Italian university hospitals. Risk factors for the isolation of multidrug-resistant (MDR) or non-MDR P. aeruginosa in blood cultures were identified by a case-case-control study, and a cohort study evaluated the clinical outcomes of such infections. We identified 106 patients with P. aeruginosa BSI over the 2-year study period; 40 cases with MDR P. aeruginosa and 66 cases with non-MDR P. aeruginosa were compared to 212 controls. Independent risk factors for the isolation of MDR P. aeruginosa were: presence of central venous catheter (CVC), previous antibiotic therapy, and corticosteroid therapy. Independent risk factors for non-MDR P. aeruginosa were: previous BSI, neutrophil count <500/mm3, urinary catheterization, and presence of CVC. The 21-day mortality rate of all patients was 33·9%. The variables independently associated with 21-day mortality were presentation with septic shock, infection due to MDR P. aeruginosa, and inadequate initial antimicrobial therapy.

Impact of limited cephalosporin use on prevalence of methicillin-resistant Staphylococcus aureus in the intensive care unit.

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a leading pathogen causing nosocomial infections. Many studies have shown that the restricted use of antibacterials is associated with a decline in resistance. To establish whether an intervention protocol designed to limit the use of cephalosporins can lower mRSA infection rates and impact on Gram-negative bacteria susceptibility in an intensive Care Unit (ICU), we conducted a prospective, non-randomized, before-after intervention study in an 18-bed ICU in Genoa, Italy. The intervention was a hospital antibiotic control policy and the observation was routine monitoring for nosocomial infections and antibiotic use, recording periodically the incidence density and MRSA prevalence. The intervention included a new antibiotic guideline that restricted the use of cephalosporins for all ICU inpatients. The analysis showed that the intervention determined a significant reduction in cephalosporin usage (-70.3%), while fluoroquinolones, mainly ciprofloxacin, increased after introduction of the antibiotic policy (+46.5%). A significant reduction in the percentage of MRSA infections (-30%) and heterogeneous susceptibility patterns in Klebsiella pneumoniae and Pseudomonas aeruginosa were noted.

Colistin and rifampicin in the treatment of multidrug-resistant Acinetobacter baumannii infections.

OBJECTIVES: The increased incidence of nosocomial infections by multidrug-resistant organisms has motivated the re-introduction of colistin in combination with other antimicrobials in the treatment of infections. We describe the clinical and microbiological outcomes of patients infected with multidrug-resistant Acinetobacter baumannii who were treated with a combination of colistin and rifampicin. PATIENTS AND METHODS: Critically ill patients with pneumonia and bacteraemia caused by A. baumannii resistant to all antibiotics except colistin in medical and surgical intensive care units were enrolled. Clinical and microbiological responses and safety were evaluated. RESULTS: Twenty-nine patients (47 +/- 14 years and APACHE II score 17.03 +/- 3.68), of whom 19 were cases of nosocomial pneumonia and 10 were cases of bacteraemia, were treated with intravenous colistin sulphomethate sodium (2 million IU three times a day) in addition to intravenous rifampicin (10 mg/kg every 12 h). All A. baumannii isolates were susceptible to colistin. The mean duration of treatment with intravenous colistin and rifampicin was 17.7 (+/-10.4) days (range 7-36). Clinical and microbiological responses were observed in 22 of 29 cases (76%) and the overall infection-related mortality was 21% (6/29). Three of the 29 evaluated patients (10%) developed nephrotoxicity when treated with colistin, all of whom had previous renal failure. No cases of renal failure were observed among patients with normal baseline renal function. No neurotoxicity was noted. CONCLUSIONS: Colistin and rifampicin appears to be an effective and safe combination therapy for severe infections due to multidrug-resistant A. baumannii.

New diagnostic tools for neonatal sepsis: the role of a real-time polymerase chain reaction for the early detection and identification of bacterial and fungal species in blood samples.

Early diagnosis and treatment of neonatal sepsis are essential to prevent severe and life threatening complications. Consequently, rapid diagnostic tests capable to differentiate infected from non-infected newborns have the potential to make a significant impact on neonatal care. A new real-time polymerase chain reaction (PCR; LightCycler SeptiFast test M GRADE) has been proposed in the routine assessment of neonatal sepsis for the detection and identification of bacterial and fungal DNA from microorganisms which cause approximately 90% of all blood stream infections. The LightCycler SeptiFast test can detect and identify simultaneously the 25 most important bacterial and fungal species causing bloodstream infections within few hours by using a small volume of a single whole blood sample. Real-time PCR can be easily incorporated into the hospital setting for term or near-term infants admitted to the neonatal intensive care unit for sepsis evaluation.

Antimicrobial use and resistance among Gram-negative bacilli in an Italian intensive care unit (ICU).

Gram-negative bacilli antimicrobial resistance remains a significant problem for patients in the intensive care unit (ICU). We performed a retrospective analysis of microbiological data and antibiotic consumption over a 4-year period (2000-2003) in an Italian ICU. Pseudomonas aeruginosa and Klebsiella pneumoniae represented approximately 40% of all isolates. The most significant trend in antimicrobial use was an increase in use of 3(rd )generation cephalosporins, imipenem, and ciprofloxacin. A significant trend toward an increase in resistance rates to piperacillin, 3( rd )generation cephalosporins and ciprofloxacin was observed for K. pneumoniae and a positive correlation between resistance and drug-usage was evident for K. pneumoniae and piperacillin, cefotaxime, ceftazidime, cefepime, and ciprofloxacin, but not for piperacillin/tazobactam. No statistically significant correlations were evidenced for P. aeruginosa. Trends in resistances were studied also for Serratia spp and Proteus spp. Isolation rates of extended-spectrum beta-lactamase (ESBL)-producing strains in pathogens studied were high, especially for K. pneumoniae (72%, 160/222) and Proteus spp (41%, 18/43). In conclusion, the study showed high resistance among Gram-negative organisms isolated in the ICU and significant ESBL production. A significant correlation between antibiotic consumption and increasing resistance was evident for K. pneumoniae.

6-(14C)-orotate uptake and rna synthesis by liver from thyroidectomized rats treated with 3,5,3'-triiodo-1-thyronine (t3).

It has been shown that T3 administration to thyroidectomized rats induces a marked increase of the in vivo labelling of liver nuclear RNA by 6-[14C]-orotic acid and, although to a lesser extent, of the radioactivity of the acid-soluble fraction. Therefore, in evaluating the real increase in RNA synthesis induced by T3 administration it has been taken into account that the hormone stimulates the uptake of the labelled precursor by the liver and enhances the specific activity of the nucleoside and nucleotide pool. The greater penetration of orotate into the liver does not depend on the increased RNA synthesis since it is not prevented by the administration of actinomycin D which markedly inhibits the transcriptional process. These findings indicate that the increased uptake of orotate and the stimulation of RNA synthesis represent distinct effects of the thyroid hormone on its target tissue.