title: Epidemiological characterisation of Streptococcus pneumoniae from India using multilocus sequence typing.
abstract: OBJECTIVE
  The aim of this study was to utilize the multilocus sequence typing (MLST) technique to characterise Streptococcus pneumoniae among clinical isolates in India. MLST was used to determine clonality, to establish genetic relatedness, to check for correlation between serotypes and sequence types (STs) and its relevance associated with antibiotic resistance.
  
  
  METHODS
  Forty consecutive invasive S. pneumoniae isolates in children<5 years were characterised. Preliminary identification of serotype and antibiotic susceptible profile was followed with MLST technique to identify the STs of the isolates. STs were then analysed for clonality using an eBURST algorithm and genetic relatedness using Sequence Type Analysis and Recombinational Tests version 2 software.
  
  
  RESULTS
  The most common ST was ST63. Among the forty isolates, we identified nine novel STs, six of which had known alleles but in new combinations, three of which had new alleles in their sequence profile. The new STs assigned were 8501-8509. One clonal complex was found among the 40 strains characterised. The most common serotypes in this study were serotype 19F, 14 and 5. Non-susceptibility to penicillin and erythromycin was observed in 2.5% and 30% of the isolates, respectively.
  
  
  CONCLUSIONS
  This study shows a significant number of novel STs among the 40 isolates characterised (9/40, 22.5%), however, internationally recognised strains were also circulating in India, indicating, there could be greater geographical variation in pneumococcal STs in India. Molecular epidemiology data is essential to understand the population dynamics of S. pneumoniae in India before the introduction of pneumococcal vaccines in NIP in India.
authors.forename: T
authors.initials: T
authors.lastname: Gopi
authors.forename: J
authors.initials: J
authors.lastname: Ranjith
authors.forename: S
authors.initials: S
authors.lastname: Anandan
authors.affiliation: Department of Clinical Microbiology, Christian Medical College and Hospital, Vellore - 632 004, Tamil Nadu, India.
authors.forename: V
authors.initials: V
authors.lastname: Balaji
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002675:Child, Preschool; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D010641:Phenotype; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents