Distribution of Pseudomonas aeruginosa serotypes in bacteriologic specimens and their aminoglycoside resistance.

With regard to that of other facultatively pathogenic microorganisms, the rate of isolation of Pseudomonas aeruginosa was 12.5%. Most frequently the pathogen was isolated from wound swabs, tracheal secretion, throat swabs and urine. In 2.8% of the cases it was identified as the causative pathogen of sepsis. The serotype most commonly identified was the O antigen type 6, followed by types 11 and 1. The distribution of the serotypes observed in specimens and hospitals varied altogether. Epidemiologically striking was the incidence of serotype 1 in the urological division, of type 11 in the gynecological division, of type 6 in the pediatric division, and of type 4 in the dermatological division. Between 4 to 5% of the 618 strains examined exhibited resistance to gentamicin, tobramycin and sisomicin. Insensitivity to amikacin has not been observed. There were no statistically significant differences in incidence of resistance or the pattern of resistance as far as individual serotypes or isolates from the above mentioned divisions are concerned.