Pathological Investigations Of Theileriosis (T.Annulata) In Cattle In Disteict Lahore Punjab
Material type: Book ; Format:
; Literary form:
Publisher: 2014 Dissertation note: Theileriosis is very important protozoal disease in crossbred cattle. According to an
assessment, about 250 million cattle are endangered by this disease and millions of high milk
yielding cattle are at risk of exposure to disease. It acts as a bigger restraint on livestock
improvement and production in many developing countries (Nagore et al. 2004). Theileria
annulata is the main specie that causes high morbidity and mortality. It causes heavy economic
and production losses in cattle in tropical and sub-tropical regions. The recorded mortality rates
in cattle reached to 70% (Moor house et al. 2001).
Theileria species are intracellular obligate hemoprotozoan parasites. All Theileria species
are dangerous and cause disease but two of them are important for livestock. Theileria parva and
T. annulata produces diseases named as East Coast fever and tropical theileriosis in cattle
respectively. Genus Theileria has many other species like T. buffeli, T. taurotragi, T. velifera, T.
sergenti and T. mutans. These species cause infections in wild and domesticated ruminants.
Theileria species present in large and small animals show signs like fever, anorexia,
swelling of the superficial lymph nodes, dyspnoea, lethargy, progressive anemia, constipation,
diarrhea, lacrimation and nervous symptoms (Saeed et al. 2010; Irvin and Mawmachi 1983). A
pronounced rise in body temperature, reaching 40-41.5 °C is pursued by lacrimation, depression,
swelling of the superficial lymph node and nasal discharge. The characteristic sign of tropical
theileriosis is anemia and finally haemoglobinuria occur with heavy weight losses. The clinical
course of the disease alter from per acute to acute or sub-acute to chronic (Oliveira- Sequeira et
al. 2005). The disease is lymphoproliferative in its early phases resulting enlargement of lymph
nodes, later on enters lymph destructive phase which is associated with a pronounced
leukopenia. In the piroplasms phase in erythrocytes, the parasite becomes infective for the tick
(El-Deeb and Younis 2009).
Trans placental Bovine Tropical Theileriosis causing a deadly disease in a 3 day old
neonate cross bred calf and cerebral form of the disease (turning sickness) in a cow were
incriminated to T.annulata infection. It mainly depends upon the harmful effects of the T.
annulata on lymphoid tissues and susceptibility of the host (Sudan et al. 2012).
Theileriosis is prevalent in various regions of the world including Pakistan. It is transmitted by
Hyalomma species ticks. These ticks spread T. annulata which causes tropical theileriosis
(Durrani et al. 2009). The developmental stages of Theileria inside the Hyalomma ticks varies in
different shapes and forms (Hamed et al. 2011). Therefore to increase the milk and meat
production of cattle we can prevent the spread of the disease by controlling ticks
(Hekmatimoghaddam et al. 2012). The sufficient amount of Hyalomma ticks are found in warm,
commonly hard marshland and in central and Southern Europe, south west Asia and Southern
Africa having very long dry season. A toxin is produced in the adult ticks. This toxin produce
clinical signs of mucus membrane hyperemic and moist profuse eczema (Adam et al. 2000).
The sporozoites of Theileria enter into cattle host during tick feeding and they
immediately infect mononuclear leukocytes, these sporozoites develop into macroschizonts and
induce proliferation of the host cells. Macroschizonts constantly mature into microschizonts and
finally into merozoites, which are discharged from leukocytes. These merozoites attack
erythrocytes and mature into piroplasms, become available to ticks. Infective sporozoites,
injected during tick feeding, rapidly enter target cells, escape from the surrounding host-cell
membrane and differentiate to schizonts that interact with different host-cell components
(Dobbelaereand Rottenberg 2003). This interaction includes host cell signaling pathways that
regulate proliferation and cell survival (Chaussepied and Langsley 2011) and thus cause
blastogenesis and clonal expansion of predominantly T and B cells (Fawcett et al. 1982; Baldwin
et al. 1988; Spooner et al. 1989). Merozoites released from these schizonts subsequently infect
red blood cells and become trophozoites. Lymphocytic stage of Theileria (schizonts) is the cause
of many of the severe disease manifestations like lymphadenopathy, pyrexia, thrombocytopenia,
and panleukopenia (Homer et al. 2000). Marked anemia, anisocytosis, pikilocytosis, and
leucopenia were commonly observed in bovine theileriosis (Ceci et al. 1997). Cattle may survive
the disease, but recovery and convalescence may be protracted and incomplete, this leads to
permanent debilitation, loss of productivity and prolonged carrier state. (Shahnawaz et al. 2011).
Cattle with subclinical infection in endemic regions become carrier of piroplasms and act as a
source of infection for the vectors (Brown 1997; Brown 1990; Uilenberg 1995).
The diagnosis of theileriosis in acute cases is majorly done on clinical signs and Giemsa
stained blood smears of cattle but the detection of agent is not reliable and is almost impossible
in carrier stage. Advances in molecular biological techniques have resulted in the improved
detection, identification, and genetic characterization of many hemoparasites. Species specific
polymerase chain reaction (PCR) has been developed for the detection and identification of
various Theileria species and has been shown to have higher sensitivity and specificity compared
with serological assays and examination of Giemsa-stained blood smears (Bhoora et al. 2009).
