Fabio Rossano - Academia.edu (original) (raw)

Papers by Fabio Rossano

Research paper thumbnail of Typing of Pseudomonas aeruginosa isolated from patients with VAP in an intensive care unit

New …, Jan 1, 2009

Aim of this study was to characterize isolates of Pseudomonas aeruginosa responsible for ventilat... more Aim of this study was to characterize isolates of Pseudomonas aeruginosa responsible for ventilator-associated pneumonia (VAP) in patients admitted to an ICU in order to evaluate a possible strain clonality. The study was performed from October 2004 to June 2005 in one Southern Italy ICU and 29 patients suspected of having VAP were enrolled. The etiology of VAP was established by quantitative cultures of endotracheal aspirations. Molecular characterization was carried out by PFGE. P. aeruginosa was responsible for 51% of all cases of VAP (15/29) and 12/15 strains were multi-drug resistant. High mortality (44.8%) was connected to this pathogen and evidence of strain clonality was found. The early identification of strain clonality and the application of infection control procedures are necessary to avoid the spread of pathogens such as P. aeruginosa involved in nosocomial infections.

Research paper thumbnail of Microbiology of airway disease in a cohort of patients with cystic fibrosis

BMC infectious diseases, 2006

Recent reports document an increasing incidence of new Gram-negative pathogens such as Stenotroph... more 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 ...

Research paper thumbnail of Porin from Pseudomonas aeruginosa induces apoptosis in an epithelial cell line derived from rat seminal vesicles

Infection and immunity, 1999

Micromolar concentrations of porin, purified from the outer membranes of Pseudomonas aeruginosa, ... more Micromolar concentrations of porin, purified from the outer membranes of Pseudomonas aeruginosa, induced in vitro the classic morphological and biochemical signs of apoptosis in an epithelial cell line (SVC1) derived from the rat seminal vesicle secretory epithelium. The programmed cell death (PCD) was p53 independent and associated with significant decrease of bcl-2 expression, a marked increase of c-myc transcriptional activity, and an absence of the mRNA coding for tissue transglutaminase. The Ca(2+) influx, caused by the porin treatment of SVC1 cells, appears to play an important role in the triggering of apoptosis in our biological model. The possibility that the porin property of inducing PCD plays a role in the infertility of individuals chronically infected by gram-negative bacteria is discussed.

Research paper thumbnail of Porins of Pseudomonas aeruginosa induce release of tumor necrosis factor alpha and interleukin-6 by human leukocytes

Infection and immunity, 1997

The aim of this study was to examine the ability of Pseudomonas aeruginosa components to induce r... more The aim of this study was to examine the ability of Pseudomonas aeruginosa components to induce release of cytokines from human leukocytes. Human whole-blood cultures were incubated with several concentrations of purified P. aeruginosa products, including porins, exomucopolysaccharide, lipopolysaccharide, and toxin A. Supernatants were assayed for tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) activities. All of the P. aeruginosa components except toxin A were able to stimulate the release of both cytokines. On a weight basis, porins were as effective as lipopolysaccharide and significantly more effective than exomucopolysaccharide in inducing IL-6 release (P < 0.05). Moreover, porins were more potent than either exomucopolysaccharide or lipopolysaccharide in inducing TNF-alpha release (P < 0.05). Further experiments using isolated leukocytes suggested that monocytes were the cell population predominantly responsible for the production of both cytokines. Thes...

Research paper thumbnail of Immunobiological activities of mould products: functional impairment of human monocytes exposed to aflatoxin B1

Research in microbiology, 1996

In order to elucidate the effects upon the human immune system of aflatoxin B1 produced by the fo... more In order to elucidate the effects upon the human immune system of aflatoxin B1 produced by the food-contaminating mould Aspergillus flavus, phagocytosis, microbicidal activity, superoxide production and intrinsic antiviral activity were studied in monocytes exposed to aflatoxin B1 for different times at concentrations ranging from 0.1 to 1 pg/ml. Phagocytosis and microbicidal activity were significantly impaired (p < 0.05) by aflatoxin B1 at doses as low as 0.1 pg/ml. However, pretreatment of monocytes with aflatoxin B1 did not modify intrinsic antiviral activity or superoxide production. These results confirmed data obtained from animals fed with mycotoxin-contaminated foods. The potential danger to human health of exposure to mycotoxins demonstrates the necessity for careful microbiological control of food.

Research paper thumbnail of Effects of Cetyltrimethylammonium Naproxenate on the Adherence of Gardnerella Vaginalis, Mobiluncus Curtisii, and Lactobacillus Acidophilus to Vaginal Epithelial Cells

Sexually Transmitted Diseases, 1994

A decreased concentration or total disappearance of Lactobacillus acidophilus in the vagina const... more A decreased concentration or total disappearance of Lactobacillus acidophilus in the vagina constitutes a frequent observation in bacterial vaginosis. Cetyltrimethylammonium naproxenate has been evaluated in vitro to detect antiadhesive properties at subinhibitory concentrations for Gardnerella vaginalis and Mobiluncus curtisii to vaginal epithelial cells (VEC). Bacterial strains 14C- and or 3H-labeled were tested for adherence and competition to binding sites in VECs before and after treatment at sub-MIC with cetyltrimethylammonium naproxenate. In control tests of adherence, G. vaginalis and M. curtisii had their maximal adhesion at pH 5.4, L. acidophilus at pH 4.4. Preincubation of G. vaginalis and M. curtisii with cetyltrimethylammonium naproxenate 2.5 mg/mL (subinhibitory concentration) at pH 5.4 reduced adherence to VECs respectively by 48.3% and 34.1%. The same treatment of L. acidophilus showed no statistically significant difference. Treatment of VECs alone did not modify adherence. Competition tests between L. acidophilus and G. vaginalis and between L. acidophilus and M. curtisii showed that, in small quantities, L. acidophilus could compete with G. vaginalis and M. curtisii for binding sites in VECs at pH 4.4, when pretreated with cetyltrimethylammonium naproxenate. At a higher pH (4.8 and 5.4), L. acidophilus in higher quantities did not compete for binding sites occupied by G. vaginalis and M. curtisii. Cetyltrimethylammonium naproxenate at subinhibitory concentrations modifies the adhesiveness of G. vaginalis and M. curtisii to VECs, reducing it by 48.3% and 34.1%, respectively. Adhesion of L. acidophilus to VECs is not impaired by pretreatment with cetyltrimethylammonium naproxenate at pH 4.4, even if they are in low number and compete for binding sites against pathogens. At higher pH levels, L. acidophilus did not compete for binding sites occupied by G. vaginalis and M. curtisii.

