Khodaei Farzaneh, Sadeghi Kalani Behrooz, Alizadeh Naser, Hassani Alka, Najafi Mohammad, Kalantar Enayatollah, Amini Abbas, Aghazadeh Mohammad
Immunology Research Center, Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
Department of Medical Microbiology, Iran University of Medical Sciences, Tehran, Iran.
Galen Med J. 2018 Mar 28;7:e1121. doi: 10.22086/gmj.v0i0.1121. eCollection 2018.
Group B streptococcus (GBS), also known as Streptococcus agalactiae, is well known as a causative agent for neonatal invasive diseases; it is also a major pathogen in adults. Analytic epidemiology is required to monitor the clinical isolates of GBS. However, there is insufficient information on the genetic background of GBS in Iran, and this information is needed to guide and develop a GBS vaccine.
In total, 90 well-char - acterized GBS isolates were collected from April 2014 to August 2015. In this study, molecular typing was used to disclose a relationship between the multiple-locus variable number tandem repeat analysis (MLVA) types, serotyping, and pilus islands. The isolates were characterized by the types of capsular polysaccharides and pilus islands and were examined by MLVA to study the epidemiological relationship of isolates.
The results indicate that there is a significant relationship between the distribution of serotypes and pilus island genes; GBS isolates were differentiated into 12 types by capsular polysaccharides and pilus islands analysis. The discriminatory power of an MLVA analysis was high based on the five most variable numbers of tandem repeat loci and 44 MLVA types that were identified.
This study has provided useful insights into the genetic heterogeneity of GBS isolates in Tehran and Alborz, Iran. The extensive distribution of pilus islands in various serotypes and MLVA types throughout the GBS population refers to the advancement of the pilus-based GBS vaccines.
B族链球菌（GBS），也称为无乳链球菌，是新生儿侵袭性疾病的著名病原体；它也是成人的主要病原体。需要进行分析流行病学以监测GBS的临床分离株。然而，关于伊朗GBS的遗传背景信息不足，而这些信息对于指导和开发GBS疫苗是必要的。
2014年4月至2015年8月共收集了90株特征明确的GBS分离株。在本研究中，使用分子分型来揭示多位点可变数目串联重复分析（MLVA）类型、血清分型和菌毛岛之间的关系。通过荚膜多糖和菌毛岛类型对分离株进行特征鉴定，并通过MLVA进行检测以研究分离株的流行病学关系。
结果表明血清型分布与菌毛岛基因之间存在显著关系；通过荚膜多糖和菌毛岛分析，GBS分离株可分为12种类型。基于五个最可变的串联重复位点和鉴定出的44种MLVA类型，MLVA分析的鉴别力很高。
本研究为伊朗德黑兰和阿尔伯兹GBS分离株的遗传异质性提供了有用的见解。菌毛岛在整个GBS群体的各种血清型和MLVA类型中的广泛分布表明基于菌毛的GBS疫苗有进展。
