Bacteria visualized in a rich culture established in XTC-2cell line by Gimenez staining appeared as intracellular red rods usually grouped in pairs but not connected with each other.
Manual counting of bacteria in an unlysed eukaryotic cell showed that almost all bacteria (97%) were paired.
The bacteria accumulated in the cytoplasm of cells but not in the nucleus.
The maximum number of bacteria observed in one cell numbered over 100.
Infected cells were often disrupted during centrifugation using a Cytospin (Thermo Shandon) centrifuge as revealed by subsequent staining.
The isolate was Gram-negative when extracellular bacteria were stained.

In addition, Mediannikov et al.
have examined the percentage of infected cells and the mean number of bacteria per cell in different cell lines.
The highest growth speed and the presence of a cytopathogenic effect when bacteria were cultivated in XTC-2 cells (Xenopus laevis).
A cytopathogenic effect, including cellular layer detachment and cell disruption, was observed 3–5 days after inoculation.
It was the only cell line with 100% cells infected the mean number of bacteria per cell was more than 100 in all studied series.
The growth speed and bacteria accumulation in cells were lower in cell lines of human origin (HEL and MRC5) cultivated at 32 °C but were minimal in mouse L929 cells.

Multiple attempts at cultivation of the bacteria in solid axenic media (both common and Legionella-specific) were not successful.
Bacteria visualized in a rich culture established in XTC-2cell line by Gimenez staining appeared as intracellular red rods usually grouped in pairs but not connected with each other. Manual counting of bacteria in an unlysed eukaryotic cell showed that almost all bacteria (97%) were paired. The bacteria accumulated in the cytoplasm of cells but not in the nucleus. The maximum number of bacteria observed in one cell numbered over 100. Infected cells were often disrupted during centrifugation using a Cytospin (Thermo Shandon) centrifuge as revealed by subsequent staining. The isolate was Gram-negative when extracellular bacteria were stained.
In addition, Mediannikov et al. have examined the percentage of infected cells and the mean number of bacteria per cell in different cell lines. The highest growth speed and the presence of a cytopathogenic effect when bacteria were cultivated in XTC-2 cells (Xenopus laevis). A cytopathogenic effect, including cellular layer detachment and cell disruption, was observed 3–5 days after inoculation. It was the only cell line with 100% cells infected the mean number of bacteria per cell was more than 100 in all studied series. The growth speed and bacteria accumulation in cells were lower in cell lines of human origin (HEL and MRC5) cultivated at 32 °C but were minimal in mouse L929 cells.
Multiple attempts at cultivation of the bacteria in solid axenic media (both common and Legionella-specific) were not successful.
Diplorickettsia massiliensis