Outcome of Transplantation Using Organs From Donors Infected or Colonized With Carbapenem-Resistant Gram-Negative Bacteria.

Donor-derived infections due to multidrug-resistant bacteria are a growing problem in solid organ transplantation, and optimal management options are not clear. In a 2-year period, 30/214 (14%) recipients received an organ from 18/170 (10.5%) deceased donors with infection or colonization caused by a carbapenem-resistant gram-negative bacteria that was unknown at the time of transplantation. Among them, 14/30 recipients (47%) received a transplant from a donor with bacteremia or with infection/colonization of the transplanted organ and were considered at high risk of donor-derived infection transmission. The remaining 16/30 (53%) recipients received an organ from a nonbacteremic donor with colonization of a nontransplanted organ and were considered at low risk of infection transmission. Proven transmission occurred in 4 of the 14 high-risk recipients because donor infection was either not recognized, underestimated, or not communicated. These recipients received late, short or inappropriate posttransplant antibiotic therapy. Transmission did not occur in high-risk recipients who received appropriate and prompt antibiotic therapy for at least 7 days. The safe use of organs from donors with multidrug-resistant bacteria requires intra- and inter-institutional communication to allow appropriate management and prompt treatment of recipients in order to avoid transmission of infection.

Role of empirical and targeted therapy in hospitalized patients with bloodstream infections caused by ESBL-producing Enterobacteriaceae.

BACKGROUND: Bloodstream infection (BSI) due to extended-spectrum ß-lactamase (ESBL) producing Enterobacteriaceae are a major cause of in-hospital mortality. The effect on survival of empirical and targeted antibiotic therapy in these patients remains controversial. METHODS: A prospective cohort study was conducted analyzing data from 94 patients (age 59 ± 21 years) with BSI due to ESBL producing strains (Sixty-one E. coli, 26 K. pneumoniae, 4 Proteus spp and 3 Enterobacter spp). RESULTS: Risk factors associated with 21-day mortality at univariate analysis were: recent administration of antibiotic therapy (p=0.049), higher SOFA score (p=0.05), ICU stay (p <0.01), hypotension at presentation (p =0.001) or septic shock (p <0.001) and bacteremia from source other than urinary tract (p=0.03). Regardless of antibiotic class used, no differences in survival were noted between patients receiving or not adequate initial antimicrobial treatment (37.1% vs 23.7% p=0.23); on the other hand, compared with the administration of other in vitro active antibiotics, the use of carbapenem as definitive therapy was associated with a significantly lower 21-day mortality (54.3% vs 28.5% p=0.02). CONCLUSIONS: These findings suggest that the administration of an adequate initial therapy is not associated with mortality in hospitalized patients with BSI due to Enterobacteriaceae. The severity of clinical conditions at presentation and the administration of carbapenems as definitive therapy seems to be really important in affecting the outcome of patients with BSI due to ESBL producing strains.

In vivo multiclonal transfer of bla(KPC-3) from Klebsiella pneumoniae to Escherichia coli in surgery patients.

During active surveillance at the Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT, Palermo, Italy) with the CARBA screening medium, five pairs of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae and Escherichia coli strains were isolated in each of five colonized patients. In each patient, lateral gene transfer was demonstrated by comparing K. pneumoniae and E. coli strains, both possessing KPC-3, Tn4401a and pKpQIL-IT elements. The isolates were found to be multiclonal by multilocus sequence typing (sequence type (ST) 512 related to ST258, and ST307 belonging to a clonal complex different from the habitual sequence clone ST258 isolated in Italy) and pulsed-field gel electrophoresis. The results of our study highlight the easy transfer of KPC among Enterobacteriaceae colonizing the human intestine, and the active and careful surveillance required to identify and prevent the spread of these multidrug-resistant microorganisms.

Epidemiological characterization and distribution of carbapenem-resistant Acinetobacter baumannii clinical isolates in Italy.

