Parasitology

Review Article

Molecular approaches for a better understanding of the epidemiology and population genetics of Leishmania

G. SCHÖNIANa1 c1, K. KUHLSa1 and I. L. MAURICIOa2 p1

a1 Institute of Microbiology and Hygiene, Charité University Medicine Berlin, Dorotheenstrasse 96, D-10117 Berlin, Germany

a2 London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT London, UK

SUMMARY

Molecular approaches are being used increasingly for epidemiological studies of visceral and cutaneous leishmaniases. Several molecular markers resolving genetic differences between Leishmania parasites at species and strain levels have been developed to address key epidemiological and population genetic questions. The current gold standard, multilocus enzyme typing (MLEE), needs cultured parasites and lacks discriminatory power. PCR assays identifying species directly with clinical samples have proven useful in numerous field studies. Multilocus sequence typing (MLST) is potentially the most powerful phylogenetic approach and will, most probably, replace MLEE in the future. Multilocus microsatellite typing (MLMT) is able to discriminate below the zymodeme level and seems to be the best candidate for becoming the gold standard for distinction of strains. Population genetic studies by MLMT revealed geographical and hierarchic population structure in L. tropica, L. major and the L. donovani complex. The existence of hybrids and gene flow between Leishmania populations suggests that sexual recombination is more frequent than previously thought. However, typing and analytical tools need to be further improved. Accessible databases should be created and sustained for integrating data obtained by different researchers. This would allow for global analyses and help to avoid biases in analyses due to small sample sizes.

(Received August 31 2010)

(Revised October 19 2010)

(Accepted October 19 2010)

(Online publication November 16 2010)

Correspondence:

c1 Corresponding author: Institute of Microbiology and Hygiene, Charité University Medicine Berlin, Campus Mitte, Dorotheenstrasse 96, D-10117 Berlin, Germany. Tel: +49 30 450524028. Fax: +49-30-450524902. E-mail: gabriele.schoenian@charite.de

p1 Current address: Unidade de Parasitologia e Microbiologia Médicas, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, R. da Junqueira 100, 1349-008 Lisboa, Portugal.

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