Title: Azza Negm
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2Human Pathogenic Protozoa in Bivalves Collected
from Local Markets in Alexandria
By Azza Negm
3Introduction
- Bivalves (shell fish) commonly known as Om El
Kholool and Gandofli are considered as a tasty
delicacy and are usually eaten raw. They are
however known as filter feeders concentrating
pathogenic organisms from the surrounding water
with the possibility of transmitting them to man.
4Aim of the Work
- To detect the possible presence of pathogenic
protozoa in the bivalves collected from the local
markets in Alexandria - If organisms are detected then, their infectivity
will be assessed by animal inoculation.
5Material and Methods
- The present study was conducted on two species of
bivalves Donax trunculus (Om El Kholool) and
Caelatura laronia (Gandofli) - To identify the possible presence of pathogenic
protozoa homogenization of the body of the
shellfish was done and the sedimented homogenate
was examined after staining with - Ziehl Neelsen
- Modified Trichrome
- Positive samples were pooled together and were
used to infect white mice by oral inoculation.
6- Experimental animals were grouped as follows
- Group I 10 animals infected with Gandofli
- GroupII10 animals infected with Om El Kholool
- Group III 5 animals served as non infected
controls. - Each animal was subjected to
- Stool examination
- Histopathological examination of the small
intestine
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9Conclusion
- Om el Kholool and Gandofli are potential sources
of some protozoal organisms which can easily be
transmitted to man especially that these
shellfish are usually eaten raw.
- These protozoa Microsporidia, Cryptosporidia and
Cyclospora are highly pathogenic especially in
immunosupressed patients.Therefore as a
precaution these shellfish should be properly
cooked before being eaten.
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11Detection of Trichomoniasis in Vaginal Specimens
by Both Conventional and Modern Molecular Tools
By Azza Y.Negm and Desouky Abd el Haleem
12Introduction
- Trichomoniasis has been associated with
vaginitis, cervicitis,urethritis and pelvic
inflammatory disease. In pregnancy it has been
associated with premature rupture of membranes,
premature delivery and low birthweight in
neonates.It also increases the risk of HIV
acquisition and transmission in women and was
considered a predisposing factor for cervical
cancer.
13- In men although trichomoniasis is usually
asymptomatic yet it may lead to urethritis and
infertility - Symptoms and signs of trichomoniasis are not
adequatly sensitive or specific for diagnosis
besides being asymptomatic in up to 50 of
infected individuals. So diagnostic tests are
usually required to confirm the presence of
organisms.
14Aim of the Work
To compare different techniques in diagnosis of
Trichomonas vaginalis in females
15Material and Methods
- The present study was conducted on 23 symptomatic
females. Their age ranged between 18 and 45
years. - From each female vaginal secretions were
collected on sterile cotton swabs and examined as
follows - Fresh wet mount
- Culture on Diamonds s medium
- Acridine orange stain
- PCR
16Results
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19Analysis of PCR products by 2 agarose gel
electrophoresis
20Diagnosis of T. Vaginalis infection by different
techniques
21Conclusion
- Direct Microscopy is a practical widely used
economical method, yet its sensitivity is low so
all the suspected samples which are found
negative by this method should be repeated
primarily by culture followed by PCR
22- Culture of T.vaginalis is a relatively
inexpensive option with high sensitivity but it
requires specific culture media and an incubation
period which may reach up to seven days so there
is a delay in treatment - PCR is easy to perform, highly sensitive and
specific yet it is expensive and cannot be used
for routine purposes. However it can be of great
value in undiagnosed patients.
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24Vaccination Against Congenital Toxoplasmosis
By Safeya M. Ali, Sonia R. Allam, Azza Y. Negm
and Lobna A. El Zawawy
25Introduction
- Infection of a woman with T. gondii for the first
time during pregnancy may induce her protection
but not that of her foetus. - Experimentally it was proven that immunization by
T. gondii tissue cysts induces immunity against
vertical transmission in mice. However, such a
procedure is relatively dangerous and the search
for a safer vaccine is required.
26Aim of the Work
- An attempt to convey immunity to new born of
experimentally infected pregnant mice by using
irradiated live T. gondii cyst vaccine alone, or
by the addition of IL-2 as an adjuvant as
compared to the live cyst vaccine alone or with
an adjuvant.
