Humans are often infected by parasites, sometimes even several species at a time. Such co-infections are more difficult to treat if the parasites interact with each other. An ecologist from the University of Zurich and his international team have compiled a list of the numerous possibilities as to how parasites can interact: They are most likely to do so indirectly via the food source they share.
Over 1,400 species of parasites – viruses, bacteria, fungi, intestinal worms and protozoa – are able to infect humans. In most cases, the right medicine against a parasite cures the patient.
If he or she suffers from an infection by two or more species of parasite at the same time, however, it soon be-comes more difficult to diagnose and treat. Medication can even exacerbate the medical condition if one pathogen is killed off but the second flourishes. One reason is the little-understood interactions between the parasites that reside in the same host.
In a study published in Proceedings of Royal Society B, an international team of researchers including Professor Owen Petchey from the Institute of Evolutionary Biology and Environmental Studies at the University of Zurich presents a network that explains how different pathogens and parasite groups mutually influence each other in the human body.
Surprisingly, the biologists discovered that the par-asites are most likely to interact via the food source they share – not the immune response or directly through contact with other parasites.
Complex overview with clear patterns
Co-infections are very common: Simultaneous infestations by different intestinal worms, for instance, affect around 800 million people worldwide. In order to develop effective treatment approaches for co-infections, says Owen Petchey, we need to understand the structures of the parasite communities in a host – in this case individual humans – and the interactions between the parasites better.
The ecolthen analyzed over 2,900 combinations of all these factors in an unprecedented manner.
The network displays clear patterns: The infected part of the body and the same food resource are the most common contact points that can lead to an interaction between the different parasites. “We found twice as many parasites fighting for the same energy source as parasites that elicit the same immune response and are able to interact in that way,” explains Petchey.
The manner in which the immune system responds to the individual pathogens seems to be of secondary importance, despite the fact that other studies pointed towards precisely this. The direct influence from one parasite to the next is also rarer, with the exception of HIV, Staphilococcus aureus and the Hepatitis C virus, which are known to interact directly with other pathogens.
Personalized medicine in the spotlight
The network-like overview of the various interactions of parasites that can harm humans goes beyond the usual consideration of parasite pairs. “These results can serve as a basis for the development of new, personalized treatment schemes for infected patients,” Petchey hopes. The biologist is currently testing his hypotheses of this synthesis study with different organisms.
Emily C. Griffiths, Amy B. Pedersen, Andy Fenton and Owen L. Petchey. Analysis of a summary net-work of co-infection in humans reveals that parasites interact most via shared resources. Proceedings of Royal Society B, March 12, 2014. Doi: 10.1098/rspb.2013.2286
Prof. Owen Petchey
Institute of Evolutionary Biology and Environmental Studies
University of Zurich
Tel. +41 44 635 47 70
University of Zurich
Tel. +41 44 634 44 39
Bettina Jakob | Universität Zürich
Pathogenic bacteria hitchhiking to North and Baltic Seas?
22.07.2016 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Unconventional quasiparticles predicted in conventional crystals
22.07.2016 | Max-Planck-Institut für Chemische Physik fester Stoffe
Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.
Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...
Breakup of continents with two speed: Continents initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. The final speed can be up to 20 times faster than in the first, slow extension phase.phases
Present-day continents were shaped hundreds of millions of years ago as the supercontinent Pangaea broke apart. Derived from Pangaea’s main fragments Gondwana...
Scaffolding and specialised workers help with the delivery – Heidelberg biochemists gain new insights into biogenesis
A type of scaffolding on which specialised workers ply their trade helps in the manufacturing process of the two subunits from which the ribosome – the protein...
Scientists at the Helmholtz Zentrum München have developed a new mass spectrometry imaging method which, for the first time, makes it possible to analyze hundreds of metabolites in fixed tissue samples. Their findings, published in the journal Nature Protocols, explain the new access to metabolic information, which will offer previously unexploited potential for tissue-based research and molecular diagnostics.
In biomedical research, working with tissue samples is indispensable because it permits insights into the biological reality of patients, for example, in...
Chemists at the University of Basel have succeeded in using computer simulations to elucidate transient structures in proteins. In the journal Angewandte Chemie, the researchers set out how computer simulations of details at the atomic level can be used to understand proteins’ modes of action.
Using computational chemistry, it is possible to characterize the motion of individual atoms of a molecule. Today, the latest simulation techniques allow...
15.07.2016 | Event News
15.07.2016 | Event News
11.07.2016 | Event News
22.07.2016 | Information Technology
22.07.2016 | Physics and Astronomy
22.07.2016 | Life Sciences