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https://www.arca.fiocruz.br/handle/icict/20740
ESTUDO DA FAUNA E AVALIAÇÃO DIAGNÓSTICA DE INFECÇÃO NATURAL POR LEISHMANIA SPP. DE FLEBOTOMÍNEOS (DIPTERA: PSYCHODIDAE) DO MUNICÍPIO DE RIO BRANCO (ACRE, BRASIL) EMPREGANDO ENSAIOS MOLECULARES
Phlebotomus
Patologia Molecular
Kinetoplastida
Análise do Polimorfismo de Comprimento de Fragmentos Amplificados
Pereira, Thaís de Araujo | Date Issued:
2013
Author
Affilliation
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil
Abstract in Portuguese
Casos de leishmaniose tegumentar americana vêm aumentando nos últimos anos no Estado do Acre, com a identificação de espécies distintas de Leishmania isoladas de lesões cutâneas de pacientes. Entretanto, ainda não há registros de leishmaniose visceral, e pesquisas sobre a fauna de flebotomíneos no Estado ainda são limitadas. O presente estudo teve como principal objetivo ampliar o conhecimento sobre a fauna flebotomínica no município de Rio Branco (Acre) e avaliar a taxa de infecção natural por Leishmania spp. nos insetos capturados. Foram realizadas coletas com o apoio da Secretaria Municipal de Vigilância e Saúde do município, no período de Abril 2011/Abril 2012, utilizando armadilhas luminosas dispostas em seis áreas - cinco residenciais e uma área de laser. Após identificação taxonômica segundo metodologia proposta por Galati, as fêmeas de flebotomíneos foram avaliadas individualmente para infecção natural por Leishmania spp. através de ensaios de PCR-multiplex associados à hibridização com sondas específicas (subgênero Viannia e Leishmania infantum) e revelação enzimática
Foram utilizados dois conjuntos de iniciadores por reação, sendo um desenhado para a região conservada dos minicírculos do kDNA gênero Leishmania, e outro para um gene constitutivo específico de flebótomos (cacophony) gênero Lutzomyia. Na tentativa de identificar a espécie de Leishmania encontrada nos flebotomíneos, foram realizados ensaios de PCR-RFLP, clonagem e sequenciamento do fragmento de 120 pb correspondente ao produto amplificado contendo a região conservada dos minicírculos de kDNA. Foram coletados 455 espécimes de flebotomíneos, sendo 256 fêmeas e 199 machos; 173 fêmeas foram destinadas à análise molecular diagnóstica. A identificação taxonômica dos insetos possibilitou a caracterização de 20 espécies, e sete sendo identificadas apenas até gênero. Os espécimes classificados no gênero Trichophoromyia spp. foram os mais abundantes com 146 indivíduos, seguido da espécie Trichophoromyia auraensis com 96, e Nyssomyia whitmani com 74 exemplares coletados. Os gêneros Trichophoromyia spp. e Nyssomyia spp. foram os mais abundantes, tanto nas áreas de mata como no peridomicílio
A análise diagnóstica detectou 12 fêmeas positivas para infecção por Leishmania spp., correspondendo à 6,9% (12/173). Destas, 5,2% corresponderam à Trichophoromyia spp. (9/173), 1,1% à Evandromyia saulensis (2/173) e 0,6% Pressatia spp. (1/173). O sequenciamento do produto amplificado de Leishmania spp. das 12 amostras positivas, possibilitou a construção de uma árvore filogenética, a qual revelou similaridades entre clones das amostras-teste e amostras referência de L. (V.) braziliensis, L. (V.) lainsoni, subgênero Viannia, L. (L.) amazonensis, L. (L.) chagasi, L. (L.) infantum e gênero Sauroleishmania. Devido à complexidade dos dados, maiores estudos ainda se fazem necessários para a identificação precisa das espécies de Leishmania detectadas no presente trabalho
Abstract
Notifications concerning
a
merican tegumentary leishmaniasis have increased in the
recent years
in the State of Acre, with the identification of distinct
Leishmania
species
isolated from cutaneous lesions
,
and
without records
of
v
isceral
l
eishmaniasis
in the
state.
However,
studies on the sandfly fauna in Acre are still limited
.
The main objective
of the present
investigation
was
to bring more knowledge about
the sandfly fauna
in the
municipality
of Rio Branco (Acre) and to
eva
luate natural infection
index by
Leishmania
spp.
in the
captured
sand flies. Insects
were
collected with the support of
the Municipal Surveillance and Health board
, from
April 2011
until April 2012,
u
sing
HP light traps distributed in six areas
:
five resid
ential areas and one recreation area.
Sand flies collected in these different environments were identified according to the
methodology proposed by Galati.
P
hlebotomine
females were individually
analyzed f
or
the detection of natural infection by
Leishman
ia
spp.
through the use of
multiplex PCR
assays coupled to
non
-
radioactive hybridization
with specific probes (
Viannia
subgenus
and
Leishmania infantum
)
.
For the
multiplex
PCR
two primer pairs were used, one
specific
for the conserved region of kDNA minici
rcles from
Leishmania
genus and a
second pair
that
amplifies a
specific
constitutive gene of sand
flies (
c
acoph
o
ny
)
from
the
Lutzomyia
genus
.