Research paper thumbnail of Human monocytes and gingival fibroblasts release tumor necrosis factor-α, interleukin-1α and interleukin-6 in response to particulate and soluble fractions ofPrevotella melaninogenica andFusobacterium nucleatum

International Journal of Clinical & Laboratory Research, 1993

In this study we provide evidence that structural and soluble components of periodontopathogenic ... more In this study we provide evidence that structural and soluble components of periodontopathogenic bacteria, such as Prevotella rnelaninogenica and Fusobacteriurn nucleaturn, induce the release of cytokines in vitro known to cause in vivo necrotic inflammatory phenomena and bone resorption (tumor necrosis factor-c~, interleukin-l~ and interleukin-6). Human monocytes and gingival fibroblasts were cultivated in vitro in the presence of both particulate and soluble bacterial fractions. A dose-dependent production of tumor necrosis factor-~ by monocytes and gingival fibroblasts was observed in the presence of fractions of P. melaninogenica and E nucleaturn. Interleukin-l~ was produced in approximately the same quantities in the presence of soluble fractions of either P. rnelaninogenica or F nucleaturn, but in greater quantities in response to particulate fractions of P. rnelaninogenica. Monocytes released larger amounts of interleukin-la (about 3000 pg/ml) than gingival fibroblasts (about 1500 pg/ml). Interleukin-6 was released in greater quantities by monocytes in the presence of the pellet fraction of P. rnelaninogenica (about 5.5 ng/ml), but gingival fibroblasts released larger amounts of interleukin-6, especially in the presence of particulate and soluble components of F. nucleaturn (about 12 ng/ml). The ability to induce the release of these cytokines notably increases the pathogenic potential of the bacteria involved in the damage of periodontal tissue.

Research paper thumbnail of Respiratory infections by Achromobacter xylosoxidans in a cohort of Cystic Fibrosis patients: identification, antimicrobial susceptibility and molecular epidemiology

Microbiologia Medica, 2010

Infezioni respiratorie da Achromobacter xylosoxidans in pazienti con Fibrosi Cistica: identificaz... more Infezioni respiratorie da Achromobacter xylosoxidans in pazienti con Fibrosi Cistica: identificazione, suscettibilità agli antimicrobici ed epidemiologia molecolare SUMMARY Pulmonary infections by Gram-negative bacteria such as Achromobacter xylosoxidans are recovered frequently in patients with Cystic Fibrosis. Aims of this study were to value the isolation frequency of A.xylosoxidans strains in a cohort of Cystic Fibrosis patients, to investigate their antimicrobial sensitivity and to establish possible clonal likeness among strains.A retrospective study was undertaken between January 2004 and December 2008 on 300 patients receiving care at the Regional Cystic Fibrosis Centre of "Federico II" University, Naples. Sputum samples were collected and selective media as well as commercial systems for bacterial identification were used. The activity of antimicrobial agents was determined using diffusion and micro-dilution methods. For DNA-fingerprinting, a genomic DNA macrorestriction followed by pulsed-field gel electrophoresis was carried out. A total of 238 strains from 51 patients were isolated. Strains were resistant to aztreonam, about half of these were resistant to gentamicin and trimethoprim-sulphamethoxazole. They were sensitive to piperacillin, piperacillin/tazobactam, and also to carbapenems, quinolones, cephalosporines. Macrorestriction analysis applied on some isolates showed substantial heterogeneity among strains.Actually, the prognostic role of A. xylosoxidans in Cystic Fibrosis is unclear, but this finding must imply difficulties on therapeutic approach. So, it is need to be on the look out regard such microorganisms. Preliminary results of DNA-fingerprinting indicate no evidence of clonal likeness and then of patient-to-patient spread.

Research paper thumbnail of PFGE and antibiotic susceptibility phenotype analysis of Pseudomonas aeruginosa strain chronically infecting Cystic Fibrosis patients

Microbiologia Medica, 2008

Analisi delle caratteristiche fenotipiche e genotipiche di ceppi sequenziali di Pseudomonas aerug... more Analisi delle caratteristiche fenotipiche e genotipiche di ceppi sequenziali di Pseudomonas aeruginosa isolati da pazienti con fibrosi cistica SUMMARY Pseudomonas aeruginosa is the leading cause of chronic lung infection and following pulmonary worsening of cystic fibrosis patients. To verify whether bacterial modifications regarding motility, mucoidy, and serum susceptibility proceeded from an adaptation to chronic infection or a replacement with a new strain, sequential P. aeruginosa isolates of known phenotype collected from 5 cystic fibrosis patients were typed by pulsed-field gel electophoresis (PFGE). Antimicrobial susceptibility testing of all isolates was performed by the disc diffusion method. PFGE typing demonstrated that strains dissimilar in colony morphotype and of different antibiotic susceptibility patterns could be of the same genotype. Some patients were colonized with a rather constant P. aeruginosa flora, with strains of different phenotypes but of one genotype. Instead, some patients may be colonized by more than one genotype. Secretion of mucoid exopolysaccharide and acquisition of a new antibiotic susceptibility phenotype in these strain appear to evolve during chronic colonization in cystic fibrosis patients from specific adaptation to infection rather than from acquisition of new bacterial strains.

Research paper thumbnail of Outer-membrane porins from Gram-negative bacteria stimulate platelet-activating-factor biosynthesis by cultured human endothelial cells

European Journal of Biochemistry, 1993

Porins are a family of hydrophobic proteins located in the outer membrane of the cell wall in Gra... more Porins are a family of hydrophobic proteins located in the outer membrane of the cell wall in Gram-negative bacteria. The effect of porins on the biosynthesis of platelet-activating factor (PAF) by cultured human umbilical-cord-vein-derived endothelial cells (HUVEC) was investigated. The results demonstrate that porins were able to induce a dose-dependent synthesis of PAF in HUVEC. PAF, synthesized after stimulation with porins, was mainly cell associated and the synthesis peaked at 15 min, decreasing rapidly thereafter. Experiments with radiolabeled precursors demonstrated that PAF, a 1 -O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine, was synthesized via the remodeling pathway involving the acetylation of 1 -O-alkyl-2-lyso-sn-glyceryl-3-phosphorylcholine (2-lysoPAF) generated from l-O-alkyl-2-acyl-sn-glyceryl-3-phosphorylcholine by phospholipase-A2 activity. The activation of phospholipase A2 in HUVEC stimulated by porins was detected by observing the mobilization of [i4C]arachidonic acid. In addition, the activity of acetyl-CoA :l-alkyl-sn-glycero-3phosphorylcholine 2-0-acetyltransferase was transiently increased in porin-stimulated HUVEC and, after incubation with [3H]CoASAc or [3H]acetate, the [3H]acetyl group was incorporated into newly synthesized PAF. Porins, by forming transmembrane channels, induced a sustained influx of extracellular 45Ca2+ into the cytosol. The activation of PAF synthesis by porins depended on this influx rather than on intracellular calcium mobilization, since PAF synthesis did not occur in the absence of extracellular Ca".

