Discrepancy between antibiotics administered in acute exacerbations of chronic bronchitis and susceptibility of isolated pathogens in respiratory samples: multicentre study in the primary care setting.

A national multicentre prevalence study was undertaken to determine the bacterial strains associated with mild-to-moderate acute exacerbations of chronic bronchitis (AECB) in the primary care setting and the susceptibility of isolated pathogens to different antimicrobials usually prescribed to these patients. All samples were processed by a central reference laboratory. Microdilution tests were carried out to establish the minimum inhibitory concentration (MIC) of various antimicrobials. A double-disk test was performed to establish the macrolide resistance phenotype in Streptococcus pneumoniae. Tests to detect the presence of beta-lactamase in Haemophilus influenzae and Moraxella catarrhalis and polymerase chain reaction to detect the presence of ermB and mefA genes in S. pneumoniae isolates were also performed. A total of 1537 patients were included in the trial and 468 microorganisms were isolated from sputum samples, with the most frequent isolates being S. pneumoniae (34.8%), M. catarrhalis (23.9%) and H. influenzae (12.6%). Resistance rates of pneumococci were 47.2% for penicillin, 1.2% for amoxicillin, 34.3% for macrolides (87.5% of which showed high-level resistance), 13.6% for cefuroxime/axetil and 4.2% for levofloxacin. No bacterial isolates showed resistance to telithromycin. Empirical antibiotic treatment was prescribed to 98.3% of patients, including macrolides to 36.6%, amoxicillin with or without clavulanic acid to 32.3% and fluoroquinolones to 16.1%. In conclusion, S. pneumoniae was the most frequently isolated bacteria in patients with mild-to-moderate AECB. Despite the high rates of resistance of pneumococci to macrolides, they continue to be the most widely used antibiotics in primary care to treat AECB.

A comparative study on the efficacy of the new quinolone alatrofloxacin in the treatment of experimental legionellosis in guinea pigs.

The in vivo efficacy of trovafloxacin, intraperitoneally administered as alatrofloxacin (CP-116,517), was assessed and compared with that of erythromycin, alone or in combination with rifampicin, in a model of Legionella pneumophila pneumonia in guinea pigs. Trovafloxacin (5 mg/kg administered as alatrofloxacin once daily for 7 days) gave a survival rate of 100% in infected animals. Clearance of bacteria and of bacteria-induced lesions from lungs was achieved by day 6 post-inoculation. The lungs of trovafloxacin-treated animals remained free of bacteria at day 28 post-challenge. Trovafloxacin proved as effective as erythromycin administered intraperitoneally, but was superior to erythromycin alone. or in combination with rifampicin, when given orally.

Wall mannoproteins in cells from colonial phenotypic variants of Candida albicans.

Candida albicans ATCC 26555 switched at high frequency (10(-1) to 10(-3)) between several phenotypes identified by colony morphology on a defined mineral amino-acid-containing agar medium supplemented with arginine and zinc (LAZ medium). When cells taken from colonies exhibiting distinct morphologies were plated directly onto LAZ agar, spontaneous conversion to all the variant phenotypes occurred at combined frequencies of 2.1 x 10(-1) to 9.5 x 10(-3). However, when cells taken from the different colonial phenotypes were plated directly onto an undefined medium (yeast extract/peptone/dextrose; YPD medium), or first incubated in liquid YPD medium and then cloned on YPD agar, all colonies observed exhibited the same phenotype (smooth-white). When cells from the smooth-white colonies were plated as clones on LAZ agar, the original switch phenotype reappeared. These results suggest that environmental conditions such as the growth medium (and possibly the temperature) influence switching by suppressing phenotype expression, but have no effect on genotype. The variant colony morphologies also appeared to be associated with differences in the relative proportions of yeast and mycelial cells. Zymolyase digests of wall preparations obtained from cells belonging to different colonial phenotypes were analysed by SDS-PAGE. After blotting to nitrocellulose paper, the mannoproteins were stained with Concanavalin A, with a polyclonal antiserum enriched in antibodies against mycelium-specific wall components, and with a monoclonal antibody raised against a high-molecular-mass mannoprotein band (260 kDa) specific to the walls of mycelial cells. The results suggest that phenotypic switching might be associated with changes in the degree of glycosylation in high-molecular-mass mannoproteins, or in the way these mannoproteins are bound to other cell wall components.

Chemotherapy of Aspergillus fumigatus keratitis: an experimental study.

An experimental Keratitis study of Aspergillus fumigatus was performed in 130 rabbits divided into 12 groups of ten animals each. Three antifungal drugs (myconazole, amphotericin B and pimaricin) were tested using two procedures (topical drops and subconjunctival injections) and two different concentrations (500 and 10 000 times the MIC). In each case, the drugs were applied every 3 h starting 14 h after inoculation. Miconazole was useful at 10 mg/ml concentration by topical drops and subconjunctival injections, but was less useful at 5 mg/ml. Amphotericin B was useful at 5 mg/ml concentration by topical drops and less useful at 2 mg/ml. No differences were found between the two concentrations by subconjunctival administration. Pimaricin was useful by topical drops at 50 mg/ml concentration and less useful at 10 mg/ml as well as by subconjunctival injections.