Simple inoculum standardizing system for antimicrobial disk susceptibility tests.
A collaborative study was undertaken to evaluate a simple, convenient device which expedites inoculum standardization for antimicrobial disk susceptibility tests. The Inocupac system (Minnesota Mining & Manufacturing [3M] Co., St. Paul, Minn.) was used to perform disk tests in parallel with the standard Bauer-Kirby method. Five investigators tested 100 selected isolates, each in triplicate. Inter- and intralaboratory precision of both disk procedures was essentially comparable. The Inocupac system failed to consistently provide satisfactory growth with some streptococci, but when testing common gram-negative bacilli, staphylococci, and most enterococci, the Inocupac system gave zones about the same size (+/-2 mm) as the Bauer-Kirby procedure. Interpretive agreement between the two test systems varied from 90 to 99% with different antimicrobial agents, and repeated tests with the Bauer-Kirby method demonstrated the same degree of interpretive agreement. The Inocupac system is a valid alternative method for inoculating disk susceptibility tests.
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004755:Enterobacteriaceae / Q000254:growth & development; D005069:Evaluation Studies as Topic; D008826:Microbial Sensitivity Tests / Q000295:instrumentation*; D011550:Pseudomonas aeruginosa / Q000254:growth & development; D013210:Staphylococcus / Q000254:growth & development; D013291:Streptococcus / Q000254:growth & development
D000900:Anti-Bacterial Agents