|
|
| Research on infectious
diseases transmitted among human beings, domestic animals and wildlives |
| Studies
on zoonotic protozoan parasites and microorganisms in marine mammals. |
| Yoshitaka OMATA |
|
There have been worldwide reported toxoplasmosis and brucellosis in
marine mammals. Murata et al. reported anti-T. gondii antibody positive
cases in wild and captive dolphine from Japan. However, how marine mammals
become infected in nature has not been well studied.
The aim of the present study is to examine the prevalence of zoonotic
infection in marine mammals, and compare the relationship between those
in domestic animals. Further, isolation and identification of the microorganisms
from marine mammals and assay methods for the diagnosis should be performed.
|
| |
|
Parasite faunas of wild animals and birds in the Tohoku region of Japan |
| Tadashi ITAGAKI |
| Global changes of natural environment and the protective
policy for wildlife have produced close contact between human, livestock
and companion animals and wildlife. As a result, propagation of infectious
diseases from wildlife to human, livestock and companion animals has become
a serious problem. In fact, wild animals and birds are infected with a
large number of parasite species of which some have zoonotic potentials.
The purpose of this study is to clarify parasitic faunas including zoonotic
parasites of wild animals and birds in the Tohoku region and to compare
parasitic faunas between wildlife and that kept in a zoo. 1) Parasitic
faunas of a Japanese serow, Capricornis crispus and deer, Cervus nippon
centralis: serow and deer dead in Iwate Prefecture and neighbor prefectures
are examined for ectoparasites in the surface, nematodes in the subcutaneous
tissue, sarcocysts in the muscle tissue, and helminths in the visceral
organs. Furthermore, rectal feces of the animals are examined for oocysts
and cysts of protozoa using sucrose floating technique and a direct fluorescent
antibody (anti-Cryptosporidium/Giardia antibody) technique. 2) Parasitic
fauna of a Japanese black bear, Selenarctos thibetanus japonicus: the
animals dead are examined for helminths in the visceral organs, and for
Trichinella larvae in the muscle tissue of the head using microscopic
observation and Trichinella antibodies by Ouchterlony immuno-diffusion
test. Crude Trichinella antigen (protein quantity: 3~5 mg/ml) for Ouchterlony
test are prepared with homogenizing the larvae. 3) Parasitic fauna of
a carnivore: foxes, raccoon dogs, martens, weasels are examined for ectoparasites
in the surface, Trichinella larvae in the muscle tissue and helminths
in the visceral organs. 4) Parasitic fauna of wild raptors: hawks and
owls dead in Iwate Prefecture and neighbor prefectures are examined for
helminths in the visceral organs. 5) Parasitic fauna of wild herons: herons
dead in Iwate Prefecture and neighbor prefectures are examined for helminths
in the visceral organs. 6) Parasitic fauna of wild monkey: Japanese macaque
(Macaca fuscata) and Taiwan macaque (Macaca cyclopis) distributed in the
Shimokita Peninsula, Aomori Prefecture are examined for eggs, oocysts
and cysts of parasites in feces using a sucrose floating technique and
a direct fluorescent antibody (anti-Cryptosporidium/Giardia antibodies)
technique. Trematodes and cestodes obtained are fixed in 70% ethanol and
stained with Carmin. Nematodes and acanthocephala are cleared in racto-phenol
solution. Ectoparasites are treated with 10% KOH or Gater's solution.
These prepared specimens are observed in a microscope for identification
of species. 7) Parasitic infections of wildlife kept in a zoo: The feces
are examined for eggs, oocyste and cysts of parasites using a sucrose
floating and simple sedimentation techniques and a direct fluorescent
antibody (anti-Cryptosporidium/Giardia antibodies) technique. |
| |
| Survey
of parasite infestation in wild animals and evaluation of environmental
changes |
| Katusya KITOH |
|
To evaluate the extent of zoonosis pollution, surveys of parasite infestation,such
as blood filariae, itch mite (Sarcoptes scabiei) and Trichinae, are
conducted in wild animals.
