title: Use of droplet plating method and cystine-lactose-lactng electrolyte-deficient medium in routine quantitative urine culturing procedure.
abstract: Droplet plating of 0.01 ml of 10(-2) dilutions of mixed sonically treated urines onto cystine-lactose electrolyte-deficient agar permits formation of discrete, easily counted colonies within a small circumscribed area without interference by Proteus overswarm. Each colony is considered as arising from a single viable cell. The single dilution permits precise reproducible quantitation of urine bacteria population within the range 10(4) to 10(6) cells/ml of sample. Droplet-plated counts were found to be consistently (approximately) double those determined by standard pour plate quantitation. The method requires only inexpensive readily available materials and has been performed routinely in a large-volume clinical laboratory for several years.
mesh_terms: D000362:Agar; D001419:Bacteria / Q000302:isolation & purification*; D001431:Bacteriological Techniques; D003553:Cystine; D013293:Enterococcus faecalis / Q000302:isolation & purification; D004926:Escherichia coli / Q000302:isolation & purification; D005069:Evaluation Studies as Topic; D006801:Humans; D007785:Lactose; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D011511:Proteus / Q000254:growth & development; D011549:Pseudomonas / Q000302:isolation & purification; D013211:Staphylococcus aureus / Q000302:isolation & purification; D014556:Urine / Q000382:microbiology*
chemical_list: D003553:Cystine; D000362:Agar; D007785:Lactose