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Background: Blood stream infections (BSIs) represent a major complication of allo-SCT and are a major cause of morbidity and mortality during and after bone marrow aplasia., Objectives: The objective of this study was to describe the incidence and outcome of BSIs in a cohort of patients submitted to allo-SCT, in order to track changes of the epidemiology and bacteria resistance., Methods: We retrospectively analyzed the microbiological data of 162 patients allotransplanted in Brescia University Hospital, over a period of 6 years., Results: Eighty patients experienced a BSIs for a total of 119 isolates. In 77 cases (65%) a Gram positive bacteria was isolated, being coagulase negative Staphilococci the most frequent species (77% of the cases). In 42 cases (35%) a Gram negative bacteria was isolated ( E . coli 57% and P. aeruginosa 24%). Fluoroquinolones resistance was frequent (90% for S. epidermidis , 92% for E. coli , 90% for P. aeruginosa ). Methycillin resistance of S. epidermidis was 100%, 76% of E. coli were ESBL positive and among P. aeruginosa resistance to carbapenems was 40%. The 2 years overall survival of patients with BSIs vs patients without BSIs was 46% vs 60% (HR1,48, p=0,07). P. aeruginosa and E. coli were the species with the highest mortality (50% and 33%, respectively)., Conclusions: These data confirm that BSIs, mainly sustained by Gram positive bacteria, are frequent in allotransplanted patients (50% of the cases) and may influence the outcome of allotransplanted patients, being antibiotics resistance highly frequent among these bacteria., Competing Interests: Competing interests: The authors have declared that no competing interests exist.

The purpose of this study is to analyze isolates of Clostridium difficile from patients with nosocomial acquired infection in respect to their molecular type and antimicrobial susceptibility. Fifty-nine randomly selected clinical isolates were characterized. Molecular typing was performed by rep-PCR (DiversiLab). Isolates were tested by disk diffusion towards 11 different antibiotics. All isolates were susceptible to metronidazole and vancomycin. Fifty five (93 %) isolates were resistant to erythromycin and fifty six (95 %) exhibited resistance to both clindamycin and moxifloxacin. Twenty rep-PCR types were identified, but most clinical isolates formed four major rep-PCR clusters (A1 24/59, 40 %; A2 20/59, 33 %; A3 5/59, 8 %; A4 3/59, 5 %). These results show high genetic variability, which demonstrate clearly the complexity of the strains of C. difficile and also show an increasing rate of resistance to fluoroquinolones in our region emphasizing the importance of implementing surveillance programs in order to prevent further spread of resistance in C. difficile.

Objectives: To identify bacterial species present in the lower genital tract of males and to investigate the relationship with semen quality., Methods: The microscopic analyses and cultures of 696 semen specimens, collected over five years from males investigated for subfertility, were retrospectively assessed., Results: Semen cultures were sterile in 48%; they showed a polymicrobial flora (more than two bacterial species) in 30%, and were positive (>1 × 10(3) colony forming units/ml) in 22% of the cases. Gardnerella vaginalis was the most frequently isolated bacterium, followed by Escherichia coli and Enterococcus sp. Ureaplasma urealyticum was recovered from 13 of 147 samples (9%). Of patients with bacteriospermia 42% had leukospermia (>10(6) leukocytes/ml of semen). Bacteriospermia and leukospermia did not correlate with each other although a positive correlation was found between the presence of leukocytes and G. vaginalis isolation. Semen parameters were correlated with the bacterial species isolated most frequently. In comparison with controls, sperm concentration, motility and morphology were mostly deteriorated in the presence of G. vaginalis and U. urealyticum., Conclusions: Positive seminal fluid cultures must be interpreted with caution, taking into account both raised colony counts of single isolates and leukocyte concentration in the semen. Thus the common misdiagnosis of genital tract infection, based on the presence of seminal bacteria, and unnecessary treatment with antibiotics may be avoided.