- Prevalence of blood filariae infection
Blood samples obtained from wild mammals, such as Japanese black bears,wild
raccoon dogs (Nyctereutes procyonoides) and foxes (Vulpes vulpes japonica),
are used to examine the prevalence of the filariae infections. The
data thus obtained are then studied to determine whether they can
be indicators to evaluate climate change and global warming.
- Survey of itch mite (Sarcoptes scabiei) infestation
Sarcoptic manage caused by Sarcoptes scabiei is a zoonotic parasitosis,
which is characterized by dermatitis with a severe itch. Recently,
we are apprehensive about expansion of scabiae infestation in wild
animals, such as Japanese wild boars and wild raccoon dogs, Nyctereutes
procyonoides. To examine the prevalence of itch mite (Sarcoptes scabiei)
infestation, skin samples obtained from these wild animals are used.
- Survey of Trichinae infestation
Trichinella larvae parasitize in mammalian muscles, and infect humans
by ingestion of incompletely cooked meats from the infected animals.
Trichina is found in a wide range of mammalian hostsCand is thought
to be spread among the wild animals. Thus, serum samples obtained from
wild animals such as Japanese wild boars, are used to examine the prevalence
of Trichinella infection in Gifu region.
|
| |
| Studies
on ecology and epidemiology of Salmonella in wild reptiles |
| Hideki HAYASHIDANI |
Recently, various kinds of reptiles such as snake, tortoise
and lizard have been kept as a pet in Japan. These reptiles have been
reported to harbor Salmonella at a high rate and are known to be an important
reservoir of this pathgens. Actually, Salmonella infection in children
due to those reptiles has been reported in USA and European countries.
We reported that reptiles living in the wild in Japan and Vietnam harbor
Salmonella at a high rate.
In this study, the molecular epidemiological analysis, such as pulsed-field
gel electrophoresis (PFGE) or ribotyping, and antimicrobial susceptibility
test of Salmonella originated from Japan and Vietnam is done to know the
epidemiological relationship between wild reptiles and human and elucidate
the role of the reptiles in the ecology of this pathogen in nature. Furthermore,
the mechanism that wild reptiles harbor Salmonella at a high rate is investigated
experimentally. |
| Drug
resistant and molecular epidemiological analysis of Salmonella isolated
from wild animals |
| Tsuneo FUKATA |
Salmonella have been isolated from wild
pigeons in the Osaka areas (Fukata et al., 1989). S. Typhimurium were
recovered from eight percent of wild pigeons. Wild pigeons are widely
distributed in urban and rural areas and their feces may contaminate the
poultry farms. Salmonella infections are still amongst prevalent problems
in the poultry industry. And it is indicated that Salmonella will be isolated
from other wild animals.
The purposes of this study are to isolate Salmonella from wild animals
and to analyze by antimicrobial resistance and by molecular epidemiological
method of Salmonella isolated.
One gram feces will be collected from wild animals and place into a tube
containing Hajna tetrathionate broth. After 24 hours of incubation at
37°C, subculture is made by spreading one loopful on the broth onto
Mannitol lysine crystal violet brilliant green agar. After 24 hours of
incubation at 37°C, black colonies are identified according to the
Kaffman-White schema. Salmonella isolated are analyzed antimicrobial resistance
by disc methods. The antimicorobial drugs are used sulfamethoxazole-trimethoprim
(ST), penicillin G (PCG), ampicillin (ABPC), tetracycline (TC), chloramphenicol
(CM), cephalexin (CEX) and ofloxacin (OFLX). And Salmonella isolated are
analyzed for pulsed field gel electrophoresis for indicating a chromosomal
relationship.
And we assess finally the environmental condition by these analysis of
Salmonella isolated from wild animals. |
| |
|
| Hideto FUKUSHI |
Detection of drug resistance bacteria
reflects the presence of antibiotics and related chemicals in the environment.
Animals living far away from human activity might not possess drug resistance
bacteria. Hence the detection of drug resistance bacteria in certain wild
animals should indicate that their living habitat is affected by human
activity and that the isolation rates of drug resistant bacteria should
correlate the environment pollution. In this research, we evaluate the
environment through isolation and detection of drug resistance bacteria
in endangered wild animals and analyze genotypes and plasmid profiles
of isolated bacteria.
