Applied Microbiology Laboratory, Nature and Life Sciences Faculty, A. Mira University, Bejaia, Algeria.
Int J Infect Dis. 2011 Nov;15(11):e787-94. doi: 10.1016/j.ijid.2011.07.003. Epub 2011 Oct 2.
The aim of this study was to investigate the in vitro and in vivo anti-staphylococcal activity of a lactic acid bacterial strain and its effect on the intestinal histological damage caused by Staphylococcus aureus infection.
Lactobacillus paracasei subsp. paracasei was isolated in our laboratory from breastfed newborn feces and identified phenotypically and genotypically. The strain was analyzed by spot-on-lawn and well diffusion assays for the production of bacteriocins against five antibiotic-resistant S. aureus strains isolated from the feces of hospitalized patients with antibiotic-associated diarrhea. The anti-staphylococcal activity of this strain was evaluated in fermented milk and in vivo using holoxenic rabbits.
The strain was able to produce a bacteriocin-like substance active against the staphylococcal strains. A reduction of 2 log in S. aureus cell numbers was registered in co-culture with L. paracasei in fermented milk. Administration of skimmed milk containing S. aureus (10(7) cells/ml) to healthy rabbits induced a persistent diarrheal state 5 days after the challenge. Dissection of the rabbits and consequent histological observations showed damage and an atrophy of the intestinal and colonic mucosae of the diarrheal rabbits; in contrast an arrest of the diarrhea concomitant with recovery of the intestinal villi and the colonic crypts was observed in the rabbits treated with L. paracasei-fermented milk. Furthermore, the diarrheal state persisted in spite of a decrease in the level of S. aureus cells in the feces of the rabbits receiving sterile milk; this was in contrast to the rabbits treated with L. paracasei-fermented milk, in which the decrease in the S. aureus fecal number was associated with the arrest of the diarrhea.
L. paracasei could act as a potential barrier to prevent S. aureus- associated injury and might exert its effect on the staphylococcal enterotoxins or their target.
本研究旨在探讨一株乳酸菌的体外和体内抗葡萄球菌活性及其对金黄色葡萄球菌感染引起的肠道组织损伤的影响。
本实验室从母乳喂养的新生儿粪便中分离出副干酪乳杆菌亚种，并通过表型和基因型进行鉴定。采用点植法和孔扩散法分析该菌株对 5 株从住院抗生素相关性腹泻患者粪便中分离的耐抗生素金黄色葡萄球菌的抑菌活性。采用发酵乳和体内 Holoxenic 兔模型评价该菌株的抗葡萄球菌活性。
该菌株能够产生一种针对金黄色葡萄球菌的类细菌素物质。在发酵乳中与副干酪乳杆菌共培养时，金黄色葡萄球菌的数量减少了 2 个对数级。向健康兔饲喂含金黄色葡萄球菌（10(7)个细胞/ml）的脱脂奶可在攻毒后 5 天引起持续腹泻状态。对腹泻兔进行解剖和随后的组织学观察显示，腹泻兔的肠道和结肠黏膜受损和萎缩；相比之下，用副干酪乳杆菌发酵乳治疗的兔腹泻得到了控制，同时观察到肠绒毛和结肠隐窝的恢复。此外，尽管接受无菌奶的兔粪便中金黄色葡萄球菌数量减少，但腹泻状态仍持续存在；而用副干酪乳杆菌发酵乳治疗的兔则不同，粪便中金黄色葡萄球菌数量的减少与腹泻的控制有关。
副干酪乳杆菌可作为一种潜在的屏障，防止金黄色葡萄球菌相关损伤，并可能通过其对金黄色葡萄球菌肠毒素或其靶标发挥作用。
