Antimicrobial susceptibility of clinical isolates of Enterobacteriaceae producing complex beta-lactamase patterns including extended-spectrum enzymes.

The antimicrobial susceptibility of 103 clinical isolates of Enterobacteriaceae to 11 antibiotics, was investigated, using a conventional inoculum size (5 x 10(5) CFU) and a higher inoculum size (5 x 10(8) CFU). All the isolates produced complex beta-lactamase patterns, including an extended-spectrum beta-lactamase (ESBL) of the TEM- or SHV-type plus other enzymes (a TEM-type or an SHV-type non-ESBL and/or a class C enzyme). The following repertoire of ESBLs was produced by the isolates: TEM-15, TEM-19, TEM-26, TEM-52, TEM-72, TEM-87, TEM-92, SHV-2a, SHV-5 and SHV-12, as assessed by sequencing.

Carbapenems in the treatment of severe community-acquired pneumonia in hospitalized elderly patients: a comparative study against standard therapy.

In this open, prospective, study were enrolled 204 hospitalized elderly patients with severe (88 males, 116 females, age range 70-94). Patients were randomized to receive one of the following antibiotic treatment regimens: meropenem 500 mg i.v.

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.

Meropenem stability to beta-lactamase hydrolysis and comparative in vitro activity against several beta-lactamase-producing Gram-negative strains.

The interaction between meropenem and class A, B, C and D beta-lactamases was studied by a spectrophotometric method. Class A, C and D beta-lactamases were unable to confer in vitro resistance to carbapenems. Surprisingly, several class B metallo-beta-lactamases expressed in Escherichia coli failed to confer resistance when a conventional inoculum (105 cfu/mL) was used.

Concentrations of single-dose meropenem (1 g iv) in bronchoalveolar lavage and epithelial lining fluid.

The concentrations of meropenem were measured in plasma, bronchoalveolar lavage (BAL) and epithelial lining fluid (ELF) 0.5-8 h after the administration of a single 1 g iv dose of meropenem. Thirty-five patients undergoing bronchoscopy were studied.

Interaction of cefotetan and the metallo-beta-lactamases produced in Aeromonas spp. and in vitro activity.

Aeromonas spp. are increasingly being recognized as human pathogens. The presence of metallo-beta-lactamases in these organisms represents a potential problem in antimicrobial therapy.

Multicenter randomized trial comparing meropenem (1.5 g daily) and imipenem/cilastatin (2 g daily) in the hospital treatment of community-acquired pneumonia.

An open, multicenter study with 144 patients, aged between 18 and 94 years, was performed to compare the efficacy and safety of meropenem with imipenem/cilastatin in the hospital treatment of community-acquired pneumonia. Patients were randomized to receive either intravenous meropenem (500 mg every 8 h) or intravenous imipenem/cilastatin (1,000 mg every 12 h). The primary end point was considered to be clinical efficacy and the secondary end points were bacteriological response and safety assessment.

Mechanisms of beta-lactam resistance amongst Pseudomonas aeruginosa isolated in an Italian survey.

The mechanisms of resistance to beta-lactam antibiotics in 325 isolates of Pseudomonas aeruginosa were examined. These isolates were selected because of their resistance to meropenem and imipenem (breakpoint, >4 mg/L), carbenicillin (>128 mg/L), ceftazidime (>8 mg/L), piperacillin and ticarcillin/clavulanate (>64 mg/L). The most frequent mechanism of resistance was beta-lactamase-independent, so called 'intrinsic resistance', which was found in 183 isolates and was probably due to impermeability and/or efflux mechanisms.

Effect and pharmacokinetics of netilmicin given as bolus intramuscular administration: an open comparative trial versus amikacin and fosfomycin in elderly patients affected by urinary tract infections.

A randomized comparative open clinical trial was performed on 96 hospitalized patients of both sexes, most of whom (84.4%) over 60 years of age, affected by simple and complicated urinary tract infections. Patients were divided in three unequal sized groups and treated with a single administration of netilmicin (5 mg/kg intramuscularly), of amikacin (15 mg/kg i.

[Netilmicin in a single daily dose for treatment of systemic infections].

The Authors report the results obtained in 35 patients of either sex suffering from various systemic infections and treated with netilmicin. Netilmicin has been intramuscularly administered in once daily dose of 4.5 mg/kg (mean daily dose 294.

[Antibiotic prophylaxis with netilmicin in patients undergoing cystoscopic study].

Thirty adults of either sex, in several cases affected by severe urinary pathology, underwent check cystoscopy. An intramuscular injection of netilmicin 200 mg was administered one hour before the diagnostic procedure as antibiotic prophylaxis. Treated patients were controlled up to three months after cystoscopy, in order to verify the presence of urinary infections.

[Netilmicin in single daily doses for the bacterial bronchopulmonary complications in patients with advanced bronchogenic carcinoma].

In 40 patients with bacterial bronchopulmonary complications during polychemotherapy for advanced bronchogenic carcinoma, once-daily netilmicin (4.5 mg/kg every 24 h) brought about complete resolution of the infective process in 90% of the cases and eradication of the responsible pathogen in 82%. This result must be considered good in view of the patients' precarious condition due to their advanced neoplastic disease.

[Netilmicin in the treatment of infections of the lower urinary tract].

The authors treated 30 patients (11 females and 19 males) with cystitis or cystopyelitis. Patients were randomly assigned to one of the following treatments: a) netilmicin 200 mg daily, b) netilmicin 200 mg + ampicillin 1 g daily. Clinical and bacteriologic results were positive in all cases with resolution of clinical signs of infection and negative cultures at the end of treatment.

[Endobronchial administration of netilmicin in patients with bronchopulmonary infections seen in the neurosurgical intensive care unit].

The Authors report the results obtained in the treatment of bronchopulmonary infections in patients hospitalized in the Neurosurgical Intensive Care Unit. Netilmicin was administered by systemic and endobronchial routes. The cleaning of the bronchial tree was always performed.