Biomedical subjects
Publications and source records attributed to M Pestel.
Bordetella bronchoseptica is a rarely reported cause of human infection, but is a common respiratory tract commensal of mammals. Human infection with B. bronchoseptica is almost always associated with severe underlying disease and contact with an appropriate animal reservoir. We report a case of pneumonia with shock caused by B. bronchoseptica in an immunocompetent patient.
Explore the source record for details and available documents.
A synergistic bactericidal effect between penicillin, vancomycin, and gentamicin has been described against enterococci highly resistant to beta-lactams and glycopeptides. Since such a synergy was also observed in vitro between ceftriaxone, teicoplanin, and gentamicin against Enterococcus faecium 70/90, the efficacy of different combinations including penicillin or ceftriaxone, vancomycin or teicoplanin, and gentamicin was compared in vivo in experimental endocarditis. In vitro, all four triple combinations provided a bactericidal effect. In rabbits, after a 5-day treatment, the ceftriaxone-vancomycin-gentamicin combination was the most effective, both in reducing the total bacterial titers and in eradicating the subpopulation resistant to the synergy. Compared with the 5-day regimen, 10- and 20-day regimens of ceftriaxone-vancomycin-gentamicin, each followed by a 3-day antibiotic-free period, increased the number of sterilized animals but failed to avoid the emergence of resistant bacteria, which occurred in 10%-20% of animals.
The antimicrobial susceptibilities of 118 clinical isolates of coagulase-negative staphylococci to teicoplanin were determined by disc diffusion and the Epsilometer test (E test) and the results were compared with the MICs determined by the agar dilution method of the National Committee for Clinical Laboratory Standards (NCCLS). There was a poor correlation of r = 0.5 between the zone diameters of inhibition and agar dilution MICs and 10 and four of the 11 isolates for which the MICs were > or = 32 mg/L were misclassified as susceptible by the disc test after applying the interpretative criteria of the NCCLS and the Comité de l'Antibiogramme de la Société Française de Microbiologie (CASFM), respectively. The E test tended to result in MICs that were lower than those determined by agar dilution and only 66% of MIC were within +/- 1 log2 dilution of each other. Only one of 11 resistant strains was detected by the E test and, although there was no false resistance, six resistant strains were misclassified as susceptible after applying the criteria of the NCCLS as were four such isolates when the criteria of the CASFM were employed, probably as a result of using too light an inoculum. Disc diffusion is not a reliable means of determining the susceptibility of coagulase-negative staphylococci but might be replaced by the E-test provided that discrepant results can be resolved by using a denser inoculum.
The effects of 16 different beta-lactam-fosfomycin combinations against 50 bloodstream enterococci were compared by a disk diffusion technique. Cefotaxime exhibited the best interaction. By checkerboard studies, the cefotaxime-fosfomycin combination provided a synergistic bacteriostatic effect against 45 of the 50 isolates (MIC of cefotaxime at which 90% of the isolates were inhibited, >2,048 micrograms/ml; MIC of fosfomycin at which 90% of the isolates were inhibited, 128 micrograms/ml; mean of fractional inhibitory concentration indexes, 0.195). By killing curves, cefotaxime (at 64 micrograms/ml) combined with fosfomycin (at > or = 64 micrograms/ml) was bactericidal against 6 of 10 strains tested.
Recently, interest in the enzyme nucleoside diphosphate kinase (EC2.7.4.6) has increased as a result of its possible involvement in cell proliferation and development. Since NDP kinase is one of the major sources of GTP in cells, it has been suggested that the effects of an altered NDP kinase activity on cellular processes might be the result of altered transmembrane signal transduction via guanine nucleotide-binding proteins (G-proteins). In the cellular slime mould Dictyostelium discoideum, extracellular cAMP induces an increase of phospholipase C activity via a surface cAMP receptor and G-proteins. In this paper it is demonstrated that part of the cellular NDP kinase is associated with the membrane and stimulated by cell surface cAMP receptors. The GTP produced by the action of NDP kinase is capable of activating G-proteins as monitored by altered G-protein-receptor interaction and the activation of the effector enzyme phospholipase C. Furthermore, specific monoclonal antibodies inhibit the effect of NDP kinase on G-protein activation. These results suggest that receptor-stimulated NDP kinase contributes to the mediation of hormone action by producing GTP for the activation of GTP-binding proteins.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.