27Material and Methods
- Strains
- Virulent RH strain of T gondii was maintained by
serial IP passages of tachyzoites in mice. These
were used for challenge of pregnant female mice. - Avirulent KSU strain of T. gondii used for
production of vaccines
28- Vaccines
- Irradiated Cyst vaccine (ICV) Gamma rays applied
to the live vaccine - Irradiated Cyst vaccine IL-2 (ICV-IL-2).
- Live Cyst vaccine (LCV Prepared from brains of
three months old infected mice with KSU strain - Live Cyst vaccine IL-2 (LCV IL-2)
- Vaccines were administered orally before mating
in a dose of 5 cysts per mouse. - IL-2 was given IP in a dose of 0.2ml
29- 3. Grouping of Pregnant Female Mice
- Control Groups
- Normal non infected
- Non immunized infected
- Immunized non infected
- Experimental Groups Immunized Infected
- Subgroup 1 (S1) received ICV
- Subgroup 2 (S2) received ICV IL-2
- Subgroup 3 (S3) received LCV
- Subgroup 4 (S4) received LCV IL-2
30- All pregnant females were sacrificed near full
term (18-21 days). - Blood samples were collected and infection if
present was proved by ELISA. - Tissues were also examined by histopathological
sections. - Pups were removed by CS.
- Cord and Placental blood films were stained with
Giemsa. - Tissues from each pup were homogenized and
injected IP into normal mice which were later
examined for the presence of tachyzoites.in their
peritoneal exudates.
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34Results Conclusion
- Pre-immunization with the current vaccines
offered significant protection of both dams and
pups. - The highest level of protection was noticed in
mice which received
35- LCV-IL-2, followed by ICV-IL-2, then LCV and the
least protection was elicited in dams immunized
with ICV alone. - Thus there is a possibility of applying such
vaccines not only in mice but also in other
mammalian hosts including human.
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37DETECTION OF COPROANTIGEN IN EARLY TRICHINELLOSIS
By Boulos L.M., Ibrahim I.R., Negm A.Y., And
Aly S.M.
38Introduction
- Prompt diagnosis of early trichinosis not only
relieves patients of unpleasant symptoms and
serious complications, but can also avoid
unnecessary and costly evaluations. Moreover,
misdiagnosis of such early cases would be greatly
minimized.
39- Nowadays, coproantigen detection has proved to
be useful in diagnosis of many parasitic
infections such as G.lamblia, E.histolytica,
E.multilocularis, C.parvum and many other
parasites. However its use in diagnosis of
T.spiralis infection has not yet been assessed.
40Aim of the work
- Study the possibility of early diagnosis of
T.spiralis by detection of coproantigen in stool
using both the ELISA, as well as the Co-A test.
41Material and Methods
Parasite
The strain of T.spiralis was obtained from
infected pigs meat from the main slaughter house
in Alexandria.
42Exp. mice
CoproAg detection
Ag preparation
Adult crude Ag
Larval crude Ag
20 mice 300 L/m
20 mice 300 L/m
30 mice 500 L/m
43Preparation of hyperimmune sera (HIS)
HIS raised against T.spiralis Ags were prepared
in both rabbits and guinea pigs.
44Preparation of stool samples for Coproantigen
detection
Stoolanalysis
Preparation of faecal supernatant fractions 2000
g/30 min
Stoolcollection
45Modified double sandwich ELISA
Coproantigen detection
Co-agglutination test
46Detection of T.spirals antigen in stool of mice
at different durations using ELISA test
47Detection of T.spirals antigen in stool of mice
at different durations using CoA test
- Negative reaction Very weak ve Weak
ve Moderately ve High ve
48ve reaction
-ve reaction
Co-A reaction
49Advantages
Simple, rapid
Early detection
Non invasive
Past and present infection
Monitoring of parasitic development
50Conclusion
The current experimental study which was
carried out primarily as a model for human
trichinosis, indicated that coproantigen
detection was possible, even as early as the
first day post infection.
51 The use of hyperimmune sera raised against
larval antigen is preferred since the latter is
more easily prepared in terms of amount and
cleanliness.
52 The detection of coproantigens has showed a
great potential benefit for clinical and
epidemiological use and could play an important
part in the surveillance and control of
trichinosis in both developed and developing
countries.
