Normal respiratory/oral flora, mixed respiratory/oral flora, or equivalent
Candida species or yeast not otherwise specified
Coagulase-negative Staphylococcus species
Enterococcus species
Reproduced from: National Healthcare Safety Network (NHSN). Surveillance for Ventilator-associated Events. Device-associated Module: Ventilator-Associated Event Protocol, January 2014. Centers for Disease Control and Prevention. Available at: http://www.cdc.gov/nhsn/acute-care-hospital/vae/ (Accessed August 22, 2014).