Novel macroarray-based method of Corynebacterium diphtheriae genotyping: evaluation in a field study in Belarus

Area of Science:

• Microbiology
• Epidemiology
• Molecular Biology

Background:

• Corynebacterium diphtheriae causes diphtheria, a significant public health concern.
• Accurate strain typing is crucial for understanding and controlling diphtheria outbreaks.
• Existing methods may lack the discriminatory power for detailed epidemiological investigations.

Purpose of the Study:

• To evaluate a novel macroarray-based spoligotyping method for typing C. diphtheriae.
• To assess the utility of this method in a field study setting in Belarus.
• To determine if spoligotyping can resolve transmission links in diphtheria cases.

Main Methods:

• DNA fingerprinting of 20 C. diphtheriae biotype gravis toxigenic isolates.
• Macroarray-based spoligotyping utilizing two clustered regularly interspaced short palindromic repeats (CRISPR) loci.
• Comparison of spoligotyping results with epidemiological data and ribotyping profiles.

Main Results:

• All 20 C. diphtheriae strains shared an identical ribotype ('Rossija').
• Spoligotyping differentiated these strains into three distinct spoligotypes.
• The method helped resolve suspected transmission links within the epidemiological network.

Conclusions:

• The macroarray-based spoligotyping method is a valuable tool for C. diphtheriae strain typing.
• Utilizing both CRISPR loci enhances the method's discriminatory power.
• Generated data are suitable for digital exchange and database storage, facilitating global surveillance.