We prospectively analysed the microbiological isolates of all febrile/infectious episodes occurring at our haematology unit during 2 consecutive 18-month periods. Microbiologically documented infections (MDI) and antibiotic resistance were correlated with type and status of haematological disease, neutropenia, levofloxacin prophylaxis, central venous catheter and clinical outcome. Three hundred and ten MDI were observed and 369 pathogens were isolated. Gram-negative bacteria represented 49.3% and Gram-positive bacteria 40.9% of all pathogens. Fungal infections represented only 8.9% of MDI. A significant decrease in Staphylococcus aureus (p < 0.001) and an increase in enterococci, viridans streptococci and Pseudomonas spp. (p = 0.004) were observed during the second period. Four multiresistant (Multi-R) Pseudomonas were isolated, all during the last 12 months. The death rate in MDI was 8.7%, bacteria accounting for 70.4% of them. Enterococci, streptococci and Pseudomonas spp. infections were involved in 44.4% of MDI with an unfavourable outcome. Multi-R pathogens were involved in 4 cases (3 vancomycin-resistant enterococci and 1 Multi-R Pseudomonas), their death rate being 25%. Multivariate analysis showed that an infection due to a mycotic or a Multi-R pathogen was associated with an unfavourable outcome. The recent emergence of enterococci, viridans streptococci and Pseudomonas spp., particularly if Multi-R, is a major concern in haematological patients.

Background: Urinary tract infections are associated with substantial morbidity and recurrent infections. Antibiotic therapy is generally initiated empirically because early treatment decreases the rate of morbidity resulting from UTI. Unfortunately, antibiotic resistance has become an increasingly pressing problem in many countries. In this study, the resistance patterns of urinary isolates to commonly used antimicrobials were determined in order to evaluate the options for empirical antibiotic therapy of UTI in out- and in- patients., Material/methods: A retrospective study was carried out on urine samples examined in this laboratory in 2002-2005. The isolates were divided into the following three groups: isolates from hospital inpatients, isolates from community outpatients, and isolates from catheterized patients., Results: Escherichia coli was the most common etiologic agent isolated, followed by Enterococcus faecalis and Klebsiella pneumoniae. Over the four-year period, a decrease in the isolation of Pseudomonas aeruginosa and a parallel increase in Candida spp. in hospitalized patients were observed. Against Gram-positive isolates, enterococci in particular, ampicillin and glycopeptides demonstrated the best, most consistent activity. Among Escherichia coli isolates, nitrofurantoin, cephalosporins, and penicillin/betalactams were the best options for therapeutic treatment because of the presence of a rate of resistance to cotrimoxazole and fluoroquinolones of over 10%, while the most active drug against Pseudomonas aeruginosa was piperacillin/tazobactam., Conclusions: Region-specific surveillance studies provide additional information about the type of pathogens causing UTIs and their antimicrobial susceptibility patterns. Therefore, these data can serve as a basis to develop national country-specific guidelines for the empirical treatment of UTIs.

Twelve monoclonal antibodies (mAbs) directed against cell-surface antigens of Myxococcus virescens cells were developed and partially characterized. All of them recognized multiple, diffuse proteic bands in Western blot and four were also reactive to living bacteria, as assessed by flow cytometry. The four latter mAbs recognized antigens common to a number of vegetative forms and spores. The selective expression of proteins recognized by mAbs on the microorganisms and the possible applications of mAbs to the study of myxobacterial cell interaction are discussed.

The in vitro antibacterial activity of the new fluoroquinolone Bay y3118 against 609 clinical isolates was evaluated. Bay y3118 exhibited activity against a broad spectrum of organisms, including Gram-negative bacilli, Gram-positive cocci, mycobacteria. The activity of Bay y3118 was often superior to that of other quinolones. Against Gram-negative bacilli its activity was similar to that of ceftriaxone, cefotaxime, ceftazidime and imipenem except for Serratia marcescens, Klebsiella pneumoniae, Enterobacter spp. and Xanthomonas maltophilia, where its activity was superior. Gentamicin and piperacillin sometimes were less active. Bay y3118 was active against a large number of Gram-positive cocci. The fluoroquinolones tested were active against all the strains of Mycobacterium tuberculosis, but only Bay y3118 was effective against Mycobacterium avium.

