Detection of Biofilm Formation by Escherichia coli and Staphylococcus aureus Associated with Canine Pyometra

Abstract

Background: Antibiotic resistance is one of the major problems encountered in the therapy of canine pyometra. The ability of bacteria to form biofilm is implicated as one of the factors responsible for this. Escherichia coli and Staphylococcus aureus are the predominant bacteria associated with pyometra in canines and are known for their biofilm formation. Keeping in this view, a preliminary study was conducted to detect the biofilm forming strains of E. coli and S. aureus, if any, associated with canine pyometra. Methods: A total of 25 samples were collected, which included uterine discharges from cases of closed pyometra and anterior vaginal swabs from open pyometra. The isolates of E. coli and S. aureus were identified based on the cultural, morphological and biochemical characteristics. These isolates were subjected to antibiotic sensitivity test employing disc diffusion method. For biofilm detection, the isolates were screened by Congo red agar method, tube method and tissue culture plate method. Result: From 25 samples, two Streptococcus spp., thirteen Staphylococcus spp., seven E.coli, five Klebsiella spp. and two Pseudomonas spp. were isolated. All the isolates were found to be multi-drug resistant on antibiogram. The tissue culture plate and Congo red agar method was found more sensitive to detect the biofilm formation by S. aureus and E.coli isolates, respectively. The biofilm forming strains showed higher degree of antibiotic resistance in comparison with non-formers, indicating it as one of the major reasons for failure of antibiotic therapy in canine pyometra.