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I Stock

Publications and source records attributed to I Stock.

27 records · Page 2Linked to original sources

Identification and natural antibiotic susceptibility of Morganella morganii.

Our data should elucidate whether or not natural antibiotic susceptibility can be used as an aid for subspecies or biovar discrimination of Morganella morganii (II). Furthermore, our goal was to create a database of the natural susceptibility of M. morganii (III) and we were interested in the relative frequency of the recently described subspecific taxa (I). On the basis of trehalose fermentation (TRE), ornithine decarboxylase (ODC), and lysine decarboxylase (LDC) activities, we determined the biovar for 90 clinical isolates of M. morganii. Within these strains we examined the natural antibiotic susceptibility of 53 morganellae to 70 antibiotics by determination of the MICs with a microdilution procedure. (I): 80 strains (89%) of all morganellae belonged to M. morganii ssp. morganii (TRE-), with biovar A (LDC-, ODC+) predominating (67 strains). The remaining strains of this subspecies were identified as biovar B (LDC+, ODC+; 12 strains) and biovar C (LDC-, ODC-, one strain). Ten strains of M. morganii ssp. sibonii (TRE+) were found: four strains belonged to biovar F (LDC variable, ODC-) and six strains to biovar G (LDC-, ODC). (II): With one exception we found no significant differences in antibiotic susceptibility between different biovars. M. morganii ssp. morganii strains are more susceptible to tetracycline than strains of M. morganii ssp. sibonii, but there is no evidence that this parameter could be useful to differentiate biovars within a subspecies. It could be shown that 8 of 30 strains of biovar A and 2 of 12 strains of biovar B were tetracycline resistant. However, one M. morganii ssp. sibonii strain was clinically susceptible to tetracycline according to French and American standards. (III): The natural population of M. morganii is primarily (naturally) resistant to certain penicillins like benzylpenicillin, oxacillin, and amoxicillin, first and second generation cephalosporins (excluding cefoxitin), cefpodoxime, all antibiotics of the ML group (macrolides and lincosamides), sulfamethoxazole, glycopeptides, fosfomycin, and fusidic acid, naturally sensitive to aminoglycosides, piperacillin, mezlocillin, ticarcillin, third and fourth generation cephalosporins, carbapenems, aztreonam, quinolones, trimethoprim, cotrimoxazole, and chloramphenicol. M. morganii is naturally resistant to a wide range of antibiotics. The natural resistance pattern is useful for validation of sensitivity tests. Susceptibility to antibiotics is an unsuitable parameter for the discrimination of the described subspecific taxa of M. morganii. M. morganii strains that do not belong to biovar A are rare.

Anti-Bacterial Agents↗

Natural antibiotic susceptibility of Providencia stuartii, P. rettgeri, P. alcalifaciens and P. rustigianii strains.

The natural antibiotic susceptibility of 38 Providencia rettgeri, 35 P. stuartii, 23 P. alcalifaciens and 20 P. rustigianii strains was examined. MIC values were determined by a microdilution procedure and evaluated by a table calculation programme. P. stuartii was the least susceptible Providencia sp. and was naturally resistant to tetracyclines, some penicillins, older cephalosporins, sulphamethoxazole and fosfomycin and to antibiotics to which other species of Enterobacteriaceae are also resistant. It was naturally sensitive to modern penicillins and cephalosporins, carbapenems and aztreonam, but its susceptibility to aminoglycosides and quinolones was difficult to assess. P. alcalifaciens and P. rustigianii strains were the most susceptible Providencia spp. They were naturally sensitive or intermediate to tetracyclines and sensitive to aminoglycosides and quinolones. Susceptibility to sparfloxacin, biapenem and sulphamethoxazole permitted the discrimination of P. alcalifaciens and P. rustigianii strains. The natural antibiotic susceptibility of P. rettgeri strains was between that of P. stuartii and that of the other providenciae. P. rettgeri was resistant to tetracyclines and fosfomycin, but more susceptible to aminoglycosides, quinolones, fosfomycin and numerous beta-lactam antibiotics than P. stuartii. A database is described of the natural antibiotic susceptibilities of Providencia spp. It can be used for the validation of antibiotic susceptibility test results of these micro-organisms.

Anti-Bacterial Agents↗

[Examination of the diastolic function of the left ventricle by Doppler echocardiography in coronary disease].

The authors examined the left ventricular diastolic function at rest and in pain-free period in patients with chest pain but without previous myocardial infarction. Two patient group were formed according to the results of coronarography: 15 patients had significant coronary artery stenosis, while the coronarography was negative in case of 11 patients. Four Doppler echocardiographic parameters were taken and their sensitivity, specificity, positive and negative predictive values were determined on the base of the result of the coronarography. The small number of patients allows only preliminary evaluation but the results suggest that the altered diastolic function enhances the probability of the presence of significant coronary artery disease, while a normal diastolic function decreases its probability.

Coronary Disease↗