O1群E1Tor型霍乱弧菌溶原性测定的机理研究

The mechanism of applying lysogenicity in phage-biotyping scheme for subtyping O1 E1 Tor Vibrio cholerae strains

目的 确定我国O1群El Tor生物型霍乱弧菌“噬菌体-生物分型”方案中“溶原性测定”中检测噬菌体的种类,研究溶原性测定的原理.方法 选择O1群El Tor型霍乱弧菌76株、O1群古典株8株、O139群菌株34株,利用溶原性测定方法检测菌株溶原性,检测菌株自发产生的溶原性噬菌体种类,检测阳性和阴性菌株染色体中该前噬菌体基因组,并检测这些菌株对溶原性噬菌体919TP（弧菌噬菌体K139家族）的敏感性.结果 O1群El Tor型菌株溶原性测定为阳性的19株菌,其释放的噬菌体主要为K139家族,具有溶原化的K139噬菌体,并对溶原性噬菌体919TP的敏感性为阴性;O1群El Tor型菌株22株对溶原性噬菌体919TP的敏感性为阳性,溶原性测定全部为阴性,基因组中不含有K139噬菌体;6株O1群古典型菌株溶原性检测为阳性株,但产生的噬菌体不是K139类;0139群菌株中5株溶原性测定为阳性,能检测到溶原性K139噬菌体基因组,并且34株菌全部不能被919TP感染.结论 O1群El Tor型霍乱弧菌“噬菌体-生物分型”方案中溶原性测定指标主要检测的是菌株释放K139类噬菌体的能力,即是否有K139噬菌体的溶原化并释放子代,“对溶原性噬菌体的敏感性”检测的是菌株能否被K139家族噬菌体（919TP）感染,因此生物分型中“溶原性测定”与“对溶原性噬菌体的敏感性”两个指标是相关联的.

Objective To determine the principle of applying lysogenicity in Phage-Biotyping Scheme developed for the subtyping of O1 E1 Tor Vibrio cholerae strains.Methods 118 V.cholerae strains including 76 E1 Tor strains,8 classical strains and 34 serogroup O139 were selected to analyze the lysogenicity and sensitivity to lysogenic phage 919TP as described in the Manuals of cholera prevention and control,the genes of this phage were also determined among the genome sequences of these strains and the phages produced by them.Results All O1 E1Tor Vibrio cholerae 19 strains that produced positive results in lysogenicity,had the lysogenic K139 phage in genome and could both resist to lysogenic phage 919TP and release the K139 family phage.All the O1 E1Tor Vibrio cholerae 22 strains that produced positive results in sensitivity to the lysogenic phage,had no K139 family phage genes and got negative results in lysogenicity.However,the phages of this family were not released from 6 classical strains with positive lysogenicity result.Five serogroup O139 strains were detected releasing temperate phages K139 without the sensitivity to phage 919TP.Conclusions Applying the lysogenicity in Phage-Biotyping Scheme for subtyping O1 E1 Tor Vibrio cholerae strains is based on the ability to produce lysogenic bacteriophage K139.The index of ＆quot;sensitivity to the lysogenic phage＆quot; was also associated with this ability.