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Bovine mastitis is an inflammation of the mammary glands of cows and causes significant economic losses in dairy cattle. Staphylococcus aureus is one of the microorganisms most commonly isolated. Novel agents are required in agricultural industries to prevent the development of mastitis. The production of biofilm by Staph. aureus facilitates the adhesion of bacteria to solid surfaces and contributes to the transmission and maintenance of these bacteria. The effect of the essential oils of Syzygium aromaticum (clove; EOSA) and Cinnamomum zeylanicum (cinnamon; EOCZ) and their major components, eugenol and cinnamaldehyde, on Staph. aureus biofilm formation on different surfaces was investigated. The results showed a significant inhibition of biofilm production by EOSA on polystyrene and stainless steel surfaces (69.4 and 63.6%, respectively). However, its major component, eugenol, was less effective on polystyrene and stainless steel (52.8 and 19.6%, respectively). Both EOCZ and its major component, cinnamaldehyde, significantly reduced biofilm formation on polystyrene (74.7 and 69.6%, respectively) and on stainless steel surfaces (45.3 and 44.9%, respectively). These findings suggest that EOSA, EOCZ, and cinnamaldehyde may be considered for applications such as sanitization in the food industry. [ABSTRACT FROM AUTHOR]

Mastitis is an important disease for the dairy industry worldwide, causing economic losses and reducing milk quality and production. Staphylococcus aureus is a worldwide agent of this intramammary infection, which also causes foodborne diseases. The objective of this study was to determine the frequency of methicillinsusceptible Staphylococcus aureus (MSSA) isolates in milk of mastitis cows in Brazil and to analyze the genetic lineages and the content of antimicrobial resistance genes and virulence factors among these isolates. Fifty-six MSSA isolates were recovered from 1,484 milk samples (positive for the California mastitis test) of 518 cows from 11 different farms in Brazil (representing 51% of total Staph. aureus obtained), and they were further characterized. Methicillin-susceptible Staphylococcus aureus were isolated from 3.7% of California mastitis test-positive tested milk samples and from 6.2% of tested mastitic cows. Methicillin-susceptible Staphylococcus aureus isolates were characterized by spa typing, agr typing, and multilocus sequence typing, and resistance and virulence traits were investigated by PCR. Seven spa types were identified among MSSA (% of isolates): t127 (44.6), t605 (37.5), t002, t1784, t2066 (1.8), and 2 new ones: t10856 (10.7) and t10852 (1.8). Five distinct sequence types (ST) were detected (% of isolates): ST1 (46.4), ST126 (37.5), ST133 (10.7), ST5 (3.6), and a novel ST registered as ST2493 (1.8). Resistances were detected for streptomycin, chloramphenicol, and tetracycline. One strain contained the chloramphenicol resistance gene (fexA; included within transposon Tn558) and 3 strains contained the tetracycline resistance gene [tet(K)]. Methicillin-susceptible Staphylococcus aureus strains were susceptible to most of the antibiotics studied and lacked the virulence genes of Panton-Valentine leukocidin (lukF/S-PV), toxic shock syndrome toxin 1 (tst), exfoliative toxin A (eta), and exfoliative toxin B (etb), as well as the genes of the immune evasion cluster. Methicillin-susceptible Staphylococcus aureus isolates were detected in a relatively low proportion of cows with mastitis (6.2%) and recovered isolates presented high diversity of genetic lineages, with CC1 and CC126 the predominant clonal complexes, and CC133 also being detected. Larger epidemiological studies with molecular characterization of isolates are required to deepen the knowledge on the circulating genetic lineages among the cow population with mastitis. [ABSTRACT FROM AUTHOR]

We investigated the effects of different types and doses of inoculants for ensiling rehydrated corn grain. Shelled corn was finely ground and rehydrated to 35% moisture. Treatments were as follows: (1) control (no additives); (2) Lactobacillus plantarum and Pediococcus acidilactici (LPPA) at a theoretical application rate of 1 × 10 5 cfu/g; (3) LPPA at 5 × 10 5 cfu/g; (4) LPPA at 1 × 10 6 cfu/g; (5) Lactobacillus buchneri (LB) at 1 × 10 5 cfu/g; (6) LB at 5 × 10 5 cfu/g; and (7) LB at 1 × 10 6 cfu/g. We detected no effect of inoculant dose. Gas losses were greater in silages treated with LB compared with control and LPPA silages. Treating silages with LB reduced the concentrations of lactic acid and ethanol and increased silage pH and concentrations of acetic acid, propionic acid, and 1,2-propanediol. At silo opening, silages treated with LB had higher counts of lactic acid bacteria but lower yeast counts than the control silage. Aerobic stability was greater for silages treated with LB and lower for silages treated with LPPA compared with the control. The LB reduced dry matter (DM) losses during aerobic exposure, whereas LPPA increased them. Prolamin content was lower in silages treated with LB compared with the control, resulting in greater ruminal in situ DM degradability. Inoculating LB to a dose of 1 × 10 5 cfu/g increased aerobic stability and ruminal in situ DM degradability of rehydrated corn grain silage. The addition of LPPA did not alter the fermentation process and worsened the aerobic stability of rehydrated corn grain silage. Further studies are warranted to confirm these conclusions in other corn hybrids, inoculants, and their combinations., (Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)