Samples will be collected in Okinawa prefecture, Chubu area and Hokkaido.
The samples are feces of some endangered animals. Isolation of Escherichia
coli and Enterococci willl be examined by the standard method. Mimimun
inhibitory concentration (MIC) should be estimated by NCCLS.
Genomic analyses are examined by puse-field gel electrophoresis. Plasmid
profiling is also examined by the standard method.
We would like to show the relatedness between environmental changes and
ecological dynamics of E. coli and Enterococci through isolation, drug
resistance evaluation and molecular analysis of E. coli and Enterococci
in endangered wild animals. |
| |
| Pathology
of infectious diseases in wild animals. |
| Kosuke OKADA |
|
Abstract: Because the Japanese serow (Capricornis crispus) has been
designated as a "Special Protected Animal" and is a very rare
species in the field of systematic zoology, aggressive steps have been
taken to protect this animal. Due to an increase in numbers in recent
years, their living area has expanded and issues such as damage to people
or farm products that may result from crossing with human living space
have become more serious. In addition, concerns about the spread of
common infectious diseases to humans and domestic animals have been
rising. Because there are many cattle breeding areas near the living
area of Japanese serow, there is also concern about the epidemic spread
of infectious diseases to the Bovidae family. More adequate preservation
methods of Japanese serow are needed.
Contagious pustular dermatitis, caused by infection with the parapox
virus, induces cauliflower-like thickened lesions and ulcerations in
the skin covering the whole body including the face and limbs. Histologically,
marked papillary growth of the epidermis is seen, and prickle cells
exhibit vacuolar degeneration and include eosinophilic inclusion bodies
in the cytoplasm.
The purpose of this study is to determine the pathology of infectious
diseases as part of biological research of Japanese serow living in
Iwate and Akita Prefectures.
- To perform antibody tests on the parapox virus, which has the most
significant effect on the dynamics of the population of Japanese serow.
- To search for the cause of death of wild animals by pathological
examination.
|
| |
| A
role of Japanese wild boars and mosquitoes in the natural infectious cycle
of Japanese encephalitis virus in Japan |
| Nobuyuki MINAMOTO |
It has been reported that the Japanese
encephalitis virus (JEV) isolates changed genotypes III to I in Japan
recently. While pigs were monitored in JEV-infection to predict epidemic
of Japanese encephalitis in Japan to date, wild animals have barely been
surveyed. The serum samples from 45 wild boars, 96 macaques, 64 deer,
40 raccoon dogs, and 43 nutrias in Japan were tested for virus neutralizing
(VN) antibodies against JEV in our first project. The positive rate for
VN test was 20.0% in these wild boars. This result shows that Japanese
wild boars are sensitive for JEV. In contrast, 4.2% and 1.6% of the macaques
and deer tested, respectively, were sero-positive for VN test, showing
that these animals are occasionally infected with JEV. These findings
raise the possibility that Japanese wild boars have played a role as a
reservoir for JEV before introduction of pigs into Japan. In our second
project, we will focus on the wild boar as a target animal for serological
investigation for JEV.
It is demonstrated that the ecology of blood feeding insects, which carries
zoonotic agents, is changing with environmental changes. In our first
project, the mosquitoes were collected in Iriomote Island where is located
in the southernmost part of our country and Gifu city and investigated
for the gene of flaviviruses by RT-PCR. To date, the gene of flaviviruses
was undetectable in a total of 28,382 mosquitoes (Armigeres, Aedes, Culex
and so on) collected in Iriomote Island. On the other hand, the gene of
flavivirus was amplified by RT-PCR from one sample (Culex) of 13,715 mosquitoes
(Culex, Anopheles, Aedes and so on) collected in Gifu city. Sequence analysis
of this amplified gene revealed that this virus belongs to old genotype
III of JEV in prevailing before 1990 in Japan. In this project, the prevalence
of flaviviruses including JEV will be investigated by detection of viral
gene or virus isolation from the mosquitoes that will be collected in
Iriomote Island and Gifu city following our first project.
