Antibacterial properties of contact defensive secretions in neotropical Crematogaster ants

Quinet Y (1), Vieira RHSF (2), Sousa MR (3), Evangelista-Barreto NS (3), Carvalho FCT (2), Guedes MIF (3), Alves CR (3), de Biseau JC (4), Heredia A (1)

(1) Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará State, Brazil; (2) Institute of Marine Sciences, Federal University of Ceará, Fortaleza, Ceará State, Brazil; (3) Laboratory of Human Biochemistry, State University of Ceará, Fortaleza, Ceará State, Brazil; (4) Evolutionary Eco-Ethology, Free University of Brussels, Brussels, Belgium.

Abstract: Crematogaster ants use their contact venoms to compete with other ants. Although those venoms are used primarily as repellent and toxic secretions, they may have other functions. The present study aimed to test the antibacterial property of abdominal venom of three neotropical Crematogaster ant species (C. distans, C. pygmaea and C. rochai) against gram-negative (Escherichia coli and Pseudomonas aeruginosa) and gram-positive (Enterococcus faecalis and Staphylococcus aureus) bacteria. Sterile filter paper was soaked with C. distans, C. pygmaea or C. rochai crude venom and placed on an agar dish that was inoculated with bacterial suspensions. The agar dish was incubated overnight at 37°C and examined for zones of growth inhibition. For each tested venom and bacterial strain, three venom concentrations were used, with six replicates for each concentration: 1, 2 and 4 DGE (Dufour’s gland equivalent). The venom of C. pygmaea, but not those of C. rochai and C. distans, inhibited the growth of all tested gram-positive and gram-negative bacterial strains. This is the first evidence of antibacterial properties of contact venoms in Crematogaster ants and it supports the claim that ant venoms are multifunctional. It is hypothesized that only C. pygmaea venom showed antibacterial activities due to its nesting habits.

Key words: Hymenoptera, Formicidae, Crematogaster, sting apparatus, contact venoms.

ACKNOWLEDGMENTS

We thank Dr. Ana Maria S. Assreuy and Dr. Yves Roisin for reviewing a draft of the manuscript and improving the English text, as well as the three anonymous reviewers whose suggestions greatly improved our manuscript.

COPYRIGHT

© CEVAP 2012

SUBMISSION STATUS

Received: April 4, 2012.

Accepted: August 20, 2012.

Abstract published online: September 3, 2012.

Full paper published online: November 30, 2012.

CONFLICTS OF INTEREST

The authors declare no conflicts of interest.

FINANCIAL SOURCE

Ana Heredia was supported by a fellowship (DCR-CNPq) and Yves Quinet by a grant from the National Council for Scientific and Technological Development (CNPq), project n. 473939/2004-5.

CORRESPONDENCE TO

Yves Patric Quinet, Av. Paranjana, 1700, Fortaleza, CE, 60740-000, Brasil. Phone: +55 85 3101 9749. Fax: +55 85 3101 9810. Email: yvesq@terra.com.br.