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英文摘要
Salmonella panama, an important pathogen in infants and children, belongs to serogroup D1. This serotype causes mostly gastroenteritis, but sometimes may cause invasive diseases such as bacteremia, meningitis, osteomyelitis and arthritis. From 1989 to 1996, 297 nontyphoid Salmonella strains were isolated from the pediatric patients in southern Taiwan, among them six were from patients with meningitis. Of the six, four were S. panama. Furthermore, of the 18 clinical S. panama isolated from different pediatric patients in NCKU hospital, 14 were from invasive diseases, including bacteremia and meningitis (invasion rate 77.8%). These suggest that S. panama may be more invasive than other nontyphoid Salmonella species. The 18 clinical S. panama isolates from NCKU hospital were shown to be of different clones when analyzed by three molecular typing techniques: plasmid profile, random amplified polymorphic DNA (RAPD) and infrequent-restriction-site PCR (IRS-PCR) analyses, suggesting that there was no clone associated specifically with the invasive diseases. Nine of the strains were tested for their virulence in mice and none of them could kill the mouse at a dose of 104 bacteria per mouse. Invasion of S. panama into human epithelial cells, which is thought to be an essential early step in pathogenesis of salmonellae, was also examined. S. panama isolates from different origin show equally invasive for epithelial cells. Compared with S. typhimurium strains, S. panama strains were found to be more invasive for the HEp-2 cells, but were equally invasive for the T84 cells and less invasive for the Caco-2 cells. Finally, the genome difference between S. panama and S. typhimurium was identified by PCR-select subtraction technique. Further studies on the S. panama specific sequence may help us identify factors contributing to the virulence of S. panama in human.
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