No organisms were identified on gram stain.
An exudates was produced, although polymorphs were observed rarely, and no microorganisms were identified on Gram stain.
13 ABM was considered if bacteria were identified on gram stain or isolated on culture from cerebrospinal fluid (CSF), CSF antigen tests for Haemophilus influenzae or Streptococcus pneumoniae were positive, or there was a CSF leucocyte count of at least 10 per µl and the blood to CSF glucose ratio was less than 0.67.
Pili have recently been identified on several gram-positive bacteria (5 – 7 ).
MRSA was identified on the basis of Gram stain morphology, positive catalase and coagulase tests and growth on Mueller-Hinton agar plates containing 6 µg·mL−1 oxacillin.
Clostridium difficile was tentatively identified on the basis of Gram stain and morphology, characteristic horse manure odour, L-proline aminopeptidase activity (Oxoid), and then confirmed by the latex agglutination test (C. difficile test kit DR1107A, Oxoid).
C. difficile was presumptively identified on the basis of Gram stain and detection of L-proline aminopeptidase activity (Pro Disc, Remel, Lenexa, KS, USA) and confirmed by identification of the triose phosphate isomerase gene (9 ).
The microbiological ITT (MITT) population was the subset of the ITT population who had at least one Gram-negative pathogen identified on bronchoalveolar lavage (BAL) or mini-BAL at a density >104 CFU/mL with an imipenem MIC <8 μg/mL.
Growth of Nocardia spp was identified on colony morphology, musty odor, gram stain morphology, partial acid fastness, presence of aerial hyphae, decomposition of casein, tyrosine, xanthine, hypoxanthine, urease production and gelatin hydrolysis.
SA was identified on the basis of colony aspect, Gram staining, and catalase, and coagulase production (Pastorex®, Fumouze, Levallois-Perret, France).
Isolates were identified on the basis of colony pigment, Gram staining, and catalase activity.
