This multicenter study evaluated the performance of the Cepheid Xpert Carba-R assay, a qualitative PCR test designed for the rapid detection of bla _KPC , bla _NDM , bla _VIM , bla _IMP , and bla _OXA-48 carbapenem resistance genes from bacterial isolates grown on blood agar or MacConkey agar. The results were compared to those obtained from bidirectional DNA sequence analysis of nucleic acid extracted from pure colonies.

Bloodstream infections caused by multidrug-resistant, Gram-negative (MDRGN) bacteria represent a significant cause of morbidity and mortality. Prompt diagnosis and appropriate empiric treatment are the most important determinants of patient outcome. The objective of our study was to assess the epidemiology and clinical outcome of MDRGN sepsis in a tertiary-care pediatric hospital during a 12-month period. It was a retrospective, observational study of MDRGN bacteremia including all patients <18 years of age, hospitalized during 2011, with documented bacteremia caused by Enterobacteriaceae or non-fermentative bacteria. Overall, 136 blood cultures in 119 patients were included. The median age of patients was 1.1 years; 86.3% of patients had an underlying disease. The cumulative incidence of Gram-negative bloodstream infections was 5.4/1000 hospital admissions and the infection rate was 0.65/1000 hospital days. Most frequently isolated strains were Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa; 67.6% of infections were hospital acquired. The percentage of multidrug-resistant (MDR) organisms among isolated species was 39%. The crude rate of mortality was 16% and sepsis-related mortality was 9.2%. The mortality rate among patients with an antibiotic-resistant isolate was 22.6%. Factors significantly associated with sepsis-related mortality were antibiotic resistance (odds ratio: 4.26, 95% confidence interval: 1.07-16.9) and hospital acquisition of infection (odds ratio: 1.13, 95% confidence interval: 1.05-1.22). This study demonstrates the high mortality of hospital-acquired MDRGN bacteremia in children. International networks focusing on clinical management and outcomes of MDRGN in children are required. Study of novel antibiotics active against Gram-negative bacteria should include children early in the clinical trial development programs.

In this study we evaluated the antibacterial activity of mastic gum, a resin obtained from the Pistacia lentiscus tree, against clinical isolates of Helicobacter pylori. The minimal bactericidal concentrations (MBCs) were obtained by a microdilution assay. Mastic gum killed 50% of the strains tested at a concentration of 125 microg/ml and 90% at a concentration of 500 microg/ml. The influence of sub-MBCs of mastic gum on the morphologies of H. pylori was evaluated by transmission electron microscopy. The lentiscus resin induced blebbing, morphological abnormalities and cellular fragmentation in H. pylori cells.

Klebsiella pneumoniae is at the forefront of antimicrobial resistance for Gram-negative pathogenic bacteria, as strains resistant to third-generation cephalosporins and carbapenems are widely reported. The worldwide diffusion of these strains is of great concern due to the high morbidity and mortality often associated with K. pneumoniae infections in nosocomial environments. We sequenced the genomes of 89 K. pneumoniae strains isolated in six Italian hospitals. Strains were selected based on antibiotypes, regardless of multilocus sequence type, to obtain a picture of the epidemiology of K. pneumoniae in Italy. Thirty-one strains were carbapenem-resistant K. pneumoniae carbapenemase producers, 29 were resistant to third-generation cephalosporins, and 29 were susceptible to the aforementioned antibiotics. The genomes were compared to all of the sequences available in the databases, obtaining a data set of 319 genomes spanning the known diversity of K. pneumoniae worldwide. Bioinformatic analyses of this global data set allowed us to construct a whole-species phylogeny, to detect patterns of antibiotic resistance distribution, and to date the differentiation between specific clades of interest. Finally, we detected an ∼1.3-Mb recombination that characterizes all of the isolates of clonal complex 258, the most widespread carbapenem-resistant group of K. pneumoniae . The evolution of this complex was modeled, dating the newly detected and the previously reported recombination events. The present study contributes to the understanding of K. pneumoniae evolution, providing novel insights into its global genomic characteristics and drawing a dated epidemiological scenario for this pathogen in Italy.

We assessed the clinical relevance and performed molecular characterization of 36 multidrug-resistant strains of Corynebacterium striatum. Pulsed-field gel electrophoresis confirmed a single clone, possessing erm(X), tetA/B, cmxA/B, and aphA1 genes, but few related subclones. This strain is emerging as a pathogen in Italy.

We report on the first case of a catheter-related recurrent bacteremia caused by Kocuria kristinae , a gram-positive microorganism belonging to the family Micrococcaceae , in a 51-year-old woman with ovarian cancer. This unusual pathogen may cause opportunistic infections in patients with severe underlying diseases.