From these researches, we will clarify the current status and dynamics
of JEV in nature of Japan and make the comprehensive assessments of the
environment by analyzing these data. |
| |
| Survey
for virus infections and prion disease in wild animals |
| Naotaka ISHIGURO |
Large mammals in Japan, especially, sika
deer (Cervus nippon) and Japanese wild boar (Sus scrofa leuocmystax) are
widely distributed in Kyushu, Shikoku and Honshu Islands. The increase
in numbers of sika deer and Japanese wild boar have caused serious agricultural
problems because they damage farms and eat crops. Such increase of animals
and wildly distribution of sika deer and wild boar may be a potential
source for infectious diseases to human being. To estimate the possibility
of infectious diseases from wild animals to human, extensive survey of
several infectious diseases in wild animals should be done by serological
and biochemical analyses.
Two diseases hepatitis E and chronic wasting disease (CWD) are examined
in sika deer. Serum samples are collected from sika deer killed by hunters
and examined for antibody to hepatitis E virus (HEV) by ELISA method.
After the HEV gene is isolated by RT-PCR, the genotype of HEV is compared
with those detected from the other sources. Surveillance of CWD is conducted
by performing Western blot analysis of tissue samples from sika deer.
Samples of the obex of the medulla oblongata are digested by proteinase
K and tested for the presence of PrPSc using Western blot analysis.
Serosurvey for two virus infections hepatitis E and Aujeszky's disease
is done in serum samples from Japanese wild boars. Serum samples are collected
from wild boars killed by hunters and examined for antibody to HEV by
ELISA method. After isolated by RT-PCR, genotypes of HEV are phylogenetically
analyzed. To estimate the genetic background of Japanese wild boars, we
examine haplotypes of mitochondrial DNA and genotypes of the nuclear glucosephosphate
isomerase-processed pseudogene, because distribution of HEV in Japanese
wild boars is locally limited. Phylogeographical analyses of Japanese
wild boars provide useful information about the frequency and distribution
of viral infections in the area. |
| |
| Ecology
of herpesviruses and chlamydiae in wild animals |
| Hideto FUKUSHI |
The sources of most emerging and re-emerging
diseases have been belived to be wild animals. However, less findings
indicated the scientific evidences. Herpesviruses widely spread in nature
and are in co-evolution with their natural hosts. The herpesviruses seldom
show strong virulence in their natural hosts. However, once they overcome
the species barrier, lethal pathogenicity is expressed in alien hosts.
Chlamydia also seems to be in co-evolution with birds and are known as
one of zoonotic agents. It is unclear that these herpesviruses and chlamydia
in wild animals and birds are maintained in nature and have potential
infectivity in domestic animals and human beings. In this research we
would like to find the spreading situation of herpesviruses and chlamydia
in wild animals and birds and potential source of infection for various
species.
Materials for examination would be feces and blood of wild mammals and
birds. DNA and RNA are extracted by the standard methods. PCR is examined
to detect herpesviruses and chlamydia by our established methods. The
amplified products should be read to determine base sequence. We analyze
relatedness between isolation rates and living habitat in order to reveal
certain relatedness between environment and pathogens. |
| |
| Pathological
analysis on infectious diseases in wildlife and zoo animals |
| Tokuma YANAI |
Nowadays wildlife and its surroundings
have been changed largely. Especially, the roles of wildlife as reservoir
or carrier in outbreaks of some emerging infections such as SARS or avian
influenza were widely noticed. In addition, the control of some infections
is still an important problem to be solved. On the other hand, an occurrence
of zoonotic infections such as chlamydiosis in zoo animals became a big
problem of public hygiene.
In this study, a large number of wildlife found dead and sent to Gifu
University The 21 Century COE program Wildlife Infectious Diseases Research
Center are necropsied and examined for emerging and reemerging diseases
that bring serious affection in conservation of these wildlife. Detailed
goals are as follows: 1) Clarification of pathogenesis on massive deaths
of wild birds. 2) Detection of infectious diseases in psittacine birds.
3) Pathological study of avian malaria in penguins. 4) Detection of mycotic
diseases in birds. 5) Pathological study on parapox virus infection in
Japanese serow. 6) Disease monitoring of waterfowls. 7) Detection of emerging
infections in wild and zoo animals. |
