Shafia Tehseen Gul

Immunosuppressive effects of arsenic in broiler chicks exposed to Newcastle disease virus

Abstract To assess the effects of prolonged exposure to arsenic (As, as arsenate) on host immune competence overall and resistance to Newcastle disease (ND) viral infection in particular, a study was carried out in broiler chicks. At 7 days of age, chicks were assigned to groups that would undergo varying vaccination, challenge, and/or As exposures; Group 1 was a control; Group 2 was to receive Newcastle disease virus (NDV) only; two groups (Groups 3, 4) were to be given As daily (50 mg/kg, by gavage) from Days 7–35 of the experiment. All groups underwent normal vaccination on Days 5, 23, and 32 against live NDV (B1 type, LaSota strain); two groups (Groups 2, 4) were challenged with field-isolated NDV at Day 24. At Days 14, 21, 28, and 35 of age, subsets of chicks in each group were evaluated. The results showed feed intake and weight gain were lower in As-treated and NDV-challenged chicks. In As-treated chicks, absolute and relative spleen weights were significantly greater, whereas those of the thymus significantly lower, over the entire 35-day period. Effects on bursa weights (absolute, relative) were only significantly reduced through Day 21. Antibody titers against ND were significantly reduced (vs. control) over the whole 35 days in birds that received As alone, but only significantly depressed through the first 21 days in birds that received As + NDV; thereafter, titers were significantly greater (in parallel with effects in birds that received NDV alone). In contrast, antibody responses to T-dependent antigen (Sheep red blood cells [SRBC]) were significantly lower in As only- and As + NDV-treated chicks throughout the study period. Among birds exposed to As (alone or with NDV), in situ phagocytic activity was elevated and cutaneous sensitivity responses decreased during the period from Day 28 to Day 35. NDV alone had spurious effects on phagocytic activity but did cause significant reductions in cutaneous sensitivity responses. It was concluded that arsenic decreased immunity in broiler chicks, thereby making them prone to ND.

Cutaneous form of pox infection among captive peafowl (Pavo cristatus) chicks

The present study was carried out to investigate the epidemiology and lesions of avian pox in captive peafowl chicks. Overall values of morbidity, mortality and case fatality were 45.2%, 27.1% and 60.0%, respectively. The chicks of 9 to 12 weeks of age showed a significantly (P<0.001) higher prevalence rate than other age groups. The morbidity and mortality due to avian pox in peafowl chicks was significantly (P<0.001) reduced when kept in mosquito-proof cages and hatched under broody chicken hens. Morbidity due to poxvirus infection on the peafowl farm was 82%, 26% and 12% in successive years. This reduction might have been the result of the introduction of mosquito-proof nets after year 1, although this was not the subject of a controlled experiment. All of the peafowl chicks suffering from dry pox showed pustular and nodular lesions on eye lids, beak, legs and toes. Distribution of lesions in different body parts varied significantly (P<0.023). Lesion diameters were less than 1 cm (59.73%), 1 to 2 cm (23.75%) and more than 2 cm (16.87%). Histopathological studies revealed extensive proliferation of subdermal connective tissue and infiltration of heterophils and macrophages. The keratinocytes showed degenerative changes in the form of cytoplasmic vacuolation, ballooning and hyper-chromatic nuclei. Eosinophilic intracytoplasmic inclusions (Bollinger bodies) in keratinocytes were consistently present. It was concluded that avian pox rendered high morbidity, mortality and case fatality in peafowl chicks.

Effect of sub-lethal doses of thiamethoxam (a neonicotinoid) on hemato-biochemical parameters in broiler chicks

Abstract This project was designed to observe the hemato-biochemical effects of sub-lethal doses of thiamethoxam (TMX) in broiler chicks. A-day old chicks (n = 90) were procured from the local market and maintained under standard housing conditions and divided into five equal groups (18 birds/group). The experimental trial continued for 45 days. Sub-lethal doses of TMX including 50, 100, 200 and 400 mg/kg B.W. to groups A, B, C and D were administered through crop tube, respectively. Group E served as a control. Blood and serum samples were collected from each group on 10th, 17th, 24th, 31st, 38th and 45th day of the experiment. The data were analyzed through ANOVA by MSTAT-C. All hematological parameters were determined. Serum samples were analyzed for ALT, AST, total proteins and urea. It was concluded from this study that even sub-lethal doses of TMX have toxic effects on hematology and biochemical parameters.

Protective effects of vitamin E on sodium arsenite-induced toxicity, testicular measurements and histopathological studies of testes in Teddy goat bucks.