Research paper thumbnail of Secondary metabolites of Aspergillus exert immunobiological effects on human monocytes

Research in Microbiology, 1999

This project focused on the effects of aflatoxin B1 (AFB1), a food-contaminating mycotoxin produc... more This project focused on the effects of aflatoxin B1 (AFB1), a food-contaminating mycotoxin produced by fungi, genus Aspergillus, on the release and genetic expression of some important cytokines, i.e., (interleukin-1α (IL-1α), IL-6, tumor necrosis factor-α (TNFα)) by human monocytes. Monocytes, preincubated for different time periods with concentrations of AFB1 ranging from 0.01 to 1.0 pg/mL, were then activated with bacterial lipopolysaccharide. Cytokine levels were measured by immunoassay and mRNA by cDNA amplification. Pretreatment of monocytes with AFB1 resulted in a decrease in IL-1, IL-6 and TNFα release already at a concentration of 0.05 pg/mL. The gene expression of the cytokines considered was drastically affected by treatment with AFB1. In fact, AFB1 completely blocked the transcription of IL-1α, IL-6 and TNFα mRNAs, while it did not affect -actin mRNA at the concentrations used. It therefore appears that AFB1 exerts its effect on cytokine release through selective inhibition of specific mRNA, without affecting general protein synthesis. © Elsevier, Paris Aspergillus / aflotoxin B1 / cytokine / immunosuppression / microbiological control / gene expression * Correspondence and reprints rossano@unina.it Abbreviations: AFB1, aflatoxin B1; ConA, concanavalin A; IL, interleukin; LPS, lipopolysaccharide; RT-PCR, reverse transcription-polymerase chain reaction; TNF, tumor necrosis factor. Res. Microbiol. 150 (1999) 13−19

Research paper thumbnail of Oral candidiasis: a comparison between conventional methods and multiplex polymerase chain reaction for species identification

Oral Microbiology and Immunology, 2009

Research paper thumbnail of Porins and lipopolysaccharide stimulate platelet activating factor synthesis by human mesangial cells

Kidney International, 1992

Porins and lipopolysaccharide stimulate platelet activating factor synthesis by human mesangial c... more Porins and lipopolysaccharide stimulate platelet activating factor synthesis by human mesangial cells. Porins, a family of hydrophobic proteins located in the outer membrane of the cell wall of gram-negative bacteria and Iipopolysaccharide (LPS), were shown to stimulate the synthesis of platelet activating factor (PAF), a phospholipid mediator of inflammation and endotoxic shock, by cultured human glomerular mesangial cells (MC). The synthesis of PAF induced by porins was rapid (peak at 20 mm) and independent either from contamination by LPS or from generation of an endotoxin-induced cytokine such as tumor necrosis factor (TNF) since it was not prevented by cycloheximide, an inhibitor of protein synthesis or anti-TNF blocking antibodies. LPS also stimulated PAF synthesis by MC. However, the kinetic of PAF synthesis induced by LPS was biphasic with an early and transient peak at 10 minutes and a second and sustained peak at three to six hours. This second peak required an intact protein synthesis and was prevented by anti-TNF antibodies, suggesting the dependency on LPS-induced synthesis of TNF. Experiments with labeled precursors demonstrated that in MC, either after stimulation with porins or LPS, PAF was synthetised via the remodeling pathway that involves acetylation of l-0-alkyl-sn-glyceryl-3-phosphorylcholine (2-lyso-PAF) generated from 1-0-alkyl-2-acyl-sn-glyceryl-3-phosphorylcholine by phospholipase A2 (PLA2) activity. Porins and LPS, indeed, induced PLA2dependent mobilization of ['4C]-arachidonic acid that was inhibited by p-bromodiphenacylbromide (PBDB). PBDB, an inhibitor of PLA2, also blocked PAF synthesis by preventing the mobilization of 2-lyso-PAF, the substrate for PAF-specific acetyltransferase. The addition of 2-lyso-PAF restored PAF synthesis. The activity of acetyl C0A:2-lyso-PAF acetyltransferase was increased in porin-as well as in LPS-stimulated MC and, after cell preincubation with [3H]-acetyl CoA, [3H]-acetyl was incorporated in the newly synthetised PAF. The activation of PAF synthesis by porins was dependent on extracellular Ca2. Porins by forming trans-membrane channels determined a sustained influx of 45Ca2 into the cytosol. The inhibitory effect of trifluoperazine, an inhibitor of Ca2-ca!modulin complexes, on PAF synthesis by porinstimulated MC suggested that calmodulin mediated the Ca2-dependent activation of enzymes involved in PAF synthesis.

Research paper thumbnail of Rapid and reliable MALDI-TOF mass spectrometry identification of Candida non-albicans isolates from bloodstream infections

Journal of Microbiological Methods, 2013

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) fin... more Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) fingerprinting has recently become an effective instrument for rapid microbiological diagnostics and in particular for identification of micro-organisms directly in a positive blood culture. The aim of the study was to evaluate a collection of 82 stored yeast isolates from bloodstream infection, by MALDI-TOF MS; 21 isolates were identified also directly from positive blood cultures and in the presence of other co-infecting micro-organisms. Of the 82 isolates grown on plates, 64 (76%) were correctly identified by the Vitek II system and 82 (100%) by MALDI-TOF MS; when the two methods gave different results, the isolate was identified by PCR. MALDI-TOF MS was unreliable in identifying two isolates (Candida glabrata and Candida parapsilosis) directly from blood culture; however, direct analysis from positive blood culture samples was fast and effective for the identification of yeast, which is of great importance for early and adequate treatment.

Research paper thumbnail of Chryseobacterium respiratory tract infections in patients with cystic fibrosis

Journal of Infection, 2007

Objectives: To investigate the prevalence of infections by Chryseobacterium in a cohort of cystic... more Objectives: To investigate the prevalence of infections by Chryseobacterium in a cohort of cystic fibrosis (CF) patients, to assess the antimicrobial susceptibility of these strains, to examine their DNA fingerprinting and to evaluate some clinical outcomes of patients infected by these bacteria. Methods: Patients (300) attending a Regional Cystic Fibrosis Unit were enrolled in this study over 4 years. Natural or induced sputum samples were processed for microscopic and cultural tests. For phenotypic identification, automated and manual systems were used. For chemosusceptibility test, an automatic broth microdilution test and a disk-diffusion test were used and strains underwent DNA fingerprinting by pulsed-field gel electrophoresis (PFGE). Results: Thirty-five strains of Chryseobacterium were isolated from 22 patients. These strains showed a broad-spectrum antimicrobial resistance, with activity only for trimethoprime sulfamethoxazole and quinolones. PFGE profiles of all isolates were generally heterogeneous, suggesting independent circulation. Conclusions: This is the first report about clinical isolates of Chryseobacterium spp from CF patients in an Italian Centre. The infection by Chryseobacterium was not associated to a deterioration of pulmonary function and mortality: therefore, all patients infected by Chryseobacterium were co-infected by Pseudomonas aeruginosa and 3 of these were also co-infected by Burkholderia cepacia complex.

