Central Laboratories Friedrichsdorf, Friedrichsdorf, Germany.
Food Microbiol. 2013 Sep;35(2):121-8. doi: 10.1016/j.fm.2013.03.005. Epub 2013 Apr 3.
Cronobacter is associated with outbreaks of rare, but life-threatening cases of meningitis, necrotizing enterocolitis, and sepsis in newborns. This study was conducted to determine the effect of organic acids on growth of Cronobacter in laboratory medium and reconstituted powdered infant formula (PIF) as well as the bacteriostatic effect of slightly acidified infant formula when combined with neonatal gastric acidity. Inhibitory effect of seven organic acids on four acid sensitive Cronobacter strains was determined in laboratory medium with broth dilution method at pH 5.0, 5.5 and 6.0. Acetic, butyric and propionic acids were most inhibitive against Cronobacter in the laboratory medium. The killing effect of these three acids was partially buffered in reconstituted PIF. Under neonatal gastric acid condition of pH 5.0, the slightly acidified formula which did not exert inhibition effect solely reduced significantly the Cronobacter populations. A synergistic effect of formula moderately acidified with organic acid combined with the physiological infant gastric acid was visible in preventing the rapid growth of Cronobacter in neonatal stomach. The study contributed to a better understanding of the inhibitory effect of organic acids on Cronobacter growth in different matrixes and provided new ideas in terms of controlling bacteria colonization and translocation by acidified formula.
阪崎克罗诺杆菌与罕见但危及生命的新生儿脑膜炎、坏死性小肠结肠炎和败血症的爆发有关。本研究旨在确定有机酸对实验室培养基和重新配制的婴儿配方粉（PIF）中克罗诺杆菌生长的影响，以及当与新生儿胃酸度结合时，轻微酸化婴儿配方的抑菌效果。采用肉汤稀释法，在 pH 值为 5.0、5.5 和 6.0 的实验室培养基中，测定了七种有机酸对四种酸敏感的阪崎克罗诺杆菌菌株的抑制作用。乙酸、丁酸和丙酸对实验室培养基中的阪崎克罗诺杆菌抑制作用最强。这三种酸在重新配制的 PIF 中的杀菌作用部分被缓冲。在 pH 值为 5.0 的新生儿胃酸条件下，单独不具有抑制作用的轻微酸化配方可显著减少阪崎克罗诺杆菌的数量。在生理婴儿胃酸的作用下，用有机酸适度酸化的配方与阪崎克罗诺杆菌在新生儿胃中的快速生长具有协同作用。该研究有助于更好地理解有机酸对不同基质中阪崎克罗诺杆菌生长的抑制作用，并为酸化配方控制细菌定植和转移提供了新的思路。
