Techniques for the Detection and Identification of Pathogenic Bacteria


The maturity of clinical microbiology laboratories still calculate on culture for the discovery of utmost bacterial pathogens from clinical samples. Traditionally, culture is performed using general purpose agar- predicated media (e.g. blood agar) that will support the growth of a wide range of pathogens. Each type of colony that is recovered is also excavated to identify likely pathogens. For the discovery of certain pathogens, it's essential to use more specific culture media. For illustration, ‘discriminative’ media target differences in the metabolic exertion of bacteria utilising biochemical indicator systems (e.g. the incorporation of a sugar( nutrition) plus a pH indicator (to sense metabolites digested nutrient) to indicate the likely presence of a specific pathogen. Culture media may also be ‘picky’ (by incorporation of antimicrobials) to reduce the amount of commensal§ leafage suitable to grow and thereby increase the liability of separating a particular target pathogen. For illustration, to isolate Salmonella from a excreta sample that may contain dozens of other species, it's essential to use a culture medium that is both picky (e.g. by the use of antimicrobials analogous as cefsulodin and novobiocin) and discriminative by detecting hydrogen sulfide product or specific enzymes.