Loading...
Assam Agricultural University, Jorhat
Assam Agricultural University is the first institution of its kind in the whole of North-Eastern Region of India. The main goal of this institution is to produce globally competitive human resources in farm sectorand to carry out research in both conventional and frontier areas for production optimization as well as to disseminate the generated technologies as public good for benefitting the food growers/produces and traders involved in the sector while emphasizing on sustainability, equity and overall food security at household level.
Genesis of AAU -
The embryo of the agricultural research in the state of Assam was formed as early as 1897 with the establishment of the Upper Shillong Experimental Farm (now in Meghalaya) just after about a decade of creation of the agricultural department in 1882. However, the seeds of agricultural research in today’s Assam were sown in the dawn of the twentieth century with the establishment of two Rice Experimental Stations, one at Karimganj in Barak valley in 1913 and the other at Titabor in Brahmaputra valley in 1923. Subsequent to these research stations, a number of research stations were established to conduct research on important crops, more specifically, jute, pulses, oilseeds etc. The Assam Agricultural University was established on April 1, 1969 under The Assam Agricultural University Act, 1968’ with the mandate of imparting farm education, conduct research in agriculture and allied sciences and to effectively disseminate technologies so generated. Before establishment of the University, there were altogether 17 research schemes/projects in the state under the Department of Agriculture. By July 1973, all the research projects and 10 experimental farms were transferred by the Government of Assam to the AAU which already inherited the College of Agriculture and its farm at Barbheta, Jorhat and College of Veterinary Sciences at Khanapara, Guwahati.
Subsequently, College of Community Science at Jorhat (1969), College of Fisheries at Raha (1988), Biswanath College of Agriculture at Biswanath Chariali (1988) and Lakhimpur College of Veterinary Science at Joyhing, North Lakhimpur (1988) were established. Presently, the University has three more colleges under its jurisdiction, viz., Sarat Chandra Singha College of Agriculture, Chapar, College of Horticulture, Nalbari & College of Sericulture, Titabar. Similarly, few more regional research stations at Shillongani, Diphu, Gossaigaon, Lakhimpur; and commodity research stations at Kahikuchi, Buralikson, Tinsukia, Kharua, Burnihat and Mandira were added to generate location and crop specific agricultural production packages.
Browse
15 results
Search Results
ThesisItem Open Access DNA POLYMORPHISM IN MITOCHONDRIAL GENES ENCODING ND1, CO1 AND CYTB IN CANINE MALIGNANT TUMOURS(College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati, 2020-01) REHMAN, SHAKEEL-UL; Borah, ProbodhMalignant tumours in dogs are frequently reported. The types of malignancies commonly reported in canines include female breast cancers, lymphomas, adenomas and carcinomas of mast cells. Specific mutations and polymorphism in mitochondrial genes have been shown to be associated with different types of human malignancies. However, similar studies in respect to malignant tumours in dogs are very limited. Hence in the present study, an attempt was made to identify frequency of occurrence of mutation and polymorphism in gene sequences encoding NADH dehydrogenase subunit 1 (ND1), cytochrome b (CYTB) fragments of mtDNA and cytochrome c oxidase subunit 1 (CO1) in dogs, and to define the association of DNA polymorphic mutations with different tumour types. Based on histopathology, out of 10 tumours examined 5 (50%) were found to be of epithelial and the rest 5 (50%) of mesenchymal origin. Two of the five epithelial tumors were recognized as adenonocarcinoma and three as squamous cell carcinoma. Of the five mesenchymal tumors, four were identified as fibrosarcoma and one as liposarcoma. Of the 10 cases, 8 (80%) were recorded in local and 2 (20%) in crossbred dogs. While 7 (70%) cases were recorded in male, 3 (30%) were observed in females. Location-wise, two each of the tumours were observed in skin and mammary gland, while one each was observed in mouth, left flank, abdominal region, testicle, right