Schmidt Lisa D, Kohrt Laura J, Brown David R
Department of Veterinary and Biomedical Sciences, University of Minnesota, 1988 Fitch Avenue, St. Paul, MN 55108-6010, USA.
Comp Immunol Microbiol Infect Dis. 2008 Jan;31(1):63-9. doi: 10.1016/j.cimid.2007.04.003. Epub 2007 Jun 4.
Salmonella Typhimurium DT104 is a zoonotic enteropathogen of increasing concern for human health. In this study, the influence of growth phase on invasiveness of a S. Typhimurium DT104 field isolate and two reference strains (SL1344 and ATCC 14028) was compared in IPEC J2 cells and mucosal explants from porcine ileum. Internalized bacteria were quantified by a gentamicin resistance assay. After 90 min of exposure to the apical aspect of epithelial monolayers or luminal surface of explants, internalization of all S. Typhimurium strains in mid-logarithmic phase of bacterial growth was comparable. Internalization of stationary phase bacteria was reduced relative to log phase bacteria, with DT104 exhibiting the greatest decrease. Growth phase-related differences in S. Typhimurium invasion are similar in porcine intestinal epithelial cells and mucosal explants, but may be greater in multidrug-resistant strains.
鼠伤寒沙门氏菌DT104是一种对人类健康日益引起关注的人畜共患肠道病原体。在本研究中,比较了生长阶段对一株鼠伤寒沙门氏菌DT104田间分离株和两株参考菌株(SL1344和ATCC 14028)在猪小肠上皮细胞系IPEC J2和猪回肠黏膜外植体中的侵袭力的影响。通过庆大霉素抗性试验对内化细菌进行定量。将细菌暴露于上皮单层的顶端或外植体的管腔表面90分钟后,处于细菌生长对数中期的所有鼠伤寒沙门氏菌菌株的内化情况相当。相对于对数期细菌,稳定期细菌的内化减少,其中DT104的减少最为显著。鼠伤寒沙门氏菌侵袭力的生长阶段相关差异在猪肠道上皮细胞和黏膜外植体中相似,但在多重耐药菌株中可能更大。