Effects of long-distance transportation on blood constituents and composition of the nasal microbiota in healthy donkeys

Abstract

Background This study aims to determine the effects of transportation on the nasal microbiota of healthy donkeys using 16S rRNA sequencing. Results Deep nasal swabs and blood were sampled from 14 donkeys before and after 21 hours’ long-distance transportation. The values of the plasma hormone (cortisol (Cor), adrenocorticotrophic hormone (ACTH)), biochemical indicators (total protein (TP), albumin (ALB), creatinine (CREA), lactic dehydrogenase (LDH), aspartate transaminase (AST), creatine kinase (CK), blood urea (UREA), plasma glucose (GLU)) and blood routine indices (white blood cell (WBC), lymphocyte (LYM), neutrophil (NEU), red blood cell (RBC), hemoglobin (HGB)) were measured. 16S rRNA sequencing was used to assess the nasal microbiota, including alpha diversity, beta diversity, and phylogenetic structures. Results showed that levels of Cor, ACTH, and heat-shock protein 90 (HSP90) were significantly increased (p < 0.05) after long-distance transportation. Several biochemical indicators (AST, CK) and blood routine indices (Neu, RBC, and HGB) increased markedly (p < 0.05), but the LYM decreased significantly (p < 0.05). Nine families and eight genera had a mean relative abundance over 1%. The predominant phyla in nasal microbiota after and before transportation were Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Transportation stress induced significant changes in terms of nasal microbiota structure compared with those before transportation based on principal coordinate analysis (PCoA) coupled with analysis of similarities (ANOSIM) (p < 0.05). Among these changes, a notably gain in Proteobacteria and loss in Firmicutes at the phylum level was observed. Conclusions These results suggest transportation can cause stress to donkeys and change the richness and diversity of nasal microbiota. Further studies are required to understand the potential effect of these microbiota changes on the development of donkey respiratory diseases.

Nasopharyngeal Microbiomes in Donkeys Shedding Streptococcus equi Subspecies equi in Comparison to Healthy Donkeys

“…According to the microbial composition analysis, the dominant phyla were Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes in both groups. The results of healthy donkeys in this study are comparable with Zhao's study conducted in clinically healthy donkeys with non-guarded nasal swabs (17). Similar results have also been mentioned in studies of healthy URT microbiomes in horses (37), cattle (21), humans (44), as well as in swine (45).…”

“…S. equi swabs submitted from group S for culture of S. equi were processed as previously described ( 24 ). Namely, Colombia blood agar (Huankai Microbial, Guangzhou, China) was used to streak the collected swabs for bacterial culture ( 17 ). Cultures were incubated at 37°C for 24 h. Isolates were sub-cultured two times on blood agar before being identified.…”

“…equi swabs submitted from group S for culture of S. equi were processed as previously described (24). Namely, Colombia blood agar (Huankai Microbial, Guangzhou, China) was used to streak the collected swabs for bacterial culture (17).…”

“…The harmonious coexistence of microbiota is necessary to maintain the health of the URT of animals ( 16 ). Dysbiosis of these microbial populations is associated with disruption of respiratory tract health ( 17 ) and increased risk of respiratory tract infection ( 18 ). The nasopharynx, as part of the URT, frequently harbors both commensal and pathogenic bacteria ( 19 ).…”

“…Investigation of the relationship between nasopharyngeal microbes impacted by respiratory tract diseases is anticipated to increase understanding of the pathogenesis of URT infections ( 19 ). Changes of the nasal microbial population before and after long distance transportation in clinically healthy donkeys has recently been reported ( 17 ). However, samples obtained using non-guarded swabs might be exposed to contaminants from different parts of the URT including sinuses, nostrils, and oropharynx, each colonized with its own system of microorganisms ( 20 ).…”