elbow and left forelimb. The dogs suffering from the neoplastic growth in different parts of the body were within the range of 5 - 13 years of age. Analysis of three mtDNA gene fragments established a relatively low level of molecular genetic variation between the tissues (tumour tissue, normal tissue and blood) of the individuals examined. Majority of the mutational changes in the ND1, COI and CYTB gene fragments in the analyzed tissues in most of the dogs with tumours were insertions and deletions. Only a few polymorphisms were noted in the partial gene fragments of the analyzed tissues when compared to reference successions. Multiple substitutions and insertions have been noted in ND1 gene fragment; these included four substitutions (C218T, T455C, G498A and C666T) and three insertions (341InsC, 355InsC and 718InsT). However, no mutations were recorded in ND1 gene fragment from any of the three types of tissues examined in case of a dog affected with squamous cell carcinoma. Changes in CYTB gene fragment included two substitutions (C322T and T799C) and one insertion (303InsG) mutation. Polymorphism C322T in the CYTB fragment was noted in 40% of the samples analysed. No mutation was, however, detected in this gene fragment in one case of fibrosarcoma. In the COI gene fragment, A735G polymorphic mutation was recorded in all (100%) the 10 cases of malignant tumours investigated in the present study. In this gene fragment, instances of mutations recorded were comparatively lesser. Except for C218T mutation observed in ND1 gene fragment seven cases of canine malignant tumour that induced S (Serine) to Y (Tyrosine) variation in the amino acid sequence of the coded protein at position 72, no other substitution mutation recorded in this gene fragment could cause a variation at the level of amino acid sequence. On the other hand, none of the mutations detected in CYTB gene fragment could induce any change in the level of amino acid sequence of the coded protein. Similarly, the only substitution mutation in the CO1 gene fragment that induced a change at the amino acid level was A813T mutation observed in a case of fibrosarcoma, which caused a G (Glycine) to A (Alanine) variation at 71 position. Results of the present study showed the effect of two alleles (ND1: 218, CO1: 813) on the amino acid sequence of the coded proteins which suggested consequently their potential role in carcinogenesis. However, the sample size in the present study was too small to infer conclusively about the association of the mutations and polymorphisms identified in the present study with specific malignant tumours in dog.ThesisItem Open Access EXPRESSION OF CAP PROTEIN OF PORCINE CIRCOVIRUS TYPE 2 (PCV2) AND EVALUATION OF ITS IMMUNOGENICITY IN MICE(College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati, 2022-03) BORAH, DEBARUN; Hazarika, GirinThe present study was conducted with an aim to express the Cap protein of Porcine Circovirus Type 2 (PCV2) in a prokaryotic host and to assess its immunogenicity in mice. The recombinant pET32a/CT-His plasmid containing a codon-optimised PCV2 cap gene was transformed into E. coli BL21(DE3) cells for expression of the Cap protein after 8 hours of IPTG induction at 37°C. Subsequent SDS-PAGE analysis revealed an intense band of 46 kDa. Following successful purification by affinity chromatography using Ni-NTA column under denaturing conditions, the recombinant protein was refolded by dialysis. In western blot analysis of the purified protein, a 46.0 kDa-sized intense band was detected in the PVDF membrane. In four groups of Swiss albino mice consisting of six mice in each group, the immunological response to the purified recombinant Cap protein was assessed and compared to that of a commercial vaccine. Group 1 served as the control group receiving PBS, while Group 2 received a commercial vaccine, Group 3 received the recombinant Cap protein, and Group 4 received the Cap protein combined with Freund's adjuvant. On the 14th day post-primary immunization, each group of mice received a booster dose of the corresponding inoculum. Serum was collected from all the experimental animals on 0, 7th, 14th, 21st, 28th, 35th, and 42nd days after immunization. As detected by indirect ELISA, the mean antibody level against PCV2 was significantly higher in Group 4 getting Cap protein