Investigation of Enteropathogenic Escherichia coli and Salmonella spp. in Aquatic Environments of Taiwan and the Quantitative Analysis of Antibiotic Resistance Genes and Class 1 Integron in Salmonella spp
| Autor: | Tzung-Yu Shen, 沈宗佑 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 Salmonella is a common enteric pathogen with a worldwide distribution that comprises a large number of serotypes which characterized by corresponding to different hosts specificities. Most of Salmonella strains have great varieties of antibiotics resistance and it becomes a major public health concern. In this study, we detected the existence of Salmonella in Puzih river, Kaupin river, reservoir, and wastewater treatment plants by polymerase chain reaction (PCR) and identified the serotypes of Salmonella by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). In addition, we used PCR and disk diffusion method to evaluate the antibiotic resistance and the resistant genes of Salmonella. The thirteen Salmonella isolates from culture method were further identified as S. Typhimurium, S. Bareilly, S. Albany, S. Newport by serological identification, PFGE and MLST. We also used seven house-keeping genes (aroC, dnaN, hemD, hisD, purE, sucA, thrA) to analyze the serotypes of Salmonella isolates. The results show that the predictions of 11 Salmonella serotypes by PFGE and MLST are with similar out of the total 13 colonies. For antibiotic resistance study Salmonella show that the highest percentage of resistance in the following antimicrobial agents: sulfadiazine (41.7%), chloramphenicol (33.3%), ampicillin (33.3%), tetracycline (41.7%), nalidixic acid (16.7%), streptomycin (25.0%), gentamicin (25.0%), amoxicillin-clavulanic acid (25.0%), kanamycin (8.3%)and ciprofloxacin (8.3%). Most of thirteen Salmonella isolates had more than one resistence gene and with different combinations of target antibiotics. Furthermore, we also found that the presence of the class 1 integron were often emergent with multi-drug resistance in Salmonella isolates. The results showed the serious situation of multi-drug resistant about different serotypes of Salmonella in Taiwan. We suggest keep monitoring the changes of antobiotics resistance trends of Salmonella in the environment continuously. In addition to monitoring the environmental water, we also quantified the resistance genes in several wastewater treatment plants by real-time PCR, and compared the removel percentage among different treatment units. In the enteropathogenic Escherichia coli, we used real-time PCR with broth method to quantity the amount of enteropathogenic Escherichia coli in environmental samples. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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