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Phylogenetic relatedness among leptospiral strains belonging to same serovar recovered from patients with different

K Natarajaseenivasan1, P Vijayachari, S Sharma

  • 1Regional Medical Research Centre, Indian Council of Medical Research, WHO Collaborative Centre for Diagnosis, Research, Reference and Training in Leptospirosis, Port Blair 744101, Andaman and Nicobar Islands, India.

Infection, Genetics and Evolution : Journal of Molecular Epidemiology and Evolutionary Genetics in Infectious Diseases
|January 11, 2005
PubMed

Insights

Leptospirosis strains vary genetically, even within the same serovar. This genetic diversity influences disease severity and clinical presentation, with regional strains showing unique patterns.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • Leptospirosis is a widespread zoonotic disease caused by diverse Leptospira serovars.
  • Clinical manifestations of leptospirosis range from mild to severe, with inconsistent correlations between serovar and disease presentation.
  • Understanding the genetic diversity of Leptospira strains is crucial for disease control and epidemiology.

Purpose of the Study:

  • To genetically differentiate Leptospira isolates from human leptospirosis cases with varying severity and from rodent reservoirs.
  • To investigate the genetic relatedness of Leptospira strains within and between different geographical regions.
  • To determine if genetic fingerprinting can discriminate between strains causing different clinical syndromes.

Main Methods:

  • Random Amplified Polymorphic DNA (RAPD) fingerprinting was employed.
  • Specific primers (PB1, M16, B11, B12) were used for DNA amplification.
  • Isolates from human patients (mild and severe leptospirosis) and rodents from the same areas were analyzed.

Main Results:

  • RAPD fingerprinting revealed five distinct genetic clusters among the analyzed Leptospira strains.
  • Leptospira strains of the same serovar (Ratnapura) exhibited genetic dissimilarity between South India (hepato-renal) and Andaman (pulmonary) isolates.
  • Identical fingerprint patterns were observed between human and rodent isolates from the same geographical areas, suggesting regional strain specificity.

Conclusions:

  • Genetic variability among Leptospira strains, even within the same serovar, contributes to diverse clinical outcomes.
  • Leptospira strains circulating in different geographical regions possess unique genetic profiles, irrespective of serovar.
  • RAPD fingerprinting is a valuable tool for discriminating Leptospira strains and understanding their epidemiological patterns.

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