Effect of moisture content of the medium on colony morphology of Campylobacter fetus subsp. jejuni

Abstract

Reduction in the moisture content of the medium produced a profound effect on the colony morphology of Campylobacter fetus subsp. jejuni. Fresh medium produced flat, grayish, spreading colonies with an irregular shape and watery appearance. Plates that were incubated at 30°C for 48 h produced round, convex, butyrous colonies with an entire edge. Plates incubated at 30°C for 24 h before inoculation produced colonies of an intermediate nature; they were round and raised, but not convex, and slightly watery or mucoid in nature. This marked effect produced by moisture content of the medium was reproducible and may account for the variation in colonies observed by other investigators.