Short reports EVect of desiccation on the ultrastructural appearances of Acinetobacter baumannii and Acinetobacter lwoYi

An Acinetobacter baumannii isolate survived desiccation beyond 30 days and an Acinetobacter lwoYi isolate up to 21 days. For both species, desiccation resulted in a significant increase in the proportion of round cells (A baumannii, 40% to 80%; A lwoYi, 51% to 63%) and a significant decrease in rod shaped cells (A baumannii, 58% to 13%; A lwoYi, 46% to 34%). Electronmicroscopic examination showed that there was also a corresponding significant increase in the cell wall thickness (A baumannii, up to 53%; A lwoYi, up to 26%). Desiccated A baumannii cells became more electron-dense and had significantly thicker cell walls (×1.3) than those of A lwoYi. Cell wall structures of A baumannii strains with diVerent abilities to resist desiccation deserve further study. (J Clin Pathol 1998;51:786–788)