The Slow-Growing Pigmented Water Bacteria: Problems and Sources

Abstract

This chapter discusses the problems and sources of slow-growing pigmented water bacteria. The extent to which water can serve as a bacterial growth medium is one of the least recognized facets of bacteriology. Many bacteria reproduce in water; among the genera that will grow in water of unquestioned potable quality are: Pseudomonas; Xanthomonas; Achromobacter; Escherichia; Aerobacter; Streptococcus; Desulfouibrio; and Crenothrix. The slow-growing pigmented water bacteria that are thus often missed are usually those nonfermentative rods that may require up to 15 days at room temperature, and grow best on agar surface. Lactose broth tubes when held for 15 days at room temperature may produce a pigmented growth, often quite mucoid. Most of the pigments associated with many of the slow-growing water bacteria appear to belong to the group of unsaponifiable fat-soluble natural pigments usually yellow to red in color and are most common among marine bacteria, where over half of the organisms isolated to date are considered to be chromogenic. The chapter discusses the infection hazards with pigmented water bacteria in great detail.