4 - Isolation and Identification of Bacteria from Clinical Specimens

Abstract

Publisher Summary This chapter presents a list of the steps followed in the isolation and identification of bacteria from clinical specimens. It also presents a simplified guide for the presumptive recognition of common groups of bacteria. The genera of some important gram-positive aerobes are determined by some characteristics. The most frequently recovered aerobic gram-negative bacteria are the members of the Enterobacteriaceae family. They are rod-shaped organisms producing colonies of moderate size. They are fermenters and it is customary to inoculate Triple Sugar Iron agar slants from the colonies of suspected enterics. The chapter highlights a number of features that aid in the tentative recognition of gram-negative genera It presents a list of the the organisms recovered from the respiratory system, the central nervous system, the urinary tract infections, the joints, canine otitis externa, equine cervix, and the eyes. the chapter also describes the organisms associated with canine skin infections, abscesses and ulcers of the skin and subcutis, genital infections, and mastitis. There are two procedures that are frequently used to obtain material for inoculation from tissue and organs. The goals of primary inoculation of media are to cultivate the organisms and to obtain discrete colonies. The chapter reviews the selection of routinely used media for primary inoculation.