with Freund's adjuvant, than in Group 2 receiving the commercial vaccine, and Group 3 receiving the Cap protein alone. The recombinant Cap protein was found to be immunogenic in mice and was capable of inducing a specific IgG response, as detected by indirect ELISA. Based on the results of the present study, it may be concluded that the recombinant Cap protein expressed in E. coli is a promising immunogen and may be further explored as a vaccine candidate against PCV2. Use of the recombinant protein as a potential diagnostic antigen may also be explored in future.ThesisItem Open Access Toxin gene profiling of Clostridium difficile in food and food products of animal origin(Assam Agricultural University, Khanapara,Guwahati, 2017-07) HAZARIKA, RITAM; SHARMA, R.K.The present work was undertaken with a view to investigate the presence of Clostridium difficile in food and food products of animal origin and profiling of toxin genes. A total of 235 samples were collected from different sources including raw meat (beef, pork, chicken and chevon), meat products (dry beef, dry pork, cooked chicken, chicken sausage and chicken salami), raw cow milk, milk product (Indian paneer) and fish products (dry fish and canned fish). Out of the total 235 samples, initially 56 (23.83%) samples revealed suspected colonies of C. difficile. All the suspected colonies exhibited the typical colony morphology with horse manure odour and typical Gram-positive rod shaped cell with sub-terminal spores. Among 56 tentative isolates, 17 (7.23%) could be confirmed as C. difficile, based on the detection of species specific gluD (GDH) and tpi (triose phosphate isomerase) genes. The 17 confirmed C. difficile isolates comprised of 15 (8.24%) from raw meat and meat product samples and remaining two (11.11%) from fish product samples. None of the samples from cooked chicken, raw chevon, chicken sausage, chicken salami, canned fish, cow milk and paneer yielded any C. difficile isolates. All the 17 C. difficile isolates were screened for detection of glutamate dehydrogenase (GDH) protein and toxin A and /or toxin B by enzyme immuno assay (EIA), out of which all isolates were found positive for GDH protein and six were found to be phenotypically positive for toxin production. The C. difficile isolates were characterized by PCR for detection of toxin genes (tcdA, tcd B and binary toxin) and PaLoc region. Antimicrobial resistance pattern was also tested against nine different antimicrobial agents by E-test. Altogether, six C. difficile isolates were found to be toxigenic. Out of which two were from chicken samples and four from pork samples. All the toxigenic isolates from chicken (2) samples possessed both tcdA and tcdB (A+ B+), while all the pork isolates (4) carried variant toxin genes (A-B+). All the (A-B+) isolates from pork were found to harbour the binary toxin genes (cdtA and cdtB). Based on the detection of PaLoc region comprising regulatory genes tcdC, tcdR and tcdE revealed that the two toxigenic chicken isolates (A+ B+) possessed tcdC and tcdE ,while the remaining four toxigenic pork isolates (A-B+) carry tcdR and tcdE, respectively. All the 17 C. difficile isolates showed higher resistance pattern to ciprofloxacin (70.59%), followed by cefotaxime (58.82%), clindamycin (29.41%) and tetracycline (17.64%) but 100 per cent sensitive to chloramphenicol, moxifloxacin, tigecycline, metronidazole and vancomycin. All the beef isolates were clindamycin- resistant with an MIC of 96 - 128 mg/ml. While, all C. difficile isolates from pork and dry fish were sensitive to the antimicrobials tested except ciprofloxacin and cefotaxime, the four chicken isolates were sensitive to the antimicrobials except ciprofloxacin.ThesisItem Open Access Toxin gene profiling of Clostridium difficile in food and food products of animal origin(Assam Agricultural University, Khanapara,Guwahati, 2017-07) HAZARIKA, RITAM; SHARMA, R. K.The present work was undertaken with a view to investigate the presence of Clostridium difficile in food and food products of animal origin and profiling of toxin genes. A total of 235 samples were collected from different sources including raw meat (beef, pork, chicken and chevon), meat products (dry beef, dry pork, cooked chicken, chicken sausage and chicken salami), raw cow milk, milk product (Indian paneer) and fish