MULTI DRUG RESISTANCE PROFILE AND ANTIBIOFILM ACTIVITY OF GARLIC OIL ON STAPHYLOCOCCUS AUREUS ISOLATED FROM MILK OF CATTLE SUFFERING WITH MASTITIS

Abstract

The present study was undertaken on 164 bovine milk samples (cow = 113 and Buffalo = 51) collected from various dairy farms in and around Rewa (Madhya Pradesh, India) and only 24 samples (6.83%) were found to be positive for mastitis when screened through California Mastitis Test (CMT). The prevalence of subclinical mastitis in cattle was 21%. All 17 isolates were phenotypically characterized by mannitol fermentation, biochemical tests (acetoin production by Voges-Proskauer test), beta-galactosidase test susceptibility to novobiocin (5 µ µµg disk), resistance to polymyxin B (300 µg disk). We also observed the biofilm formation ability of all the Staphylococcus aureus strains (n=17) by Congo Red Agar (CRA), Microtiter plate (using crystal violet), and light microscopy method, 90% sensitivity was seen through microtiter plate method. Antibiofilm activity of garlic oil was undertaken on positive isolates (3%, 2%, and 1% concentration) along with positive and negative control in every microtiter plate assay. Maximum inhibition was observed at 3% concentration with O.D values ranging from 0.021±0.007 to 0.291 ± 0.005 in all the samples with percent inhibition (50 to 60%). Multi-drug resistance profiles of biofilm-producing isolates were also undertaken against polymyxin, novobiocin, tetracyclines, cotrimoxazole, clindamycin, cefoxitin, and cefoperazone. Eighty-two (82) percent of isolates showed resistance against polymyxin, 52% against novobiocin and erythromycin, and all the isolates showed 100% sensitivity against tetracyclines and cefoxitin.

Keywords

• biofilm
• bovines
• garlic oil
• mastitis
• milk
• microtiter plate assay