G.R. Carter and John R. Cole, Jr.

Publisher Summary

This chapter provides an outline of the current Bergey classification with a listing of the genera associated with animals and humans. It is important that the clinical microbiologist have some familiarity with the kinds of organisms encountered normally in and on animals. Such knowledge is necessary in the interpretation of the results of microbiologic examinations. The so-called normal flora consists of the wide variety of bacteria and fungi that live in or on normal animals without producing disease. Many potential pathogens and opportunistic organisms are included in this flora. The kinds and numbers of bacteria present vary greatly with different circumstances. The intestinal flora of the young animal differs markedly from that of the older animal. Geographic location, nutrition, and climate also influence the flora. The technical procedures employed to recover pathogenic organisms give a distorted idea of the kinds and numbers of bacteria present. The normal flora of domestic animals has not been studied in as much detail as that of human beings. The little information that is available and the firsthand experience in the diagnostic laboratory indicate a considerable similarity between the normal flora of humans and domestic animals. This chapter reviews some kinds of bacteria that are expected to occur normally in and on domestic animals. Many of the bacteria, fungi, and viruses encountered in the diagnostic veterinary microbiology laboratory have the potential for causing disease in humans. The chapter also highlights some safety recommendations for veterinary microbiology laboratories.

Classification

Bergey’s Manual of Systematic Bacteriology, Volumes 1 and 2 (1,2), provides a comprehensive listing of many established species and their characteristics. Generally speaking, the names used in the aforementioned volumes will be employed in this manual. For the most part these bacterial names are the ones listed in the Approved Lists of Bacterial Names (3) published by the American Society for Microbiology. As new information becomes available, changes in names and occasionally reclassification are recommended. The new names and reclassifications are generally accepted by the scientific community after publication or listing in the International Journal of Systematic Bacteriology.

An outline of the current Bergey classification with a listing of genera associated with animals and humans is provided below. The various bacteria are discussed in the text, usually in the same order in which they appear in the outline.