Differential Inhibition of Mollicute Growth: an Approach to Development of Selective Media for Specific Mollicutes

The energy-generating pathways of Mycoplasma spp. are diverse. Thus, it was predicted that the ability of inhibitors of these pathways to block growth would vary among species. This prediction was tested with 14 Mycoplasma species and potential inhibitors. The greatest differentiation among test species was obtained using fluoride, iodoacetate (IAA), β-fluoropyruvate (FP), cibacron blue (CB), l-citrulline, and carbonyl cyanide m-chlorophenylhydrazone. A range of other potential inhibitors, including l-arginine analogues, had little inhibitory effect on growth, and d-arginine was shown to be a growth substrate for arginine-hydrolyzing species. Fluoride selectively inhibited the growth of mycoplasmas that were able only to ferment sugars to lactate and/or to hydrolyze arginine. In contrast, IAA was most effective against organic acid-oxidizing species, and l-citrulline inhibited arginine-hydrolyzing species. Mycoplasma verecundum, a species for which energy sources have not been identified, was relatively resistant to FP. Similarly, Acholeplasma laidlawii was distinguished by its CB resistance.

支原体属（Mycoplasma）物种的能量产生途径具有多样性。因此，学界推测，上述途径的抑制剂对不同支原体物种的生长阻滞能力存在差异。本研究以14种支原体及潜在抑制剂对该推测展开了验证。实验结果显示，使用氟化物、碘乙酸盐（IAA）、β-氟丙酮酸（FP）、西邦蓝（CB）、L-瓜氨酸及羰基氰基间氯苯腙时，受试支原体物种间的分化效果最为显著。其余多种潜在抑制剂（包括L-精氨酸类似物）几乎对支原体生长无抑制作用，而D-精氨酸则被证实可作为精氨酸水解型支原体的生长底物。氟化物可选择性抑制仅能通过发酵糖类生成乳酸、或/且能够水解精氨酸的支原体生长。与之相反，碘乙酸盐（IAA）对有机酸氧化型支原体的抑制效果最佳，而L-瓜氨酸则可抑制精氨酸水解型支原体的生长。维库支原体（Mycoplasma verecundum）——一种尚未明确其能量来源的物种——对β-氟丙酮酸（FP）表现出相对抗性。同理，莱氏无胆甾原体（Acholeplasma laidlawii）则以对西邦蓝（CB）具有抗性为显著特征。