We studied the effect of subinhibitory concentrations of lomefloxacin on bacterial adherence, assessing the presence of fimbriae in E. coli and the adherence to uroepithelial cells of Staphylococcus saprophyticus. The degree of inhibition of fimbriae in E. coli in the log-phase is directly proportional to subminimal inhibiting concentrations (sub-MIC). On the contrary, there is no effect when the bacteria are in a stationary phase. In the case of Staphylococcus saprophyticus the adherence to epithelial cells was observed at concentrations of 1/2 and 1/4 the MIC.

Cells infected with human immunodeficiency virus type 1 (HIV-1) develop viral antigens which can be detected by immunofluorescence. We developed a flow cytometric immunofluorescence assay (FIFA) which provides a quantitative analysis of HIV-1 p24 using a monoclonal antibody (mAb) as a specific reagent. The reduction of HIV p24 antigen expression in viral infected cells was then used to determine HIV neutralizing antibody titers in human sera. Results obtained by FIFA for detecting neutralizing antibodies against HIV-1, when compared with results obtained by indirect immunofluorescence assay (IFA), showed an overall index of agreement of 94.1%. The correlation between the neutralizing antibody titers obtained with each method was found to be highly significant (ro = 0.8; p < 0.01). The simple methodology and the adaptability of this FIFA to various assay conditions make it suitable for routine purposes and for assessing the efficacy of vaccination strategies.

The Authors describe their experience in rapid diagnosis of mycobacterial infections using a combination of a radiometric blood culture (Bactec 13 A) and a nucleic acid hybridization system (Gen probe, Accuprobe) to detect and identify Mycobacteria. They found out that a high number of septicaemias in HIV positive patients are due to Mycobacterium avium, while in HIV negative subjects Mycobacterium tuberculosis is the most frequent mycobacterium.

This in vitro study of thiamphenicol activity against 247 strains of Gram-positive and 195 strains of Gram-negative pathogenic bacteria showed no significant changes from past activity. Of the 442 strains involved, thiamphenicol proved: - Effective (MIC = less than or equal to 0.5-4 micrograms/ml) against 131 strains, mostly streptococci, pneumococci and enterococci. - Moderately effective (MIC = 8-64 micrograms/ml) against 252 strains, mostly staphylococci, Salmonella, Citrobacter, K. pneumoniae, Enterobacter, E. coli and Proteus. - Ineffective (MIC = 64 micrograms/ml) against 59 strains, mostly Proteus, E. coli and K. pneumoniae. Against 23 strains of Neisseria gonorrhoeae, thiamphenicol generally proved as effective as penicillin G and cefuroxime and more effective than spectinomycin.

Rufloxacin (MF-934) is a new quinolone which shows in vitro antibacterial activity against E. coli, Salmonella, Klebsiella, Proteus and Staphylococcus spp. Lower in vitro activity was observed with Pseudomonas, Serratia, Enterobacter and the streptococci group D. The antimicrobial activity of MF-934 in vitro is higher than that of nalidixic acid but lower than that of ciprofloxacin, ofloxacin, pefloxacin or norfloxacin. The protective effects of MF-934 in systemic infections in mice are lower than those of ciprofloxacin and ofloxacin. In respiratory infections in rats and in subcutaneous infections in guinea-pigs, the protective effects of MF-934 are of the same order as ciprofloxacin and ofloxacin. This is probably due to the pharmacokinetic properties of MF-934, i.e. the long half-life and tissue concentrations higher than plasma levels.

