Table 5.

Microbiologically Positive Microorganism Identifications Made by Clinical Culture and Automated Microscopy

Specimen (Patient No.-Day)	CPIS	Discharge Status	Clinical Culture		Automated Microscopy
			Identification	Concentration (cfu/ml)	Identification	Concentration (cfu/ml)
3-D1	4	SNF	Staphylococcus aureus*,†	104–105	Fastidious organism‡	1.07 × 104
5-D7	3	Died	No isolate§	—	Enteric||	1.28 × 105
6-D1	6	Home	Stenotrophomonas maltophilia	>105	S. maltophilia	7.68 × 105
6-D3	9	Home	S. maltophilia	104–105	S. maltophilia	1.60 × 104
8-D7	9	Died	S. aureus*,**	>105	S. aureus	1.11 × 106
8-D10	9	Died	S. aureus	104–105	S. aureus	1.42 × 105
17-D1	7	SNF	Klebsiella pneumoniae*	104–105	Unknown/enteric	1.87 × 104
22-D3	8	Home	S. aureus*	104–105	S. aureus	4.00 × 104
33-D7	6	Home	Candida**,††	104–105	S. aureus‡‡	6.64 × 104

Definition of abbreviations: cfu = colony-forming units; CPIS = Clinical Pulmonary Infection Score; SNF = skilled nursing facility.

^*Polymicrobial sample containing mixed respiratory bacteria.

^†Polymicrobial sample containing lactose-fermenting gram-negative bacillus (10³–10⁴ cfu/ml).

^‡False-negative microscopy result; organism grew only in flowcell containing fastidious growth media, but S. aureus identification test was not activated in that flowcell. S. aureus was correctly identified when the specimen was analyzed further after unblinding.

^§Negative result by clinical culture; no growth to date.

^||False-positive microscopy result; ventilator-associated pneumonia was diagnosed in this patient on the basis of clinical criteria.

^**Polymicrobial sample containing yeast (10⁴–10⁵ cfu/ml) (not Candida albicans or Cryptococcus neoformans).

^††Negative result by clinical culture; colonization by Candida species in a patient who was not immunosuppressed.

^‡‡False-positive microscopy result; however, the patient presented with a CPIS equal to or greater than 6 and diffuse infiltrates on chest radiograph. Gram-positive clustered cocci were identified. Further analysis determined that a coagulase-negative Staphylococcus species was present.