Tracheostomy Cultures
A total of 82 tracheostomy cultures were obtained for 76 patients (Table 5). Of these, 44 (54%) had many polymorphonuclear leukocytes (PMNs) on tracheostomy gram stain. Most bacterial growth was quantified as moderate or heavy growth (n=141/224, 63%). The majority of cultures were polymicrobial (n=70, 85%). From 82 cultures, 224 organisms were isolated, of which P. aeruginosa was most common (n=68, 30%), followed by Serratia marcescens (n=32, 14%) andStaphylococcus aureus (n=27, 12%). Eleven (41%) of isolatedS. aureus organisms were methicillin-resistant.