Table 1. Detection of bacterial pathogens in bronchoalveolar lavage by PCR/ESI-MS (IRIDICA).
| Primary and potential pathogens | IRIDICA-positive | |
|---|---|---|
| Total | Confirmed by culture and/or PCR | |
| Gram-positive bacteria | ||
| Staphylococcus aureus | 33 | 27a |
| Streptococcus pneumoniae | 17 | 6 |
| Corynebacterium pseudodiphteriticum | 1 | - |
| Gram-negative bacteria | ||
| Haemophilus influenzae | 20 | 16 |
| Klebsiella pneumoniae | 4 | 4 |
| Enterobacter cloacae-complex | 5b | 4 |
| Escherichia coli | 2c | 2 |
| Escherichia vulneris | 1 | - |
| Proteus mirabilis | 2 | 1 |
| Proteus vulgaris | 1 | - |
| Klebsiella oxytoca | 1 | - |
| Pseudomonas aeruginosa | 8 | 7 |
| Stenotrophomonas maltophilia | 2 | 1 |
| Chryseobacterium indologenes | 1 | - |
| Atypical/ fastidious speciesd | ||
| Nocardia species | 1 | 1 |
| Bordetella pertussis | 1 | 1 |
| Legionella pneumophila | 1 | 1 |
| Mycoplasma pneumoniae | 1 | 1 |
aPositive in culture or for nuc; one negative sample was not available for further investigation.
bFor one sample, both E. cloacae-complex and E. cancerogenus was reported by IRIDICA; this result was counted as one isolate belonging to the E. cloacae-complex.
cFor one sample, both E. coli and E. coli/Shigella was reported by IRIDICA; this result was counted as one E. coli isolate.
dPresence of these bacteria was confirmed by conventional PCR assays (L. pneumophila, B. pertussis, M. pneumoniae), sequencing (Nocardia species), special culture (L. pneumophila) or detection of urinary antigen (L. pneumophila).