Structural alterations to Proteus mirabilis as a result of exposure to haemolymph from the larvae of Galleria mellonella.

Scanning and transmission electron microscopy was used to examine Proteus mirabilis, strain 11-1A, for morphologic alterations following exposure to normal and immune cell-free haemolymph obtained from Galleria mellonella larvae. It was found that both normal and immune haemolymph exerted effects on the bacterial cells, with immune haemolymph affecting a much higher percentage of cells than normal haemolymph. The morphological damage observed by scanning electron microscopy (SEM) included abnormal shapes, blebbing of the cell wall, surface erosion and lysis of the cell. Transmission electron microscopy showed evidence of damage to the cell wall and supported the results obtained from SEM.