3株猪源绿色气球菌的分离鉴定

Isolation and identification of 3 strains of Aerococcus viridans from swine

关键词:  猪  绿色气球菌  分离鉴定  机会致病菌

Key words:  swine  Aerococcus viridans  isolation and identification  opportunistic bacterium

摘要:

为确定云南省不同地区3个猪场仔猪发生四肢运动障碍的病原因素,无菌采集病死仔猪内部组织样品,采用血琼脂分离培养病原菌,随后对分离菌株做形态观察、生化试验、药敏试验及16S rRNA基因测序分析。结果：从3个猪场病料中均分离到菌落及个体形态一致的细菌,其16S rRNA基因序列与NCBI中7株绿色气球菌参考菌株的同源性均在99%以上,据此判定为绿色气球菌(Aerococcus viridans)；3个分离菌株均对克拉霉素、头孢曲松和青霉素敏感,对复方新诺明、庆大霉素和卡那霉素耐药。鉴于病死猪有检出其他病原体感染的情况和未见该菌单独有强致病力的报道,研究结果提示绿色气球菌是危害猪健康养殖的重要机会致病菌。

Abstract:

In order to determine the pathogenic agent causing limb disability of piglets from 3 pig farms in different areas of Yunnan Province, the tissue samples from internal organs of dead piglets were aseptically collected for pathogen isolation using blood agar and the resulting bacterial isolates were then subjected to morphological examination, biochemical tests, drug susceptibility tests and sequencing of 16S rRNA gene. Consequently, bacteria obtained from the samples of the 3 pig farms had the same colony and individual morphology, and their 16S rRNA gene sequences shared a higher than 99% homology with 7 reference strains of Aerococcus viridans deposited in NCBI, which proved that the isolates were A. viridans. The 3 isolates were sensitive to clarithromycin, ceftriaxone and penicillin, and resistant to cotrimoxazole, gentamicin and kanamycin. Considering the situation that other pathogen-caused infection was involved in some dead cases and no reports that this bacterium itself had high pathogenicity, the results here indicated that A. viridans could be an important opportunistic bacterium that did harm to the health of pigs.