A new antibiotic improves treatment of parasitic infections

A team of researchers from the Universitat Autònoma de Barcelona, lead by Professor Jordi Alberola, has demonstrated the efficacy and safety of a new type of antibiotic, belonging to the family called antimicrobial peptides, for treating canine leishmaniasis, which is a disease that also affects humans. It is the first time that these antibiotics have been demonstrated to be useful against parasitic diseases in real clinical situations. The antibiotic can also improve treatment of other infections, parasitic or not, in that no side effects have been observed and it is very difficult for organisms to develop resistance to them. In addition, it can also have a direct application as a drug for treating co-infection of leishmaniasis with HIV, which 10 % of people with AIDS suffer from. The findings will be published this month (February) in the magazine Antimicrobial Agents and Chemotherapy, which is the most prestigious in its field.

Twelve million people around the world are affected by leishmaniasis; 400 million more are at risk of suffering the disease and every year between 60,000 and 100,000 people die from it. Furthermore, nearly 2 million new cases are reported every year. The different forms of leishmaniasis are caused by unicellular parasites of the Leishmania genus, which are mainly spread by biting insects, similar to mosquitoes, called phlebotoms. Clinical manifestations range from slight cutaneous lesions to visceral complications that may lead to the individual’s death.

Dogs are the main reservoir of the parasite in Spain and in the rest of the Mediterranean basin, the Middle East and South America. Epidemiological studies show that around 70% of dogs in the Mediterranean area are infected. Consequently, eradication of the disease in dogs is considered to be one of the main objectives for improving human health.

A team of researchers at the Universitat Autònoma de Barcelona headed by Professor Jordi Alberola of the Department of Pharmacology, Therapeutics and Toxicology, working in collaboration with researchers at the Pompeu Fabra University and the CSIC [Spanish Council for Scientific Research] have described, for the first time, the safety and efficacy of a new type of antibiotic from the antimicrobial peptide family, little studied up until now, against canine leishmaniasis. These latter researchers had already demonstrated the efficacy in laboratory cell cultures, but the efficacy in real clinical situations against parasitic diseases had never been demonstrated.

The researchers have obtained very promising results in a preliminary study on 8 dogs affected by the disease: no adverse affects were detected; the parasitic load is decreased, and it seems to have long term effects, which could be very useful for use in therapies applied to people or animals that live in areas where medicines cannot easily be shipped to (as is the case in the principal areas affected by leishmaniasis).

One of the most direct applications of the antibiotic would be its use as a drug for treating co-infection of leishmaniasis and HIV. This new type of infection affects approximately 10 % of people who have AIDS, but in the case of the risk group made up of intravenous drug users it may be as high as 70%.

The research findings will be published this month (February) in the magazine Antimicrobial Agents and Chemotherapy, the most prestigious in its field. The findings were carried out in collaboration with Laboratorios Calier S.A and researchers at the Pompeu Fabra University and by the Spanish Council for Scientific Research (CSIC).