The persistence of biofilm-associated antibiotic resistance of Staphylococcus aureus isolated from clinical bovine mastitis cases in Australia

Abstract

The aim of this investigation was to determine the persistence of biofilm-associated antibiotic resistance developed by methicillin-sensitive Staphylococcus aureus (MSSA), of different capsular types, during biofilm formation. Because of superiority of the tissue culture plate (TCP) over the Congo Red Agar (CRA) method for measuring biofilm formation, it was used to determine the persistence of the antibiotic resistance developed by the isolates in biofilms. The antibiotic resistance was found to persist for 3-4 wk post-propagation as planktonic subcultures. Interestingly, some strains even developed resistance to vancomycin and/or teicoplanin. However, no association of either biofilm formation or persistent antibiotic resistance with the major capsular phenotype was observed. These observations highlight the potential significance of (a) determining the antibiograms of S. aureus subcultured from biofilms developed in vitro using the TCP method as well as from planktonic cultures for formulation of an optimal therapeutic strategy, and (b) continuing to identify predominant non-capsular antigens contributing to biofilm formation, regardless of the capsular phenotype for the development of an effective potentially broad-spectrum vaccine for prevention of bovine mastitis caused by S. aureus.

Genotypic and phenotypic detection of capsular polysaccharide and biofilm formation in Staphylococcus aureus isolated from bovine milk collected from Brazilian dairy farms

“…The presence of cap genes in all of the isolates analysed was also reported in the studies conducted by Tollersrud et al (2000); Salasia et al (2004); Bardiau et al (2014), and Khichar and Kataria (2014), with S. aureus isolated from bovine mastitis, as well as by Verdier et al (2007), with S. aureus isolated from human infections. Nevertheless, Reinoso et al (2008) and Camussone et al (2012) in Argentina, Babra et al (2013) in Australia and Marques et al (2013) in Brazil reported lower percentages of S. aureus isolates collected from bovine mastitis samples carrying the cap gene.…”

“…A higher proportion of cap5 isolates (compared to cap8 isolates) has also been reported by Salasia et al (2004) in Indonesia, Reinoso et al (2008) and Camussone et al (2012) in Argentina, and Khichar and Kataria (2014) in India. Other studies conducted in different countries reported that cap5 and cap8 were evenly distributed among S. aureus isolates from bovine mastitis (Bar-Gal et al 2015) or that there was a higher proportion of cap8 than cap5 isolates (Salasia et al 2004;Babra et al 2013;Marques et al 2013;Bardiau et al 2014).…”

Magnolol Inhibits the Inflammatory Response in Mouse Mammary Epithelial Cells and a Mouse Mastitis Model

“…Bovine mastitis is a major disease affecting dairy cattle worldwide and is a costly disease for dairy producers [22]. But in recent years, conventional methods have frequently been unable to prevent intramammary infection, antibiotics are not very effective in the treatment of mastitis and have a negative impact on human health [23]. Mammary epithelial cells, the most numerous cells in the mammary gland, are parts of the functional unit of the udder, which are responsible for the synthesis of many components in milk that provide nutritional and immunological support to the offspring [24].…”

Bovine Mastitis and Its Therapeutic Strategy Doing Antibiotic Sensitivity Test

“…Antibiotics are applied near the end of lactation [141] and may persist in the udder in high concentrations to destroy pathogenic bacteria for 20-70 days. The applied antibiotic has enhanced penetration capacity because of long time contact and curing intramammary infections unless resistance to novel antibiotics is developed by the entering pathogen [142]. Dry cow therapy has been described to remove nearly 100% of mastitis caused by S. agalactiae [139,143].…”