53 Coproantigen assay should be applied in
communities dealing with and suffering from
enteric diseases especially among pig raising
farmers and/or garbage collectors to depict the
actual incidence of trichinosis.
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55Experimental Conversion of Virulent RH Toxoplasma
gondii Tachyzoites in Vitro
By N.A. Hammouda, I.R. Ibrahim, E.D. Elkerdany,
A.Y.Negm and S.R. Allam
56Introduction
- Toxoplasmosis is an important protozoal disease
of humans and domestic animals. In the
intermediate host, as man Toxoplasma gondii
exists in two forms rapidly dividing
tachyzoites, which are thought to be responsible
for the acute infection, and bradyzoites which
are believed to persist for the life span of the
host.
57- However, these dormant stages are able to
reconvert into the virulent tachyzoites in
immuno-compromised patients. The factors that
influence interconversion of stages are still
unknown .
58Aim of the Work
- Our aim was to convert tachyzoites to bradyzoites
in culture simply by changing the pH of the
culture medium. Changes in the morphology, DNA
content and cell cycle phases during
transformation were assessed.
59Material and Methods
Conversion of Tachyzoites
- RH tachyzoites, were harvested from previously
infected mice and washed in culture medium. - Macrophages were prepared from mice then
collected in culture medium (RPMI 1640) 10
foetal calf serum, L-glutamine, penicillin and
streptomycin.
60- Tachyzoites were then placed together with
macrophages in a modified medium with pH adjusted
to 8 using sodium hydroxide. - As a control organisms were cultured in the
standard (RPMI 1640) 5 foetal calf serum pH
7.4.
61Experiment
- Culture tubes were examined with their
corresponding controls at - Day 0 group 1
- Day 2 group 2
- Day 4 group 3
62- The following procedures were conducted-
- A . Giemsa and Feulgen Stains
- Giemsa stain
- Light microscopy
- Computerized image analyzer at 560 mm.
- Feulgen stain
- To determine the relative DNA content for each
individual parasite. - Tracing the cell cycle phase for each group.
- Organisms of group 2 and group 3 were compared
with group1 as well as with controls and any
morphological changes were noted
63- B. Assessment of infectivity after in vitro
incubation - Organisms from different groups were collected,
washed, counted and inoculated into mice. - Two to three months later the brains of infected
mice were homogenized and examined for Toxoplasma
cysts
64Results
65Cell cycle phases of the studied groups
66Conclusion
- It was possible to transform tachyzoites to a
slowly proliferating stage simply by changing the
pH of the culture medium. This observation will
facilitate the study of the differences between
the stages, and help in understanding more of the
mechanism of the disease thus allowing better
control of toxoplasmic reactivation.
67- Attenuation of toxoplasmic organisms by this
simple method, combined with assessment by
morphometry, DNA and cell cycle phase
measurements and evaluation of their infectivity
may help in the development of vaccines against
Toxoplasma and other parasites.
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69A New Approach in Cultivation of Leishmania major
Using Human Urine
By Mona M. El Temsahy and Azza Y. Negm
70Introduction
- A number of culture media, especially liquid
media designed for the bulk cultivation of
Leishmania contain either fetal calf serum (FCS)
or a blood lysate as one of their essential
ingredients.
71- Serum is a complex, highly variable and difficult
to characterise reagent, beside being expensive. - Using blood lysate in culture media, makes the
medium translucent, and preparation of a sterile
blood lysate is quite difficult. A cheap easily
available, serum-free but good medium has been a
goal for researchers.
72Aim of the Work
- The aim of the present work was to investigate
the possibility of using human urine as an
alternative ingredient for cultivating and
isolating Leishmania major.
73Material and Methods
Parasite
L. major MHOM/SN/OO/DK1
- I- In vitro Leishmania culture
- Promastigotes grown on Tanabes medium were
collected, washed and counted to reach a final
concentration of 106 parasites/ml.
74RPMI 1640 5 urine
RPMI 1640 10 FCS
RPMI 1640
- Parasites were counted on alternate days starting
from day two to day 14 to estimate the number of
parasites/ml.
75II- Isolation of Leishmania
- Amastigotes were withdrawn from the footpads of
infected Swiss albino mice and inoculated into
the urine supplemented medium to determine the
possibility of isolation on such medium.
