1.
Isolation Of Surface Antigen 1 Gene Of Toxoplasma Gondii And Its Cloning In The Expression Plasmid
by Farooq Riaz (2008-VA-231) | Dr. Muhammad Imran Rashid | Prof. Dr. Kamran Ashraf | Dr. Jawad Nazir.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: Toxoplasma gondii is an obligate intracellular protozoan parasite which comes under the classification of phylum Apicomplexa, subclass Coccidiasina (Cornelissen et al. 1984). Toxoplasmosis is one of the more common parasitic zoonoses world-wide caused by Toxoplasma gondii which is a facultatively heteroxenous, polyxenous protozoon that has developed several potential routes of transmission within and between different host species (Tenter et al. 2000). It is the most important source of toxoplasmosis in humans and animals, with cat as definite host and warm-blooded animals as intermediate host (Frenkel et al. 1970). It was first described by Nicolle, Manceaux and Splendore in 1908 from rodents Ctenodactylus gondii (Black and Boothroyd 2000).
Toxoplasmosis is a worldwide parasitic disease and it is estimated that about one-third total population of the world is seropositive for Toxoplasma gondii (Tenter et al. 2000). Prevalence of infection varies between countries, geographical areas and ethnic groups living within a specific region. In Humans, infection rates range from 50% to 83% in Brazil (Tenter et al. 2000; Dubey et al. 2012). Seropositivity of Toxoplasma gondii in China is about 8% with continuously increase while in USA its 10-15%, 50-70% in France and 20% in UK (Dubey and Jones 2008; Zhou et al. 2008; Jones et al. 2009). Prevalence of toxoplasmosis is higher in males (79%) as compared to females (63.4%) and the age dependent sero-prevalence reaches >92% in age group of 40 to 50 (Coêlho et al. 2003).
Transmission occurs through the ingestion of contaminated vegetable /water with oocysts, as well as the ingestion of contaminated raw/undercooked meat with tissue cysts (Gajadhar et al. 2006). Transmission may also occurs by ingestion of sporulated oocysts, or bradyzoites within cysts present in the tissues of numerous food animals (Esteban-Redondo et al. 1999). In humans, transmission of Toxoplasma gondii happens mainly by eating raw or undercooked contaminated meat, raw cow’s milk and birds eggs, swallowing oocysts dis-charged in feces of infected cats, inoculation of trophozoites through the skin, or by inhalation (Wallace 1971; Wallace 1973; Bannister 1982).
In humans, mostly infections (congenitally or post-natally acquired) are asymptomatic. Congenital infection occurs only when a woman becomes infected during pregnancy. Congenital infections acquired during the first trimester are more severe than those acquired in the second and third trimester (Desmonts and Couvreur 1974). The main clinical signs associated with toxoplasmosis are anorexia, weight loss, lethargy, dyspnea, ocular signs, pyrexia, vomiting and diarrhea, jaundice, myositis, encephalitis and abortion. Humans become infected when they ingest the toxoplasma at infective stages (oocysts and tissue cysts) found in some cat feces and in raw meats.
In addition to being hazardous to livestock animals, the T. gondii infection is also important due to its zoonotic implications (Jittapalapong et al. 2005). Congenital abnormalities in humans, such as microcephaly, hydrocephaly, chorioretinitis, convulsion, cerebral calcification, epilepsy, blindness, deafness, and mental retardation may occur if the mother acquires infection during pregnancy (Jones et al. 2003). In addition to congenital anomalies, T. gondii also causes severe neuropathologic infections in immuno-compromised hosts, such as AIDS and cancer patients receiving chemotherapy (Del Valle and Piña-Oviedo 2005).
Seroprevalence studies of T. gondii among domestic animals in South-Western Pakistan has indicated considerable prevalence (25% in cattle, 2.5% sheep) (Zaki 1995) and suggesting potential transmission to the human community. Small scale study in urban area of Rahim Yar Khan (Punjab), Pakistan has revealed that the overall prevalence of toxoplasmosis in food animals is 19% (Ramzan et al. 2009). Another study has already been published that untreated patients with leprosy in Pakistan have shown significant seroprevalence (29.6%) of antibodies against T. gondii (Hussain et al. 1992).
Vaccine against toxoplasmosis is not available yet with one exception (“Toxovax” for sheep). Vaccine against T. gondii in animals used for human consumption may block the possible transmission to humans (Bhopale 2003). SAG1, among one of the major antigenic components of Toxoplasma gondii is a major surface antigen identified on the surface membrane of this parasite using a monoclonal antibody (Handman et al. 1980). SAG1 is an important surface antigen, expressed by tachyzoite form of T. gondii and is a putative candidate for vaccine and diagnostic against toxoplasmosis (Sharma et al. 1983; Godard et al. 1990). Immunization with SAG1 adjuvanted with saponin Quil A or incorporated in lysosomes provided total protection after challenge (Bülow and Boothroyd 1991; Khan et al. 1991). SAG1 is single copy gene with no introns (Burg et al. 1988), regulates both humoral as well as cellular Th1 immune responses (Liu et al. 2008) and is powerful candidate for vaccine against toxoplasmosis. SAG1 is a potent candidate of diagnostics for detection of serum antibodies against toxoplasmosis in Man and animals (Abu-Zeid 2002).
Availability: Items available for loan: UVAS Library [Call number: 2258-T] (1).
2.
