Hamilton-Miller J M, Shah S
Department of Medical Microbiology, Royal Free and University College, Royal Free Campus, London NW3 2PF, UK.
J Antimicrob Chemother. 2000 Dec;46(6):941-9. doi: 10.1093/jac/46.6.941.
Phenotypes of resistance to the macrolide-lincosamide-ketolide-streptogramin (MLKS) group of antibiotics have been determined in 540 clinical isolates of staphylococci (210 Staphylococcus aureus and 330 coagulase-negative species). Results of disc diffusion tests using erythromycin A, oleandomycin, rokitamycin, clindamycin, telithromycin, quinupristin and dalfopristin delineated four main groups corresponding to those defined classically using erythromycin and clindamycin only, but with sub-divisions. Resistance to erythromycin was more common in coagulase-negative strains (56%) than in S. aureus (16%); telithromycin, clindamycin, quinupristin-dalfopristin and rokitamycin were active against >97% of S. aureus strains and >88% of the coagulase-negative strains. The commonest resistance phenotype was 'inducible MLS(B)' (12% in S. aureus, 31% in coagulase-negative strains); this group could be divided in terms of the different inducing abilities of erythromycin and oleandomycin. 'Constitutive MLS(B)' and 'MS' phenotypes were more often found in coagulase-negative strains (11 and 13%, respectively) than in S. aureus (2 and 1%). Novel phenotypes were found during the isolation of constitutively resistant mutants from inducible strains, and of resistant mutants from 'MS' strains. This extended phenotyping scheme has revealed further complexities and evolutionary possibilities in patterns of resistance to this group of antibiotics.
已对540株葡萄球菌临床分离株（210株金黄色葡萄球菌和330株凝固酶阴性菌）进行了对大环内酯-林可酰胺-酮内酯-链阳菌素（MLKS）类抗生素的耐药表型测定。使用红霉素A、竹桃霉素、罗他霉素、克林霉素、泰利霉素、奎奴普丁和达福普汀进行纸片扩散试验的结果划分出四个主要组，与仅使用红霉素和克林霉素经典定义的组相对应，但有细分。凝固酶阴性菌株对红霉素的耐药性（56%）比金黄色葡萄球菌（16%）更常见；泰利霉素、克林霉素、奎奴普丁-达福普汀和罗他霉素对>97%的金黄色葡萄球菌菌株和>88%的凝固酶阴性菌株有活性。最常见的耐药表型是“诱导型MLS(B)”（金黄色葡萄球菌中为12%，凝固酶阴性菌株中为31%）；该组可根据红霉素和竹桃霉素不同的诱导能力进行划分。“组成型MLS(B)”和“MS”表型在凝固酶阴性菌株中（分别为11%和13%）比在金黄色葡萄球菌中（分别为2%和1%）更常见。在从诱导型菌株中分离组成型耐药突变体以及从“MS”菌株中分离耐药突变体的过程中发现了新的表型。这种扩展的表型分析方案揭示了对这类抗生素耐药模式中进一步的复杂性和进化可能性。
