Genetic analysis by RAPD technique of first strains of Streptococcus agalactiae serotype IX in Misiones, Argentina

NOVOSAK, M.; LACZESKI M; BOBADILLA, F.; CORTESE, J.; PEGELS, E.; OVIEDO, P.; QUIROGA, M.; DELGADO, O.; VERGARA, M.

Buenos Aires

Congreso; 18th International Congress of Infectious Diseases; 2018

International Society for Infectious Diseases with SADI

Streptococcus agalactiae (GBS), colonizes the human gastrointestinal and urogenital tract. It is the main cause of perinatal diseases by vertical transmission from mother to child during birth. Meningitis, pneumonia and sepsis are the main clinical presentations. It is classified into 10 serotypes (Ia, Ib, II to IX) according to the structure of its capsular polysaccharide. Serotype IX was the last reported and there is little data about its epidemiology. The first isolates of GBS serotype IX in Argentina were informed by our research group.Studies on GBS for epidemiological purposes use molecular techniques that study genetic diversity among closely related organisms, including the random amplification of polymorphic DNA (RAPD). It is an accessible and sensitive method based on the use of arbitrary primers to amplify polymorphic DNA segments, being a powerful technique to differentiate strains of GBS. The objective of this study was to determine possible clonal relationships among isolates of serotype IX GBS detected in the province of Misiones, Argentina.Isolates were recovered from 3281 vagino-rectal swabs of pregnant women with 35-37 weeks of gestation, between 2004 and 2014. Of 316 isolates of GBS, 11 serotype IX strains were identified. RAPD was performed using primer OPS 11 5'AGTCGGGTGG 3'. A dendrogram was built using the Nei and Li algorithm as distance method and, as group analysis method, the Unweighted Pair Group Method with the Arithmetic Mean (UPGMA) using the statistical software for Excel, XLSTAT 2017. The dendrogram shows 5 clonal subgroups with low percentage of similarity (≤ 45%) corresponding to the mean similarity value calculated, which indicates the high genetic diversity among these strains. It was determined that the 11 strains studied belong to 11 different clones.We conclude that there is clonal diversity of isolates of serotype IX GBS circulating in the region. We highlight the utility of the RADP technique for epidemiological studies. It is necessary to carry out studies on the genetic diversity of GBS, with epidemiological aims, that contribute to prevention and treatment strategies of perinatal infections caused by GBS.