Molecular and sequencing study and identification of novel SeM-type in beta-hemolytic streptococci involving the upper respiratory tract in Iran.
Authors: Moghaddam Sina, Lotfollahzadeh Samad, Salehi Taghi Zahraei, Hassanpour Ali, Manesh Hamid Tavanaei, Tamai Iraj Ashrafi
Journal: BMC veterinary research
Summary
# Editorial Summary Strangles and strangles-like disease caused by beta-haemolytic streptococci remain a significant economic burden in equestrian facilities worldwide, yet epidemiological characterisation of circulating strains remains incomplete in many regions. Researchers in Iran conducted molecular and phylogenetic analysis of local streptococcal isolates, employing SeM-typing via DNA sequencing and comparative analysis using Neighbour-joining methods to establish evolutionary relationships between strains and determine antibiotic resistance profiles. The investigation identified a novel SeM-97 allele variant in Iranian isolates, which demonstrated distinct phylogenetic clustering from previously documented SeM types when compared against reference sequences (FM204883), suggesting regional strain divergence. For equine practitioners, this work underscores the importance of strain-level characterisation in outbreak investigations, as distinct SeM types may have different epidemiological patterns and potentially variable responses to management interventions; additionally, antimicrobial resistance profiling of locally circulating strains can inform evidence-based therapeutic protocols in endemic regions. Understanding the molecular diversity of Streptococcus equi subsp. equi populations supports more targeted biosecurity strategies and provides baseline data for vaccine development programmes tailored to regional pathogenic profiles.
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Practical Takeaways
- •Understanding local SeM types in your region can help trace strangles outbreak sources and epidemiological patterns on your facility
- •Molecular typing of streptococcal isolates provides data to improve outbreak management and biosecurity protocols
- •Regional variation in SeM types may influence vaccination strategy decisions and disease control planning for strangles prevention
Key Findings
- •Novel SeM-97 type identified in Iranian beta-hemolytic streptococci isolates causing strangles
- •Phylogenetic analysis revealed distinct clustering patterns of Iranian streptococcal isolates using Neighbor-joining methodology
- •SeM-97 sequence demonstrated similarity to SeM-3 reference sequence with variations in amino acid composition