| Summary: | 碩士 === 國立臺灣大學 === 獸醫學研究所 === 93 === Abstract
Ornithobacterium rhinotracheale (ORT), a newly recognized pathogen, is associated with respiratory diseases in avian species. To date, little is known about ORT infection in Taiwan. Therefore, tracheal swabs and serum samples were collected from the chickens and pigeons for the isolation, biochemical characteristics, antimicrobial susceptibility, sequence analysis, and antibody survey of ORT. The results showed that the ORT isolation rate of chickens and pigeons were 8.3 % (28/337) and 9 % (12/133), respectively. The identical results of biocode 0-0-2-0-0-0-4 were observed in all the isolates using API 20NE identification system. These isolates showed positive results in alkaline phosphatase (C4), estrase lipase (C8), leucine arylamidase, acid phosphatase, and oxidase reactions, but negative to MacConkey, SIM, TSI, catalase, lysine, ornithine, phenylalanine, sucrose, sorbitol, and dulcitol reactions. Most isolates (>70%) were resistant to trimethoprim-sulfamethoxazole, erythromycin, and clindamycin, but susceptible to ampicillin, amoxicillin, penicillin, and ceftiofur (>85%) by agar disc diffusion method. As for the analysis of 16S rRNA sequence, high similarities (98–100%) were revealed among the isolates in this study and the previously published sequence data. The chicken and pigeon isolates were divided into different clusters in phylogenetic tree. By using commercial ELISA kits, the antibody positive rates of broilers, hybrid broilers, layers, and breeders were 29.7% (221/745), 60.7% (403/664), 70.3% (204/290), and 93.9% (341/363), respectively. To our knowledge, this is the first report of the isolation of ORT from chickens and pigeons in Taiwan, and the results indicated that ORT infection is common in Taiwan.
Abbreviations: SIM, sulfide-indole-motility; TSI, triple sugar iron; ELISA, enzyme-linked immunosorbeat assay.
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