Milk microflora with S. aureus alike colony characteristics limits its identification over selective and differential agar media

Abstract

Staphylococcus aureus is considered a significant public health concern, owing to its involvement in food poisoning outbreaks. Milk and milk products are consumed by almost all age groups and serves as a vital nutrition source. Being highly nutritious milk serves as a promising matrix for the proliferation of S. aureus and other potential pathogens. Rapid detection of food-borne pathogens like S. aureus is vital for ensuring consumer safety. Conventional methods are still considered as the gold standard for pathogen detection in food matrices. Analysis using these methods involves sample plating over selective agar media, followed by microscopic analysis and biochemical tests. Although phenotypic detection based on colour and colony characteristics over selective and differential media is indicative, its sensitivity is compromised by organisms that display colony characteristics similar to the target organism. In this study we attempted to identify organisms from milk matrix showing characteristics similar to S. aureus over different agar media that are claimed to be selective for S. aureus. Identification of these organisms depicting S. aureus alike colony characteristics and development of more selective media can help to expedite S. aureus identification from milk and milk products with more confidence.