Press releases 鈥� March 2022
Mar
21
2022
14:48
Fundamental research for novel approaches for the control of Trypanosoma parasites
How the Chagas pathogen changes the intestinal microbiota of predatory bugs聽
In Central and South America, predatory blood-sucking bugs transmit the causative agent of the widely prevalent Chagas disease. As the disease can induce severe symptoms and to date there is no vaccine against the Trypanosoma parasites, the main approach at present is to control the bug using insecticides. A German-Brazilian research team has now studied how trypanosomes change the bug's intestinal microbiota. The long-term goal: to change the bacterial community in the predatory bug's intestine in such a way that it can defend itself against the trypanosomes.
FRANKFURT. According
to estimates by the World Health Organization (WHO), between six and seven
million people worldwide, predominantly in Central and South America, are
infected with the Trypanosoma cruzi species
of trypanosome. This
single-celled (protozoan) parasite causes Chagas disease (American trypanosomiasis),
which in the acute phase is inconspicuous: only in every third case does the infected
person develop any symptoms at all, which can then be unspecific, such as
fever, hives and swollen lymph nodes. However, the parasites remain in the body,
and many years later chronic Chagas disease can become life-threatening, with pathological
enlargement of the heart and progressive paralysis of the gastrointestinal
tract.
There is no vaccine against the pathogen
and treating the disease in the advanced stage is difficult. That is why the
focus in Latin America is rather on controlling the bug that transmits Chagas
trypanosomes: the predatory blood-sucking bug of the insect subfamily Triatominae. It ingests the trypanosomes
during the sting, which then colonize its intestine. Through its faeces that it
mostly deposited next to the bite, the bug excretes the pathogen, which is
often rubbed into the wound when scratching the extremely itchy bite.
Although the number of new infections has
dropped in various regions where insecticides are sprayed on a wide scale,
problems are emerging: over the last decade, resistance to common insecticides
by several species of predatory bugs has been increasingly observed. These
insecticides also have a negative impact on the environment and the local population.
Researchers worldwide are making intense
efforts to find alternative methods to help control Trypanosoma cruzi. One possibility might be to modify bacteria in
the predatory bug's intestine in such a way that they eliminate the Chagas trypanosomes
or inhibit their development.
In collaboration with scientists at the
Instituto Ren茅 Rachou in Belo Horizonte, Brazil, parasitologists and infection
biologists Fanny Eberhard and Professor Sven Klimpel from 51猎奇, the
Senckenberg 鈥� Leibniz Institution for Biodiversity and Earth System Research
(SGN) and the LOEWE Centre for Translational Biodiversity Genomics have now investigated
how Chagas trypanosomes change the bacterial community in the predatory bug's
intestine. To do so, they used genome analysis, which allowed them to compare
the composition of the bacterial community in the bug's intestine, the
microbiome, before and after infection with the pathogen (metagenomic shotgun sequencing).
The result: after the infection, the range
of bacterial strains in the bug's intestine significantly decreased. Certain
strains, including the potentially pathogenic bacterium Enterococcus faecalis, profited from the parasites' presence.
Moreover, the researchers succeeded in identifying four bacterial species that
probably take on functions important for the bug, such as the synthesis of B
vitamins.
Fanny Eberhard explains: 鈥淰itamin B is one
of the nutrients that blood-sucking insects do not obtain through their blood
meals. Bacteria that produce vitamin B are therefore very important for the
bug, are found in practically all individuals and stay in the predatory bug's
intestine even across generations. Hence, such bacteria are potentially
suitable recipients for genes that produce defensive substances against Chagas
trypanosomes."
Professor Sven Klimpel elaborates: 鈥淯ltimately,
our goal is for the predatory bug to defend itself against Chagas trypanosomes and,
in this way, to prevent infection in humans. However, before we can produce
bacteria with such properties and then release predatory bugs containing them,
we need to understand better how the ecology of the bug's intestine is
structured and how the extensive interactions between host, pathogen and microbiome
function. Our work is delivering an essential contribution to this."