Research paper thumbnail of A multi-society position paper on the prevention and management of nosocomial and severe infections: the Italian Society for Infectious Diseases, the Italian Multidisciplinary Society of Hospital Infections, the Italian Society of Chemotherapy, the Italian Society of Respiratory Medicine, the Ita...

International Journal of Infectious Diseases, 2010

Research paper thumbnail of Commonly used antibiotics induce expression of Hsp 27 and Hsp 60 and protect human lymphocytes from apoptosis

International Immunopharmacology, 2004

Heat shock proteins (Hsps) are abundant molecular chaperones participating in the cytoprotection.... more Heat shock proteins (Hsps) are abundant molecular chaperones participating in the cytoprotection. The kinetics of synthesis of Hsps closely correlates with the kinetics of development of resistance to cell death. In this study, we analysed the probable involvement of Hsp 27 and Hsp 60 in the protection of cells undergoing apoptosis. Human lymphocytes cultured in the presence of ampicillin or ceftriaxone produced Hsp 60 and Hsp 27, estimated by immunoblotting in a timedependent manner and the increased levels of Hsp 60 and Hsp 27 correlated with enhanced resistance of the lymphocytes to apoptosis, as determined by flow cytometry. Cultures treated with ampicillin or ceftriaxone also exhibited smaller numbers of apoptotic cells than untreated cultures when exposed to the apoptosis-inducing agent staurosporine (1 mM). In contrast, cloramphenicol induced the production of only small amounts of Hsp 60, and no resistance apoptosis. Further studies are needed to clarify the potential role of Hsp 27 and Hsp 60 in the resistance of human cells to apoptosis and the effects of antibiotics on this phenomenon. D

Research paper thumbnail of Application of a computerised method to measure static pressure volume curve in acute respiratory distress syndrome

Intensive Care Medicine, 2000

To assess the safety and the bedside feasibility of a new computerised method to record the stati... more To assess the safety and the bedside feasibility of a new computerised method to record the static pressure-volume curves (Pst/V) of the respiratory system. The Pst/V curves were recorded in 13 medical patients with the acute respiratory distress syndrome (ARDS). During the Pst/V curve tracing the following parameters were recorded: time required for the recording and the automatic analysis of the Pst/V curve and modifications in electrocardiograms, blood pressure, and arterial oxygen saturation (SaO(2)). The study was performed in the intensive care unit of the University of Naples &quot;Federico II&quot;. No statistically significant modifications in heart rate (HR, b min(-1)), blood pressure (BP, mmHg), and SaO(2) were observed between conditions at baseline (HR 97.2 +/- 17.7; BP 65.4 +/- 9.3; SaO(2) 93.6 +/- 2.0), during the recording (HR 99.8 +/- 19.5; BP 66.2 +/- 11.6; SaO(2) 93.7 +/- 2.4), and 2 min after the procedure (HR 98.2 +/- 17.8; BP 65.2 +/- 11.7; SaO(2) 93.7 +/- 1.9). The Pst/V curves were recorded in 8.38 +/- 1. 19 min and fully analysed in 2.69 +/- 0.85 min. Mean value of static compliance was 41.1 +/- 12.7 ml cmH(2)O(-1). A lower inflection point was found in ten patients (mean value 9.2 +/- 1.9 cmH(2)O). In ARDS patients, the present new computerised method gave valuable data to ordinary intensivists and was shown to be safe, easy, and fast.

Research paper thumbnail of Effects of ventilation in ventral decubitus position on respiratory mechanics in adult respiratory distress syndrome

Intensive Care Medicine, 1997

Objective: To assess the potential benefits of a period of ventilation in ventral decubitus (VD) ... more Objective: To assess the potential benefits of a period of ventilation in ventral decubitus (VD) on oxygenation and respiratory mechanics in the adult respiratory distress syndrome (ARDS). Design: In a stable condition during baseline ventilation in dorsal decubitus (DD), after 15 min of ventilation in VD and after 10 min of restored DD, the following parameters were studied: arterial blood gas tension, haemodynamics and static respiratory compliance (Crs), evaluated with the rapid airway occlusion technique. Setting: The study was completed in the intensive care units of university hospitals as part of the management of the patients studied. Patients: Twelve patients (7 males, 5 females, mean age 51.8 + 16.6 years) suffering from ARDS of different aetiologies. Interventions: Before and during each evaluation, the patients were kept under stable haemodynamic and metabolic conditions. The ventilatory setting was kept constant. All the patients were sedated, paralysed and mechanically ventilated.

Research paper thumbnail of Typing of Vancomycin-Resistant Enterococcus faecium Strains in a Cohort of Patients in an Italian Intensive Care Unit

Infection, 2007

Background: Vancomycin-resistant enterococci (VRE) have become a major cause of nosocomial infect... more Background: Vancomycin-resistant enterococci (VRE) have become a major cause of nosocomial infections. The increase of vancomycin-resistant Enterococcus faecium (VR-Efm) in an intensive care unit (ICU) of an Italian university hospital from 2003 through 2004, led us to evaluate the phenotypic and genetic features of these strains. The prevalence of different bacterial species in this ICU is described. The antibiotic resistance profiles of VR-Efm strains, their van-genotype and pulsed-field gel electrophoresis (PFGE) profiles were also analyzed. Materials and Methods: From January 2003 to December 2004, VR-Efm strains were collected from several biological samples. Bacteria were identified using standard biochemical reactions and automated systems. Antibiotic susceptibility was evaluated by disk diffusion and microdilution methods. Resistance to glycopeptides was confirmed by the E test. Vancomycin-resistant genotypes (vanA, vanB) were identified by PCR. Strains were typed by PFGE. Results: Fifty E. faecium strains were isolated from a total of 700 patients. Of these, 26 were vancomycin-resistant and were isolated from 26 different patients. We also found one strain with resistance to linezolid. The vanA genotype was identified in 20/26 strains and vanB in the remaining strains. A major pulsed-field cluster (''A'') was identified. In this cluster, 14 strains were identified (A1-A14) and 25 out of 26 VR-Efm belonged to it. Only one strain showed a different pattern (strain type ''B''). All isolates with the vanA genotype belonged to cluster ''A'', therefore five out of six isolates with the vanB genotype belonged to cluster A. The only strain with type B pattern was the vanB genotype. Conclusions: Isolation of VR-Efm was very frequent (52%) in our cohort of patients and the vanA genotype was the most frequent (77%). We found 25 out of 26 VR-E. faecium strains to be epidemiologically related by PFGE (cluster A). Strains with distinct genotypes shared closely related PFGE profiles. The occurrence of one major cluster among patients of a single unit indicated intra-facility VRE transmission.

