Parasite genetics and drug resistance

Kala-Azar is considered an emerging disease in Ethiopia where it is frequently associated with HIV/AIDS, the leading cause of adult illness and death. Untreated, Kala-Azar is usually fatal, but with appropriate treatment the fatality rate drops to 10% or less. However, the prognosis for HIV positive patients is far worse. VL/HIV co-infection is characterized by significantly lower cure rates, higher drug toxicity, higher relapse rates, and higher mortality rates than those for VL in non-HIV-infected individuals. The prevalence of HIV in the Kala-Azar endemic regions of Ethiopia is 11–13% and even higher amongst the VL patients (29-40%).

Sodium stibogluconate (generic SSG or Pentostam) is still the first line of treatment for VL in Ethiopia. However, approximately 5% of HIV negative patients and 50% of HIV positive VL co-infected patients experience relapses within a year following treatment. In the case of the HIV co-infection frequent relapses are inevitable with patients become less responsive to treatment after each successive relapse. While SSG remains effective during initial relapses increasing unresponsiveness to antimonials develops and treatment with second line drugs, such as liposomal amphotericin B (AmBisome), pentamidine or paromomycin, is recommended to prevent development of drug resistance. Treatment of successive relapses may lead to the development of multi-drug resistance.
VL and post-kala-azar dermal leishmaniasis (PKDL) patients and perhaps asymptomatic carriers, are the putative reservoir hosts of anthroponotic L. donovani. PKDL is a complication of VL characterized by a macular, maculopapular, and nodular rash in patients who recover from VL. As many as 50% of the Sudanese VL patients treated with sodium stibogluconate become PKDL patients that harbor parasites in their skin where they are accessible to biting sand flies. In Ethiopia the rates of PKDL amongst treated patients are much lower, but asymptomatic infections are common and may well be of importance as parasite reservoirs.
We will focus on developing useful molecular markers for detecting and characterizing L. donovani parasites that cause distinct pathologies, as well as determining parasite sensitivity/resistance to different drugs. In order to define risk factors associated with disease development and transmission, the base line clinical, immunological and parasitological status of study cohorts in endemic villages will be establish and followed at 3 month intervals. Parasites isolated from VL patients, with specific emphasis on patients not responding to treatment with SSG, Ambisome or paromomycin, or PKDL patients will be characterized and used for studies on mechanisms of drug resistance in field isolates, as well as factors associated with PKDL, respectively. Attempts will be made to identify prognostic markers for drug resistance or development of PKDL. Availability of accurate clinical histories and human DNA samples will be used in analysis of genetic markers associated with VL and PKDL.

Project personnel

Prof. Charles L. Jaffe PhD (project leader) cjaffe@cc.huji.ac.il
Dr. Mary Dan-Goor PhD, Research associate) maryd@savion.huji.ac.il
Hanan Jaber, M.Sc (PhD candidate) hananjstar@yahoo.com
Arie Zackay, M.Sc (PhD candidate) zackay@gmx.de

Charles Jaffe’s Leishmaniasis Biomedical Research Group is at the Kuvin Center for the Study of Infectious and Tropical Diseases within The Institute for Medical Research Israel-Canada at the Hebrew University Faculty of Medicine in Ein Kerem, Jerusalem, Israel. Charles has been studying leishmaniasis for many years in several countries. His laboratory is a Center for Leishmaniasis Diagnosis in Israel, and has carried out extensive research on the development of new diagnostic assays. Other research in his laboratory focuses on vaccine and new drugs to treat these leishmaniasis, as well as basic research on the role of Protein kinases, specifically PKA and Casein kinases, in parasite survival.

