Veterinary Clinical Biochemistry and Laboratory Diagnosis-II

BIOCHEMICAL CHARACTERISTICS

• Observing colonial characteristics and morphology on Gram staining, can make preliminary bacterial identification.
• However, the final characterization of an unknown bacterial isolate to identify it to the genus and species levels is usually accomplished by testing for certain enzyme systems that are unique to each species and serve as identification markers.
• In the laboratory, these enzyme systems are detected by inoculating a small portion of well-isolated bacterial colony into a series of cultures media containing specific substrates and chemical indicators that detect pH changes, or the presence of specific byproducts.
• The clinical microbiologist must select appropriate sets or differential characteristics that will permit the identification of each group of bacteria.