Use of Syzygium cumini (L.) ethanol extract against bacteria from bovine mastitis

Mastitis is an inflammation of the mammary gland caused by microorganisms, usually bacteria, which invade the udder, multiply and produce toxins that are harmful to the mammary gland. Clinical mastitis signs include secretion abnormal, swollen, fever, rapid pulse, loss of appetite, dehydration and death may occur. Although mastitis causes several economic losses for producers, there are very few experimental studies, which validate the therapeutic properties of medicinal plants as alternative control of this disease. Here, bacteria obtained from udder of different clinical cases of mastitis in cows were cultured in appropriate culture media and tested by in vitro assay using ethanol extract from Syzygium cumini leaves (after preliminary screening using other plants) as potential antibiotic. Staphylococcus, Streptococcus and Corynebacterium strains were employed in these assays of agar diffusion method (Kirby Bauer modified). We used 30 microliters of concentrated ethanol extract of S. cumini in all tests. After 24h, growing inhibition halo of 13 mm was observed in Staphylococcus coagulase positive; 10 mm in Staphylococcus aureus and 11 mm in Staphylococcus intermedius. Strains of Corynebacterium were no inhibited by the extract and only a growth attenuation halo of 13 mm was observed when we used this strain. Frequent antibiotic use puts selective pressure on bacteria, and causes resistance to spread. The emergence of antibiotic resistance creates a new challenge for animal health, and there is no simple solution. Thus, the discovery of new natural antibiotics with different mechanisms of action becomes an interesting alternative arm in the fight against bacterial infections.