The authors studied the microorganisms found in urocultures of three groups of elderly patients giving an exact map of the microbiology and epidemiology of the urinary tract infections of elderly patients. They shown also the calibrated loop seeding method as the most efficient to evaluate low bacterial concentration in urines which in these patients are significant.

The effect of ceftriaxone against Gram-negative and Gram-positive strains of different clinical isolates has been compared to that of other cephalosporins such as cefuroxime, cefoxitin and cefotaxime. Cefotaxime and ceftriaxone have a notably higher activity against Enterobacteriaceae than cefuroxime and cefoxitin. If ceftriaxone activity is compared to cefotaxime activity, it may be seen that the former shows a stronger action against Pseudomonas, Proteus rettgeri, Enterobacter and Serratia. Against Staphylococcus aureus and enterococci the four antibiotics show a low level of activity. The effect of a microorganism's temporary contact with ceftriaxone was tested by a method whereby the antibiotic was removed with an ion-exchanging resin. Ceftriaxone shows rapid bactericidal activity against sensitive bacteria and if it is used at concentrations slightly higher than MIC, as in vivo against bacteria of average sensibility, we notice a 10-18 h bacteriostatic effect during which a prevalence of filamentous shapes of gram-negative bacteria is observed.

The susceptibility in vitro of aerobic bacteria to cefoxitin and other cephalosporins was determined. The strains were isolated from clinical specimens during 1979 and 1983. The in vitro activity of cefoxitin and other antibiotics against anaerobic bacteria was investigated. The resistance of 5 cephalosporins to inactivating enzymes of bacterial origin was compared.

In recent years, due to the frequent use of antimicrobial agents, strains resistant to antibiotics have been seen with increasing frequency among hospital isolates. We have compared the susceptibility to different beta-lactam drugs of Pseudomonas spp. and Staphylococcus aureus strains, isolated during a 10-yr period (1974-1984) from pathological specimens of different units of Spedali Civili of Brescia Medical School. We have also analyzed the plasmid DNA profile of representative Staphylococcus aureus strains isolated in 1984.

A stable hybridoma cell line secreting specific antibodies against human interferon-gamma (IFN-gamma) and designated IGMB-14 has been established. It belongs to the IgG1, kappa subclass and it reacts in Western blot with the 28 kDa and 56 kDa polypeptides present in two different affinity purified IFN-gamma preparations. Peripheral blood mononuclear cells (PBMC) from a healthy individual, stimulated in vitro by PHA, were analysed for IFN-gamma production both when viable and following fixation. The presence of cytoplasmic or surface IFN-gamma was visualized by an indirect immunofluorescence assay using monoclonal antibody (MAb) IGMB-14 and a single laser FACS-III fluorescence-activated cell sorter. The staining permitted the detection of newly synthesized cytoplasmic IFN-gamma molecules in lymphocytes at day 1 after PHA stimulation and surface IFN-gamma at day 2. IFN-gamma was expressed on almost all the CD4+ lymphocytes as shown by a double staining technique. The specificity of the reaction was confirmed by Western blots and abolishing IFN-gamma staining by pretreatment of MAb IGMB-14 with IFN-gamma. The presence of surface IFN-gamma was also visualized on freshly isolated PBMC from two patients suffering from measles and AIDS but not on PBMC from a healthy individual. The experiments showed that this immunofluorescent method is useful for the detection, enumeration, and phenotypic characterization of IFN-gamma-producing cells in vitro and, in addition, for evaluating the presence of PBMC expressing IFN-gamma on their surface during a viral disease.

The antibacterial activity of teicoplanin and vancomycin against 231 clinical isolates of staphylococci and enterococci was evaluated by standardized agar dilution testing. The two antibiotics showed similar activity against staphylococci. However teicoplanin was significantly more active against enterococci. Killing curves indicated that the bactericidal activity of teicoplanin at the concentration of 2 X MIC was equal to its activity at 8 X MIC.