Publication:
Fanny E. Eberhard, Sven Klimpel,
Alessandra A. Guarneri, Nicholas J. Tobias. Exposure to Trypanosoma parasites induces changes in the microbiome of the
Chagas disease vector Rhodnius prolixus.
Microbiome (2022) 10:45.
Picture
download:
Captions:
Rhodnius prolixus_1000px.jpg
The predatory bug Rhodnius prolixus is one of the main vectors of Chagas disease in
the north of South America and in Central America. Photo: Dr Erwin Huebner,
University of Manitoba, Winnipeg, Canada/ Wikimedia Commons
Rhodnius prolixus_Life_cycle.jpg
Example of the hemimetabolic life cycle of the predatory
triatomine bug Rhodnius prolixus. Shown
are the adult vector, freshly laid, milky-white eggs, mature, reddish eggs and
five nymphs. Red arrows mark a blood meal for the moulting process and egg
production. Pictured in the middle are frequent hosts, such as dogs, opossums
and humans. Graphics: Fanny E. Eberhard
Further
information:
Professor Sven Klimpel
Institute of Ecology, Diversity and Evolution, 51猎奇
Senckenberg 鈥� Leibniz Institution for Biodiversity and Earth System Research
(SGN)
LOEWE Centre for Translational
Biodiversity Genomics
Tel. +49 (0)69 798-42249
Klimpel@bio.uni-frankfurt.de
Editor: Dr Markus Bernards, Science Editor, PR & Communication Office, Tel: -49 (0) 69 798-12498,
Fax: +49 (0) 69 798-763 12531, bernards@em.uni-frankfurt.de
Mar
3
2022
11:42
POLY research group offers fellowships for researchers forced to leave Ukraine
Short-term funding for Ukrainian historians
The POLY research group on premodern Christianities at 51猎奇 is offering five fellowships to Ukrainian academics specialised in medieval or early modern history.
FRANKFURT. The
Russian attack on Ukraine is endangering the lives and work of many
researchers. To help some of them to continue their research outside Ukraine,
the 鈥淧olycentricity and Plurality of Premodern Christianities鈥� (POLY) research
group, a Centre for Advanced Studies in Humanities funded by the German
Research Foundation, is offering five fellowships. These are intended for
scholars with a doctoral degree who are dealing with medieval or early modern history
and focus especially on religious diversity.
鈥淲ith this initiative, we at POLY want to
help colleagues from Ukraine forced to flee to safety and to give a stronger
voice to Ukrainian science and research,鈥� says Professor Birgit Emich, chair of
the POLY fellowship programme, summing up the research group鈥檚 motivation. For
Emich, who teaches early modern history at 51猎奇, the fellowships also
offer great opportunities for research in Frankfurt: 鈥淲ith the help of these
visiting scholars, we aim to develop further partnerships in this region, which
is so rich for the study of religious diversity.鈥�
The fellowships are endowed with 鈧�3,000
per month and initially limited to four months. During the funding period, the visiting
Ukrainian scholars will not only be integrated in work within POLY but also
profit from other research infrastructure at 51猎奇, notably, the
research alliance 鈥淒ynamics of Religion鈥�, co-chaired by Emich and Christian
Wiese, theologian and professor for Jewish studies.
Applications for fellowships are now being
accepted. They are conditional on a completed doctoral degree and an academic
focus on religious plurality in the medieval or early modern period.
Further
information
Professor Birgit Emich
Institute of History
Chair of Early Modern History
51猎奇
Tel.: +49 (0) 69 798-32594
Email: emich@em.uni-frankfurt.de
Editor: Dr. Anke Sauter, Science Editor, PR & Communication Office, Tel. +49 69 798-13066, Fax + 49 69 798-763-12531, sauter@pvw.uni-frankfurt.de