Growth in glucose-based medium and exposure to subinhibitory concentrations of imipenem induce biofilm formation in a multidrug-resistant clinical isolate of Acinetobacter baumannii.

Background: Acinetobacter baumannii is emerging as an important nosocomial pathogen. Multidrug resistance, as well as ability to withstand environmental stresses, makes eradication of A. baumannii difficult, particularly from hospital settings.

Multiple CTX-M-type extended-spectrum beta-lactamases in nosocomial isolates of Enterobacteriaceae from a hospital in northern Italy.

Twelve isolates of Enterobacteriaceae (1 of Klebsiella pneumoniae, 8 of Escherichia coli, 1 of Proteus mirabilis, and 2 of Proteus vulgaris) classified as extended-spectrum beta-lactamase (ESBL) producers according to the ESBL screen flow application of the BD-Phoenix automatic system and for which the cefotaxime MICs were higher than those of ceftazidime were collected between January 2001 and July 2002 at the Laboratory of Clinical Microbiology of the San Matteo University Hospital of Pavia (northern Italy). By PCR and sequencing, a CTX-M-type determinant was detected in six isolates, including three of E. coli (carrying bla(CTX-M-1)), two of P.

Resistance surveillance in Italy: four-year results from the MYSTIC program.

The MYSTIC program is an international, multicenter surveillance study that compares the activity of meropenem, in centers that are prescribers, with that of imipenem, ceftazidime, piperacillin/tazobactam, ciprofloxacin and gentamicin. These Italian data are from 3 centers (neutropenia, cystic fibrosis and intensive care units). A total of 2,072 (238 Gram-positive and 1,834 Gram-negative) aerobic microorganisms were collected during the study.

Emerging extended-spectrum beta-lactamases in Proteus mirabilis.

Beta-lactamase production was detected in 147 (52%) of 282 consecutive nonduplicate Proteus mirabilis isolates obtained over a 1-year period from the S. Matteo Hospital of Pavia (northern Italy). Seventy isolates (48% of the beta-lactamase producers) were found to produce extended-spectrum beta-lactamases (ESBLs), identified as PER-1 (first report in this species) and TEM-52 in 52 and 18 isolates, respectively.

[Behavior of Helicobacter pylori in 3d and 4th age-bracket patients].

Aims And Background: Helicobacter pylori is known to be the pathogenic agent of atrophic gastritis and above all ulcer disease. It is also thought to play a role, together with other factors, in the development of stomach cancer and is currently the focus of numerous studies. In industrialised countries, infection is relatively commonplace in children, whereas its incidence rises more steeply in patients aged over 35, reaching a mean prevalence of 50% in over 60 year olds.

Comparative activity of piperacillin/tazobactam against clinical isolates of extended-spectrum beta-lactamase-producing Enterobacteriaceae.

beta-Lactam resistance on the part of the Enterobacteriaceae causes serious therapeutic problems in our institutions due to their production of extended-spectrum beta-lactamases (ESbetaLs). We studied the in vitro activity of beta-lactam/beta-lactamase inhibitor combinations and third-generation cephalosporins and monobactams against 71 clinically relevant Enterobacteriaceae which produced TEM- and SHV-derivative ESbetaLs. Of the single drugs and combinations tested, piperacillin/tazobactam proved to be the most effective.

The role of tissue colonization and bacterial resistance in recurrent tonsillitis.

Unsuccessful medical therapy for treatment of acute tonsillitis frequently results in onset of recurrent or chronic forms rendering surgical treatment necessary. We have studied some of the factors involved in the evolution of these chronic or recurrent forms and, in particular, the distribution of different bacterial strains in tonsillar tissue, their response to treatment with antibiotics and mechanisms of bacterial resistance. The distribution of bacterial flora (saprophytic and pathogenic) present on the surface of the tonsils, in the crypts and in the tonsillar tissue was studied in a control population of 30 children (20 boys and 10 girls) aged between 2-13 years, all affected with chronic tonsillitis and submitted to tonsillectomy.

Extended-spectrum beta-lactamases from Klebsiella pneumoniae strains isolated at an Italian hospital.

Eighteen strains of Klebsiella pneumoniae recently isolated from hospitalized patients were resistant or moderately resistant to oxyimino-cephalosporins (ceftazidime and/or cefotaxime), aztreonam, cefoxitin and all but one were susceptible to imipenem. Analysis of enzymes produced by these clinical isolates revealed a wide pattern of extended-spectrum beta-lactamases. All isolates produced one or more beta-lactamases that were characterized preliminarily by their isoelectric point.

[Pulmonary aspergillosis in acute leukemia. Description of a case and review of the literature].

A case of pulmonary multiple mycosis, recognized by cultural and radiological investigation, during chemotherapy for poorly outcoming acute leukemia is reported. The factors enhancing disseminated aspergillosis in haematologic malignancies as well as the need of early diagnosis and effective therapy in fungal infections complicating leukemias are also discussed in the light of the last 25 years literature.

[Prospective use of immunofluorescence polarization in the study of enzymes modifying aminoglycosides].

A number of assays have been described for aminoglycoside-modifying enzymes; the aim of our investigation was to check the validity of polarized immunofluorescence assay for aminoglycoside enzymes. We have studied three enzymes encoded by R-factors from clinical isolates of Enterobacteriaceae conferring various patterns of aminoglycoside-resistance. The assay resulted valid: this is a simple, rapid and sensitive method.