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Department of Tropical
Parasitology
Institute of Maritime and Tropical Medicine
Head: Dr. Przemysław Myjak
Staff members
Beata Biernat
Beata Szostakowska
Alicja Rost
Przemysław Myjak
Maria Racewicz
Halina Pietkiewicz
Joanna Stańczak
Agnieszka Adamczyk
Balbina
and: Wiesława Kruminis-Łozowska
Maria Piesik
Ewa Zieliniewicz
Halina Pietkiewicz
Beata Biernat
Molecular diagnostics and epidemiology
of parasitic and arthropod-transmitted
diseases
Previous and current research
The Department carries out research in the field of:
occurrence, biology, ecology and physiology of tropical and
selected cosmopolitan parasites of man and animals;
medical acaroentomology, epidemiology of the parasitic
and arthropod-borne diseases; immunology and
experimental chemotherapy of the parasitic diseases,
biochemistry and genetics of parasites; ecto- and
endoparasites of rodents – reservoirs of infectious diseases.
PROTOZOA
Amoebiosis: Entamoeba histolytica-E. dispar
The infection with E. histolytica sensu lato is one
of the most common parasitic infections
in humans worldwide and occurs in about 10% of
the world population.
Clinical symptoms are observed in 10% of the
infected people only and are related to
E. histolytica infection, while 90% of the cases are
asymptomatic and most frequently attributed to
E. dispar infection.
People infected with E. dispar do not require
medical treatment. It is therefore of vital
importance to differentiate these two
amoebic species which are morphologically
identical. It is possible using molecular
methods.
We demonstrated that in Poland, among the
imported and indigenous strains of
E. histolytica s.l., E. dispar occurred most
frequently (90%) and its phenotyp i.e.
zymodeme I, was the most common one.
E. histolytica occurred more rarely but also
in persons who did not travel abroad.
(grant No 4 P05A 107 08)
Myjak et al. 2000.
Malaria
Plasmodium falciparum, P. vivax, P. ovale,
P. malariae
According to WHO data,
from 300 to 500 millions of people
worldwide are yearly newly
infected with malaria.
Detection of Plasmodium DNA is alternative
to standard microscopy examinations.
For the most cases the same results are
obtained by both microscopic examinations
and PCR.
However, for cases with parasitemia of less
than 0.1%, parasites can not be speciated by
microscopy or diagnostic findings are
doubtful. Then, only PCR gives correct
diagnosis.
Moreover, PCR is useful in detection of
Plasmodium spp. in patients with fever of
unknown origin.
(grant No 4 P05A 008 14)
Myjak et al. 2002
The most dangerous among 4 species of
human malaria is P. falciparum.
Very serious problem is increasing drug
resistance of this parasite against common
medicines like chloroquine, pyrimethamine
and sulfadoxine.
We investigate, using DNA sequencing and PCR-RFLP methods,
drug-resistance of P. falciparum isolates to these three
medicaments.
(grant No 6 P05B 046 20)
Myjak et al. 2002
Toxoplasmosis
This is the most worldwide
parasitic invasion caused by
Toxoplasma gondii.
In healthy individuals, generally is
clinically asymptomatic.
However, it may cause severe complications in pregnant women
(cause severe damage to the fetus) and immunocompromised
patients
In most cases, infection with this parasite is caused
by consumption of meat containing cysts and consists
90% of per os infections.
10% of per os infections is caused by oocysts originated
from cat’s faeces.
Congenital cases of toxoplasmosis take place rarely but
are very dangerous for new-born babies.
Diagnosis of acute infection generally relies on serological
methods and results depend on antigens used.
Most commercial serological assays detect antibodies by
means of native antigens originating from T. gondii grown
in vivo or in vitro. The production of these antigens is
rather expensive and constant quality of the antigen
preparations cannot be easily guarranted.
Recombinant antigens could overcome these drawbacks since
they can be produced inexpensively and free from host
contamination.
We assess the usefulness of recombinant antigens
(proteins SAG1, GRA1, GRA7 and mixture of
these tree recombinant proteins) produced by
Technical University of Gdańsk, Department of
Microbiology in serodiagnostics of toxoplasmosis.
Results obtained indicate that these antigents can be
used in practical diagnostic of the disease in
ELISA-IgG and ELISA-IgG-avidity tests.
(grant No 4 P05A 103 18)
Hiszczyńska-Sawicka et al. 2003.
Cryptosporidiosis
Cryptosporidiosis is caused by
Cryptosporidium spp.,
widespread protozoans that
primarily infects the intestinal
epithelium of vertebrates.
Parasites cause acute diarrhea in immunocompetent
humans or fatal illness in immunocompromised or
immunosupressed individuals such as patients with
AIDS.
Transmission of the parasite occurs by the faecal-oral
route.
In our Department various molecular
methods are used in the research on
epidemiology of cryptosporidiosis.
We study the role of cattle and rats as a reservoirs
of Cryptosporidium in rural and urban
environment in Poland, as well as role of
synanthropic flies as transport hosts for this
pathogen.
(grant No 6 P04C 024 21)
As the occurrence
of Cryptosporidium outbreaks in
drinking water (USA, Canada, UK, the
Netherlands) have brought an
increased need for detection at levels
necessary to protect human health,
we carry on investigation on the
contamination of surface water and
water supply by oocysts of different
species of this parasite.
(grant NATO LST.CLG.979765)
Cryptosporidium parvum
is considered as a biological weapon!!!
HELMINTHES
Cestodes.
Echinococcosis: Echinococcus multilocularis – E. granulosus
E. multilocularis, a parasite of foxes occurring in the northern regions
of Eurasia and North America, is causative agent of alveolar
echinococcosis (AE).
