Affiliation:
1. Department of Microbiology, College of Physicians & Surgeons, Columbia University, New York, New York 10032
Abstract
ABSTRACT
In previous reports we described a 22-kb
Legionella pneumophila
chromosomal locus containing 18 genes. Thirteen of these genes (
icmT
, -
R
, -
Q
, -
P
, -
O
, -
M
, -
L
, -
K
, -
E
, -
C
, -
D
, -
J
, and -
B
) were found to be completely required for intracellular growth and killing of human macrophages. Three genes (
icmS
, -
G
, and -
F
) were found to be partially required, and two genes (
lphA
and
tphA
) were found to be dispensable for intracellular growth and killing of human macrophages. Here, we analyzed the requirement of these genes for intracellular growth in the protozoan host
Acanthamoeba castellanii
, a well-established important environmental host of
L. pneumophila
. We found that all the genes that are completely required for intracellular growth in human macrophages are also completely required for intracellular growth in
A. castellanii
. However, the genes that are partially required for intracellular growth in human macrophages are completely required for intracellular growth in
A. castellanii
. In addition, the
lphA
gene, which was shown to be dispensable for intracellular growth in human macrophages, is partially required for intracellular growth in
A. castellanii
. Our results indicate that
L. pneumophila
utilizes the same genes to grow intracellularly in both human macrophages and amoebae.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Immunology,Microbiology,Parasitology