Research paper thumbnail of Typing of Pseudomonas aeruginosa isolated from patients with VAP in an intensive care unit

New …, Jan 1, 2009

Aim of this study was to characterize isolates of Pseudomonas aeruginosa responsible for ventilat... more Aim of this study was to characterize isolates of Pseudomonas aeruginosa responsible for ventilator-associated pneumonia (VAP) in patients admitted to an ICU in order to evaluate a possible strain clonality. The study was performed from October 2004 to June 2005 in one Southern Italy ICU and 29 patients suspected of having VAP were enrolled. The etiology of VAP was established by quantitative cultures of endotracheal aspirations. Molecular characterization was carried out by PFGE. P. aeruginosa was responsible for 51% of all cases of VAP (15/29) and 12/15 strains were multi-drug resistant. High mortality (44.8%) was connected to this pathogen and evidence of strain clonality was found. The early identification of strain clonality and the application of infection control procedures are necessary to avoid the spread of pathogens such as P. aeruginosa involved in nosocomial infections.

Research paper thumbnail of Microbiology of airway disease in a cohort of patients with cystic fibrosis

BMC infectious diseases, 2006

Recent reports document an increasing incidence of new Gram-negative pathogens such as Stenotroph... more 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 ...

Research paper thumbnail of Porin from Pseudomonas aeruginosa induces apoptosis in an epithelial cell line derived from rat seminal vesicles

Infection and immunity, 1999

Micromolar concentrations of porin, purified from the outer membranes of Pseudomonas aeruginosa, ... more Micromolar concentrations of porin, purified from the outer membranes of Pseudomonas aeruginosa, induced in vitro the classic morphological and biochemical signs of apoptosis in an epithelial cell line (SVC1) derived from the rat seminal vesicle secretory epithelium. The programmed cell death (PCD) was p53 independent and associated with significant decrease of bcl-2 expression, a marked increase of c-myc transcriptional activity, and an absence of the mRNA coding for tissue transglutaminase. The Ca(2+) influx, caused by the porin treatment of SVC1 cells, appears to play an important role in the triggering of apoptosis in our biological model. The possibility that the porin property of inducing PCD plays a role in the infertility of individuals chronically infected by gram-negative bacteria is discussed.

Research paper thumbnail of Porins of Pseudomonas aeruginosa induce release of tumor necrosis factor alpha and interleukin-6 by human leukocytes

Infection and immunity, 1997

The aim of this study was to examine the ability of Pseudomonas aeruginosa components to induce r... more The aim of this study was to examine the ability of Pseudomonas aeruginosa components to induce release of cytokines from human leukocytes. Human whole-blood cultures were incubated with several concentrations of purified P. aeruginosa products, including porins, exomucopolysaccharide, lipopolysaccharide, and toxin A. Supernatants were assayed for tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) activities. All of the P. aeruginosa components except toxin A were able to stimulate the release of both cytokines. On a weight basis, porins were as effective as lipopolysaccharide and significantly more effective than exomucopolysaccharide in inducing IL-6 release (P < 0.05). Moreover, porins were more potent than either exomucopolysaccharide or lipopolysaccharide in inducing TNF-alpha release (P < 0.05). Further experiments using isolated leukocytes suggested that monocytes were the cell population predominantly responsible for the production of both cytokines. Thes...

Research paper thumbnail of Immunobiological activities of mould products: functional impairment of human monocytes exposed to aflatoxin B1

Research in microbiology, 1996

In order to elucidate the effects upon the human immune system of aflatoxin B1 produced by the fo... more In order to elucidate the effects upon the human immune system of aflatoxin B1 produced by the food-contaminating mould Aspergillus flavus, phagocytosis, microbicidal activity, superoxide production and intrinsic antiviral activity were studied in monocytes exposed to aflatoxin B1 for different times at concentrations ranging from 0.1 to 1 pg/ml. Phagocytosis and microbicidal activity were significantly impaired (p < 0.05) by aflatoxin B1 at doses as low as 0.1 pg/ml. However, pretreatment of monocytes with aflatoxin B1 did not modify intrinsic antiviral activity or superoxide production. These results confirmed data obtained from animals fed with mycotoxin-contaminated foods. The potential danger to human health of exposure to mycotoxins demonstrates the necessity for careful microbiological control of food.

Research paper thumbnail of Effects of Cetyltrimethylammonium Naproxenate on the Adherence of Gardnerella Vaginalis, Mobiluncus Curtisii, and Lactobacillus Acidophilus to Vaginal Epithelial Cells

Sexually Transmitted Diseases, 1994

A decreased concentration or total disappearance of Lactobacillus acidophilus in the vagina const... more A decreased concentration or total disappearance of Lactobacillus acidophilus in the vagina constitutes a frequent observation in bacterial vaginosis. Cetyltrimethylammonium naproxenate has been evaluated in vitro to detect antiadhesive properties at subinhibitory concentrations for Gardnerella vaginalis and Mobiluncus curtisii to vaginal epithelial cells (VEC). Bacterial strains 14C- and or 3H-labeled were tested for adherence and competition to binding sites in VECs before and after treatment at sub-MIC with cetyltrimethylammonium naproxenate. In control tests of adherence, G. vaginalis and M. curtisii had their maximal adhesion at pH 5.4, L. acidophilus at pH 4.4. Preincubation of G. vaginalis and M. curtisii with cetyltrimethylammonium naproxenate 2.5 mg/mL (subinhibitory concentration) at pH 5.4 reduced adherence to VECs respectively by 48.3% and 34.1%. The same treatment of L. acidophilus showed no statistically significant difference. Treatment of VECs alone did not modify adherence. Competition tests between L. acidophilus and G. vaginalis and between L. acidophilus and M. curtisii showed that, in small quantities, L. acidophilus could compete with G. vaginalis and M. curtisii for binding sites in VECs at pH 4.4, when pretreated with cetyltrimethylammonium naproxenate. At a higher pH (4.8 and 5.4), L. acidophilus in higher quantities did not compete for binding sites occupied by G. vaginalis and M. curtisii. Cetyltrimethylammonium naproxenate at subinhibitory concentrations modifies the adhesiveness of G. vaginalis and M. curtisii to VECs, reducing it by 48.3% and 34.1%, respectively. Adhesion of L. acidophilus to VECs is not impaired by pretreatment with cetyltrimethylammonium naproxenate at pH 4.4, even if they are in low number and compete for binding sites against pathogens. At higher pH levels, L. acidophilus did not compete for binding sites occupied by G. vaginalis and M. curtisii.

