Heltberg O, Bruun B
Acta Pathol Microbiol Immunol Scand B. 1984 Apr;92(2):115-8. doi: 10.1111/j.1699-0463.1984.tb02804.x.
A prospective study evaluating the usefulness of polymyxin susceptibility testing in unveiling coagulase-negative S. aureus strains was undertaken. During a six months study period, 14 staphylococcal isolates from four patients were initially found to lack coagulase activity and to be polymyxin resistant; in comparison, approximately 1500 ordinary, coagulase-positive, polymyxin resistant S. aureus isolates were found during the same period. One isolate from each of the four patients together with a previously isolated coagulase-negative S. aureus strain from our own collection were further characterized. Two of the strains turned out to show delayed coagulase activity on retesting, while the other three strains failed to produce clotting in any coagulase assay. Judged by thermostable nuclease activity, phage typing and biochemical profiles these three coagulase-negative strains are bona fide S. aureus strains. The polymyxin test thus appears to be useful in disclosing S. aureus variants not identified as S. aureus by routinely performed coagulase assays.
开展了一项前瞻性研究，评估多粘菌素药敏试验在揭示凝固酶阴性金黄色葡萄球菌菌株方面的作用。在为期6个月的研究期间，最初从4名患者中分离出14株葡萄球菌，这些菌株缺乏凝固酶活性且对多粘菌素耐药；相比之下，在同一时期发现了约1500株普通的、凝固酶阳性的、对多粘菌素耐药的金黄色葡萄球菌分离株。对4名患者中每人分离出的1株菌株以及我们自己收集的1株先前分离出的凝固酶阴性金黄色葡萄球菌菌株进行了进一步鉴定。重新检测时，其中2株菌株显示出延迟的凝固酶活性，而其他3株菌株在任何凝固酶试验中均未产生凝块。根据热稳定核酸酶活性、噬菌体分型和生化谱判断，这3株凝固酶阴性菌株是真正的金黄色葡萄球菌菌株。因此，多粘菌素试验似乎有助于发现通过常规凝固酶试验未鉴定为金黄色葡萄球菌的金黄色葡萄球菌变种。
