Rumen microbiome structure and metabolites activity in dairy cows with clinical and subclinical mastitis

Abstract

Background Due to the high prevalence and complex etiology, bovine mastitis (BM) is one of the most important diseases to compromise dairy cow health and milk quality. The shift in milk compositions has been widely investigated during mastitis, but recent studies suggested that gastrointestinal microorganism also has a crucial effect on the inflammation of other peripheral tissues and organs, including the mammary gland. However, research focused on the variation of rumen inner-environment during mastitis is still limited. Therefore, the ruminal microbial profiles, metabolites, and milk compositions in cows with different udder health conditions were compared in the present study. Furthermore, the correlations between udder health status and ruminal conditions were investigated. Based on the somatic cell counts (SCC), California mastitis test (CMT) parameters and clinical symptoms of mastitis, 60 lactating Holstein dairy cows with similar body conditions (excepted for the udder health condition) were randomly divided into 3 groups (n = 20 per group) including the healthy (H) group, the subclinical mastitis (SM) group and the clinical mastitis (CM) group. Lactation performance and rumen fermentation parameters were recorded. And rumen microbiota and metabolites were also analyzed via 16S rRNA amplicon sequencing and untargeted metabolomics, respectively. Results As the degree of mastitis increased, rumen lactic acid (LA) (P < 0.01), acetate, propionate, butyrate, valerate (P < 0.001), and total volatile fatty acids (TVFAs) (P < 0.01) concentrations were significantly decreased. In the rumen of CM cows, the significantly increased bacteria related to intestinal and oral inflammation, such as Lachnospiraceae (FDR-adjusted P = 0.039), Moraxella (FDR-adjusted P = 0.011) and Neisseriaceae (FDR-adjusted P = 0.036), etc., were accompanied by a significant increase in 12-oxo-20-dihydroxy-leukotriene B4 (FDR-adjusted P = 5.97 × 10− 9) and 10beta-hydroxy-6beta-isobutyrylfuranoeremophilane (FDR-adjusted P = 3.88 × 10− 10). Meanwhile, in the rumen of SM cows, the Ruminiclostridium_9 (FDR-adjusted P = 0.042) and Enterorhabdus (FDR-adjusted P = 0.043) were increased along with increasing methenamine (FDR-adjusted P = 6.95 × 10− 6), 5-hydroxymethyl-2-furancarboxaldehyde (5-HMF) (FDR-adjusted P = 2.02 × 10− 6) and 6-methoxymellein (FDR-adjusted P = 2.57 × 10− 5). The short-chain fatty acids (SCFAs)-producing bacteria and probiotics in rumen, including Prevoterotoella_1 (FDR-adjusted P = 0.045) and Bifidobacterium (FDR-adjusted P = 0.035), etc., were significantly reduced, with decreasing 2-phenylbutyric acid (2-PBA) (FDR-adjusted P = 4.37 × 10− 6). Conclusion The results indicated that there was a significant shift in the ruminal microflora and metabolites associated with inflammation and immune responses during CM. Moreover, in the rumen of cows affected by SM, the relative abundance of several opportunistic pathogens and the level of metabolites which could produce antibacterial compounds or had a competitive inhibitory effect were all increased.

Application of Metabolomics in Diagnosis of Cow Mastitis: A Review

“…A study on rumen microbes with cow mastitis revealed that the infected degree of udder. The concentrations of lactic acid, acetate, propionate, butyrate, valerate, and total volatile fatty acids in rumen were significantly decreased (63). Bacteria associated with intestinal inflammation and oral inflammation are significantly increased in the rumen of dairy cows with clinical mastitis.…”

“…Bacteria associated with intestinal inflammation and oral inflammation are significantly increased in the rumen of dairy cows with clinical mastitis. The ruminiclostridium_9 and enterorhabdus were increased with the increasing of methenamine, 5-hydroxymethyl-2-furancarboxaldehyde (5-HMF) and 6-methoxymellein in the rumen of subclinical mastitis (63). In addition, the bacteria and probiotics produced by shortchain fatty acids (SCFAs) in rumen were significantly reduced with decreasing of 2-phenylbutyric acid (2-PBA) (63).…”

“…The ruminiclostridium_9 and enterorhabdus were increased with the increasing of methenamine, 5-hydroxymethyl-2-furancarboxaldehyde (5-HMF) and 6-methoxymellein in the rumen of subclinical mastitis (63). In addition, the bacteria and probiotics produced by shortchain fatty acids (SCFAs) in rumen were significantly reduced with decreasing of 2-phenylbutyric acid (2-PBA) (63). Zhong et al (96) compared the rumen changes of high and low SCC in cow and found that cows with higher SCC (3 × 10 6 /mL) had lower milk yield, poorer milk composition content, reduced rumen VFA concentrations and higher rumen bacterial diversity.…”

Full-Length SSU rRNA Gene Sequencing Allows Species-Level Detection of Bacteria, Archaea, and Yeasts Present in Milk

“…As our study design was intended to be a proof-of-principle concerning a species-level detection of potentially pathogenic bacteria in milk, we assessed whether we could find such species in our dataset. However, these bacteria could also be simple contaminants, as previously reported [12,14,[46][47][48][49]. Nevertheless, in many of those previously performed studies, short-amplicon sequencing strategies were applied targeting either V1-V2, V3-V4 or V4 alone.…”

The Raw Milk Microbiota from Semi-Subsistence Farms Characteristics by NGS Analysis Method

“…The contamination of milk with bacteria mainly results from poorly cleaned and poorly disinfected milking equipment, lack of hygiene during milking or handling of the milk, and bacteria present in the barn. Moreover, the presence of environmental pathogens such as Escherichia coli , Klebsiella spp., Streptococcus dysgalactiae and Streptococcus uberis may contribute to the development of mastitis in dairy cattle, which is an “occupational disease” of high-yielding dairy cows [ 5 , 6 ]. The disease is caused by bacteria and other microorganisms that enter the teats.…”