title: Differential susceptibility of indole-positive and -negative strains of Klebsiella pneumoniae to cefazolin, choramphenicol and tetracycline.
abstract: Biochemical properties and antibiotic susceptibilities of 168 clinical isolates of Klebsiella pneumoniae were tested. On the basis of the indole reaction, 30 isolates (18%) were indole-positive and 138 isolates (82%) were indole-negative. A significant difference in antibiotic susceptibility was found in each of the two groups of isolates. Of the indole-negative isolates, 82.6% were susceptible to cefazolin at 6.25 microgram/ml or lower, while the indole-positive isolates varied in susceptibility to cefazolin. All of the indole-positive isolates were susceptible to chloramphenicol and tetracycline, but the indole-negative isolates varied in their susceptibility to these antibiotics. Whereas there was no relationship between indole production and susceptibility to cephalothin among the K. pneumoniae isolates studied, it appeared that there was a correlation between the indole reaction and susceptibility to cefazolin, chloramphenicol and tetracycline.
mesh_terms: D002437:Cefazolin / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology*; D002512:Cephalothin / Q000494:pharmacology; D002701:Chloramphenicol / Q000494:pharmacology*; D005839:Gentamicins / Q000494:pharmacology; D007211:Indoles / Q000096:biosynthesis*; D007612:Kanamycin / Q000494:pharmacology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D013752:Tetracycline / Q000494:pharmacology*
chemical_list: D002511:Cephalosporins; D005839:Gentamicins; D007211:Indoles; D007612:Kanamycin; D002701:Chloramphenicol; D013752:Tetracycline; D002437:Cefazolin; D002512:Cephalothin