Bacterial colonization of nursing home residents on admission to an acute care hospital

Very little data obtained in a prospective, controlled fashion examines the prevalence of colonization with antibiotic-resistant bacteria and yeast in nursing home residents on admission to acute-care hospitals. We cultured swabs taken from all nursing home patients admitted to a medical centre on selected days of the week. Age-matched control patients were also enrolled. Nasal, pharyngeal, and rectal or perineal swabs were done within 24 h of admission. Susceptibility to gentamicin was used as a marker for antibiotic resistance. Most nursing home patients (45/56) were colonized with gentamicin-resistant isolates of coagulase-negative staphylococci; in the control group, 24 patients only carried these organisms (P = 0.0001 chi square). The only resistant Gram-negative bacteria were recovered from control patients (3/56 vs. 0/56 nursing home residents; P = 0.12, Fisher's exact test). Yeast were common colonizers of both nursing home residents and controls but were more frequently recovered from nursing home patients (P = 0.03, chi square). Although colonization by antibiotic-resistant staphylococci of nursing home residents on admission to an acute-care hospital was common, resistant Gram-negative bacilli were not found in this study. Additional investigations are needed to determine the risk of infection/colonization with resistant organisms in this population.