Table 4.

Microbial isolation from surveillance cultures in the three study groups

	OPC	OPC-ETT match	ETA	ETA-ETT match
Total number of different microorganisms isolated	150 (100)	51 (100)	133 (100)	51 (100)
Microorganism
Gram-positive bacteria
Enterococcus faecalis	15 (10)	4 (7.8)	10 (7.5)	4 (7.8)
Enterococcus faecium	13 (8.6)	2 (3.9)	5 (3.9)	1 (2.0)
Staphylococcus aureus	9 (6.0)	3 (5.9)	15 (11)	4 (7.8)
Staphylococcus epidermitis	2 (1.3)	1 (2.0)	2 (1.5)
Beta hemolytic streptococcus group A	1 (0.7)		1 (0.7)
Streptococcus pneumoniae			1 (0.7)
Gram-negative bacteria
Klebsiella species	9 (6.0)	1 (2.0)	4 (3.1)	2 (3.9)
Stenotrophomonas maltophilia	8 (5.2)	4 (7.8)	7 (5.3)	4 (7.8)
Pseudomonas aeruginosa	6 (4.0)	4 (7.8)	5 (3.9)	4 (7.8)
Haemophilus influenzae	4 (2.7)		5 (3.9)
Enterobacter cloacae	2 (1.3)		2 (1.5)
Serratia marcescens	3 (2.0)	1 (2.0)	1 (0.7)	1 (2.0)
Escherichia coli*	4 (2.7)	1 (2.0)	2 (1.5)
Citrobacter freundii	2 (1.3)	1 (2.0)	1 (0.7)	1 (2.0)
Chryseobacterium indologenes	2 (1.3)	2 (3.9)	3 (2.3)	2 (3.9)
Acinetobacter sp.	1 (0.7)		1 (0.7)
Other bacterial species	5 (3.4)		8 (6.2)
Yeast
Candida species	60 (40)	27 (53)	52 (39)	27 (53)
Candida albicans	41 (27)	21 (41)	37 (28)	21 (41)
Candida dubliniensis	8 (5.3)	1 (2.0)	6 (4.5)	1 (2.0)
Candida parapsilosis	2 (1.3)	1 (2.0)	2 (1.5)	1 (2.0)
Candida tropicalis	2 (1.3)	1 (2.0)	2 (1.5)	1 (2.0)
Other candida species	7 (4.7)	3 (5.9)	5 (3.9)	3 (5.9)
Other yeasts, not candida	4 (2.7)		8 (6.0)	1 (2.0)

Note: Data are presented as numbers (percentages). The percentage of positive cultures is related to how many patients were colonized with the specific microorganism. *Includes Escherichia coli producing extended-spectrum beta-lactamase (ESBL). Approximately 25% of oropharyngeal cultures and 18% of endotracheal cultures were polymicrobial. Abbreviations: OPC oropharyngeal culture, ETA endotracheal culture, ETT endotracheal tube