The Cytology of Pseudomonas spp. as Revealed by a Silver-Plating Staining Method

Abstract

Summary: A modification of Fontana’s silver-plating method was devised and used for the eytological study of 214 isolates of Pseudomonas spp. Many features, such as flagella, cross-walls or septa, capsules and slime were thereby clearly demonstrated simultaneously and easily. Comparisons were made with other published methods for staining flagella, capsules and slime, and good agreement was obtained. No totally non-flagellate isolate was found, nor were flagella lost during maintenance for 3–5 ½ years in the laboratory. The number of flagella/rod and also bipolar flagellation were found to be characters of little value for species differentiation. The flagellation of young cultures was not found to be significantly different from that observed in older cultures; the polar position of the flagella was confirmed. Flagella curvature (wavelength and amplitude) as seen in silver-plated organisms prepared under reasonably standardized conditions, was noted and considered to have no usefulness for subgeneric classification.