Research paper thumbnail of Human monocytes and gingival fibroblasts release tumor necrosis factor-α, interleukin-1α and interleukin-6 in response to particulate and soluble fractions ofPrevotella melaninogenica andFusobacterium nucleatum

International Journal of Clinical & Laboratory Research, 1993

In this study we provide evidence that structural and soluble components of periodontopathogenic ... more In this study we provide evidence that structural and soluble components of periodontopathogenic bacteria, such as Prevotella rnelaninogenica and Fusobacteriurn nucleaturn, induce the release of cytokines in vitro known to cause in vivo necrotic inflammatory phenomena and bone resorption (tumor necrosis factor-c~, interleukin-l~ and interleukin-6). Human monocytes and gingival fibroblasts were cultivated in vitro in the presence of both particulate and soluble bacterial fractions. A dose-dependent production of tumor necrosis factor-~ by monocytes and gingival fibroblasts was observed in the presence of fractions of P. melaninogenica and E nucleaturn. Interleukin-l~ was produced in approximately the same quantities in the presence of soluble fractions of either P. rnelaninogenica or F nucleaturn, but in greater quantities in response to particulate fractions of P. rnelaninogenica. Monocytes released larger amounts of interleukin-la (about 3000 pg/ml) than gingival fibroblasts (about 1500 pg/ml). Interleukin-6 was released in greater quantities by monocytes in the presence of the pellet fraction of P. rnelaninogenica (about 5.5 ng/ml), but gingival fibroblasts released larger amounts of interleukin-6, especially in the presence of particulate and soluble components of F. nucleaturn (about 12 ng/ml). The ability to induce the release of these cytokines notably increases the pathogenic potential of the bacteria involved in the damage of periodontal tissue.

Research paper thumbnail of Respiratory infections by Achromobacter xylosoxidans in a cohort of Cystic Fibrosis patients: identification, antimicrobial susceptibility and molecular epidemiology

Microbiologia Medica, 2010

Infezioni respiratorie da Achromobacter xylosoxidans in pazienti con Fibrosi Cistica: identificaz... more Infezioni respiratorie da Achromobacter xylosoxidans in pazienti con Fibrosi Cistica: identificazione, suscettibilità agli antimicrobici ed epidemiologia molecolare SUMMARY Pulmonary infections by Gram-negative bacteria such as Achromobacter xylosoxidans are recovered frequently in patients with Cystic Fibrosis. Aims of this study were to value the isolation frequency of A.xylosoxidans strains in a cohort of Cystic Fibrosis patients, to investigate their antimicrobial sensitivity and to establish possible clonal likeness among strains.A retrospective study was undertaken between January 2004 and December 2008 on 300 patients receiving care at the Regional Cystic Fibrosis Centre of "Federico II" University, Naples. Sputum samples were collected and selective media as well as commercial systems for bacterial identification were used. The activity of antimicrobial agents was determined using diffusion and micro-dilution methods. For DNA-fingerprinting, a genomic DNA macrorestriction followed by pulsed-field gel electrophoresis was carried out. A total of 238 strains from 51 patients were isolated. Strains were resistant to aztreonam, about half of these were resistant to gentamicin and trimethoprim-sulphamethoxazole. They were sensitive to piperacillin, piperacillin/tazobactam, and also to carbapenems, quinolones, cephalosporines. Macrorestriction analysis applied on some isolates showed substantial heterogeneity among strains.Actually, the prognostic role of A. xylosoxidans in Cystic Fibrosis is unclear, but this finding must imply difficulties on therapeutic approach. So, it is need to be on the look out regard such microorganisms. Preliminary results of DNA-fingerprinting indicate no evidence of clonal likeness and then of patient-to-patient spread.

Research paper thumbnail of PFGE and antibiotic susceptibility phenotype analysis of Pseudomonas aeruginosa strain chronically infecting Cystic Fibrosis patients

Microbiologia Medica, 2008

Analisi delle caratteristiche fenotipiche e genotipiche di ceppi sequenziali di Pseudomonas aerug... more Analisi delle caratteristiche fenotipiche e genotipiche di ceppi sequenziali di Pseudomonas aeruginosa isolati da pazienti con fibrosi cistica SUMMARY Pseudomonas aeruginosa is the leading cause of chronic lung infection and following pulmonary worsening of cystic fibrosis patients. To verify whether bacterial modifications regarding motility, mucoidy, and serum susceptibility proceeded from an adaptation to chronic infection or a replacement with a new strain, sequential P. aeruginosa isolates of known phenotype collected from 5 cystic fibrosis patients were typed by pulsed-field gel electophoresis (PFGE). Antimicrobial susceptibility testing of all isolates was performed by the disc diffusion method. PFGE typing demonstrated that strains dissimilar in colony morphotype and of different antibiotic susceptibility patterns could be of the same genotype. Some patients were colonized with a rather constant P. aeruginosa flora, with strains of different phenotypes but of one genotype. Instead, some patients may be colonized by more than one genotype. Secretion of mucoid exopolysaccharide and acquisition of a new antibiotic susceptibility phenotype in these strain appear to evolve during chronic colonization in cystic fibrosis patients from specific adaptation to infection rather than from acquisition of new bacterial strains.

Research paper thumbnail of Outer-membrane porins from Gram-negative bacteria stimulate platelet-activating-factor biosynthesis by cultured human endothelial cells

European Journal of Biochemistry, 1993

Porins are a family of hydrophobic proteins located in the outer membrane of the cell wall in Gra... more Porins are a family of hydrophobic proteins located in the outer membrane of the cell wall in Gram-negative bacteria. The effect of porins on the biosynthesis of platelet-activating factor (PAF) by cultured human umbilical-cord-vein-derived endothelial cells (HUVEC) was investigated. The results demonstrate that porins were able to induce a dose-dependent synthesis of PAF in HUVEC. PAF, synthesized after stimulation with porins, was mainly cell associated and the synthesis peaked at 15 min, decreasing rapidly thereafter. Experiments with radiolabeled precursors demonstrated that PAF, a 1 -O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine, was synthesized via the remodeling pathway involving the acetylation of 1 -O-alkyl-2-lyso-sn-glyceryl-3-phosphorylcholine (2-lysoPAF) generated from l-O-alkyl-2-acyl-sn-glyceryl-3-phosphorylcholine by phospholipase-A2 activity. The activation of phospholipase A2 in HUVEC stimulated by porins was detected by observing the mobilization of [i4C]arachidonic acid. In addition, the activity of acetyl-CoA :l-alkyl-sn-glycero-3phosphorylcholine 2-0-acetyltransferase was transiently increased in porin-stimulated HUVEC and, after incubation with [3H]CoASAc or [3H]acetate, the [3H]acetyl group was incorporated into newly synthesized PAF. Porins, by forming transmembrane channels, induced a sustained influx of extracellular 45Ca2+ into the cytosol. The activation of PAF synthesis by porins depended on this influx rather than on intracellular calcium mobilization, since PAF synthesis did not occur in the absence of extracellular Ca".

