Application of PCR-RFLP on Molecular Epidemiological Study of Staphylococcus aureus Isolated from Milk of Dairy Cows and Goats

• Main Authors: Tung, Chia-Chi, 董佳琦
• Other Authors: 莊士德
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/25338057676892628529

碩士 === 國立中興大學 === 獸醫學系 === 92 === Staphylococcus aureus is a frequent cause of bovine and ovine contagious mastitis. Total of 23 bovine strains and 12 ovine strains obtained from 8 dairy cattle farms and 5 dairy goat farms in the west part of Taiwan were characterized by phenotypic and genotypic methods. Biotyping with API Staph® identification system assigned the bovine and ovine strains to 5 and 3 types. Additionally, the most common biotype of bovine and ovine strains was accounted for 73.91% and 75%, respectively. Twenty-three bovine strains and 12 ovine strains could be divided into 7 and 4 antibiogram patterns, respectively. Penicillin resistance was the most frequent among the bovine and ovine isolates（100%）. Penicillin/ampicillin resistance was observed in 73.91% and 58.33% of the bovine and ovine isolates, respectively. To analyze the epidemiological relationship, the isolates were subjected to DNA fingerprinting by PCR-RFLP analysis of the 16S-23S rRNA gene spacer region（spacer）and repeating elements of coagulase gene（coa）. All of the isolates could be typed by PCR amplification of coa. However, one bovine and one ovine isolate could not produce the PCR amplicon of spacer. Screening by PCR-RFLP of spacer and coa grouped bovine strains into 4 and 5 patterns, respectively, and ovine strains were grouped into 3 spacer and 3 coa patterns. From the aspect of the distribution of the strains, the same genotype investigated between different farms maybe due to the predominant strain in Taiwan. In our study, the genotypes between strains isolated from one dairy goat farm were identical. Exceptionally, only one strain exhibited a different type from the others within one farm. The isolates of cows and goats revealed no genotype in common which indicates the host-specificity in S. aureus infection.