Stern N J, Svetoch E A, Eruslanov B V, Perelygin V V, Mitsevich E V, Mitsevich I P, Pokhilenko V D, Levchuk V P, Svetoch O E, Seal B S
USDA-ARS, Russell Research Center, Athens, GA 30604, USA.
Antimicrob Agents Chemother. 2006 Sep;50(9):3111-6. doi: 10.1128/AAC.00259-06.
We evaluated anti-Campylobacter jejuni activity among >1,200 isolates of different lactic acid bacteria. Lactobacillus salivarius strain NRRL B-30514 was selected for further study. The cell-free, ammonium sulfate precipitate from the broth culture was termed the crude antimicrobial preparation. Ten microliters of the crude preparation created a zone of C. jejuni growth inhibition, and growth within the zone resumed when the crude preparation was preincubated with proteolytic enzymes. Bacteriocin OR-7, derived from this crude preparation, was further purified using ion-exchange and hydrophobic-interaction chromatography. The determined amino acid sequence was consistent with class IIa bacteriocins. Interestingly, OR-7 had sequence similarity, even in the C-terminal region, to acidocin A, which was previously identified from L. acidophilus and had activity only to gram-positive bacteria, whereas OR-7 had activity to a gram-negative bacterium. Bacteriocin activity was stable following exposure to 90 degrees C for 15 min, also consistent with these types of antibacterial peptides. The purified protein was encapsulated in polyvinylpyrrolidone and added to chicken feed. Ten day-of-hatch chicks were placed in each of nine isolation units; two groups of birds were challenged with each of four C. jejuni isolates (one isolate per unit). At 7 days of age, one group of birds was treated with bacteriocin-emended feed for 3 days, and one group was left untreated. At 10 days of age, the birds were sacrificed and the challenge strain was enumerated from the bird cecal content. Bacteriocin treatment consistently reduced colonization at least one millionfold compared with levels found in the untreated groups. Nonchallenged birds were never colonized by C. jejuni. Bacteriocin from L. salivarius NRRL B-30514 appears potentially very useful to reduce C. jejuni in poultry prior to processing.
我们评估了1200多株不同乳酸菌对空肠弯曲菌的抗菌活性。唾液乳杆菌菌株NRRL B - 30514被选作进一步研究。肉汤培养物中的无细胞硫酸铵沉淀物被称为粗抗菌制剂。10微升粗制剂可产生空肠弯曲菌生长抑制区，当粗制剂与蛋白水解酶预孵育时，该区域内的生长恢复。从该粗制剂中获得的细菌素OR - 7，通过离子交换和疏水相互作用色谱进一步纯化。所确定的氨基酸序列与IIa类细菌素一致。有趣的是，OR - 7即使在C端区域也与嗜酸乳杆菌酸菌素A具有序列相似性，酸菌素A先前从嗜酸乳杆菌中鉴定出来，仅对革兰氏阳性菌有活性，而OR - 7对革兰氏阴性菌有活性。细菌素活性在90℃下暴露15分钟后仍保持稳定，这也与这类抗菌肽相符。纯化后的蛋白被包裹在聚乙烯吡咯烷酮中并添加到鸡饲料中。将10只刚孵化的雏鸡放入9个隔离单元中的每一个；两组鸡分别用四种空肠弯曲菌菌株中的一种进行攻毒（每个单元一种菌株）。在7日龄时，一组鸡用添加细菌素的饲料处理3天，另一组不处理。在10日龄时，处死鸡并从鸡盲肠内容物中计数攻毒菌株。与未处理组相比，细菌素处理始终使定殖量减少至少100万倍。未攻毒的鸡从未被空肠弯曲菌定殖。唾液乳杆菌NRRL B - 30514产生的细菌素在禽类加工前减少空肠弯曲菌方面似乎具有潜在的很大用途。
