Oropharyngeal colonization with aerobic gram-negative bacilli in respiratory therapists: period prevalence.

During a 3-month winter period, swab pharyngeal cultures for aerobic gram-negative bacilli were obtained weekly for 3 weeks from 44 hospital-based respiratory therapists and 53 nontherapist control hospital personnel. The swab cultures were inoculated directly onto MacConkey agar plates. Aerobic gram-negative bacilli were isolated from 9.1% of the respiratory therapists and from 9.4% of the control subjects. One respiratory therapist was colonized with the same organism on all three occasions, whereas all other colonized subjects were only transiently colonized. Thus, despite frequent exposure to patients and aerosols likely to contain aerobic gram-negative bacilli, respiratory therapists do no appear to have higher pharyngeal colonization rates than other hospital personnel.