Beggs W H, Andrews F A
Antimicrob Agents Chemother. 1975 May;7(5):636-9. doi: 10.1128/AAC.7.5.636.
We have examined and compared the effects of monovalent and divalent cation salts on dihydrostreptomycin (DSM) action against Mycobacterium smegmatis. The Sauton synthetic liquid medium used was supplemented with test salts on the basis of ionic strength (mu). Turbidimetric growth experiments showed that 0.02 M MgSO(4) (mu = 0.08) prevented growth inhibition by 0.1 mug of dihydrostreptomycin per ml, but 0.02 M NaCl (mu = 0.02) did not. However, at molarities equivalent to mu = 0.08, four monovalent cation salts, including NaCl, Na(2)SO(4), NH(4)Cl, and (NH(4))(2)SO(4), all prevented inhibition by dihydrostreptomycin. When magnesium and sodium salts were compared at mu = 0.02, 0.04, and 0.05, two distinct growth protective patterns were seen. These data were indicative of two different mechanisms of dihydrostreptomycin antagnosim by salts; the first being divalent cation and concentration dependent, and the second being nonspecific and ionic strength dependent. Viability studies supported the existence of two mechanisms.
我们已经研究并比较了单价和二价阳离子盐对二氢链霉素（DSM）抗耻垢分枝杆菌作用的影响。所使用的索顿合成液体培养基根据离子强度（μ）添加了测试盐。比浊法生长实验表明，0.02M硫酸镁（μ = 0.08）可防止每毫升0.1微克二氢链霉素对生长的抑制作用，但0.02M氯化钠（μ = 0.02）则不能。然而，在摩尔浓度相当于μ = 0.08时，四种单价阳离子盐，包括氯化钠、硫酸钠、氯化铵和硫酸铵，均能防止二氢链霉素的抑制作用。当在μ = 0.02、0.04和0.05下比较镁盐和钠盐时，观察到两种不同的生长保护模式。这些数据表明盐对二氢链霉素拮抗作用存在两种不同机制；第一种是二价阳离子和浓度依赖性的，第二种是非特异性和离子强度依赖性的。活力研究支持了这两种机制的存在。
