Rapid detection of chloramphenicol resistance in Haemophilus influenzae.
We compared a rigid (1-h) screening method for the detection of chloramphenicol acetyltransferase (CAT) activity with the standard spectrophotometric CAT assay to determine whether CAT-mediated chloramphenicol resistance in Haemophilus influenzae could be determined upon primary isolation. Of 58 H. influenzae cell sonicates, 28 had detectable CAT activity when the chloramphenicol-dependent production of free coenzyme A from acetyl coenzyme A was measured spectrophotometrically (standard method). These 28 strains were identified as producing CAT by the rapid method which uses lysed cell suspensions and a color change to detect CAT. The remaining 30 strains did not have CAT activity detectable by either method. This 1-h test for CAT should prove to be useful for the early presumptive identification of chloramphenicol resistance in H. influenzae.
D000123:Acetyltransferases / Q000378:metabolism; D002701:Chloramphenicol / Q000494:pharmacology*; D015500:Chloramphenicol O-Acetyltransferase; D004352:Drug Resistance, Microbial; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000201:enzymology; D008826:Microbial Sensitivity Tests
D002701:Chloramphenicol; D000123:Acetyltransferases; D015500:Chloramphenicol O-Acetyltransferase