Subacute ruminal acidosis (SARA) represents one of the most important metabolic subclinical disordersof high producing dairy cows, having serious impact in both animal health and herd profitability. The aim ofthis study was to confirm the presence of SARA in Greek dairy herds and record its prevalence and riskfactors. Ruminal fluid samples, via rumenocentesis, were obtained from a total of 153 ...

Thioredoxin reductase (encoded by trxB) protects Staphylococcus aureus against oxygen or disulfide stress and is indispensable for growth. Among the different sarA family mutants analyzed, transcription of trxB was markedly elevated in the sarA mutant under conditions of aerobic as well as microaerophilic growth, indicating that SarA acts as a negative regulator of trxB expression. Gel shift an...

The objective of this study was to investigate the effect of the pattern of concentrate-rich feeding on subacute ruminal acidosis (SARA), its severity, and the corresponding changes in VFA concentration. Eight rumen-cannulated Holstein cows were assigned to a 2 × 2 crossover design with 2 SARA challenge models and 2 experimental runs ( = 8 per treatment). Each run lasted for 40 d, consisting of...

The expression of virulence determinants in Staphylococcus aureus is controlled by global regulatory loci (e.g., sarA and agr). The sar (Staphylococcus accessory regulator) locus is composed of three overlapping transcripts (sarA P1, P3, and P2, transcripts initiated from the P1, P3, and P2 promoters, respectively), all encoding the 124-aa SarA protein. The level of SarA, the major regulatory p...

The staphylococcal accessory regulator locus (sarA) encodes a DNA-binding protein (SarA) that modulates expression of over 100 genes. Whether this occurs via a direct interaction between SarA and cis elements associated with its target genes is unclear, partly because the definitive characteristics of a SarA binding site have not been identified. In this work, electrophoretic mobility shift ass...

to estimate the prevalence of subacute ruminal acidosis (sara) in dairy cows, a total of 196 ruminalfluid samples were drawn by rumenocentesis from 10 dairy herds of khorasan razavi province, northeast ofiran. two groups of 12 cows, early lactation and mid-lactation cows were sampled in each dairy herd andruminal ph was determined immediately using a portable ph-meter. a total of 54 cows (27.6%...

The staphylococcal accessory regulator (encoded by sarA) is an important global regulator of virulence factor biosynthesis in Staphylococcus aureus. To further characterize its role in virulence determinant production, an sarA knockout mutant was created by insertion of a kanamycin antibiotic resistance cassette into the sarA gene. N-terminal sequencing of exoproteins down-regulated by sarA ide...