Bacteria divert resources from growth for magellanic penguin chicks

Abstract

The influence of bacteria on the growth of their wild avian hosts is unknown. We tested experimentally whether administration of a wide‐spectrum antibiotic (cephalosporine) during early development of magellanic penguin (Spheniscus magellanicus) chicks had any effect on their growth rates in the wild. Chicks that were injected in two occasions with cephalosporine grew faster than control untreated chicks. The positive effect of medication on nestling growth disappeared after the treatment ceased, did not alter haematological indices indicative of health status, had no influence on chick survival until near independence and was related to a changed bacterial composition of the faecal microbiota of treated chicks when compared with that from control chicks. These results were similar to those obtained for poultry with antimicrobials promoting growth and chick nutrient assimilation rates. Gram‐positive bacilli in the diphtheroid genus Corynebacterium are likely candidates to cause decreased growth rates in magellanic penguin chicks.

Age-related changes in abundance of enterococci and Enterobacteriaceae in Pied Flycatcher (Ficedula hypoleuca) nestlings and their association with growth

“…Knowledge about the prevalence of bacteria in natural avian populations is limited, and their effects on the general health of wild birds are poorly understood. Recently, bird-bacteria interactions have received much attention, as shown by studies on the effect of bacteria on avian growth (Lombardo et al 1996;Lucas and Heeb 2005;Mills et al 1999;Moreno et al 2003;Potti et al 2002), their association with sexually transmitted diseases (Kulkarni and Heeb 2007;Lombardo et al 1996;Poiani and Wilks 2000), their degradation of feathers Ichida 1999, 2004;Goldstein et al 2004;Gunderson et al 2009;Ruiz-Rodríguez et al 2009c), the effect of nest sanitation on bacteria (Mennerat et al 2009;Peralta-Sánchez et al 2010) and uropygial gland secretions as antimicrobial defences (Martín-Vivaldi et al 2010;Møller et al 2009;Shawkey et al 2003;Soler et al 2008).…”

“…However, the information concerning gut bacterial communities in natural avian populations is scant and information concerning the development of these communities during the period of nestling growth extremely limited. Most previous studies have sampled bacterial communities in chicks only once, just before fledging (Berger et al 2003;Lombardo et al 1996;Lucas and Heeb 2005;Moreno et al 2003;Potti et al 2002). However, Mills et al (1999) detected cloacal microbes shortly after nestlings hatched and found that the nestlings were colonized by more types of microbes as they got older, indicating that development of gut microbial communities occurs gradually after hatching.…”

“…There is some evidence for negative correlations of intestinal bacteria with nestling growth rate in the wild (Lombardo et al 1996;Mills et al 1999;Potti et al 2002). In the only experimental study on the effects of bacteria on growth in wild birds, Potti et al (2002) observed that Magellanic Penguin Spheniscus magellanicus chicks that were treated with a wide-spectrum antibiotic grew faster than control chicks which were not treated.…”

Environmental Factors Shape the Community of Symbionts in the Hoopoe Uropygial Gland More than Genetic Factors

“…Previous studies have shown that the dominant group of cultivable bacteria in the UGS of hoopoes belongs to the genus Enterococcus (14,35,36) and that some isolated strains from hoopoes produce compounds with strong antagonistic activity against other bacterial species (15,16). Enterococci are common bacteria that can be found in soil and plants (37,38) or in the gastrointestinal tract of birds (39,40) and could therefore be easily acquired from different sources. Moreover, it is known that the antimicrobial properties of different Enterococcus bacterial strains harbored by hoopoes differ and that those with broader antimicrobial spectra are the most common in the UGS of hoopoes (35,36).…”

A place for host–microbe symbiosis in the comparative physiologist's toolbox

“…Unfortunately, generating germ-free animals can be highly challenging for studies with non-laboratory terrestrial vertebrates, especially if they are difficult to maintain or manipulate in captivity, or the question of interest must be asked and studied in the field. That said, microbial transplants have been performed between wild-caught rodents (Kohl et al, 2014c) and antibiotic treatments have been administered to penguins in the field (Potti et al, 2002). Creative solutions tailored to specific study systems will be required to advance our knowledge of how hostmicrobiome symbioses affect the physiology, ecology and evolution of individual animals and their populations.…”