Molecular Diagnosis Of Anaplasmosis In Buffaloes
by Muhammad Salman (2008-VA-135) | Prof. Dr. Khalid Saeed | Dr. Muhammad Imran Rashid | Dr. Wasim Shehzad.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: Bovine Anaplasmosis is a tick-borne haemo-rickettsail disease, caused by Anaplasma species transmitted mechanically by flies, biologically by ticks and blood contaminant fomites. It is an economically important tick-borne disease of buffalo in tropical and sub-tropical areas of the world. In current study, we developed and optimized PCR first for detecting Anaplasma at genus level in buffaloes. One hundred (100) blood samples were collected from buffaloes around the Lahore region. The stained thin blood films were examined microscopically and 37% blood samples were found positive for intra-erythrocytic bodies which were then selected for DNA extraction. The DNA was extracted using commercially available kit for eventual use in optimization of PCR for diagnosis of bovine Anaplasmosis. The primers were designed targeting 16S rRNA gene of Anaplasma. For the detection, the PCR product was run in 2% agarose gel stained with ethidium bromide and thirty seven samples showed the amplification band at 179bp. The selected samples were sent for ABI sequencing to Singapore for the accurate detection of the Anaplasma species. The sequencing results were blasted with database of Genbank and we observed homology with Anaplasma phagocytophilum. We found 37% prevalence of Anaplasmosis in buffaloes through PCR. However more studies are required to confirm the species of Anaplasma infecting buffaloes (Bobalus bobalis) by designing species specific primers. Furthermore, additional studies are needed to establish the epidemiology of Anaplasmosis by using molecular tools in different geographical areas of the country for their better control.
Availability: Items available for loan: UVAS Library [Call number: 2389-T] (1).
3.
Occurrence And Economic Losses From Theileriosis On Commercial Dairy Farm Of Holstein Friesian
by Muhammad Rashid (2014-VA-503) | Dr. Muhammad Imran Rashid | Prof. Dr. Khalid Saeed | Dr. Liaquat Ahmad.
Material type: ; Literary form:
not fiction
Publisher: 2016Dissertation note: Background: Theileriosis is a tick-borne disease and it is transmitted by the bite of ticks.
Previous work on disease problems in the study area suggested that Ticks and Tick-Borne
Diseases (TTBDs) are the major constraints to cattle production. They cause economic losses to
farmers in terms of cattle mortality, loss of body weight, loss of milk production and costs of
control of TTBDs by use of acaricides. Theileria is one of the major threat to cattle as it causes
anemia, weight loss, decrease production, mortality, treatment cost and cost for the control of
theileria. The proper data for losses atributed to theileriosis is still not available in Pakistan. For
this purpose a study was carried out in a commercial exotic dairy farm to evaluate losses
associated with theileriosis
Methodology: The study was done during the period of theileriosis to calculate its economic
effect on animal health and production. A total of 150 animals were selected randomly using
random number sample formula. The animal tag numbers were compared with random number
table, comparing animals were slecteded for study. Thin blood smear was performed for
diagnosis haemoparasite, further PCR was performed on those animals that were found +ve for
intraerythrocytic bodies. Faecal examination, California mastitis test, teat abnormality and
parturition history were recorded for the screening of these factors that decrease milk production.
After final grouping, milk production was recorded to identify the effect of theileriosis on
production. As theileriosis cause anemia due to destruction of RBC’s. body condition scoring
was also performed. Physical examination (lymph node and body temperature) of animals were
also performed to evaluate the clinical and subclinical theileriosis.
Results: For the evaluation of theileriosis, microscopy was performed on all the animals’ blood
samples. Haemoparasites were found in 28.67%. These were further processed by PCR for the
CHAPTER 6
SUMMARY
Summary
55
detection of theileriosis. Theileria was found in 27.90%. Screening of clinical and subclinical
mastitis by Califirnia Mastitis Test and microscopy for gastrointestinal parasite were performed.
On faecal examination, there found nematode, cestode and balantidium in 51.72%, 60.92% and
42.53%% respectively. After deworming with Valbazine and curafluke, nematode, cestode
(monzia), balantidium and coccidiosis were found in 0%, 39.13, 43.48% and 4.35% respectively.
Before grouping clinical and subclinical mastitis were found in 5.38% and 24.62% respectively.
After grouping clinical and subclinical mastitis were evaluated by California mastitis test with
two weeks interval. At 7th week clinical and subclinical mastitis were 3.85% and 7.69% due to
improved management. The decrease in milk production for clinical and subclinical theileriosis
was 87 lit./animal and 42.77 lit./animal. Costs for control, treatment and mortality were 0.12%,
0.20% and 13.09% respectively from overall farm expenditure. The prevalence of haemoparasite
was 28.67%, while the prevalence of theileriosis was 8%. The new cases of theileriosis were
recorded and incidence of theileriosis was found to be 2.25%. Overall losses due to theileriosis
was 13.70%.
Outcomes: We can conclude from our finding that theileriosis has drastic affect on the
profitability of the farms. Then losses can be attributed to decreased milk production and
mortality. Medications and control measure for theileriosis have added effect on the losses at
exotic animal breed dairy farms.
Perspectives: Cost analysis studies need to be done on different dairy farms of cattle of different
breeds at different ecological/climatic zones of Pakistan so that investors would know the risks
of establishing dairy farms. Availability: Items available for loan: UVAS Library [Call number: 2515-T] (1).
