Premium
Parachlamydia acanthamoeba Is Endosymbiotic or Lytic for Acanthamoeba polyphaga Depending on the Incubation Temperature
Author(s) -
GREUB GILBERT,
SCOLA BERNARD,
RAOULT DIDIER
Publication year - 2003
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2003.tb07437.x
Subject(s) - acanthamoeba , biology , incubation , protozoa , microbiology and biotechnology , amoeba (genus) , lytic cycle , lysis , naegleria , virology , biochemistry , virus
A bstract :Parachlamydiaceae are potential emerging pathogens that naturally infect free‐living amoebae. We investigated the affects of incubation temperature on the growth and cytopathic effect of P. acanthamoeba in Acanthamoeba polyphaga . A. polyphaga were infected with P. acanthamoeba and incubated at different temperatures for ten days. Bacterial growth was quantified by real‐time PCR. Cytopathic effects were determined by counting the number of cysts and viable amoebae (unstained with trypan blue) in Nageotte counting chambers. Uninfected amoebae cultures were used as negative control. At 32, 35, and 37°C, we observed a significant decrease in the number of viable A. polyphaga that contrasted with the delayed and smaller decrease in the number of living A. polyphaga observed at 25, 28, and 30°C. Higher incubation temperature, which is associated with amoebal lysis, surprisingly was not associated with increased growth rate. P. acanthamoeba is lytic for A. polyphaga at 32–37°C but endosymbiotic at 25–30°C. This suggests that A. polyphaga may be a reservoir of endosymbionts at the lower temperature of the nasal mucosa, which may be liberated by lysis at higher temperature, for instance, when the amoeba is inhaled and reaches the lower respiratory tract.