Amblyomma sculptum : genetic diversity and rickettsias in the B razilian C errado biome

• Published in: Medical and veterinary entomology Vol. 31; no. 4; pp. 427 - 437
• Main Authors: BITENCOURTH, K., AMORIM, M., DE OLIVEIRA, S. V., CAETANO, R. L., VOLOCH, C. M., GAZÊTA, G. S.
• Format: Journal Article
• Language: English
• Published: 01-12-2017
• ISSN: 0269-283X; 1365-2915
• DOI: 10.1111/mve.12249

Amblyomma sculptum
(
I
xodida:
I
xodidae)
B
erlese, 1888 is the most important tick vector in
B
razil, transmitting the bioagent of the most severe form of spotted fever (
SF
) in part of the
C
errado (in the states of
M
inas
G
erais and
S
ão
P
aulo). In another part of the
C
errado (
C
entral‐
W
est region of
B
razil), a milder form of
SF
has been recorded. However, neither the rickettsia nor the vector involved have been characterized. The aim of the current study was to analyse genetic variation and the presence of rickettsia in
A. sculptum
in
C
errado, from silent areas and with the milder form of
SF
. Samples were subjected to
DNA
extraction, amplification and sequencing of 12
S
r
DNA
, cytochrome oxidase subunit
II
and
D
‐loop mitochondrial genes (for tick population analyses), and
glt
A
,
htr
A
,
omp
A
and
gene
D
(sca4) genes for rickettsia researches. Exclusive haplotypes with low frequencies, high haplotype diversity and low nucleotide diversity, star‐shaped networks and significant results in neutrality tests indicate
A. sculptum
population expansions in some areas.
Rickettsia amblyommatis
,
Candidatus
R
ickettsia andeanae and
Rickettsia felis
were detected. The
A. sculptum
diversity is not geographically, or biome delimited, pointing to a different potential in vector capacity, possibly associated with differing tick genetic profiles.