This life threatening disease is caused
by the larva (metacestode)
of E. multilocularis that develops in the
liver and forms a sponge-like mass
proliferating through the tissue.
Sometime it is difficult to differentiate between
E. multilocularis and E.granulosus or liver cancer.
Different molecular techniques help do differentiation or
confirmation of E. multilocularis infection.
To exactly determine the causative agent of Polish AE cases
we study a panel of specimens comparatively by histology,
serology and DNA analysis. To this end we have developed
two E. multilocularis-specific microsatellite markers and
sequenced a fragment of mitochondrial 12S rDNA.
Our results definitively prove the occurrence of
autochthonous human AE in Poland.
(grant No 4 P05D 042 12 )
Myjak et al. 2003 (in press)
Nematodes from the family Anisakidae – parasites of fish, sea mammals,
fish-eating birds and, accidentally, also humans.
Anisakid nematodes occur in a larval
stage in many species of marine fish
(in the Baltic Sea mainly herring but
also cod, flatfish and other). Adult
are parasites of sea mammals.
Humans became infected after
consumption of raw or wrongly
processed fish
Worldwide, more than twelve
thousand of documented cases of
anisakiasis in man have been
reported so far, mainly with larvae of
Anisakis simplex and Pseudoterranova
decipiens
Since the beginning of 90. we have been
conducting the following studies:
•Estimation of infection of fish from the Southern
Baltic Sea with anisakid nematodes.
The prevalence, intensity and seasonal
character of fish infection were estimated.
grants: No 4 411 92 03 and No 6 P04G 053 11
Investigation of anisakid with molecular methods
(multilocus allozyme electrophoresis and PCR-based
techniques like PCR-RFLP and DNA sequencing)
The method of identification of anisakid species occurring in the Baltic
Sea using molecular techniques was elaborated (as it is difficult or
sometime impossible to distinguish species of Anisakidae on the basis
of their morphology)
It was established that Hysterothylacium actum from different fish
species and place of occurrence belongs to one species
(grants No 6 P04C 084 10 and No 6 P04C 041 16)
Szostakowska et al. 2001; Szostakowska et al. 2002.
At present, we continue molecular investigations
of anisakid nematodes by studying of population
structure of Contracaecum rudolphii,
parasite of cormorants nesting in Northeastern Poland
In this field we collaborate with University of Gdańsk, Department of
Genetics and Cytology and Agricultural University in Warsaw,
Department of Zoology
(grant No 3 P04C 099 23)
Arthropod-borne diseases
In many parts of the world a group
of the smaller arthropod
animals, the mites, ticks, bugs,
lice, fleas, and flies, has always
been and still is a most serious
factor in the dissemination of
diseases.
Molecular techniques are widely
used for identification of vectors
of different infectious diseases
as well as for detection and
differentiation of the etiologic
agents of these diseases.
Identification of vectors
Molecular taxonomy can improve the quality of ecological
and epidemiological studies because:
Members of species complexes can be identified
Morphologically similar species can be identified at any life
stages
Current technology allows visualization of biochemical and
protein markers in small arthropods
The remainder of specimen homogenate can be used for
identification of associated microorganisms, whether they
be pathogens or potential biological control agents, and for
estimation of genetic variation in population genetic
studies
A diagnostic PCR assay has been developed that enables
identification sibling mosquito species by means of the
length of their PCR product.
In our Laboratory it has been used to identify three cryptic
species of native anophelinae mosquitoes of Anopheles
maculipennis complex:
An. atroparvus
An. maculipennis s.s.
An. messeae,
potential vectors of Plasmodium spp., the etiologic agent of
malaria.
(grant No 6 P04C 019 18)
Kubica-Biernat et al. 2001.
Anopheles maculipennis complex
Detection and differentiation
of tick-borne pathogens
Borrelia burgdorferi s.l.:
including B. burgdorferi s.s., B.
garinii and B. afzelii, spirochetes
being etiologic agent of Lyme
borreliosis, the disease that can
affect a variety of systems
including the skin, heart, joints,
and nervous system.
(grant no 6 P04C 037 10)
Stańczak et al. 1999, 2000, 2002
Anaplasma phagocytophilum (formerly HGE
agent), the causative agent of human granulocytic
ehrlichiosis (HGE), an obligate intracellular
bacterium that targets mainly granulocytes of
various mammalian species and man.
(grant No 6 P04C 047 17)
Grzeszczuk et al. 2002, Stańczak et al. 2002, Stańczak et al. in print.
Babesia spp., intraerythrocytic protozoan parasites which
cause babesiosis, a world wide haemolytic disease of wild
and domestic animals, and humans.
(grant No 6 P04C 047 17)
Stańczak et al. – in print.
Moreover, PCR can serve as a confirmation test for
proper diagnosis of Lyme borreliosis, HGE and babesiosis
by detection agents of diseases in tissue biopsies and body
fluids.
(grant No 3 P5D 097 25)
Mosquito biological control in the Vistula Spit
The application of chemical insecticides has been the most common and
widely used method in Poland. However, the appearance of resistance to
great number of them as well as their negative impact on the natural
environment determined one’s attention to biological agents, especially
Bacillus thuringiensis israelensis (B.t.i.).
In 2000, we started the first mosquito abatement program based on B.t.i.
preparations in Poland which included:
•Mapping of mosquito breeding places
•Monitoring of mosquito populations
•Applications of B.t.i. formulations
•Evaluation of the efficacy
The overall efficiency of the control was 99.2%.
(grant Leonardo da Vinci of European Union and collaboration with
KABS – German Mosquito Control Association)
Kubica-Biernat et al. 2000, 2001.