Abstract
Background: 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. Materials and Methods: In total, 90 well-characterized 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. Results: 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. Conclusions: 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. [GMJ.2018;7:e1121]
Highlights
Streptococcus agalactiae, or group B streptococcus (GBS), may be one of the common causative agents of neonatal diseases such as respiratory diseases, septicemia, and meningitis in the first 6 days of life, as well as from 1 week up to 3 months old [1]
multiple-locus variable number tandem repeat analysis (MLVA) was done by individual polymerase chain reaction (PCR) and agarose gel electrophoresis of the amplicons as shown in (Figure-1)
A phylogenetic tree was made using MLVA profiles; in total, this dendrogram has three clusters that consist of two major clusters designated as A and B and one smaller cluster known as C, as shown in (Figure-2)
Summary
Streptococcus agalactiae, or group B streptococcus (GBS), may be one of the common causative agents of neonatal diseases such as respiratory diseases, septicemia, and meningitis in the first 6 days of life (early-onset disease), as well as from 1 week up to 3 months old (late-onset disease) [1]. The analysis of bacterial isolates using multiple genotyping methods provides significant information for creating a genetic relationship between isolates for epidemiological purposes and phylogenetic research [6]. Among these techniques, pulsedfield gel electrophoresis (PFGE) has more discriminatory power. The aim of this study is to determine the genetic diversity and phylogenetic analysis of GBS isolates through the MLVA method, and with the help of an epidemiological study, their association with different serotypes, antibiotic resistance patterns, and pilus islands genes in clinical isolates of GBS in an epidemiological study. 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. [GMJ.2018;7:e1121] DOI:10.22086/gmj.v0i0.1121
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
