BSAC standardized disc susceptibility testing method (version 7)

Abstract

The changes that have been made to the previous version of the recommendations (version 6) are as follows: medium and incubation condition for testing Acinetobacter spp. (Tables 1 and 6); use of cefoxitin as an indicator antibiotic for detecting methicillin/oxacillin/cefoxitin resistance in coagulase-negative staphylococci (Tables 1, 6 and 11); MIC breakpoint for co-trimoxazole based on the trimethoprim concentration in a 1:19 combination with sulfamethoxazole (Tables 7, 10, 11, 12, 15, 16 and 19); advice on the use of azithromycin for the treatment of infections with Salmonella typhi (footnote to Table 7); amendment to the recommendation for cefuroxime for the treatment of infections with Proteus mirabilis (footnote Table 7); MIC and zone diameter breakpoints for Stenotrophomonas maltophilia only (Table 10); MIC breakpoints for daptomycin (Tables 11 and 15); clarification for staphylococci that the neomycin zone diameter breakpoints are for topical use only and differentiate the isolates outside the 'wild-type' population in Table 11; clarification for beta-haemolytic streptococci that the linezolid zone diameter breakpoints relate to an MIC breakpoint of 2 mg/L as no data for the intermediate category are currently available (Table 15); clarification that strains with reduced susceptibility to fluoroquinolones give no zone of inhibition with a 30 microg nalidixic acid disc (Tables 16 and 21); erythromycin is no longer used for therapy of Neisseria gonorrhoeae, but may be tested for epidemiological purposes (Table 17); clarification that the ciprofloxacin zone diameter breakpoint for Neisseria meningitidis relates to the MIC breakpoint of 0.03 mg/L as no data for the intermediate category are currently available; clarification that the ciprofloxacin zone diameter breakpoints for Campylobacter spp. relate to an MIC breakpoint of 0.5 mg/L as no data for the intermediate category are currently available; clarification that for ciprofloxacin and vancomycin zone diameter breakpoints for coryneform organisms relate to an MIC breakpoint of 0.5 and 4 mg/L, respectively, as no data for the intermediate category are currently available; MIC and zone diameter breakpoints for Gram-negative rods isolated from urinary tract infections have been expanded to include Klebsiella spp.; and a definition of coliforms is also included (Table 26).