franiolek1
23.01.09, 16:21
Int J Med Microbiol. 2009 Jan 13; [Epub ahead of print]
Tick saliva affects both proliferation and distribution of
Borrelia burgdorferi
spirochetes in mouse organs and increases transmission of
spirochetes to ticks.
Horka H, Cerna-Kyckova K, Skallova A, Kopecky J.
Laboratory of Vector-Host Interactions, Institute of Parasitology,
Biology
Centre AS CR, Faculty of Science, University of South Bohemia,
Branisovska 31,
370 05 Ceske Budejovice, Czech Republic.
Ixodes ricinus tick saliva-activated transmission of Borrelia
burgdorferi sensu
stricto spirochetes was studied on the C3H/HeN mouse model. The
influence of the
feeding of uninfected nymphs on the proliferation and distribution
of
intradermally inoculated spirochetes was compared with the effect
of
co-inoculated saliva or salivary gland extract (SGE),
respectively. Spirochete
loads in murine tissues were evaluated using real-time q-PCR. SGE
induced
significantly increased spirochete numbers in the skin on the days
4 and 6
post-infection (p.i.). On the other hand, decreased bacterial load
in the heart
of SGE-treated mice was demonstrated in comparison with control
animals. The
inoculation of tick saliva increased spirochete load in the
urinary bladder on
day 6 p.i., while the number of spirochetes in the heart declined
on day 6 p.i.
The feeding of I. ricinus nymphs raised the spirochete load in the
bladder on
the days 4 and 6 p.i. On day 6, the number of spirochetes found in
the heart was
significantly lower than in controls. The prevalence of
spirochetes in ticks
infected by feeding on mice was more than 10 times higher when the
mice were
infected with the mixture of spirochetes and saliva or SGE, in
comparison with
spirochetes alone. The presence of SGE in the infectious inoculum
increased the
spirochete burden per tick from 0 to almost 28,000. Taken
together, these
results show a very early effect of tick saliva on the
proliferation and
distribution of Borrelia spirochetes in the host, probably due to
the effect of
saliva on the host innate immunity mechanisms.
PMID: 19147403 [PubMed - as supplied by publisher]
