Biofilm Profile of Coagulase Negative Staphylococci Bacteria from Milk Isolate of Dairy Cows with Subclinical Mastitis

Staphylococcus sp. is a pathogenic bacteria that causes subclinical mastitis. These bacteria are divided into coagulase-negative Staphylococci (CoNS) and coagulase-positive Staphylococci (CoPS). CoNS bacteria are a group of normal flora on human and animal skin. However, several studies have proven that CoNS bacteria are the most commonly isolated microorganisms from the milk of dairy cows with subclinical mastitis. The ability to form biofilms is an important virulence factor for CoNS bacteria. Detection of biofilm formation was carried out on 54 samples of CoNS bacteria in the form of Stored Biological Material (BBT), which were isolated from the milk of dairy cows with subclinical mastitis with positive California mastitis test (CMT) 2 (++). Detection of biofilm formation was performed qualitatively by Congo red agar (CRA) and test tube (TT) methods. Phenotypic confirmation results showed that 54 isolates (100%) were CoNS bacteria. Biofilm formation detection results showed that 51 out of 54 isolates (94.44%) were positive for biofilm formation. Thus, it can be concluded that CoNS bacteria have the ability to form biofilms as a form of self-protection and virulence factor.