• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of procbhomepageaboutsubmitalertseditorial board
Proc Biol Sci. Apr 22, 2004; 271(1541): 785–788.
PMCID: PMC1691666

Interference competition and parasite virulence.

Abstract

Within-host competition between parasites, a consequence of infection by multiple strains, is predicted to favour rapid host exploitation and greater damage to hosts (virulence). However, the inclusion of biological variables can drastically change this relationship. For example, if competing parasite strains produce toxins that kill each other (interference competition), their growth rates and virulence may be reduced relative to single-strain infections. Bacteriocins are antimicrobial toxins produced by bacteria that target closely related strains and species, and to which the producing strain is immune. We investigated competition between bacteriocin-producing, insect-killing bacteria (Photorhabdus and Xenorhabdus) and how this competition affected virulence in caterpillars. Where one strain could kill the other, and not vice versa, the non-killing strain was competitively excluded, and insect mortality was the same as that of the killing strain alone. However, when caterpillars were multiply infected by strains that could kill each other, we did not observe competitive exclusion and their virulence was less than single-strain infections. The ubiquity and diversity of bacteriocins among pathogenic bacteria suggest mixed infections will be, on average, less virulent than single infections.

Full Text

The Full Text of this article is available as a PDF (358K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Bremermann HJ, Pickering J. A game-theoretical model of parasite virulence. J Theor Biol. 1983 Feb 7;100(3):411–426. [PubMed]
  • Brown Sam P, Hochberg Michael E, Grenfell Bryan T. Does multiple infection select for raised virulence? Trends Microbiol. 2002 Sep;10(9):401–405. [PubMed]
  • Chao L, Hanley KA, Burch CL, Dahlberg C, Turner PE. Kin selection and parasite evolution: higher and lower virulence with hard and soft selection. Q Rev Biol. 2000 Sep;75(3):261–275. [PubMed]
  • Cohan Frederick M. What are bacterial species? Annu Rev Microbiol. 2002;56:457–487. [PubMed]
  • Czárán Tamás L, Hoekstra Rolf F. Killer-sensitive coexistence in metapopulations of micro-organisms. Proc Biol Sci. 2003 Jul 7;270(1522):1373–1378. [PMC free article] [PubMed]
  • Czárán Tamás L, Hoekstra Rolf F, Pagie Ludo. Chemical warfare between microbes promotes biodiversity. Proc Natl Acad Sci U S A. 2002 Jan 22;99(2):786–790. [PMC free article] [PubMed]
  • Davies CM, Fairbrother E, Webster JP. Mixed strain schistosome infections of snails and the evolution of parasite virulence. Parasitology. 2002 Jan;124(Pt 1):31–38. [PubMed]
  • Durrett R, Levin S. Allelopathy in Spatially Distributed Populations. J Theor Biol. 1997 Mar 21;185(2):165–171. [PubMed]
  • Forst S, Dowds B, Boemare N, Stackebrandt E. Xenorhabdus and Photorhabdus spp.: bugs that kill bugs. Annu Rev Microbiol. 1997;51:47–72. [PubMed]
  • Frank SA. A kin selection model for the evolution of virulence. Proc Biol Sci. 1992 Dec 22;250(1329):195–197. [PubMed]
  • Frank SA. Models of parasite virulence. Q Rev Biol. 1996 Mar;71(1):37–78. [PubMed]
  • Herre EA. Population structure and the evolution of virulence in nematode parasites of fig wasps. Science. 1993 Mar 5;259(5100):1442–1445. [PubMed]
  • Kerr Benjamin, Riley Margaret A, Feldman Marcus W, Bohannan Brendan J M. Local dispersal promotes biodiversity in a real-life game of rock-paper-scissors. Nature. 2002 Jul 11;418(6894):171–174. [PubMed]
  • Pagie L, Hogeweg P. Colicin diversity: a result of eco-evolutionary dynamics. J Theor Biol. 1999 Jan 21;196(2):251–261. [PubMed]
  • Riley Margaret A, Wertz John E. Bacteriocins: evolution, ecology, and application. Annu Rev Microbiol. 2002;56:117–137. [PubMed]
  • Riley MA, Goldstone CM, Wertz JE, Gordon D. A phylogenetic approach to assessing the targets of microbial warfare. J Evol Biol. 2003 Jul;16(4):690–697. [PubMed]
  • Schjørring Solveig, Koella Jacob C. Sub-lethal effects of pathogens can lead to the evolution of lower virulence in multiple infections. Proc Biol Sci. 2003 Jan 22;270(1511):189–193. [PMC free article] [PubMed]
  • Sharma Sadhana, Waterfield Nicholas, Bowen David, Rocheleau Thomas, Holland Lisa, James Richard, ffrench-Constant Richard. The lumicins: novel bacteriocins from Photorhabdus luminescens with similarity to the uropathogenic-specific protein (USP) from uropathogenic Escherichia coli. FEMS Microbiol Lett. 2002 Sep 10;214(2):241–249. [PubMed]
  • Turner PE, Chao L. Prisoner's dilemma in an RNA virus. Nature. 1999 Apr 1;398(6726):441–443. [PubMed]
  • Waterfield Nicholas R, Daborn Phillip J, Dowling Andrea J, Yang Guowei, Hares Michelle, ffrench-Constant Richard H. The insecticidal toxin makes caterpillars floppy 2 (Mcf2) shows similarity to HrmA, an avirulence protein from a plant pathogen. FEMS Microbiol Lett. 2003 Dec 12;229(2):265–270. [PubMed]
  • West Stuart A, Buckling Angus. Cooperation, virulence and siderophore production in bacterial parasites. Proc Biol Sci. 2003 Jan 7;270(1510):37–44. [PMC free article] [PubMed]

Articles from Proceedings of the Royal Society B: Biological Sciences are provided here courtesy of The Royal Society

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...