The Use of Quantitative Sterile Brush Culture and Gram Stain Analysis in the Diagnosis of Lower Respiratory Tract Infection

Diagnostic value of direct examination of the protected specimen brush in ventilator-associated pneumonia

“…TEAGUE et al [30] used two brushes, one for bacterial culture and one for direct examination (direct smear of the brush onto a glass slide) and showed that Gram-stain correlated with the growth of bacteria in concentration ≥10 6 cfu·ml -1 (corresponding to a growth ≥10 3 cfu·ml -1 of Ringer's solution), and they failed to show bacteria in all cases in which growth on culture was ≤10 5 cfu·ml -1 (which corresponds to a growth of ≤10 2 cfu·ml -1 of Ringer's medium). Similarly POLLOCK et al [29] reported a 76% sensitivity when smearing the brush directly onto a glass slide before putting it into the holding medium.…”

“…However, unless two brushes for each individual patient are used, as TEAGUE et al [30], direct smearing of the brush carries two risks. Firstly, the procedure can potentially contaminate the specimen which is subsequently cultured, although a careful technique can overcome this problem.…”

“…The need for at least 24 h to obtain the result of quantitative culture is, however, the major problem with this technique. Direct examination of PSB specimens could overcome this problem, but the diagnostic yield of direct examination remains controversial [29][30][31][32][33][34]. Thus, the use of bronchoalveolar lavage (BAL) along with the PSB has been advocated, in order to obtain rapid diagnostic information based on the percentage of cells containing intra-cellular micro-organisms [32,35,36].…”

Relative Value and Cost-Effectiveness of Culture and Special Stains in Fine Needle Aspirates of the Lung

“…Mycobacteria are similar to fungi in that while culture is more sensitive than acid-fast staining in most pulmonary specimens, 7,19,21 in open lung biopsy specimens acid-fast staining is more sensitive. 13,15,20 In this series only one case of mycobacterial infection was identified, and it was detected by both methods.…”

“…For example, for most organisms in most pulmonary specimens, cultures appear to be more sensitive than special stains. [2][3][4][7][8][9]14,17,19,21 However, in open lung biopsies, silver and acid-fast stain appear to be more sensitive for fungi and mycobacteria than culture. 15,20 Similar studies comparing the relative sensitivity of culture and special stains in lung FNA specimens have not been performed.…”