A "MS-2 Microbiology System" (Abbott) has been used to identify and to assess the susceptibility patterns of clinically isolated bacteria from highly compromised patients. Automatically obtained results by the analysis of 300 specimens were compared to those of traditional methods. The automated system was in good agreement with API (81%) while in 4% of the strains there were major discrepancies, and 5% of the experiments were carried out with slow growing bacteria which normally give poor results in automatic systems. Antimicrobial susceptibility testing was satisfactory in 84% of the specimens with 7% of minor discrepancies and 9% of major ones. The evaluation of MIC for slow growing organisms like Haemophilus, Diplococcus and anaerobes belonging to the Bacteroides genus, was the same using either automatic or standard procedures.

Anti-Bacterial Agents↗

PubMed1980

[Automated direct antimicrobial susceptibility testing of urine specimens].

Two microscopical screening methods have been used to assay the suitability of urine samples for automated direct antimicrobial susceptibility testing by the means of a "MS-2 Microbiology System" apparatus. Gram stained smears showed if specimens were monomicrobic and fresh-mount bacterioscopy gave information about presumptive counts to establish inoculum size. The results obtained by the automated method have been compared with those of the direct disk diffusion method and the classical Stokes method on a single isolated colony. The three systems were reliable and only 7% of specimens gave major discrepancies and 15% minor errors. The influence of each antibiotic drug and of each bacterial species on the discrepancies has been discussed. Direct susceptibility testing by MS-2 seems to be accurate and in the same time so fast (5-6 h vs. 18-24 h) to appear very useful in the rational guide of chemotherapy in the more severe UTI.

Anti-Bacterial Agents↗