B族链球菌基因分型与新生儿侵袭性感染临床表现的相关性研究

The relevance of genotype and clinical manifestations of group B streptococcus invasion infection in neonates

目的分析新生儿B族链球菌(GBS)感染基因型分布特点,探讨GBS基因型与新生儿侵袭性感染临床表现的相关性。方法收集本院及深圳市人民医院新生儿科2008年1月至2014年8月新生儿侵袭性GBS感染病例。采用多位点序列分型技术,对分离收集GBS的7个管家基因序列进行测序,并与BLAST数据库中的序列进行比对,确定菌株序列型(ST)。结果共纳入26例患儿,收集到26株GBS。26株GBS基因型中ST17 13株、ST12 4株、ST19 4株、ST171、ST456、ST485、ST23及未知型各1株。新生儿GBS感染临床表现为化脓性脑膜炎者9例,其中ST17 4例,ST12、ST19各2例,ST23 1例;临床表现为败血症者17例,其中ST17 11例,ST12 2例,ST19 3例,ST23 1例。结论新生儿GBS侵袭性感染的基因型以ST17为主;GBS基因型ST17与临床表现为脑膜炎及败血症均有相关性。

Objective To study the distribution of group B streptococcus （GBb） genotype and the relationship between GBS genotypes and clinical manifestations. Methods Neonates infected with streptococcus agalactiae in our Hospital and Shenzhen People＇s Hospital from Jan. 2008 to Aug. 2014 were recruited for study. Multilocus sequence typing technique was used to identify the sequencing of 7 housekeeping genes. The results were analyzed and compared with sequence information in blast database, and then strains of type sequence （ST） were confirmed. Results There were 26 strains of GBS were collected, and a total of 8 STs were identified in all isolates. They were ST17, ST12, ST19, ST171, ST456, ST485, ST23, and NT. ST17 were seen in 13 isolates; ST12 and ST19 were seen in 4 isolates; ST171, ST456, ST485, ST23 and NT were seen in 1 isolate, respectively. There were 9 neonates with purulent meningitis, in which ST17 accounted for 44.4% （4/9 cases）, ST12 and ST19 each accounted for 22. 2% （2/9 cases）, and ST23 11.1% （1/9 cases）. There were 17 neonates with sepsis, in which ST17 accounted for 64.7% （11/17 cases）, ST12 11.8% （2/17 cases）, ST19 17.6% （3/17 cases） and ST23 5.9% （1/17 cases）. Conclusions The major genotype of neonatal GBS invasive infection is ST17. ST17 are relevant with meningitis and septicemia.