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Abstract Background Oncolytic viral therapy represents an alternative therapeutic strategy for the treatment of cancer. We previously described GLV-1h68, a modified Vaccinia Virus with exclusive tropism for tumor cells, and we observed a cell line-specific relationship between the ability of GLV-1h68 to replicate in vitro and its ability to colonize and eliminate tumor in vivo. Methods In the current study we surveyed the in vitro permissivity to GLV-1h68 replication of the NCI-60 panel of cell lines. Selected cell lines were also tested for permissivity to another Vaccinia Virus and a vesicular stomatitis virus (VSV) strain. In order to identify correlates of permissity to viral infection, we measured transcriptional profiles of the cell lines prior infection. Results We observed highly heterogeneous permissivity to VACV infection amongst the cell lines. The heterogeneity of permissivity was independent of tissue with the exception of B cell derivation. Cell lines were also tested for permissivity to another Vaccinia Virus and a vesicular stomatitis virus (VSV) strain and a significant correlation was found suggesting a common permissive phenotype. While no clear transcriptional pattern could be identified as predictor of permissivity to infection, some associations were observed suggesting multifactorial basis permissivity to viral infection. Conclusions Our findings have implications for the design of oncolytic therapies for cancer and offer insights into the nature of permissivity of tumor cells to viral infection.

Abstract Background The Pseudomonas aeruginosa major constitutive outer membrane porin protein F (OprF) has been shown to be a protective antigen and was previously used to activate an immunological response in a mouse model of lung pneumonia. The purpose of our study was to demonstrate the ability of mouse dendritic cells pulsed with purified or recombinant OprF to protect mice against P. aeruginosa infection and inflammation. Both native (n-OprF), isolated and purified from PAO1 bacterial strain, and recombinant (histidin-conjugated) OprF (His-OprF), obtained by cloning of the oprF gene into the pET28a expression vector, were used to stimulate dendritic cells in vitro before adoptive transfer into prospective recipient mice with P. aeruginosa pulmonary infection. Results Similar to n-OprF, His-OprF activated dendritic cells in vitro, inducing the costimulatory molecule expression as well as cytokine production. Upon adoptive transfer in vivo, porin-pulsed dendritic cells (DCs) induced Th1-mediated resistance to infection and associated inflammatory pathology caused by either the PAO1 strain or a clinically-isolated mucoid strain. Conclusions This study highlights the pivotal contribution of DCs to vaccine-induced protection against P. aeruginosa infection and associated inflammation.

Abstract Background Bacteria that belong to the genus Sphingobacterium are Gram-negative, non-fermentative bacilli, ubiquitous in nature and rarely involved in human infections. The aims of this study were to evaluate the epidemiology of infection by Sphingobacterium in a cohort of patients affected by Cystic Fibrosis (CF), the antibiotic susceptibility and the DNA fingerprinting of the isolated strains and to analyze some clinical outcomes of the infected patients. Findings Between January 2006 and June 2008, patients (n = 332) attending the Regional CF Unit in Naples, Italy, were enrolled. Sputum samples were processed for microscopic, cultural, phenotypic identification and antibiotic susceptibility testing. DNA fingerprinting was performed by pulsed-field gel electrophoresis (PFGE). A total of 21 strains of Sphingobacterium were isolated from 7 patients (13 of S. spiritovorum, 8 of S. multivorum). S. multivorum isolates were more resistant than those of S. spiritovorum. PFGE profiles were in general heterogeneous, which suggested independent circulation. Conclusions This is the first Italian report about respiratory tract infections by Sphingobacterium in CF patients. In our cohort, these infections were not associated with a deterioration of pulmonary function during the follow-up period. Although the exact role of this microorganism in CF lung disease is unknown and the number of infected patients was small, this study could represent an important starting-point for understanding the epidemiology and the possible pathogenic role of Sphingobacterium in CF patients.

Abstract Background Recent reports document an increasing incidence of new Gram-negative pathogens such as Stenotrophomonas maltophilia and Alcaligenes xylosoxidans isolated from patients with Cystic Fibrosis, along with an increase in common Gram-negative pathogens such as Pseudomonas aeruginosa and Burkholderia cepacia complex. Furthermore, the increase in multidrug-resistance of such organisms makes the therapeutic management of these patients more problematic. Therefore, careful isolation and identification, and accurate studies of susceptibility to antibiotics are critical for predicting the spread of strains, improving therapeutic measures and facilitating our understanding of the epidemiology of emerging pathogens. The first aim of this study was to determine the incidence and the prevalence of colonization by Gram-negative organisms isolated from respiratory samples of Cystic Fibrosis patients in the Regional Referral Cystic Fibrosis Centre of Naples; the second was to evaluate the spectrum of multidrug-resistance of these organisms. Methods Patients (n = 300) attending the Regional Cystic Fibrosis Unit were enrolled in this study over 3 years. Sputum was processed for microscopic tests and culture. An automated system, Phoenix (Becton Dickinson, Sparks, Maryland, USA), was used for phenotypic identification of all strains; the API 20 NE identification system (bioMérieux, Marcy l'Etoile, France) was used when the identification with the Phoenix system was inaccurate. A PCR-RFLP method was used to characterize the organisms in the Burkholderia cepacia complex. A chemosusceptibility test on microbroth dilutions (Phoenix) was used. Primary outcomes such as FEV1 were correlate with different pathogens. Results During the period of study, 40% of patients was infected by Pseudomonas aeruginosa, 7% by Burkholderia cepacia complex, 11% by Stenotrophomonas maltophilia and 7% by Alcaligenes xylosoxidans. Of the strains isolated, 460 were multidrug-resistant. Multiresistant were Pseudomonas aeruginosa and Burkholderia cepacia complex. Conclusion The results confirm previously reported data; in particular, they show an increase the isolation of non-fermentative Gram-negative bacteria in Cystic Fibrosis patients. They also demonstrate increased resistance to antibiotics. Beta-lactams are rarely effective, with exception of ceftazidime, which is the most efficacious agent against multiresistant strains. Aminoglycosides and quinolones are poorly efficacious.