DETECTION OF BIOFILM PRODUCTION BY STAPHYLOCOCCUS AUREUS AND IN-VITRO INHIBITION OF BIOFILM USING SERUM ANTIBODIES

The biofilm producing ability of Staphylococcus aureus has been implicated for development of different diseases in animals and humans. The presence of biofilms makes the bacterial population resistant to a wide range of antibiotics. Biofilms are also antigenic structures of the bacterial population. Therefore, the present study was planned to evaluate the biofilm-producing ability of S. aureus and in-vitro inhibition of biofilm production using serum samples from rabbits immunized with biofilm-producing S. aureus bacterin-toxoid. A total of 64 S. aureus isolates were harvested from lactating cows and buffaloes suffering from clinical and sub-clinical mastitis. The biofilm-producing ability of S. aureus isolates was determined by tube method and micro-plate assays. The rabbits were vaccinated using strong biofilm producing S. aureus bacterin-toxoid. The ability of serum antibodies to inhibit in-vitro biofilm production was assessed by performing a biofilm inhibition assay. The results showed that 71.87% and 56.25% of the isolates were positive for biofilm production in tube method and micro-plate assays, respectively. T he serum samples collected at days 30, 45 and 60 post-immunization completely inhibited the biofilm production by S. aureus. Our results suggested that both micro-plate assay and tube method can be used for determination of biofilm production, however micro-plate assay is quantitative, more accurate and reliable. The study also concluded that the antibodies produced against biofilm producing S. aureusbacterin-toxoid seems helpful to avert the attachment of bacteria, which may further implicate the better control of chronic infections