Westergren G, Emilson C G
Scand J Dent Res. 1980 Jun;88(3):236-43. doi: 10.1111/j.1600-0722.1980.tb01220.x.
Three chlorhexidine-sensitive strains of Streptococcus sanguis developed resistance to chlorhexidine when grown as continuous cultures in a fermenter containing medium with increasing concentrations of the drug. The MIC of the test strains increased by between two and three dilution steps and these high values were maintained after daily transfer in drug-free medium for at least 15 d. In addition, the resistance of one of the strains persisted for more than 1 month of continuous growth in drug-competent sensitive S. sanguis to increased chlorhexidine resistance, thus proving that resistance to this drug is an inheritable trait. Immunoelectrophoretic experiments showed that certain changes in the antigenic pattern of the Chxr variants had occurred as compared with their sensitive wild-type strains. Antigenic extracts of the Chxr variants and all Chxr recombinants tested contained consistently less protein than those of the sensitive wild-types.
三株对洗必泰敏感的血链球菌在含有浓度不断增加的该药物的培养基中进行连续培养时，对洗必泰产生了耐药性。测试菌株的最低抑菌浓度增加了两到三个稀释度，并且在无药物培养基中每日传代至少15天后，这些高值仍保持不变。此外，其中一株菌株的耐药性在有药物的敏感血链球菌中持续连续生长超过1个月，对洗必泰的耐药性增加，从而证明对该药物的耐药性是一种可遗传的性状。免疫电泳实验表明，与敏感野生型菌株相比，洗必泰耐药变异株的抗原模式发生了某些变化。所测试的洗必泰耐药变异株和所有洗必泰重组体的抗原提取物所含蛋白质始终比敏感野生型的少。