In order to identify the
Leishmania
spp. infecting sand flies, PCR
-
RFLP experiments, c
loning and sequencing
of the
120 bp fragment corresponding to
amplified products containing the conserved region of kDNA minicircles, were
performed.
A
total of
455
phlebotomine
specimens
w
as
collected
being
25
6
females and
199 males
;
173 females were individually submitted to molecu
lar diagnosis
.
The
taxonomic identification revealed
20
phlebotomine
species identified
,
where
seven
of
were possible
to be charactherized
only to
the
genus
level
. The specimens
classified as
Tric
h
ophoromyia
sp
p
.
genus
were the most abundant with 146 indi
v
i
duals, followed by
the species
Tric
h
ophoromyia auraensis
with 96, and
Nyssomyia whitmani
with 74
specimens collected.
Tric
h
ophoromyia
spp. and
Nyssomyia
spp.
genus
were the most
prevalent
in the florest
areas,
as well as in the peridomiciliary environmen
t.
The
diagnostic analyzes detected
12 female phlebotomines
positive for
Leishmania
spp.
infection,
corresponding to
6
.9
% (12/173)
.
From these,
5
.
2%
were related to
Tric
h
ophoromyia
spp. (9/173), 1
.
1%
to
Evandromyia
s
aulensis
(2/173)
and
0,6%
to
Pressatia
s
pp. (1/173).
Following
sequencing the
Leishmania
spp. amplified product
derived from the 12 positive phlebotomine samples, a phylogenetic tree was constructed Notifications concerning
a
merican tegumentary leishmaniasis have increased in the
recent years
in the State of Acre, with the identification of distinct
Leishmania
species
isolated from cutaneous lesions
,
and
without records
of
v
isceral
l
eishmaniasis
in the
state.
However,
studies on the sandfly fauna in Acre are still limited
.
The main objective
of the present
investigation
was
to bring more knowledge about
the sandfly fauna
in the
municipality
of Rio Branco (Acre) and to
eva
luate natural infection
index by
Leishmania
spp.
in the
captured
sand flies. Insects
were
collected with the support of
the Municipal Surveillance and Health board
, from
April 2011
until April 2012,
u
sing
HP light traps distributed in six areas
:
five resid
ential areas and one recreation area.
Sand flies collected in these different environments were identified according to the
methodology proposed by Galati.
P
hlebotomine
females were individually
analyzed f
or
the detection of natural infection by
Leishman
ia
spp.
through the use of
multiplex PCR
assays coupled to
non
-
radioactive hybridization
with specific probes (
Viannia
subgenus
and
Leishmania infantum
)
.
For the
multiplex
PCR
two primer pairs were used, one
specific
for the conserved region of kDNA minici
rcles from
Leishmania
genus and a
second pair
that
amplifies a
specific
constitutive gene of sand
flies (
c
acoph
o
ny
)
from
the
Lutzomyia
genus
.
In order to identify the
Leishmania
spp. infecting sand flies, PCR
-
RFLP experiments, c
loning and sequencing
of the
120 bp fragment corresponding to
amplified products containing the conserved region of kDNA minicircles, were
performed.
A
total of
455
phlebotomine
specimens
w
as
collected
being
25
6
females and
199 males
;
173 females were individually submitted to molecu
lar diagnosis
.
The
taxonomic identification revealed
20
phlebotomine
species identified
,
where
seven
of
were possible
to be charactherized
only to
the
genus
level
. The specimens
classified as
Tric
h
ophoromyia
sp
p
.
genus
were the most abundant with 146 indi
v
i
duals, followed by
the species
Tric
h
ophoromyia auraensis
with 96, and
Nyssomyia whitmani
with 74
specimens collected.
Tric
h
ophoromyia
spp. and
Nyssomyia
spp.
genus
were the most
prevalent
in the florest
areas,
as well as in the peridomiciliary environmen
t.
The
diagnostic analyzes detected
12 female phlebotomines
positive for
Leishmania
spp.
infection,
corresponding to
6
.9
% (12/173)
.
From these,
5
.
2%
were related to
Tric
h
ophoromyia
spp. (9/173), 1
.
1%
to
Evandromyia
s
aulensis
(2/173)
and
0,6%
to
Pressatia
s
pp. (1/173).
Following
sequencing the
Leishmania
spp. amplified product
derived from the 12 positive phlebotomine samples, a phylogenetic tree was constructed revealing similarities between clones from the samples
-
test and reference samples from
L
. (
V.
)
br
aziliensis
,
L
. (
V
.)
lainsoni
,
Viannia
subgenus
,
L
. (
L
.)
amazonensis
,
L
. (
L.
)
chagasi,
L
. (
L
.)
infantum
and
Sauroleishmania
genus
.
Due to the complexity of the
generated data, more studies are still needed for the precise identification of
Leishmania
parasi
tes detected in the present work.
DeCS
LeishmaniosePhlebotomus
Patologia Molecular
Kinetoplastida
Análise do Polimorfismo de Comprimento de Fragmentos Amplificados
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