Characterisation of Bergeyella spp. isolated from the nasal cavities of piglets

Abstract

The aim of this study was to characterise bacteria in the genus Bergeyella isolated from the nasal passages of healthy piglets. Nasal swabs from 3 to 4 week-old piglets from eight commercial domestic pig farms and one wild boar farm were cultured under aerobic conditions. Twenty-nine Bergeyella spp. isolates were identified by partial 16S rRNA gene sequencing and 11 genotypes were discriminated by enterobacterial repetitive intergenic consensus (ERIC)-PCR. Bergeyella zoohelcum and Bergeyella porcorum were identified within the 11 genotypes. Bergeyella spp. isolates exhibited resistance to serum complement and phagocytosis, poor capacity to form biofilms and were able to adhere to epithelial cells. Maneval staining was consistent with the presence of a capsule. Multiple drug resistance (resistance to three or more classes of antimicrobial agents) was present in 9/11 genotypes, including one genotype isolated from wild boar with no history of antimicrobial use. In conclusion, Bergeyella spp. isolates from the nasal cavities of piglets showed some in vitro features indicative of a potential for virulence. Further studies are necessary to identify the role of Bergeyella spp. in disease and within the nasal microbiota of pigs.

Sow Contact Is a Major Driver in the Development of the Nasal Microbiota of Piglets

“…In agreement, some genera such as Moraxella, Rothia and Staphylococcus, have been identified in teat skin and tonsils of piglets [24]. Other common members of swine microbiota, such as Porphyromonas and Flavobacteriaceae (Bacteroidetes) [31,32], Corynebacterium (Actinobacteria) [15,24], Neisseriaceae (Proteobacteria) [24] and Treponema (Spirochaetes) [31] or Bergeyella [33], Haemophilus [18,24] and Mycoplasma [22,34], were also identified as sowderived in BSL3 samples, as they were found in the core microbiota of piglets that had contact with their sows. In contrast, an increase in Firmicutes and Bacteroidetes was found in the groups with no or limited contact with their sows (L3-NC and L3-LC), mainly due to an increase of taxa commonly found in the gastrointestinal tract of healthy pigs, such as Lachnospiraceae, Ruminococcaceae and other taxa from the Clostridiales order [31,35,36]; or Prevotella (also found in tonsils) [31,32,37], S24-7 [38] and Bacteroides [31,32,36,39] from Bacteroidales.…”

“…Qualitative analysis showed that the longer the sow-piglet contact time was, the more common taxa were found between BSL3 and farm piglets, including swine nasal colonizers, such as Bergeyella [33], Glaesserella (Haemophilus) [18,24], and members from Moraxellaceae [15,18,24], or others found in the pig microbiota relatively abundant as Corynebacterium [15,24], Treponema [31] and Porphyromonas [31,32]. However, the reduced abundance of some taxa containing potential pathogens in L3-FC compared to FB-FR, such as Pasteurellaceae [15,18,24], Bergeyella [33], or Mycoplasma [22,34], may reflect the effect of the high biosecurity facilities as compared to the farm group. Noteworthy, Enhydrobacter was found in higher relative abundance in L3-FC compared to the nasal core microbiota from healthy farms [18].…”

Antimicrobial removal on piglets promotes health and higher bacterial diversity in the nasal microbiota

“…Although there is no available confirmation that Bergeyella can be pathogenic to pigs, some species has been associated to human septicaemia and endocarditis 24 . Experimental support to the putative pathogenicity of Bergeyella in pigs has been obtained in in vitro studies with nasal isolates from this bacterial genus 25 . The reduction in the abundance of pathogens reported may be the result of direct competition of the microbiota against pathogen colonization or indirectly by an improved maturation of the immune system 11 .…”

Feed additives for the control of post-weaning Streptococcus suis disease and the effect on the faecal and nasal microbiota

“…Regarding major changes in nasal microbial composition after weaning, we found the same Bacteroides and Prevotella inverse apparent association observed in the faeces. Remarkably, several genera associated to health (such as Lachnospira and Blautia from Lachnospiraceae, and Faecalibacterium and Ruminococcus from Ruminococcaceae) relatively increased, probably promoting the immune and anti-stress functions 29 , while Bergeyella and Fusobacterium, which have been associated to disease [30][31][32] , showed to relatively decrease over time.…”