Fung J C, McKinley G, Tyburski M B, Berman M, Goldstein J
J Clin Microbiol. 1984 May;19(5):714-6. doi: 10.1128/jcm.19.5.714-716.1984.
Colistin-nalidixic acid agar, although recently recommended as a replacement for blood agar for primary plating of urine specimens ( Fung et al., J. Clin. Microbiol. 16:632-636, 1982), has also been reported to suppress the growth of some strains of staphylococci that are susceptible to colistin (polymyxin E). The susceptibility of 11 species of staphylococci to polymyxins was determined, and the ability of these species to grow on colistin-nalidixic acid agar was examined. Although the MICs for most of the strains tested were 8 micrograms/ml or less, only a few coagulase-negative staphylococci grew on or were inhibited by colistin-nalidixic acid agar. This descrepancy was explained by the antagonistic effects that medium components, such as physiological concentrations of magnesium and calcium and 5% sheep blood, had on the activity of polymyxin. Colistin-nalidixic acid agar is still recommended for routine urine processing; however, the poor growth of 13% of the Staphylococcus saprophyticus strains tested suggests that blood agar should be included in the primary plating battery of urine specimens obtained from female outpatients.
黏菌素-萘啶酸琼脂，尽管最近被推荐作为尿液标本初次接种时替代血琼脂的培养基（Fung等人，《临床微生物学杂志》16:632 - 636，1982年），但也有报道称它会抑制某些对黏菌素（多黏菌素E）敏感的葡萄球菌菌株的生长。测定了11种葡萄球菌对多黏菌素的敏感性，并检测了这些菌种在黏菌素-萘啶酸琼脂上的生长能力。尽管大多数测试菌株的最低抑菌浓度为8微克/毫升或更低，但只有少数凝固酶阴性葡萄球菌能在黏菌素-萘啶酸琼脂上生长或被其抑制。这种差异可由培养基成分（如生理浓度的镁和钙以及5%的羊血）对多黏菌素活性的拮抗作用来解释。黏菌素-萘啶酸琼脂仍被推荐用于常规尿液处理；然而，所测试的13%腐生葡萄球菌菌株生长不佳，这表明从女性门诊患者采集的尿液标本初次接种培养基组合中应包括血琼脂。