76- Assessment of infectivity after repeated
subculture on urine supplemented medium
Mice
inoculated with promastigotes repeatedly
subcultured on urine supplemented media
inoculated with promastigotes repeatedly
subcultured on ordinary media for the same
duration
77Results
I. Growth curves of Leishmania promastigotes
Mean number of promastigotes/ml culture media in
the three studied groups
78- II- Isolation
- Leishmania amastigotes withdrawn from footpads of
infected mice could not be isolated on
urine-supplemented media. - III- Maintenance and infectivity
- Mice inoculated with promastigotes repeatedly
subcultured on urine-supplemented media showed
typical lesion two weeks post infection as
compared to the control group.
79Conclusion
- Human urine is an inexpensive, readily available
growth supplement for culture and maintenance of
L.major without affecting the parasite
infectivity. - No sophisticated facilities are required for its
preparation, making it ideal for researchers
working in developing countries.
80- Since the medium is free of blood or its
products, it is well suited for immunologic as
well as biochemical work on the parasite. - Urine supplemented media is not suitable for
isolation of Leishmania.
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82Morphology, Histochemistry and Infectivity of
Blastocystis hominis Cyst
By Iman F. Abou el Naga and Azza Y. Negm
83Introduction
- Blastocystis hominis is a protozoal parasite
frequently found in human fecal samples. - Cystic and trophic stages were reported, the
latter has different morphological forms. The
life cycle of this parasite has not been
definitely established and in recent years
several studies suspected that the cystic form is
the infective stage of this protozoa.
84Aim of the Work
- The present work aimed at studying the morphology
and histochemistry of the cystic stage using
different staining techniques. The infectivity of
this stage was also verified by experimentally
infecting albino mice.
85Material and Methods
- One hundred and twenty diarrheic stool samples
were collected from different departments of
Alexandria University hospitals and examined as
follows. - Direct saline and iodine smears.
- Formol-ether concentration technique.
- Morphological study was undertaken for both
trophic and cystic stages present in the positive
stool samples using - Iodine smear
- Sargeaunts stain.
86- In vitro encystations was done by keeping fresh
stool containing trophozoites of Blastocystis in
2.5 potassium dichromate at 4ºC for 2 weeks. - The in vitro induced cysts were subjected to
- Morphological study
- Histochemical study
- Test of infectivity
87- I- Morphological study
- Light microscope
- Direct and iodine smears
- Sargeaunts stain
- Iron haematoxyline stain
- Transmission electron microscope
- II- Histochemical study
- Alcian blue used for study of carbohydrates.
- Sudan III used for study of lipids.
88III- Test of infectivity
10 mice were inoculated with 1 ? 104 cyst/mouse
1 week P.I
Stool analysis
2 weeks P.I
Mice were sacrificed and small and large
intestine were studied histopathologically
89Results
- Morphological study
- Light microscopic examination of the cysts found
in stool and the in vitro induced cysts showed
that both had the same morphology.
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92Conclusion
- Infective Blastocystis cysts could be induced in
vitro. - The morphological similarity between these
induced cysts and those recovered in stool
samples facilitates further studies on this
protozoa as regards the life cycle and the
development of control strategies to prevent its
transmission.
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94Effect of Topical Agents on Cercariae of
Schistosoma mansoni
By Azza Y. Negm, Iman R. Ibrahim, Mona M. El
Temsahy and Mervat Z. El Azzouni
95Introduction
- In Egypt schistosomiasis is still considered a
major health problem despite the massive efforts
to eradicate the disease.
96- Skin is the commonly known route of entry for
this parasite into humans as the cercariae can
penetrate intact skin within minutes after water
contact. - Therefore, several topically applied substances
have been screened for their ability to confer
protection against cercarial penetration.
97Aim of the Work
- The present work aimed to study the effect of
local application of DEET (N-N-Diethyl
Toluamide), controlled release DEET and white
ppt. ointment (Ammoniated Mercury) on cercariae
of S.mansoni both in vitro and in vivo.
98Material and Methods
- Parasite
- S.mansoni cercariae shed from infected
Biomphalaria alexandrina snails. - Drugs used
- DEET (N-N-Diethyl Toluamide).
- Controlled release DEET.
- White precipitate ointment (Ammoniated Mercury).
