Antimicrobial susceptibility testing automated

A variety of commercial kits and automated systems are available to test the abilities of bacteria to assimilate, ferment, decarboxylate, or cleave selected organic compounds.46 Their reliability for species identification is usually greater with cultures from clinical samples, where a limited number of bacteria are commonly encountered, and less with environmental soil and water samples, where a great many uncommon or previously unidentified species not in the database are likely to be present.29,45 Additional tests beyond those found in the commercial kits may be necessary for example, the hydrolysis of various nitriles and amides is useful for identifying Rhodococcus spp.47 Some commercial kits for clinical use feature antimicrobial susceptibility testing.21... 

Fahr, A. M. Eigner, U. Armbrust, M. Caganic, A. Dettori, G. Chezzi, C. Bertoncini, L. Benecchi, M. Menozzi, M. G. Two-center collaborative evaluation of the performance of the BD Phoenix automated microbiology system for identification and antimicrobial susceptibility testing of Enterococcus spp. and Staphylococcus spp. J. Clin. Microbiol. 2003, 41,1135-1142. 

The automated systems for simultaneous microbial identification and antimicrobial susceptibility testing are commercially available. However, although the microbial identification may be performed in less than 1 h, for example, by MALDI-TOF-MS-based systems, the time of full panel antimicrobial susceptibility testing usually requires up to 24 h (Machen et al. 2014). 

TESTING FOR MICROBIAL SENSITIVITY TO ANTIMICROBIAL AGENTS Bacterial strains, even from the same species, may vary widely in sensitivity to antibiotics. Information about the antibiotic sensitivity of the infecting microorganism is important for appropriate drug selection. Various methods are used to assess susceptibility, including disk-diffusion, dilution test, and automated broth dilution. The results are either reported on a semi-quantitative scale i.e., resistant, intermediate, or susceptible) or in terms of the minimal inhibitory concentration (MIC). 

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