1 - Methods of Growing Anaerobes

Abstract

This chapter discusses the methods of growing anaerobes. A variety of methods is available for the culture of anaerobic organisms in the clinical laboratory. Exclusion of oxygen from part of the medium is the simplest method and is effected by growing the organism within the culture medium as a shake or fluid culture. When an oxygen-free or anaerobic atmosphere is required for obtaining surface growths of anaerobes, anaerobic jars provide the method of choice. Some of the methods for obtaining anaerobiosis in a jar are also applicable to single tube or plate cultures, but for laboratories that intend to undertake anaerobic bacteriology seriously, anaerobic jars are essential. More sophisticated methods for the surface culture of anaerobes are the pre-reduced anaerobically sterilized (PRAS) roll-tube technique and use of the anaerobic cabinet or glove box. These two techniques utilize complex and expensive equipment, are time consuming, and require specially trained staff and specialized medium preparation facilities. There is no doubt that these complex techniques provide the most meticulous anaerobic conditions, and are appropriately used for the isolation and study of exacting anaerobic species that are highly sensitive to oxygen. Regardless, comparative studies have shown that these methods are not superior to the anaerobic jar for the recovery of clinically significant anaerobes from pathological specimens.