Are you looking for a faster and more accurate method of strain typing? Optical Mapping could be your answer.
Optical Mapping produces high coverage, ordered, restriction maps based on hundreds of markers across the entire genome. An Optical Map offers increased accuracy and provides more genomic information than strain typing with alternative methods such as PFGE.
Below you can see a comparison of Optical Mapping and PFGE. Because Optical Maps contain hundreds of markers across the entire genome researchers obtain a much higher resolution compared to other technologies. This enables better strain discrimination among other advantages.
How are researchers using Optical Mapping?
- High resolution epidemiology
Several clusters of Salmonella Typhimurium infections appeared in Denmark in 2008 and 2009. The paper Molecular characterization of salmonella typhimurium highly successful outbreak strains published in the Foodborne Pathogens and Disease journal discusses how Optical Mapping was able to show that the strain in the largest cluster did not contain an increase content of virulence genes. However Optical Mapping did find a large insert, which was most likely a prophage, in one of the strains. The knowledge of this insert, which may confer a competitive advantage for that strain, is valuable information for epidemiologists.
- Characterizing and monitoring strain stability
In a paper titled A sustained hospital outbreak of vancomycin-resistant Enterococcus faecium bacteremia due to emergence of vanB E. faecium sequence type 203 published in the Journal of infectious Disease, researchers, with the aid of Optical Mapping, analyzed samples of Enterococcus faecium collected over a 12 year period. The results showed that over this time the strain acquired the vanB locus which resulted in an epidemic clone that exhibits vancomycin resistance.
- Tracing and linking outbreak and contamination strains to the source
In the figure below you can see the Optical Map similarity cluster of the German Enterohemorrhagic Escherichia coli O104:H4 outbreak of May 2011.
Figure. Optical Map similarity cluster of German EHEC O104:H4 outbreak.
Optical Mapping played a critical role in identifying and tracking strains in this outbreak. The paper Prospective Genomic Characterization of the German Enterohemorrhagic Escherichia coli O104:H4 Outbreak by Rapid Next Generation Sequencing Technology was published about this outbreak and discusses how Optical Mapping accelerated the characterization of the various strains and isolates collected.
- Distinguishing strains and determining genetic relatedness between multiple isolates
The paper Optical genetic mapping defines regions of chromosomal variation in serovars of S. enterica subsp. enterica of concern for human and animal health published in the journal of Epidemiology and Infection discusses how optical mapping was used to establish 2 geographical lineages (based on the presence of prophage sequences) of strains of Salmonella enterica subsp. enteric.
- Analyzing microbial mixtures for quality control and process manufacturing
Some of the differentiating technical advantages of Optical Mapping are:
- Faster time to results than gel electrophoresis and sequence based methods
- Ability to analyze “unculturable” or fastidious microbes
- Easy and quick recognition of genomic shifts
- Much lower cost than whole genome sequencing
- Easy interpretation though visual analysis using MapSolver™ software
- High precision epidemiology due to high marker density
How can you access the Optical Mapping technology?
Recently Hitachi Solutions America, Ltd. partnered with OpGen Inc. to offer the MapIt® Optical Mapping Service to its customers. Click here to learn more about Optical Mapping and the MapIt Optical Mapping Service. You can also view a webinar that describes Optical Mapping and its key application areas.