Abstract
Endemic infections with the common avian pathogen Salmonella enterica subspecies enterica serovar Typhimurium (Salmonella Typhimurium) may incur a significant cost on the host population. In this study, we determined the potential of endemic Salmonella infections to reduce the reproductive success of blue (Cyanistes caeruleus) and great (Parus major) tits by correlating eggshell infection with reproductive parameters. The fifth egg of each clutch was collected from nest boxes in 19 deciduous forest fragments. Out of the 101 sampled eggs, 7 Salmonella Typhimurium isolates were recovered. The low bacterial prevalence was reflected by a similarly low serological prevalence in the fledglings. In this study with a relatively small sample size, presence of Salmonella did not affect reproductive parameters (egg volume, clutch size, number of nestlings and number of fledglings), nor the health status of the fledglings. However, in order to clarify the impact on health and reproduction a larger number of samples have to be analyzed. Phage typing showed that the isolates belonged to the definitive phage types (DT) 193 and 99, and multi-locus variable number tandem repeat analysis (MLVA) demonstrated a high similarity among the tit isolates, but distinction to human isolates. These findings suggest the presence of passerine-adapted Salmonella strains in free-ranging tit populations with host pathogen co-existence.
Highlights
Infectious diseases pose an increasing threat to wildlife
Once birds are infected with this bacterium, it can be passed to their eggs during egg formation or during and after oviposition through eggshell contamination from the colonized gut or contaminated faeces [20]
To test whether Salmonella Typhimurium impacts upon reproductive parameters, these parameters were specified as dependent variables in linear mixed model (LMM) with as fixed effects presence or absence of Salmonella Typhimurium, fragment area, laying date and tree diversity
Summary
Infectious diseases pose an increasing threat to wildlife. Worldwide, Salmonella is one of the most important bacterial pathogens [1], affecting reptiles, birds and mammals [2,3,4,5,6,7,8,9]. Once birds are infected with this bacterium, it can be passed to their eggs during egg formation (vertical transmission) or during and after oviposition through eggshell contamination from the colonized gut or contaminated faeces (horizontal transmission) [20] Within this serovar, the phage types DT40, DT41, DT56, and DT160 are potentially adapted to passerines and can result in endemic or context-driven epizootic infections [3, 16]. The poorly known and less obvious infections with host adapted strains have been suggested to have a profound impact on the birds’ reproductive success [18, 21,22,23,24,25,26]. We correlated Salmonella presence on the birds’ eggs and Salmonella seroprevalence in fledglings with health and reproduction parameters
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
