[Determination of the sensitivity of bacteria to antibiotics by an agar diffusion method and use of the API ATB system: a comparative study]. / Détermination de la sensibilité des bactéries aux antibiotiques par méthode de diffusion en gélose et utilisation de galeries API ATB: étude comparative.

130 bacterial strains were studied for their antibiotics sensitivity by an agar diffusion method and using API ATB System: 50 Enterobacteriaceae, 12 other Gram negative bacilli, 48 Staphylococci and 20 Streptococci. The results concurred in 83 p. cent of the cases. Discrepancies were essentially observed for coagulase negative Staphylococci and Streptococci. Strains appeared more resistant by API ATB System than by the agar diffusion method. Discrepancies mostly concerned beta-lactam antibiotic sensitivity for Gram negative bacilli or aminoglycosides and macrolides sensitivity for Staphylococci. They also concerned sulfamides and trimethoprim sensitivity for all bacterial species.

[Comparative activity of habekacin and 4 other aminoglycosides against gram-negative bacilli. Evolution of resistance]. / Activité comparée de l'habékacine et de quatre autres aminosides à l'égard des bacilles Gram négatif. Evolution de la résistance.

The activity of 5 aminoglycosides compounds (habekacin, amikacin, gentamicin, netilmicin and tobramycin) was studied by an agar dilution method, against 235 strains of Enterobacteriaceae and 146 other Gram negative bacilli. 79 to 98% of susceptible strains were observed, according to the aminoglycoside compound. Habekacin and amikacin were the most effective, specially against the more frequently resistant bacteria: Enterobacter, Serratia, Hafnia, Acinetobacter, Pseudomonas aeruginosa. In comparison with a previous study, no evolution was observed in the resistance to aminoglycosides.

[Comparative study of various API galeries for the identification of gram negative bacteria]. / Etude comparative de diverses galeries API pour l'identification des bactéries à Gram négatif.

116 strains of Gram negative bacteria were identified with the use of API ATB 32 GN and Rapid 20 E galeries, in order to evaluate their performance as compared with API 20 E or API NE galeries used as reference. The identification concur (bacterial genus and species) in approximately 80 per cent of the cases. There are only 2 major discrepancies with ABT 32 GN galleries and only one with Rapid 20 E. In other cases, the profile that is obtained only permits identification of the genus but without a sufficient differentiation, requiring a study of additional characteristics or repetition of the test. These galeries enable to solve most routine diagnosis problems due to Gram negative bacteria, with the advantage of Rapid (Rapid 20 E) or automatized reading (ATB 32 GN).

[Sensitivity of Pseudomonas aeruginosa to beta-lactam antibiotics. Apropos of 338 strains isolated at the Regional Hospital Center at Nantes in 1984]. / Sensibilité aux bêta-lactamines de Pseudomonas aeruginosa. A propos de 338 souches isolées au Centre Hospitalier Régional de Nantes en 1984.

The MIC of 338 Pseudomonas aeruginosa strains isolated in 1984, in a French hospital, was determined by an agar dilution method, using seven beta-lactam antibiotics: ticarcillin, azlocillin, piperacillin, cefoperazone, ceftriaxone, cefsulodin and ceftazidime. The MIC50-MIC90 were respectively: 32-64, 8-32, 8-16, 8-16, 16-64, 4-16, 2-4 mg/l. Ticarcillin was the most frequently effective compound (95% of the strains were susceptible), 90% of the strains were susceptible to ceftazidime or piperacillin, 87% to azlocillin and 84% to cefsulodin. Cefoperazone and ceftriaxone were much less effective (43% and 19% of the strains, respectively). The study of the resistance patterns showed a higher percentage (80%) of strains susceptible to all the penicillins than the percentage of strains susceptible to cephalosporins, most of them however were susceptible to both cefsulodin and ceftazidime. It also showed the relatively low frequency of resistant strains by inducible cephalosporinase or decreased permeability. Serovar 0.12 was characterized by its multi-resistance to beta-lactam antibiotics.