title: False-positive Gram-stained smears.
abstract: The rate per 1,000 smears showing nonviable Gram-negative bacilli (false-positive smears) increased from a baseline of 10.8 to 38.5 following purchase of new culture-collection devices; the rate decreased to 8.0 following replacement of contaminated culture sets. False-positive reports led to changes in therapy for five patients. In addition to being sterile, commercial culture-collection devices should be certified by the manufacturer as being free of stainable microorganisms or as unsuitable for preparation of Gram-stained smears.
mesh_terms: D000293:Adolescent; D000328:Adult; D001431:Bacteriological Techniques; D002675:Child, Preschool; D003470:Culture Media / Q000592:standards; D005189:False Positive Reactions; D005260:Female; D006088:Gram-Negative Aerobic Bacteria / Q000302:isolation & purification; D006089:Gram-Negative Anaerobic Bacteria / Q000302:isolation & purification; D006801:Humans; D008297:Male; D013194:Staining and Labeling; D013530:Surgical Wound Infection / Q000382:microbiology; D014948:Wounds, Gunshot / Q000382:microbiology
chemical_list: D003470:Culture Media