Yasser Alraey

PhD student






I graduated from the King Abdulaziz University, Saudi Arabia in 2009 with first honour bachelor degree in Medical Technology. In 2015, I obtained an MSc in Tropical Disease Molecular Biology at LSTM. My MSc research project was on the blood behaviour of sandflies collected from Saudi Arabia under the supervision of Dr. Alvaro Acosta-Serrano. In January 2016, I returned to the Acosta-Serrano group as PhD student with a fellowship from the Saudi Arabian Cultural Bureau.


As a consequence of the ongoing Syrian tragedy, which has caused the biggest human displacement since WWII, cutaneous leishmaniasis (CL) has become a serious problem, infecting and stigmatizing hundreds of thousands of people in the Middle East. Different sandfly species can be vectors for Old World CL, depending on whether transmission is anthroponotic (caused by Leishmania tropica) or zoonotic (other mammals as reservoirs; caused by Leishmania major). L. major produces “wet” skin ulcers, whereas L. tropica causes “dry” lesions, and both types of ulcers oftentimes develop secondary (bacterial and fungal) infections. Interestingly, while L. major infections tend to self-heal within months, patients infected with L. tropica take longer to heal and are highly unresponsive to most common anti-leishmanial drugs, including sodium stibogluconate (SSG). The basis for a natural resistance to SSG by L. tropica parasites is currently unknown.

Fig. 1. Man with a leishmaniasis ulcer
on the face from Asir Province, Saudi Arabia.
Photo credit:Waleed Al-Salem.

In my PhD thesis I aim to 1) determine the molecular basis of drug resistance in L. tropica and 2) investigate how opportunistic secondary infections influences the treatment response against anti-leishmanial drugs.