Molecular tracking of infections by Leishmania infantum.
Leishmania infantum is a major opportunistic parasite in patients with acquired immune deficiency syndrome and is very variable in these subjects. Isoenzyme characterization is not able to explain this variability, since half of the stocks isolated from patients co-infected with human immunodeficiency virus and Leishmania belong to zymodeme MON-1. Amplification of L. infantum minicircles by the polymerase chain reaction (PCR) and digestion of the amplified product to reveal restriction fragment length polymorphisms (RFLP) has proved very useful in distinguishing between relapses and reinfections in co-infected, treated patients. We have confirmed the existence of a leishmaniasis outbreak among intravenous drug users in north-east Spain, previously detected by isoenzymatic analysis. We have documented persistence of the same strain of Leishmania in 2 treated co-infected patients throughout several years, regardless of the theoretical rapid evolution ascribed to kinetoplast deoxyribonucleic acid minicircle sequences. We suggest using this PCR-RFLP technique to detect reinfections in treated co-infected subjects.
WHO Collaborating Centre for Leishmaniasis, Research Unit in Tropical Medicine and International Health (FIS-ISCIII), Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain.
M A
MA
Morales
C
C
Chicharro
M
M
Ares
C
C
Cañavate
D C
DC
Barker
J
J
Alvar
D017088:AIDS-Related Opportunistic Infections / Q000150:complications; D000818:Animals; D003001:Cloning, Molecular; D016054:DNA, Protozoan / Q000032:analysis; D015658:HIV Infections / Q000150:complications; D006801:Humans; D018314:Leishmania infantum / Q000235:genetics / Q000302:isolation & purification*; D007898:Leishmaniasis, Visceral / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length
D016054:DNA, Protozoan