The objective of this study was to investigate the toxic effects of arsenic on testicular measurements and histology of adult Teddy goats bucks and to examine whether these toxic effects are scavenged by vitamin E. Twelve adult Teddy goat bucks were divided randomly into three groups, A, B and C. Group A was kept as control, the B was given sodium arsenite 5 mg/kg BW per day, and group C was fed with vitamin E 200 mg/kg BW per day + arsenic 5 mg/kg BW per day. This treatment was continued for 84 days. Analysis of data revealed that the testicular measurements (scrotal circumference, width, length and weight) were significantly reduced in arsenic‐treated animals, whereas there were ameliorating effects of vitamin E on these parameters. The major histopathological changes were present in the form of loss of germinal epithelium, atrophy of Leydig cells and vacuolations. Vitamin E in combination with sodium arsenite increased the active spermatogenesis as well as restoration of germinal epithelium. It can be concluded from the present findings that sodium arsenite causes toxicity in the male reproductive system of Teddy goat bucks with major changes in parenchyma of testes. Supplementation of vitamin E has protective effects on the toxicity of sodium arsenite on the reproductive system of male Teddy goat bucks.

Immuno-pathologic effects of oral administration of chlorpyrifos in broiler chicks.

Abstract This study sought to assess if chlorpyrifos (CPF) induced immunotoxic effects in orally-treated day-old broiler chicks. Groups of chicks received per os CPF diluted in xylene at 5, 10, and 20 mg/kg body weight (CPF-5, CPF-10, and CPF-20) orally daily for 15 days. Xylene and control groups received xylene alone (1 ml/kg BW) and physiological saline, respectively. At various times during/after the exposure regimens, different immune end-points were analyzed in the birds. Humoral immunity was examined by assessing antibody responses to sheep red blood cells. Cell-mediated immunity was measured via lymphoproliferative responses to avian tuberculin. Leukocyte phagocytic ability was measured using a carbon clearance assay. Results showed that CPF administered to broiler chicks caused a dose-dependent decrease in humoral immunity, cell-mediated immunity, and phagocytic activity. Dose- and time-related pathological changes were observed in bursa of Fabricius, spleen, and thymus in treated birds. These changes were mild, moderate, and severe, respectively, in the 5, 10, and 20 mg/kg CPF groups. The Bursa of Fabricius in treated birds showed increased inter-follicular connective tissue proliferation, severe moderate cytoplasmic vacuolation, edema, and degenerative changes such as pyknosis and fragmentation of nuclei that depleted the follicles of lymphoid cells. In the spleen, disorganization of follicular patterns, severe congestion, cytoplasmic vacuolation, degenerative changes, and hyperplasia of reticular cells were noted. The thymus in treated birds exhibited congestion, hyper-cellularity, and a presence of immature monocytes in the medullary region, as well as myoid cell necrosis. Taken together, these studies clearly demonstrated that chlorpyrifos could induce immunotoxicities in broiler birds.

Immuno-toxicological effects of different sub-lethal doses of thiamethoxam (TMX) in broiler birds

Abstract This project was designed to evaluate the immunotoxicological effects of thiamethoxam (TMX). One-day-old broiler chicks (total of 90) were procured and maintained under standard housing conditions and divided into five groups for 45 days. Group A kept as control. Different doses of TMX were administered through crop tube containing 50, 100, 200, and 400 mg/kg bwt/daily to groups B, C, D, and E, respectively. Immunological parameters including response to sheep red blood cells (SRBCs), avian tuberculin responses and carbon clearance assay were accessed. It was observed that response to SRBCs including IgM and IgG, avian tuberculin and phagocytic responses are adversely affected in a dose-dependent manner with TMX toxicity. Hence it was concluded from the results that TMX is responsible for immunosuppression in broiler chicks even at different sub-lethal doses.