Research paper thumbnail of Secondary metabolites of Aspergillus exert immunobiological effects on human monocytes

Research in Microbiology, 1999

This project focused on the effects of aflatoxin B1 (AFB1), a food-contaminating mycotoxin produc... more This project focused on the effects of aflatoxin B1 (AFB1), a food-contaminating mycotoxin produced by fungi, genus Aspergillus, on the release and genetic expression of some important cytokines, i.e., (interleukin-1α (IL-1α), IL-6, tumor necrosis factor-α (TNFα)) by human monocytes. Monocytes, preincubated for different time periods with concentrations of AFB1 ranging from 0.01 to 1.0 pg/mL, were then activated with bacterial lipopolysaccharide. Cytokine levels were measured by immunoassay and mRNA by cDNA amplification. Pretreatment of monocytes with AFB1 resulted in a decrease in IL-1, IL-6 and TNFα release already at a concentration of 0.05 pg/mL. The gene expression of the cytokines considered was drastically affected by treatment with AFB1. In fact, AFB1 completely blocked the transcription of IL-1α, IL-6 and TNFα mRNAs, while it did not affect -actin mRNA at the concentrations used. It therefore appears that AFB1 exerts its effect on cytokine release through selective inhibition of specific mRNA, without affecting general protein synthesis. © Elsevier, Paris Aspergillus / aflotoxin B1 / cytokine / immunosuppression / microbiological control / gene expression * Correspondence and reprints rossano@unina.it Abbreviations: AFB1, aflatoxin B1; ConA, concanavalin A; IL, interleukin; LPS, lipopolysaccharide; RT-PCR, reverse transcription-polymerase chain reaction; TNF, tumor necrosis factor. Res. Microbiol. 150 (1999) 13−19

Research paper thumbnail of Oral candidiasis: a comparison between conventional methods and multiplex polymerase chain reaction for species identification

Oral Microbiology and Immunology, 2009

Research paper thumbnail of Porins and lipopolysaccharide stimulate platelet activating factor synthesis by human mesangial cells

Kidney International, 1992

Porins and lipopolysaccharide stimulate platelet activating factor synthesis by human mesangial c... more Porins and lipopolysaccharide stimulate platelet activating factor synthesis by human mesangial cells. Porins, a family of hydrophobic proteins located in the outer membrane of the cell wall of gram-negative bacteria and Iipopolysaccharide (LPS), were shown to stimulate the synthesis of platelet activating factor (PAF), a phospholipid mediator of inflammation and endotoxic shock, by cultured human glomerular mesangial cells (MC). The synthesis of PAF induced by porins was rapid (peak at 20 mm) and independent either from contamination by LPS or from generation of an endotoxin-induced cytokine such as tumor necrosis factor (TNF) since it was not prevented by cycloheximide, an inhibitor of protein synthesis or anti-TNF blocking antibodies. LPS also stimulated PAF synthesis by MC. However, the kinetic of PAF synthesis induced by LPS was biphasic with an early and transient peak at 10 minutes and a second and sustained peak at three to six hours. This second peak required an intact protein synthesis and was prevented by anti-TNF antibodies, suggesting the dependency on LPS-induced synthesis of TNF. Experiments with labeled precursors demonstrated that in MC, either after stimulation with porins or LPS, PAF was synthetised via the remodeling pathway that involves acetylation of l-0-alkyl-sn-glyceryl-3-phosphorylcholine (2-lyso-PAF) generated from 1-0-alkyl-2-acyl-sn-glyceryl-3-phosphorylcholine by phospholipase A2 (PLA2) activity. Porins and LPS, indeed, induced PLA2dependent mobilization of ['4C]-arachidonic acid that was inhibited by p-bromodiphenacylbromide (PBDB). PBDB, an inhibitor of PLA2, also blocked PAF synthesis by preventing the mobilization of 2-lyso-PAF, the substrate for PAF-specific acetyltransferase. The addition of 2-lyso-PAF restored PAF synthesis. The activity of acetyl C0A:2-lyso-PAF acetyltransferase was increased in porin-as well as in LPS-stimulated MC and, after cell preincubation with [3H]-acetyl CoA, [3H]-acetyl was incorporated in the newly synthetised PAF. The activation of PAF synthesis by porins was dependent on extracellular Ca2. Porins by forming trans-membrane channels determined a sustained influx of 45Ca2 into the cytosol. The inhibitory effect of trifluoperazine, an inhibitor of Ca2-ca!modulin complexes, on PAF synthesis by porinstimulated MC suggested that calmodulin mediated the Ca2-dependent activation of enzymes involved in PAF synthesis.

Research paper thumbnail of Rapid and reliable MALDI-TOF mass spectrometry identification of Candida non-albicans isolates from bloodstream infections

Journal of Microbiological Methods, 2013

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) fin... more Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) fingerprinting has recently become an effective instrument for rapid microbiological diagnostics and in particular for identification of micro-organisms directly in a positive blood culture. The aim of the study was to evaluate a collection of 82 stored yeast isolates from bloodstream infection, by MALDI-TOF MS; 21 isolates were identified also directly from positive blood cultures and in the presence of other co-infecting micro-organisms. Of the 82 isolates grown on plates, 64 (76%) were correctly identified by the Vitek II system and 82 (100%) by MALDI-TOF MS; when the two methods gave different results, the isolate was identified by PCR. MALDI-TOF MS was unreliable in identifying two isolates (Candida glabrata and Candida parapsilosis) directly from blood culture; however, direct analysis from positive blood culture samples was fast and effective for the identification of yeast, which is of great importance for early and adequate treatment.

Research paper thumbnail of Chryseobacterium respiratory tract infections in patients with cystic fibrosis

Journal of Infection, 2007

Objectives: To investigate the prevalence of infections by Chryseobacterium in a cohort of cystic... more Objectives: To investigate the prevalence of infections by Chryseobacterium in a cohort of cystic fibrosis (CF) patients, to assess the antimicrobial susceptibility of these strains, to examine their DNA fingerprinting and to evaluate some clinical outcomes of patients infected by these bacteria. Methods: Patients (300) attending a Regional Cystic Fibrosis Unit were enrolled in this study over 4 years. Natural or induced sputum samples were processed for microscopic and cultural tests. For phenotypic identification, automated and manual systems were used. For chemosusceptibility test, an automatic broth microdilution test and a disk-diffusion test were used and strains underwent DNA fingerprinting by pulsed-field gel electrophoresis (PFGE). Results: Thirty-five strains of Chryseobacterium were isolated from 22 patients. These strains showed a broad-spectrum antimicrobial resistance, with activity only for trimethoprime sulfamethoxazole and quinolones. PFGE profiles of all isolates were generally heterogeneous, suggesting independent circulation. Conclusions: This is the first report about clinical isolates of Chryseobacterium spp from CF patients in an Italian Centre. The infection by Chryseobacterium was not associated to a deterioration of pulmonary function and mortality: therefore, all patients infected by Chryseobacterium were co-infected by Pseudomonas aeruginosa and 3 of these were also co-infected by Burkholderia cepacia complex.

