猪源绿色气球菌的分离鉴定与药敏特性研究

Isolation and identification of Aerococcus viridans from swine and research on its susceptibility characteristics

目的鉴定研究2006年和2008年本实验室分别从广东清远和广西北流两个猪场发病小猪的膝关节积液中分离到2株呈四联状或成对排列,在山羊血琼脂平板上能形成明显的α-溶血圈的G+球菌。方法采用小白鼠致病性试验、细菌常规生理生化鉴定、药敏试验、耐药基因检测及16S rRNA序列分析等方法对上述分离的2株细菌进行鉴定及药敏特性研究。结果确定这2株G+球菌为正常情况下非致病性绿色气球菌(登录号分别为:GQ161096;GQ161097)。系统发育分析表明,两分离株与绿色气球菌15MS(登录号:EU075039.1)同源性分别高达99.4%和98.7%。药敏试验及耐药基因检测发现,这2株绿色气球菌除了对新霉素、氟哌酸、恩诺沙星、菌必治和环丙沙星等5种药物呈高敏外,对先锋V等13种抗菌素均不敏感。耐药基因检测结果表明,GXBL-1可检出6个耐药基因,GDQY-1则可检出多达10个耐药基因。结论从这2株分离株耐药谱检测结果可以看出,正常菌株同样携带多重耐药基因,存在着通过质粒转座子和整合子将耐药基因转移给敏感菌,导致耐药性传播的可能,应引起足够重视。

Objective To study and identify two strains of gram positive coccus which were isolated from the effusion in knee joints of Swine from Qingyuan, Guangdong and Beiliu, Guangxi respectively and which ranked in tetragenus or in pair under microscope and showed α-haemolysis on SBA. Method Pathogenicity experiment on mice, regular physiological and biochemical identification, drug susceptibility test, test of drug-resistant genes and sequence analysis of the 16S rRNA were applied to identify the two strains and their drug susceptibility features. Result The two strains of gram positive coccus were defined to be the non-pathogenic Aerococcus viridans under normal circumstances （access No： GQ161096 and GQ161097）. The phylogenetic analysis indicated that these two strains were highly relative to Aerococcus viridans strain 15MS （ access No： EU075039.1 ） with 99.4% and 98.7% homology. Susceptibility test demonstrated that these two Aero- coccus viriclans were highly sensitive to Neomycin, Norlloxacin, Enrofloxacin, Ceftriaxone Sodium and Ciprefloxacin, but insensitive to Cefalin V and other 12 antibiotics. The detection of drug-resistant genes indicated that GXBL-1 had 6 drug-re- sistant genes and GDQY-1 had 10. Conclusion The normal strains also carry multiple drug-resistant genes which can be transferred to sensitive organisms by plasmid transposon and integron and result in the spread of drug-resistance, to which more attention should be paid .