Primers were derived from the gene encoding the 30-kDa major merozoite surface antigen for T.
annulata (Aktas et al. 2006).
Most of the previous studies on haematological parameters in T. annulata infection were
carried out on experimentally infected cattle (Sandhu et al. 1998; Singh et al. 2001). The present
investigation was conducted to study haematological parameters in cattle naturally infected with
T. annulata. Hematology has been broadly used in attempts to give information about disease
condition, performance problems and health in cattle (Rezaei and Naghadeh. 2006).
Hematological and sero-biochemical alterations are the indicators of severity of disease and are
considered to be good tools for the diagnosis, prognosis for effective therapy (Col and Uslu
2007; Nazifi et al. 2010b).
Lahore is one of the larger district in the Punjab province of Pakistan. Different cattle
breeds are reared by the people of the area for meat and milk production. The exact current
situation about the prevalence and pathogenesis of Theileriosis in the selected area is unknown.
The present study was conducted to screen cattle by finding schizonts or piroplasms in Giemsa
stained thin blood smears at slaughter house of district Lahore (Aktas et al. 2006) and later to
confirm through Polymerase Chain Reaction (PCR) (Chaisi et al. 2013) in order to implement
efforts and regulation to eradicate the spread of disease in the selected area. Data generated from
this study provided the latest status of Theileriosis, sex wise prevalence and its pathogenesis in
cattle population of Lahore. The study has also provided the necessary information to formulate
strategies for control of disease in the area. An investigation was also undertaken to ascertain the
changes in haematology as a result of Theileria annulata infection. These studies will help better
understanding of the pathogenesis and supportive therapy of this disease.
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Pathobiological Studies Of Canine Parvo Virus Infection Currently Prevailing In Dogs In Pakistan
Material type: Book ; Literary form:
Publisher: 2016 Dissertation note: Canine Parvo virus infection is causing fatal disease to dogs resulting in severe morbidity and mortality. It is becoming disastrous for canids in Pakistan. It is important to study the pathogenesis of this deadly virus. Parvovirus infection has become more pathogenic with passage of time and its pathogenicity may be enhanced due to possible mutation in field virus. The possible mutations may be the cause of vaccine failure and rapid outbreaks.
In present study, sum of 50 fecal samples from different areas were collected and properly labelled. Both serological and molecular confirmation was done.
Haemagglutination test was used as a screening test. HA test was performed to check agglutinating activity of samples as described by (Desario et al. 2005). Haemagllutination was done and only 20 samples were found positive. Positive samples were selected for polymerase chain reaction. DNA of selected samples was extracted through kit method according to protocol provided by the manufacturer. Nano drop was done to check quantity and purity of viral DNA. PCR was performed. Already reported primers were used for detection of CPV (Buonavoglia et al. 2001). The PCR product was confirmed by running the PCR product on 1.2% agarose gel. Electrophoresis was performed at 110 Volts for 30 minutes. The amplified PCR product was further purified using GeneJet Gel Extraction Kit using instructions provided by the manufacturer. Purified samples were sent to commercial lab for Sanger sequencing. The obtained sequences were examined using BLAST (Basic Local Alignment Search Tool). Sequences were compared with other sequences already obtainable from the GenBank database (http://www.ncbi.nlm.nih.gov) and were carefully aligned by BioEdit software (version 22.214.171.124) using the ClustalW method. The MEGA software program, version 6.0 was used to construct a phylogenetic tree using the neighborhood joining method.
Complete blood count was performed on whole blood samples. The samples were divided into two groups (infected & non-infected) based on the results of PCR. Paired T-Test was applied on the results obtained and results showed that all parameters statistically showed significant difference between two groups except WBC’s but still the number of WBC’s decreases in infected animal like other parameters. Serum chemistry analysis was performed on serum samples. These samples were also divided into two groups (infected & non-infected) based on the results of PCR. Paired T-Test was applied on the results obtained and results revealed that all parameters statistically showed significant difference between two groups except ALT and creatinine levels.
Results showed that new CPV-2a was found to be the major circulating strain of Pakistan as out of 7 sequenced samples, 6 were identified as CPV-2a and only 1 of them was CPV-2. PCR was found to be the most sensitive assay for the detection of CPV, as compared to HA and ICT- CPV antigen detection kit. The strain in vaccine was identified as CPV-2, this finding was considered important because it indicates one of the reason for vaccine failure. The phylogenetic analysis of strains showed that all the samples collected from different regions of Pakistan falls in one clade and branching pattern is shared with the neighboring countries especially China. This information reveals that our virus is genomically similar to our neighboring countries India and China. Upon hematology and serum chemistry analysis, it was revealed that the virus does effect the blood parameters and all the red blood cell indices were lowered except platelet count.
The present study enabled us to study pathogenesis, to determine currently prevailing strain of CPV in Pakistan, identify the cause of disease occurrence even after vaccine, to study pathogenesis of CPV, to characterize and construct phylogenetic tree of currently prevailing canine parvovirus field isolates.
Availability: Items available for loan: UVAS Library [ Call number: 2662-T] (1).