Research paper thumbnail of A multi-society position paper on the prevention and management of nosocomial and severe infections: the Italian Society for Infectious Diseases, the Italian Multidisciplinary Society of Hospital Infections, the Italian Society of Chemotherapy, the Italian Society of Respiratory Medicine, the Ita...

International Journal of Infectious Diseases, 2010

Research paper thumbnail of Commonly used antibiotics induce expression of Hsp 27 and Hsp 60 and protect human lymphocytes from apoptosis

International Immunopharmacology, 2004

Heat shock proteins (Hsps) are abundant molecular chaperones participating in the cytoprotection.... more Heat shock proteins (Hsps) are abundant molecular chaperones participating in the cytoprotection. The kinetics of synthesis of Hsps closely correlates with the kinetics of development of resistance to cell death. In this study, we analysed the probable involvement of Hsp 27 and Hsp 60 in the protection of cells undergoing apoptosis. Human lymphocytes cultured in the presence of ampicillin or ceftriaxone produced Hsp 60 and Hsp 27, estimated by immunoblotting in a timedependent manner and the increased levels of Hsp 60 and Hsp 27 correlated with enhanced resistance of the lymphocytes to apoptosis, as determined by flow cytometry. Cultures treated with ampicillin or ceftriaxone also exhibited smaller numbers of apoptotic cells than untreated cultures when exposed to the apoptosis-inducing agent staurosporine (1 mM). In contrast, cloramphenicol induced the production of only small amounts of Hsp 60, and no resistance apoptosis. Further studies are needed to clarify the potential role of Hsp 27 and Hsp 60 in the resistance of human cells to apoptosis and the effects of antibiotics on this phenomenon. D

Research paper thumbnail of Application of a computerised method to measure static pressure volume curve in acute respiratory distress syndrome

Intensive Care Medicine, 2000

To assess the safety and the bedside feasibility of a new computerised method to record the stati... more To assess the safety and the bedside feasibility of a new computerised method to record the static pressure-volume curves (Pst/V) of the respiratory system. The Pst/V curves were recorded in 13 medical patients with the acute respiratory distress syndrome (ARDS). During the Pst/V curve tracing the following parameters were recorded: time required for the recording and the automatic analysis of the Pst/V curve and modifications in electrocardiograms, blood pressure, and arterial oxygen saturation (SaO(2)). The study was performed in the intensive care unit of the University of Naples &quot;Federico II&quot;. No statistically significant modifications in heart rate (HR, b min(-1)), blood pressure (BP, mmHg), and SaO(2) were observed between conditions at baseline (HR 97.2 +/- 17.7; BP 65.4 +/- 9.3; SaO(2) 93.6 +/- 2.0), during the recording (HR 99.8 +/- 19.5; BP 66.2 +/- 11.6; SaO(2) 93.7 +/- 2.4), and 2 min after the procedure (HR 98.2 +/- 17.8; BP 65.2 +/- 11.7; SaO(2) 93.7 +/- 1.9). The Pst/V curves were recorded in 8.38 +/- 1. 19 min and fully analysed in 2.69 +/- 0.85 min. Mean value of static compliance was 41.1 +/- 12.7 ml cmH(2)O(-1). A lower inflection point was found in ten patients (mean value 9.2 +/- 1.9 cmH(2)O). In ARDS patients, the present new computerised method gave valuable data to ordinary intensivists and was shown to be safe, easy, and fast.

Research paper thumbnail of Effects of ventilation in ventral decubitus position on respiratory mechanics in adult respiratory distress syndrome

Intensive Care Medicine, 1997

Objective: To assess the potential benefits of a period of ventilation in ventral decubitus (VD) ... more Objective: To assess the potential benefits of a period of ventilation in ventral decubitus (VD) on oxygenation and respiratory mechanics in the adult respiratory distress syndrome (ARDS). Design: In a stable condition during baseline ventilation in dorsal decubitus (DD), after 15 min of ventilation in VD and after 10 min of restored DD, the following parameters were studied: arterial blood gas tension, haemodynamics and static respiratory compliance (Crs), evaluated with the rapid airway occlusion technique. Setting: The study was completed in the intensive care units of university hospitals as part of the management of the patients studied. Patients: Twelve patients (7 males, 5 females, mean age 51.8 + 16.6 years) suffering from ARDS of different aetiologies. Interventions: Before and during each evaluation, the patients were kept under stable haemodynamic and metabolic conditions. The ventilatory setting was kept constant. All the patients were sedated, paralysed and mechanically ventilated.

Research paper thumbnail of Typing of Vancomycin-Resistant Enterococcus faecium Strains in a Cohort of Patients in an Italian Intensive Care Unit

Infection, 2007

Background: Vancomycin-resistant enterococci (VRE) have become a major cause of nosocomial infect... more Background: Vancomycin-resistant enterococci (VRE) have become a major cause of nosocomial infections. The increase of vancomycin-resistant Enterococcus faecium (VR-Efm) in an intensive care unit (ICU) of an Italian university hospital from 2003 through 2004, led us to evaluate the phenotypic and genetic features of these strains. The prevalence of different bacterial species in this ICU is described. The antibiotic resistance profiles of VR-Efm strains, their van-genotype and pulsed-field gel electrophoresis (PFGE) profiles were also analyzed. Materials and Methods: From January 2003 to December 2004, VR-Efm strains were collected from several biological samples. Bacteria were identified using standard biochemical reactions and automated systems. Antibiotic susceptibility was evaluated by disk diffusion and microdilution methods. Resistance to glycopeptides was confirmed by the E test. Vancomycin-resistant genotypes (vanA, vanB) were identified by PCR. Strains were typed by PFGE. Results: Fifty E. faecium strains were isolated from a total of 700 patients. Of these, 26 were vancomycin-resistant and were isolated from 26 different patients. We also found one strain with resistance to linezolid. The vanA genotype was identified in 20/26 strains and vanB in the remaining strains. A major pulsed-field cluster (''A'') was identified. In this cluster, 14 strains were identified (A1-A14) and 25 out of 26 VR-Efm belonged to it. Only one strain showed a different pattern (strain type ''B''). All isolates with the vanA genotype belonged to cluster ''A'', therefore five out of six isolates with the vanB genotype belonged to cluster A. The only strain with type B pattern was the vanB genotype. Conclusions: Isolation of VR-Efm was very frequent (52%) in our cohort of patients and the vanA genotype was the most frequent (77%). We found 25 out of 26 VR-E. faecium strains to be epidemiologically related by PFGE (cluster A). Strains with distinct genotypes shared closely related PFGE profiles. The occurrence of one major cluster among patients of a single unit indicated intra-facility VRE transmission.