[Study of susceptibility of Haemophilus influenzae to beta-lactams by using HTM gelose (Haemophilus test medium)].
HTM agar was used for in vitro study of bêta-lactam antibiotics activity on H. influenzae. Tested strains belong to the three ampicillin phenotypes: sensitive, betalactamase production and ampicillin resistance without production of betalactamase. Using 2 micrograms ampicillin disk, diameters > or = 20 mm and < 20 mm separate ampicillin sensitive and resistant strains. The following zone-size breakpoints could be suggested: ampicillin (10 micrograms) > or = 25 and < 22 mm; amoxicillin (25 micrograms) > or = 26 mm and < 23 mm; ampicillin/sulbactam (10/10 micrograms) > or = 25 mm and < 22 mm; amoxicillin/clavulanic acid (20/10 micrograms) > or = 26 mm and < 23 mm; cefaclor (30 micrograms) > or = 25 mm and < 20 mm; cefuroxime (10 micrograms) > or = 22 mm and < 19 mm; cefixime (10 micrograms) and cefpodoxime (10 micrograms) > or = 26 mm; cefotaxime (30 micrograms) et ceftriaxone (30 micrograms) > or = 30 mm. The zone-size breakpoints concentrations, distribution of bacterial populations, mechanisms of resistance. In vitro study may screen for ampicillin resistance mechanisms.
Dabernat
H
H
Laboratoire de Microbiologie, Centre Hospitalier Universitaire Toulouse Purpan, France.
Seguy
M
M
Delmas
C
C
D000667:Ampicillin / Q000494:pharmacology; D000668:Ampicillin Resistance; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002433:Cefaclor / Q000494:pharmacology; D002439:Cefotaxime / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism; D005779:Immunodiffusion; D066298:In Vitro Techniques; D010641:Phenotype; D001618:beta-Lactamases / Q000096:biosynthesis
D000900:Anti-Bacterial Agents; D002433:Cefaclor; D000667:Ampicillin; D001618:beta-Lactamases; D002439:Cefotaxime
Etude de la sensibilité de Haemophilus influenzae aux bêtalactamines par utilisation de la gélose HTM (Haemophilus test medium).