Uterine Microbiota and Immune Parameters Associated with Fever in Dairy Cows with Metritis.
OBJECTIVE
This study aimed to evaluate bacterial and host factors causing a fever in cows with metritis. For that, we investigated uterine microbiota using a metagenomic sequencing of the 16S rRNA gene (Study 1), and immune response parameters (Study 2) in metritic cows with and without a fever.
Bacterial communities were similar between the MNoFever and MFever groups based on distance metrics of relative abundance of bacteria. Metritic cows showed a greater prevalence of Bacteroidetes, and Bacteroides and Porphyromonas were the largest contributors to that difference. A comparison of relative abundance at the species level pointed to Bacteroides pyogenes as a fever-related species which was significantly abundant in the MFever than the MNoFever and Healthy groups; however, absolute abundance of Bacteroides pyogenes determined by droplet digital PCR (ddPCR) was similar between MFever and MNoFever groups, but higher than the Healthy group. The same trend was observed in the total number of bacteria.
The activity of polymorphonuclear leukocyte (PMN) and the production of TNFα, PGE2 metabolite, and PGE2 were evaluated in serum, before disease onset, at 0 and 3 DPP. Cows in the MNoFever had decreased proportion of PMN undergoing phagocytosis and oxidative burst compared with the MFever. The low PMN activity in the MNoFever was coupled with the low production of TNFα, but similar PGE2 metabolite and circulating PGE2.


CONCLUSIONS
Our study is the first to show a similar microbiome between metritic cows with and without a fever, which indicates that the host response may be more important for fever development than the microbiome. Bacteroides pyogenes was identified as an important pathogen for the development of metritis but not fever. The decreased inflammatory response may explain the lack of a febrile response in the MNoFever group.
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America.
Soo Jin
SJ
Jeon
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America.
Federico
F
Cunha
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America.
Xiaojie
X
Ma
Department of Animal Sciences, University of Florida, Gainesville, Florida, United States of America.
Natalia
N
Martinez
Department of Animal Sciences, University of Florida, Gainesville, Florida, United States of America.
Achilles
A
Vieira-Neto
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America.
Rodolfo
R
Daetz
Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, United States of America.
Rodrigo C
RC
Bicalho
Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, United States of America.
Svetlana
S
Lima
Department of Animal Sciences, University of Florida, Gainesville, Florida, United States of America.
Jose E P
JE
Santos
Department of Animal Sciences, University of Florida, Gainesville, Florida, United States of America.|Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.
K Casey
KC
Jeong
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America.|D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville, Florida, United States of America.
Klibs N
http://orcid.org/0000-0002-6683-4476
KN
Galvão
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases; D003612:Dairying; D005260:Female; D005334:Fever / Q000150:complications / Q000276:immunology* / Q000382:microbiology*; D064307:Microbiota; D016897:Respiratory Burst; D014599:Uterus / Q000276:immunology* / Q000382:microbiology*