Heuck D, Beer W, Reissbrodt R
Robert Koch Institute, Wernigerode Branch, Germany.
J Med Microbiol. 1995 Jul;43(1):26-32. doi: 10.1099/00222615-43-1-26.
Most of 232 strains of coagulase-negative staphylococci (CNS) belonging to 16 species, and nine strains of micrococci belonging to four species, could be distinguished by their growth on an iron-poor nutrient medium. alpha-Keto-/alpha-hydroxyacids, as primary metabolites, facilitated iron supply to CNS and micrococci under various iron-limited conditions, as detected by different bioassay methods. Twelve selected CNS strains and two micrococcal strains produced significant amounts of alpha-ketoacids in iron-poor liquid nutrient media. In particular, strains of Staphylococcus cohnii, S. xylosus and S. lentus unable to grow on iron-poor media, produced high amounts of pyruvic acid and alpha-ketoglutaric acid. In bioassays, the selected CNS strains being siderophore indicator strains were fed with alpha-ketoacids at different levels of iron limitation. Strains able to grow under iron deprivation appeared to produce additional siderophores such as staphyloferrins under iron stress. alpha-Keto-/alpha-hydroxyacids may be additionally active in the iron supply of CNS and micrococci.
232株属于16个种的凝固酶阴性葡萄球菌（CNS）以及9株属于4个种的微球菌，大多数都可以通过它们在缺铁营养培养基上的生长情况加以区分。通过不同的生物测定方法检测发现，α-酮酸/α-羟酸作为初级代谢产物，在各种铁限制条件下促进了铁向CNS和微球菌的供应。12株选定的CNS菌株和2株微球菌菌株在缺铁液体营养培养基中产生了大量的α-酮酸。特别是，科氏葡萄球菌、木糖葡萄球菌和缓慢葡萄球菌中不能在缺铁培养基上生长的菌株，产生了大量的丙酮酸和α-酮戊二酸。在生物测定中，将选定的作为铁载体指示菌株的CNS菌株在不同铁限制水平下用α-酮酸喂养。能够在缺铁条件下生长的菌株在铁应激下似乎会产生额外的铁载体，如葡萄球菌铁载体。α-酮酸/α-羟酸可能在CNS和微球菌的铁供应中具有额外的活性。
