| Summary: | 碩士 === 中國醫藥學院 === 環境醫學研究所 === 91 === ABSTRACT
Salmonella spp are common aetiologic agent causing food poisoning in Taiwan. Among various serotypes, S. Typhimurium, as an important zoonotic agent, is frequently seen and widely distributed in humans and animals. It is of urgent need, through molecular epidemiologic approaches, to evaluate that human salmonella infection and their antibiotic-resistance characteristics could be acquired from animal sources. This study thus applied whole-genomic-DNA genotyping by pulsed-field gel electrophoresis(PFGE) and phenotyping by antimicrobial susceptibility test with 12 different antibiotics to elucidate these issues. By PFGE typing with Xba I digestion, the results showed that 22 and 14 major genotypes were identified in 136 human and 37 animal isolates, respectively. Importantly, 4 identical PFGE patterns were found between human and animal isolates. Human isolates had similar antibiotic-resistance distribution of ampicillin (86% vs. 78.4%), cephalothin (6.7% vs. 0%), chloramphenicol (87% vs. 78.4%), ciprofloxacin (3.7% vs. 8.1%), enrofloxacin (10% vs. 13.5%), gentamicin (8% vs. 8.1%), nalidixic acid (29% vs. 27%), nitrofurantoin (56% vs. 37%), norfloxacin (8.8% vs. 13.5%), streptomycin (80% vs. 64.9%), sulfamethoxazole-trimethoprim (20% vs. 35.1%) observed in animal isolates. Furthermore, 66% and 57% of the human and animals S. Typhimurium isolates were multi-drug-resistance strains, which were resistant to at least 5 different antibiotics tested. In conclusion, the results indicated high possibility of transmission between animals and humans, Humans might acquire antibiotic-resistant salmonella infections from animals and vice versa. The majority of S. Typhimurium isolates in Taiwan that were multi-drug resistant was also a significant clinical threat. In the future, further epidemiologic study should be conducted to identify the exact routes of S. Typhimurium transmission for efficient disease control.
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