[Transfer of the cecal flora of the hamster to the germfree C3H mouse: use of this model to study the flora of the anti-Clostridium difficile barrier]. / Transfert de la flore caecale du hamster à la souris C3H axénique: utilisation de ce modèle pour étudier la flore de barrière anti-Clostridium difficile.

The purpose of this work was the research and development of an experimental model to study anti-Clostridium difficile caecal microflora in the hamster. First the existence of this "barrier" was verified in conventional hamsters. Then, the caecal flora from these animals was orally transferred to C3H germfree mice. The barrier effect was maintained in the axenic mice. The comparative bacteriological analysis of hamster and mouse feces did not reveal important variations in the dominant anaerobic flora (P less than 0.01). After treatment with erythromycin, the barrier effect was maintained and while the disappearance of Escherichia coli was observed, the dominant anaerobic flora persisted. After dilution (10(-2] and subsequent heating (70 degrees C, 10 min) of caecal contents, the inhibitory activity against C. difficile was maintained although the number of aerobic and aerotolerant bacteria was reduced. The isolation from caecal microflora of anaerobic strains implicated in the resistance to colonization is presently underway in Freter anaerobic chambers.

[Evaluation of an experimental animal model allowing the study of the cecal microflora in the hamster, antagonistic to clostridium difficile]. / Mise au point d'un modèle expérimental animal permettant l'etude de la microflore coecale du hamster, antagoniste de Clostridium difficile.

The purpose of this study was the development and evaluation of an experimental model allowing the investigation of hamster anti-Clostridium difficile coecal microflora. The existence of this "barrier" was verified in conventional hamsters. Such hamster coecal flora was then orally transferred to C3H germ-free mice. In such animals, the "barrier effect" was maintained. After treatment with erythromycin, the colonization resistance was always maintained; despite two subsequent processes, dilutions of coecal contents (10(-2] and subsequent heating of this fluid (70 degrees C, 10 min), the inhibitory activity against C. difficile was partially maintained (10(4) UFC/g faeces). The isolation of anaerobic strains implicated in colonization resistance will next be carried out in an anaerobic chamber using this microflora.

[Frequency of isolation and antibiotic sensitivity of strains of coli bacilli from urinary tract infections isolated in private laboratories]. / Fréquence d'isolement et sensibilité aux antibiotiques des souches de colibacilles isolées en laboratoire de ville au cours d'infections urinaires.

Frequency of isolation and antibiotic susceptibility of E. coli strains isolated from urinary tract infections in private laboratory. The urinary tract infections are not the most frequent infections in man. However cytobacteriological analysis are often required for the diagnosis. The critical evaluation of 3000 analysis brings the followed conclusions: 1) 16% of the analysis correspond to a urinary tract infection; 2) the most frequently isolated germs are E. coli (65%) and Proteus mirabilis (11%); 3) E. coli is always very susceptible to antibiotics especially aminosides (100%) polymyxine E (92%), cotrimoxazole (91%) and quinolones (90%); 4) hospital bacteria can be found with a low frequency. However, in our study, Staphylococcus aureus has been isolated in 6% of the cases. This seems to be in relation with the passage of patients in an obstetric clinic.

The temperature and pH-dependent transition of hen lysozyme. Characterization of two temperature-defined domains and of an N-acetylglucosamine (inhibitor)-insensitive form.

The previously described temperature and pH-dependent transition in the solid state of hen lysozyme was studied in solution. Experiment concerning the velocity of lysis of M. luteus by lysozyme and its behavior in presence of an inhibitor (GlcNAc) as well as a reinvestigation of the Arrhenius curves over a large range of pH, demonstrated the existence of two temperature-induced domains. An inhibitor-insensitive lysozyme form was characterized at 40 degrees (physiological temperature).