摘要
目的 AP631炭疽噬菌体裂解蜡样芽胞杆菌的发现和鉴定。方法通过革兰氏染色、菌落形态特征、噬菌体裂解试验、青霉素敏感试验、溶血试验、生化试验和蛋白质毒素结晶试验对炭疽疫点现场分离的5株菌进行蜡样芽胞杆菌的鉴定,通过PCR扩增、小白鼠毒力测定试验和MLST基因检测等方法对该5株菌和本实验室保存的3株被AP631炭疽噬菌体裂解的蜡样芽胞杆菌进行毒力和基因测定。结果确定了8株可被AP631炭疽噬菌体不完全裂解的蜡样芽胞杆菌。从疫点采集分离的5株菌青霉素敏感试验阴性,炭疽毒力基因PCR扩增阴性,排除了炭疽芽胞杆菌;蛋白质毒素结晶试验染色试验为阴性,排除了苏云金芽胞杆菌;根据溶血试验和生化反应等一系列鉴别实验鉴定为蜡样芽胞杆菌。8株菌的MLST基因检测发现5株菌有新的等位基因位点或ST型。结论本研究首次证明我国使用的炭疽芽胞杆菌诊断AP631噬菌体可以不完全裂解部分蜡样芽胞杆菌,存在非特异性裂解现象,提示在今后使用噬菌体鉴定炭疽杆菌时,对于外环境分离到的可疑芽胞杆菌,特别要注意关于噬菌体不完全裂解的问题,这将为炭疽诊断标准的正确制订提供新的认识并具有重要的指导意义。
We identified the isolates which were susceptible to phage AP631,a specific Bacillus anthracis susceptible phage.Five isolates of Bacillus cereus from soil in an anthrax endemic area and 3preserved in our laboratory were identified by regular experiments including penicillin inhibition experiment,smear Gram staining,hemolysis testing,biochemical reaction,PCR analysis,mouse toxicity determination,protein crystallization dying experiment and MLST subtyping.All the tests supported the new bacterial isolates susceptible to AP631 phage was B.cereus and excluded B.anthracis and B.thuringiensis.Three laboratory preserved isolates were B.cereus which were identified previously.The five B.cereusisolates from soil were resistant to penicillin and PCR amplification targeted virulence genes showed negative in these strains.Protein crystallization dying experiment also displayed negative results,but the resultant biochemical reactions confirmed the 5strains were B.cereus.In addition,all 8 B.cereus strains were clustered as new allelic loci by MLST subtyping method.Our results demonstrate that bacterial phage AP631 is capable of lysing B.cereusin addition to B.anthracis,which suggests that there is some nonspecific lysis produced by AP631 and thereby we need pay more attention to the diagnosis of B.cereus infection to avoid misdiagnosis.
出处
《中国人兽共患病学报》
CAS
CSCD
北大核心
2016年第6期507-511,共5页
Chinese Journal of Zoonoses
基金
传染病预防控制国家重点实验室资助项目(No.2011SKLID210)~~