Selected Publications

Ehrenfreund-Kleinmam, T., Domb, A.J., Jaffe, C.L., Nasereddin, A ., Leshem, B. and Golenser, J. (2005). Effect of Amphotericin B Derivatives on Leishmania and Immune Functions. J Parasitol 9, 158-163.
Strauss-Ayali, D., Baneth, G., Shor, S., Okano, F. and Jaffe, C.L. (2005). Interleukin-12 augments a Th1-type immune response manifested as lymphocyte proliferation and interferon gamma production in Leishmania infantum - infected dogs. Int J Parasitol 35, 63-73.
Shani-Adir, A., Kamil, S., Rozenman, D., Schwartz, E., Ramon, M., Zalman, L., Nasereddin, A., Jaffe, C.L. and Ephros, M. (2005). Leishmania tropica in northern Israel– a clinical overview of an emerging focus. J Amer Acad Dermatol I53, 810-815.
Nasereddin, A., Baneth, G., Schonian, G., Kanaan, M. and Jaffe, C.L. (2005). Molecular fingerprinting of Leishmania infantum strains following an outbreak of visceral leishmaniasis in Central Israel. Journal of Clinical Microbiology 43, 6054-6059.
Nasereddin, A., Ereqat, S., Azmi, K., Baneth, G., Jaffe, C.L. and Abdeen, Z. (2006). Serological survey with PCR validation for canine visceral leishmaniasis in Northern Palestine. J Parasitol 92, 178-183.
Schwenkenbecher, J.M., Wirth, T., Schnur, L.F., Jaffe, C.L., Schallig, H., Al-Jawabreh, A., Hamarsheh, O., Azmi, K., Pratlong, F. and Schoenian, G. (2006). Microsatellite analysis reveals genetic structure of Leishmania tropica. Int J Parasitol36, 237-246.
Talmi-Frank, D., Strauss-Ayali, D., Jaffe, C.L. and Baneth, G. (2006) Kinetics, diagnostic and prognostic potential of quantitative western blot analysis and antigen-specific ELISA in experimental canine leishmaniasis. Clin Vac Immunol 13, 271-276. formerly Clin. Diag. Lab Immunol.
Bensoussan, E., Nasereddin, A., Jonas, F., Schnur, L.F. and Jaffe, C.L. (2006) Comparison of polymerase chain reaction (PCR) assays for the diagnosis of cutaneous leishmaniasis. J Clin Microbiol 44, 1435-1439.
Strauss-Ayali, D., Baneth, G. and Jaffe, C.L. (2007) Splenic immune responses during canine visceral leishmaniasis. Vet Parasitol 38, 547-564.
Reichwald, C., Shimony, O., Dunkel, U., Sacerdoti-Sierra, N., Jaffe, C.L. and Kunick C. (2008). 2-(3-Aryl-3-oxopropen-1-yl)-9-tert-butyl-paullones: A New Anti-Leishmanial Chemotype. J Med Chem. 51, 659-665.
Reichwald, C., Shimony, O., Sacerdoti-Sierra, N., Jaffe, C.L. and Kunick C. (2008). A new Heck reaction modification using ketone Mannich bases as enone precursors: parallel synthesis of anti-leishmanial chalcones. Bioorg Med Chem Lett. 18, 1985-1989.
Shimony, O. and Jaffe, C.L. (2008). Rapid fluorescent assay for screening drugs on Leishmania amastigotes. J Microbiol Methods. 75, 196-200.
Nasereddin, A., Bensoussan-Hermano, E., Sch?nian, G., Baneth, G. and Jaffe, C.L. (2008). Molecular Diagnosis and Species Identification of Old WordCutaneous Leishmaniasis using a Reverse Line Blot Hybridization Assay. J Clin Microbiol. 46, 2848-2855.
Gradoni, L., Soteriadou, K., Louzir, H., Dakkak, A., Ozensoy, S., Jaffe, C.L., Dedet, J.P., Campino, L. Ca?avate, C., Dujardin, J.C. (2008). Drug regimens for visceral leishmaniasis in Mediterranean countries. Trop Med Inter Health. 13, 1272-1276.
Nasereddin, A., Azmi, K., Jaffe, C.L., Ereqat, S., Amro, A., Sawalhah, S., Baneth, G., Sch?nian, G. and Abdeen, Z. (2009). Kinetoplast DNA heterogeneity among Leishmania infantum strains in central Israel and Palestine. Vet Parasitol. 161, 126-130.
Amro, A., Sch?nian, G., Al-Sharabati, M. B., Azmi, K., Nasereddin, A., Abdeen, Z., Schnur, L. F., Baneth, G., Jaffe, C. L., Kuhls, K. (2009). Population genetics of Leishmania infantum in Israel and the Palestinian Authority through microsatellite analysis. Microbes Inf. 11, 484-492.
Malki-Feldman, L. and Jaffe, C.L. (2009). Leishmania major: Effect of Protein kinase A and Phosphodiesterase activity on infectivity and proliferation of promastigotes. Exp. Parasitol. 123, 39-44.
Ozensoy Toz, S., Nasereddin, A., Ozbel, Y., Ertabaklar, H., Culha, G., Sevil, N., Alkan, M.Z., Jaffe, C.L. (2009). Leishmaniasis in Turkey: Molecular characterization of Leishmania from human and canine clinical samples. Trop. Med. Int. Health. 14, 1401-1406.
Nasereddin, A., Schweynoch, C., Schonian, G. and Jaffe, C.L. (2010). Characterization of Leishmania tropica axenic amastigotes. Acta Trop. 113, 72-79.
Talmi-Frank, D., Nasereddin, A., Schnur, L.F., Sch?nian, G., ?zensoy T?z, S., Jaffe, C.L. and Baneth, G. (2010). Detection and Identification of Old World Leishmania by High Resolution Melt Analysis. PLoS NTD, In press.
Yli-Kauhaluoma, J., Alakurtti, S., Bergstrom, P. Sacerdoti-Sierra, N. and Jaffe, C.L. (2010). Anti-leishmanial activity of Betulin derivatives. J. Antibiotics, In press.
Talmi-Frank, D., Jaffe, C.L., Nasereddin, A., Warburg, A., King, R., Svobodova, M., Peleg, O. and Baneth G. (2010). Leishmania tropica in Rock Hyraxes (Procavia capensis) in a Focus of Human Cutaneous Leishmaniasis. Amer. J. Trop. Med. Hyg. In press.
Alakurtti, S., Heiska, T., Kiriazis, A., Sacerdoti-Sierra, N., Jaffe, C.L. and Yli-Kauhaluoma, J. (2010). Synthesis and anti-leishmanial activity of heterocyclic betulin derivatives. Bioorg. Med. Chem. In press.