RESUMEN
A total of 709 isolates of Citrobacter species were recovered from different clinical specimens at Kasturba Medical College, Mangalore. The antimicrobial susceptibility testing of the isolates was performed using Kirby-Bauer's method of disk diffusion. All the isolates were susceptible to Imipenem (100%) and 100% resistance to Ampicillin was recorded. Susceptibility to third generation cephalosporins varied between 29 - 43%. The beta-lactamase inhibitor combination used along with beta-lactam antibiotics increased their sensitivity. The minimum inhibitory concentration (MIC) of cephotaxime to Citrobacter species was determined by agar dilution method (MIC value = or < 8 microg/ml are considered susceptible). Two hundred and fifty three strains were found to be completely susceptible, 71 strains showed intermediate susceptibility and 385 strains were completely resistant to Cephotaxime.