This study was aimed at tracing the molecular characteristics of carbapenem-resistant Acinetobacter baumannii (CRAB) clinical isolates in Italy with both pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Two hundred and two CRAB isolates were collected during 2004-2009, in two different surveillance periods, from 22 Italian hospitals that were representative for both distribution and infection. PFGE was performed, and the MLST scheme used was based on the gene sequence as published on the MLST Pasteur website http://www.pasteur.fr/mlst. Representatives of the major European clones I (RUH 875) and II (RUH 134) were used as controls. The two groups of isolates were characterized for their carbapenem resistance genes: 154 of 202 carried bla(OXA-58) alone, 21 of 202 also carried bla(OXA-23) , and 27 of 202 carried bla(OXA-23) alone. No isolates were positive for bla(OXA-24) . Genotype analysis of all isolates identified four distinct patterns by PFGE, which correlated with four distinct sequence types (STs) by MLST. The distribution of these four clusters in Italy confirmed the propensity of A. baumannii for nosocomial cross-transmission in a vast geographical area. We observed that clones A and B had similarities with European clone II and I respectively. By MLST, clone A was ST2, like European clone II, and clone B was ST1, like European clone I. PFGE and MLST showed the same discriminatory power and reproducibility. In addition, the two methods were concordant in defining CRAB Italian clones and in correlating them with the two pan-European clones.

Outbreak of KPC-3-producing, and colistin-resistant, Klebsiella pneumoniae infections in two Sicilian hospitals.

We report the first outbreak caused by colistin-resistant Klebsiella pneumoniae producing KPC-3 carbapenamase in two Italian hospitals. This spread occurred in 1 month, and was caused by eight colistin-resistant and carbapenem-resistant Klebsiella pneumoniae isolates from eight patients. A further three isolates were obtained from the intestinal tract and pharyngeal colonization. All isolates were multidrug-resistant (MDR), including being resistant to colistin, but they were susceptible to gentamicin and tigecycline. PCR detection showed that all isolates harboured the bla(KPC-3) gene associated with bla(SHV-11) , bla(TEM-1) and bla(OXA-9) . All K. pneumoniae isolates, genotyped by pulsed-field gel electrophoresis and multilocus sequence typing, belonged to the same sequence type (ST)258 clone. From our data and a review of the international literature, K. pneumoniae ST258 seems to be the most widespread genetic background for KPC dissemination in Europe.

Contamination of preservation fluid in kidney transplantation: single-center analysis.

INTRODUCTION: Contamination of preservation fluid is common, with a reported incidence of 2.2% to 28.0%, and may be a major cause of early morbidity after transplantation. Herein, we report our experience with routine examination of preservation fluid collected just before implantation, focusing on the rate of contamination and the clinical consequences to recipients. MATERIALS AND METHODS: We analyzed 62 samples of preservation fluid for microbial and fungal contamination. RESULTS: Twenty-four samples (38.7%) were contaminated with at least 1 organism. Bacterial contamination alone was observed in 18 samples; all patients received prophylactic treatment with intravenous piperacillin/tazobactam, 4.5 g/d for 10 days, without clinical sequelae. Six samples were contaminated with Candida species; all patients received prophylactic treatment with fluconazole, 100 mg/d for 3 months. One patient developed reversible acute renal failure due to ureteral obstruction by fungus balls at 30 days after transplantation. CONCLUSION: Contamination of preservation fluid occurs frequently after kidney transplantation. Bacterial contamination evolved without symptoms in most patients treated with prophylactic antibiotic therapy. Fungal contamination may be potentially life-threatening. However, graft nephrectomy is not mandatory if the involved Candida species is identified correctly and appropriate antifungal therapy is rapidly prescribed.

Cefditoren versus community-acquired respiratory pathogens: time-kill studies.

The time-kill method was used to determine the bactericidal activity of cefditoren compared with oral cephalosporins, amoxicillin, amoxicillin/clavulanate and levofloxacin against a randomly selected group of strains isolated from community-acquired respiratory tract infections (CARTIs). Cefditoren was the only agent showing significant bactericidal activity (>or=3 log(10 )reduction of viable cells) within 4 h against all Streptococcus pneumoniae strains, both penicillin-susceptible (PEN S) or -resistant (PEN R), as well as against Streptococcus pyogenes, and Moraxella catarrhalis. Against beta-lactamase positive strains of Haemophilus influenzae, cefditoren was comparable to the quinolone and more active than other cephalosporins at 24 h. Cefditoren showed the best killing kinetic profiles and this observation may be important when choosing an oral third-generation cephalosporin as initial or sequential therapy.