products (dry fish and canned fish). Out of the total 235 samples, initially 56 (23.83%) samples revealed suspected colonies of C. difficile. All the suspected colonies exhibited the typical colony morphology with horse manure odour and typical Gram-positive rod shaped cell with sub-terminal spores. Among 56 tentative isolates, 17 (7.23%) could be confirmed as C. difficile, based on the detection of species specific gluD (GDH) and tpi (triose phosphate isomerase) genes. The 17 confirmed C. difficile isolates comprised of 15 (8.24%) from raw meat and meat product samples and remaining two (11.11%) from fish product samples. None of the samples from cooked chicken, raw chevon, chicken sausage, chicken salami, canned fish, cow milk and paneer yielded any C. difficile isolates. All the 17 C. difficile isolates were screened for detection of glutamate dehydrogenase (GDH) protein and toxin A and /or toxin B by enzyme immuno assay (EIA), out of which all isolates were found positive for GDH protein and six were found to be phenotypically positive for toxin production. The C. difficile isolates were characterized by PCR for detection of toxin genes (tcdA, tcd B and binary toxin) and PaLoc region. Antimicrobial resistance pattern was also tested against nine different antimicrobial agents by E-test. Altogether, six C. difficile isolates were found to be toxigenic. Out of which two were from chicken samples and four from pork samples. All the toxigenic isolates from chicken (2) samples possessed both tcdA and tcdB (A+ B+), while all the pork isolates (4) carried variant toxin genes (A-B+). All the (A-B+) isolates from pork were found to harbour the binary toxin genes (cdtA and cdtB). Based on the detection of PaLoc region comprising regulatory genes tcdC, tcdR and tcdE revealed that the two toxigenic chicken isolates (A+ B+) possessed tcdC and tcdE ,while the remaining four toxigenic pork isolates (A-B+) carry tcdR and tcdE, respectively. All the 17 C. difficile isolates showed higher resistance pattern to ciprofloxacin (70.59%), followed by cefotaxime (58.82%), clindamycin (29.41%) and tetracycline (17.64%) but 100 per cent sensitive to chloramphenicol, moxifloxacin, tigecycline, metronidazole and vancomycin. All the beef isolates were clindamycin- resistant with an MIC of 96 - 128 mg/ml. While, all C. difficile isolates from pork and dry fish were sensitive to the antimicrobials tested except ciprofloxacin and cefotaxime, the four chicken isolates were sensitive to the antimicrobials except ciprofloxacin.ThesisItem Open Access DEVELOPMENT AND EVALUATION OF IMMUNOPOTENCY OF OUTER MEMBRANE VESICLES VACCINE OF Salmonella Typhimurium ADJUVANTED WITH CHITOSAN NANOPARTICLES(Assam Agricultural University, Khanapara,Guwahati, 2017-07) SARMAH, RAKESH KUMAR; Tamuly, ShantanuDuring the past two decades, Salmonella Typhimurium has emerged as a leading cause of human infections in many countries and the Salmonella spp has a broad host range and can infect broad array of animals causing diseases ranging from gastroenteritis to life threatening systemic infections. Salmonella enterica serovar Typhimurium is most frequently isolated serovar causing global food born outbreaks. The control of Salmonellosis can be accomplished either by vaccination or medication. Antibiotic resistance and antibiotic residue is a major hurdle in medication. The present study was conducted to study the efficacy of the chitosan nanoparticle adjuvanted outer-membrane vesicle based vaccine candidate against Salmonella Typhimurium. The OMV was extracted from Salmonella Typhimurium (MTCC-98) strain and confirmed by SDS-PAGE. The (ChNP-OMV) vaccine was synthesized by standard method and nanometer size was confirmed by TEM studies. In the immunization study three vaccine formulation were compared and injected in the 7th day and followed by booster dose on the 14th day. The humoral immune response of the target vaccine was compared with OMV based vaccine with or without booster dose and oil adjuvanted bacterin vaccine with or without booster dose by indirect ELISA. Collection of serum was done on 0th day just before vaccination, and thereafter 7, 14, 28, 45 and 60 days post primary vaccination. Humoral immune response in mice of all the experimental groups determined by using indirect ELISA. The (ChNP-OMV) vaccine was able to elicit quick and