99I- In vitro study
- Light microscopy
- Motility
- Viability
- Scanning electron microscopy
1002- In vivo study
- Experimental animals
- Group I 10 mice sprayed with DEET (OFF) prior to
infection. - Group II 10 mice painted with controlled release
DEET prior to infection. - Group III 10 mice painted with white ppt.
ointment prior to infection.
101- Infected control group
- Infected with S.mansoni only.
- Assessment of in vivo study
- Perfusion
- Histopathological study.
102Results
I- In vitro study
- Light microscopy
- Cercariae exposed to free DEET were motile for 20
min. when stained with toluidine blue most of
them took up the dye and appeared blue.
103- Cercariae exposed to controlled release DEET
formulae. Mobility was observed for five min
only. All cercariae appeared blue when stained. - Control Cercariae were motile and remained
unstained with toluidine blue stain.
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107II- In vivo study
Mean Schistosomal Worm Load Recovered From
Different Experimental Groups As Compared To The
Control Group
108Mean Number Of S. mansoni Granulomas/LPF at 7
Weeks Post Schistosomal Infection In Different
Experimental Groups As Compared To The Control
Group
109Conclusion
- Controlled release formula of DEET is recommended
for use as a safe, long acting cercaricidal
agent. - It can also be beneficial in reducing dermatitis
associated with swimmers itch.
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111Influence of Temperature and Salinity on the
Viability and Infectivity of Giardia lamblia and
Cryptosporidia parvum
By Salwa T. El Mansoury, Iman F. Abou El Naga,
Azza Y. Negm and Eglal E. Amer
112Introduction
- Giardia lamblia and Cryptosporidium parvum are
worldwide intestinal protozoa. Several human
outbreaks containing such protozoa have resulted
from drinking polluted water.
113- The factors affecting the survival and
infectivity of these protozoa in water are of
considerable importance for assessing the risk
potential of contracting the infection. Such
factors include use of disinfectants,
temperature, salinity, storage time pH etc.
114Aim of the Work
- To assess the effect of different degrees of
temperature and salinity on the viability and
infectivity of Giardia lamblia and
Cryptosporidium parvum at different storage time.
115Material and Methods
- Giardia lamblia cysts and Cryptosporidium parvum
oocysts were collected from diarrheic stool
samples from the different departments of
Alexandria University Hospital. - 1- Stool Samples
- Identification
- Giardia lamblia was identified by direct saline,
iodine smears and trichrome stain. - Cryptosporidium parvum was identified by
modified Z-N stain.
116- Preservation and Purification of Positive samples
- Giardia lamblia and Cryptosporidium parvum were
filtered through two layers of gauze and stored
in an equal amount of 2.5 potassium dichromate. - Giardia lamblia was purified by repeated washing
and sedimentation by 0.85 NaCl. - Cryptosporidium parvum was separated by
Sheathers's sugar floatation .
117- 2- Testing Viability
- I.Using fluorogenic dyes
- Fluorescence diacetate (FDA) and Propidium iodide
(PI) - Viable organisms fluoresced intensely green with
FDA and dead organisms fluoresced bright orange
with PI - II. Oral Infection of Experimental Animals and
their Stool Examination - Rats were infected with Giardia lamblia.
- Mice were infected with Cryptosporidium parvum.
118- 3-For Testing the Effect of Temperature and
Salinity - Temperature used was 100 C, 4C and -4C for
different durations of time. - Salinity was examined at 10ppt, 30ppt and 50ppt.
- 4- Assessment of Viability of Protozoa after
Exposure to the Different Factors - Vital dyes
- Animal infectivity was assessed by stool
examination and histopathological study of the
ileum
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121Conclusion
- The effect of temperature on the viability of
Giardia lamblia cysts and Cryptosporidium parvum
oocysts showed that temperature was only
effective at 100C, while at 4C and -4C, the
viability was preserved up to seven days.
122- Water used for drinking or preparing food, should
be boiled for at least 1 min, or preserved at
room temperature for at least 7 days to minimize
the risk of contracting infection. - Salinity at low concentration has an impact on
protozoal viability only if they were exposed for
long duration of time, whereas, high
concentration salinity is the most influential
factor. This demonstrates that sea food should
not be eaten unless perfectly cooked also
swimming in contaminated areas with such protozoa
should be avoided.
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