Department of Poultry Science, University of Arkansas Fayetteville, AR 72701, USA.
Department of Veterinary Medicine, National Autonomous University of Mexico, Mexico city 04510, Mexico.
Poult Sci. 2018 Feb 1;97(2):515-521. doi: 10.3382/ps/pex311.
The present study evaluated the microbiological properties of three probiotic candidate strains of lactic acid bacteria (LAB) (128; 131; CE11_2), their effect on intestinal epithelial permeability, and their ability to reduce intestinal colonization of Salmonella Typhimurium (ST) individually or as a batch culture in neonatal turkey poults. Isolates were characterized morphologically and identified using 16S rRNA sequence analyses. Each isolate was evaluated for tolerance and resistance to acidic pH, high osmotic NaCl concentrations, and bile salts in broth medium. In vitro assessment of antimicrobial activity against different enteropathogenic bacteria was determined using an overlay technique. In vitro intestinal permeability was evaluated using a stressed Caco-2 cell culture assay treated with/without the probiotic candidates. The in vivo effect of the selected LAB strains on ST cecal colonization was determined in two independent trials with neonatal turkey poults. The results obtained in this study demonstrate the tolerance of LAB candidates to pH 3, a NaCl concentration of 6.5%, and high bile salts (0.6%). All strains evaluated exhibited in vitro antibacterial activity against Salmonella Enteritidis, ST, and Campylobacter jejuni. Candidates 128 and 131 exhibited a coccus morphology and were identified as Enterococcus faecium, and bacterial strain CE11_2 exhibited clusters of cocci-shaped cells and was identified as Pediococcus parvulus. All three candidate probiotics significantly (P < 0.05) increased transepithelial electrical resistance (TEER) in Caco-2 cells following a 3-h incubation period with hydrogen peroxide compared to control and blank groups. The combination of all three candidates as a batch culture exhibited significant efficacy in controlling intestinal colonization of ST in neonatal turkey poults. Evaluation of the combination of these selected LAB strains according to performance and intestinal health parameters of chickens and turkeys are currently in process.
本研究评估了三株候选益生菌乳酸菌（LAB）（128；131；CE11_2）的微生物特性，它们对肠道上皮通透性的影响，以及它们单独或批量培养时减少鼠伤寒沙门氏菌（ST）肠道定植的能力。通过形态学特征和 16S rRNA 序列分析对分离株进行了鉴定。评估了每种分离株在肉汤培养基中对酸性 pH、高渗透压 NaCl 浓度和胆汁盐的耐受性和抗性。采用覆盖技术测定了对抗不同肠道致病菌的抗菌活性的体外评估。采用用/不用益生菌候选物处理的应激 Caco-2 细胞培养测定法评估了体外肠道通透性。通过两项独立的新生火鸡雏试验确定了所选 LAB 菌株对 ST 盲肠定植的体内影响。本研究结果表明，LAB 候选物耐受 pH3、6.5%的 NaCl 浓度和高胆汁盐（0.6%）。所有评估的菌株均表现出对肠炎沙门氏菌、ST 和空肠弯曲杆菌的体外抗菌活性。候选物 128 和 131 表现出球菌形态，被鉴定为屎肠球菌，细菌株 CE11_2 表现出球菌簇形态，被鉴定为戊糖片球菌。所有三种候选益生菌在与过氧化氢孵育 3 小时后，与对照和空白组相比，均显著（P<0.05）增加了 Caco-2 细胞的跨上皮电阻（TEER）。三种候选益生菌的组合作为批量培养，在控制新生火鸡雏 ST 肠道定植方面表现出显著疗效。目前正在根据鸡和火鸡的性能和肠道健康参数对这些选定的 LAB 菌株进行组合评估。
