Title: Development and Evaluation of A High Throughput Automated DNA Microarray For Serotyping S. Pneumoniae.
Authors: Vandana Govindan, Feroze A Ganaie, Avid Hussain, Geeta Nagaraj, K L Ravi Kumar
DOI: http://dx.doi.org/10.18535/jmscr/v4i9.69
Streptococcus pneumonia is a major human pathogen commonly responsible for pneumonia, bacteraemia, meningitis, and otitis media, especially among young children and older adults. Pneumococcal serotype identification is a prerequisite to understand pathogenesis and estimate the disease burden. It is also a basic feature needed to track changes in epidemiology as well as to optimize the vaccines. Conventional gold standard typing method (Quellung reaction) requires the use of a large panel of expensive anti-sera, is subjective with cross reactions and few strains are non type able. Modern molecular methods have provided innovative opportunities to address the problem of microbial detection. The drawbacks of some of these currently used methods include inadequate discrimination between the isolates and poor reproducibility. To contend with these issues a novel automated microarray assay based on Capsular polysaccharide genes was developed to track the 90 serotypes of S. pneumoniae. A set of 15,150 specific probes of 60bp length each, corresponding to 1680 genes was generated utilizing the sequence data source from Sanger institute/EMBL. The assay was validated on 90 standard strains sourced from Staten Serum Institute, Copenhagen. The results demonstrated discriminatory ability of the Microarray among 90 serovars. Overall 61 (67.7%) serotypes were uniquely identified and 29 (32.2%) were assigned with a combination of their homologous serotypes. Bioinformatics data analysis revealed that detection of homologous serotypes is due to homology in the CPS region
Abstract
