Fecal antibody levels as a noninvasive method for measuring immunity to gastrointestinal nematodes in ecological studies. Issue 1 (8th December 2015)

• Record Type: Journal Article
• Authors: Watt, Kathryn A.; Nussey, Daniel H.; Maclellan, Rachel; Pilkington, Jill G.; McNeilly, Tom N.
• Is Part Of: Ecology and evolution. Volume 6:Issue 1(2016:Jan.)
• Page Start: 56
• Page End: 67
• Publication Date: 2015-12-08
• Subjects: Fecal egg counts -- immunoglobulin -- Ovis aries -- Soay sheep -- strongyle nematode -- Teladorsagia circumcincta; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.1858
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Among‐individual variation in antibody‐associated immunity to gastrointestinal nematode parasites (GIN) is known be associated with life‐history traits and vital rates in wild vertebrate systems. To date, measurement of levels of antibodies against GIN antigens in natural populations has exclusively been based on invasive blood sampling techniques. Previous work in laboratory rodents and ruminant livestock suggests that antibody measures from feces may provide a viable noninvasive approach. We measured total and anti‐GIN antibodies of different isotypes (immunoglobulin (Ig) G, IgA and IgE) from paired samples of plasma and feces from free‐living Soay sheep of different ages and sexes. We tested the correlations among these measures as well as their associations with body mass and Strongyle nematode fecal egg counts (FEC). Significant positive correlations were present among plasma and fecal anti‐GIN antibody levels for IgG and IgA. Generally, correlations between total antibody levels in plasma and feces were weaker and not significant. No significant relationships were found between any antibody measures and body mass; however, fecal anti‐GIN antibody levels were significantly negatively correlated with FEC. Our data clearly demonstrate the feasibility of measuring anti‐GIN antibodies from fecal samples collected in natural populations. Although associations of fecal antibody levels with their plasma counterparts and FEC were relatively weak, the presence of significant correlations in the predicted direction in a relatively small and heterogeneous sample suggests fecal antibody measures could be a useful, noninvasive addition to current eco‐immunological studies. Abstract : The aim of this study was to determine whether measurement of parasite‐specific antibodies within fecal samples was a useful non‐invasive method of assessing immunity to gastro‐intestinal nematodes in natural populations. Using paired plasma and fecal samples from a wild population of sheep, we demonstrate that parasite‐specific antibodies within plasma and feces are positively correlated, and that levels of anti‐parasite antibodies within the feces are negatively correlated with parasite fecal egg count (FEC). The presence of detectable correlations in the predicted direction suggests fecal antibody measures could be a useful, non‐invasive addition to current eco‐immunological studies.