Amelioration of immunosuppressive effects of aflatoxin and ochratoxin A in White Leghorn layers with distillery yeast sludge

Abstract The present study was carried out with the objectives to thrash immunotoxic effects of moldy feed in commercial White Leghorn layers and to know either addition of distillery yeast sludge (DYS) in moldy feed ameliorates the immunotoxic effects or not. For this purpose, moldy feed was prepared containing OTA and AFB1 56 and 136 μg/kg, respectively. For this purpose, 100, 40-week-old White Leghorn hens were procured and kept under standard management conditions. Birds were divided into five equal groups. Birds were kept on moldy feed (ochratoxin A: 56 μg/kg and aflatoxin B1: 136 μg/kg) mixed with 0%, 0.5%, 1% and 2% DYS/kg moldy feed. Group A served as control. Blood was collected without anticoagulant to separate serum. Serum ALT, creatinine and blood urea levels significantly increased in moldy-fed group as compared to control group, while nonsignificantly different readings of serum ALT, creatinine and blood urea were recorded in moldy feed + 2% DYS and control group. Immune parameters, that is, lymphoproliferative response to PHA-P, phagocytic potential and total protein and IgG titers against sheep RBCs were significantly decreased in birds receiving moldy feed as compared to control group. Almost all parameters studied were normal compared to control group with the addition of 2% DYS in moldy feed, while 1% DYS partially ameliorated the immunotoxic effects of mycotoxins.

Evaluating the protective effects of vitamin E and selenium on hematology and liver, lung and uterus histopathology of rabbits with cypermethrin toxicity

Abstract The objective of this study was to determine the efficacy of vitamin E and selenium as protective agents against cypermethrin (CY)-induced toxicity by evaluating hematology parameters along with liver, lung and uterus histopathology of female rabbits. Thirty female rabbits were randomly divided into five equal groups with six animals in each group (designated A, B, C, D and E). Animals in group A were control animals that did not receive CY, vitamin E, nor selenium. Animals in groups B–E were injected intraperitoneally with CY at 75 mg/kg body weight once every5 days over a 32 day period, while animals in the control group received saline. Animals in group C were also given vitamin E (150 mg/kg b.wt) orally and animals in group D were given selenium (0.45 mg/kg b.wt) orally. Group E was given both vitamin E at a dose of 150 mg/kg and selenium at a dose of 0.45 mg/kg. In group B (CY only), the values of PCV were decreased at the 12th day of gestation when compared to group A. The mean value of PCV was significantly higher in group E on the 12 and 24th day when compared to the other groups. The mean values of hemoglobin (Hb) were not significantly different among groups on the 12th and 24th day of gestation. On the 12th day of the gestation period, there were nonsignificant differences in the total number of erythrocytes among all the groups. However, on the 24thdayof the gestation period, there was a significant decrease in the total number of erythrocytes in group B compared to the control group. Total leukocytes were also increased in the animals of group B on the 12th day of gestation, whereas the total leukocytes were increased on the 24th day of gestation in all groups (A–D) compared to control. Histopathological studies of tissues of liver, lungs and uterus revealed that CY altered the normal parenchyma of these tissues and this was partially ameliorated by the vitamin E and selenium treatments. In conclusion, combined use of vitamin E and selenium partially ameliorated the toxicity of CY in female rabbits.

Evaluation of DNA vaccine encoding BCSP31 surface protein of Brucella abortus for protective immunity

Brucellosis is a highly contagious and zoonotic disease and has a considerable impact on animal health and economy of a country, principally in Pakistan, where rural income largely depends upon livestock farming and dairy products. The disease burden is more in underdeveloped/developing countries due to the low economy and limited access to the diagnostic facilities. In Pakistan, the prevalence of Brucella abortus is very high, so it is the need of the hour to control this disease through more advanced methods. This study was designed with the aim to construct the DNA based vaccine of gene encoding antigenic surface protein (BCSP31). For this purpose, the BCSP31 gene was amplified, purified and ligated in pTZ57 R/T (cloning vector). Dubbed BCSP31-pTZ57 R/T vector was transformed into competent cells (DH5α). After plasmid extraction, the plasmid and pET-28a vector was restricted with EcoRI and BamHI. Again, ligation was done and dubbed pET-28a-BCSP31 transformed into E. coli (BL21). After expression, the protein was purified and used for evaluation of immunogenic response. The protective and immunogenic efficacy of the vaccine was evaluated in rabbits (n = 20). The rabbits were divided into four equal groups. Groups A-C were given purified protein diluted in normal saline @ 750, 1500 and 3000 μg/0.2 mL, respectively through intraconjunctival route. Group D was given 0.2 mL normal saline through intraconjunctival route. Specific immunoglobulin G (IgG) responses were measured through indirect ELISA on a weekly basis. The titer of IgG against the antigen was significantly (p < 0.05) higher in vaccinated groups A-C as compared to group D (control group) in a dose dependent manner. Moreover, log units of protection produced by DNA based vaccine in the rabbits (3.02) also indicated the protective efficacy of the DNA vaccine against B. abortus challenge. The response of this vaccine in rabbit suggested its potential effectiveness against Brucella abortus in large animals.