Development of the tonsillar microbiome in pigs from newborn through weaning

Abstract

BackgroundPorcine tonsils are lympho-epithelial tissues, colonized by numerous bacteria and viruses, that act as a reservoir for both host-specific pathogens and zoonotic pathogens with a high potential of transmission to humans. There are no existing studies describing the development of the tonsillar microbiome. We sequenced 16S rRNA genes from tonsillar samples of pigs to follow the development of the microbial communities from birth through weaning. Samples derived from sows were also analyzed to determine potential sources for the tonsil microbiome in piglets.ResultsThe composition of the newborn piglet tonsil microbiome could be differentiated by litter and had strong similarity to the sow teat skin as well as sow vaginal microbiome. The tonsil microbiome in these young piglets was mainly dominated by members of the Pasteurellaceae, Moraxellaceae, and Streptococcaceae families, while there were some transient members of the microbiome that were abundant at specific times, such as Staphylococcaceae in newborns and Fusobacteriaceae and Leptotrichiaceae in weeks 2 and 3. The microbiome initially differed between litters but over the following 3 weeks the communities of different litters converged in composition and then diverged in week 4 due to a combination of changes and stresses associated with weaning, including a shift from milk to a solid diet, in-feed Carbadox® and room change.ConclusionsA significant portion of the tonsil microbiome was acquired either at birth from the sow vaginal tract or within a few hours post-birth from the sow teat skin. Our data demonstrate a temporal succession in the development of the pig tonsillar microbiome through the first weeks of life, with a convergence in the composition of the microbiome in all piglets by 3 weeks of age. The combination of management practices associated with weaning coincided with dramatic shifts in the tonsillar microbiome.Electronic supplementary materialThe online version of this article (10.1186/s12866-018-1176-x) contains supplementary material, which is available to authorized users.

Association between oropharyngeal microbiome and weight gain in piglets during pre and post weaning life

“…However, the associations were stronger in the pre-weaning phase and appeared to wane with age implying that an attempt to improve weight gain through modulation of the microbiota should target early life of the piglet, particularly before 4 weeks of life. Our findings from the taxonomic analysis of the oropharyngeal microbiota were largely in agreement with studies focusing on the tonsillar microbiota [36,42,43]. However, the dominance of Streptococcus, in our study, was striking since it was only represented as a minor community member within the tonsils [42].…”

“…PCoA showed that the samples already clustered closely by day 11 of age regardless of maternal or foster sow, that nursed them. Pena Cortes et al [36] reported a litter effect in the tonsillar microbiota that disappeared by the third week. We did not observe this litter effect by the 11th day of life, probably due to the advancement in age of the piglets in our study compared to those in their study [36].…”

“…Pena Cortes et al [36] reported a litter effect in the tonsillar microbiota that disappeared by the third week. We did not observe this litter effect by the 11th day of life, probably due to the advancement in age of the piglets in our study compared to those in their study [36]. Further, the samples tended to clusters by age of the piglets except for 2 piglets at 26 days of age, that had been weaned 6 days earlier (Fig.…”

Development of the Tonsil Microbiome in Pigs and Effects of Stress on the Microbiome

“…In addition, 64 samples were collected from pigs after weaning, which included samples from 16 piglets at week 4 and 8 piglets (2 per sow) at all subsequent time points (Table 1 ). In a previous study ( 16 ), we found a strong litter effect on the tonsil microbiome that disappeared by 3 weeks of age; therefore, we analyzed 4 pigs per litter initially but reduced this number to 2 pigs per litter (8 in total) for subsequent sampling times.…”

“…We recently completed a study of the composition and development of the tonsil microbiome in piglets from birth up to 4 weeks of age ( 16 ). The tonsil microbial communities initially clustered by litter, but then converged by 3 weeks of age, regardless of litter or housing.…”