higher antibody response in the 14th day followed by steady decline up to 60th day. All the vaccine formulation elicited similar IgG response on 7th day PPI, however chitosan nanoparticle adjuvanted outer-membrane vesicle based vaccine elicited highest IgG response on 14th days PPI (with or without booster dose) with statistical significance of 95 % confidence level. Serum enzymatic test revealed that the significantly lower serum creatine kinase level in 7th and 14th day in the group of mice that was administered chitosan nanoparticle adjuvanted outer-membrane vesicle based vaccine as compared to the group of mice that was injected oil adjuvanted bacterin vaccine on 14th days PPI. However a significant decrease in antibody response was observed for the groups containing (ChNP-OMV) complex. From this study, it can be concluded that the ChNP-OMV (S. Typhimurium) vaccine was indicative of quick immune response for immediate vaccination in outbreaks against salmonellosis.ThesisItem Open Access CHARACTERIZATION AND QUALITY EVALUATION OF PIG FIBROBLAST CELLS AT DIFFERENT SUBCULTURES(Assam Agricultural University, Khanapara,Guwahati, 2017-07) DHAR, PRIYA; Nath, N. Ch.Fibroblast cells are the most common cells of connective tissue. In the present study, porcine fibroblast cells were isolated, cultured and subcultured upto six passages from adult and fetal skin samples. The time required to attain 70% confluence in primary culture of fetal fibroblast cells was found to be 26.40±2.40 hours, which was significantly lower (p≤0.01) than 67±4.80 hours of adult fibroblasts culture. The cells were maintained upto six passages which was 38.8 days for adult and 26 days for fetal fibroblast cells. The fetal fibroblast cells (days) required significantly lower (p≤0.01) time to subculture than adult fibroblast cells. Morphologically the isolated cells had fibroblastic character like typical fusiform shape, turgor vitalis cytoplasm, centrally located nuclei and flame like migration pattern upto sixth passage. The subculture time and cell viability (%) was significantly (p≤0.01) better from third subculture onwards upto sixth subculture as compare to primary and secondary cultures. TUNEL assay revealed a decreasing trend of apoptotic index from primary culture onwards to sixth subculture for both adult and fetal fibroblast cells. Fetal fibroblast cells maintained a lower apoptotic index than adult fibroblast in each of the subcultures. Therefore, fibroblast cells were found to be better from third subculture onwards to sixth subculture in regards to subculture time, viability (%), apoptotic index and in maintaining its normal morphological characteristics. ALP is considered as important marker for identification of pluripotent embryonic stem cells as well as multipotent mesenchymal stem cells. Isolated fibroblast cells of all the subcultures showed activity for ALP test indicating their progressive and undifferentiated quality and may be of multipotent in nature.ThesisItem Open Access MOLECULAR CHARACTERIZATION AND GENOTYPING OF STAPHYLOCOCCI ASSOCIATED WITH BOVINE MASTITIS(Assam Agricultural University, Khanapara,Guwahati, 2017-07) DUTTA, MADHUSMITA; Borah, P.Mastitis is an important disease of dairy cows and buffaloes causing huge economic losses in the form of reduced milk production. It is an inflammation of the mammary gland (udder) that causes physical and chemical changes in milk, and leads to pathological condition of the glandular tissue. It is generally associated with poor hygienic and husbandry practices. The present study was undertaken with a view to isolate and identify Staphylococcus aureus from both mastitic and apparently normal bovine milk samples. The study also included molecular typing of representative isolates and detection of important virulence-associated genes by PCR. A total of 204 milk samples comprising both clinically affected (14) and apparently normal (190) milk were used for this study. The apparently normal milk samples were subjected to California mastitis test, of which 85.79 % tested positive for sub-clinical mastitis. Bacteriological and biochemical examinations were performed to isolate and identify staphylococci associated with mastitis. A total of 60 (33.8%) out of 177 milk samples yielded Staphylococcus aureus, which were confirmed by polymerase chain reaction (PCR) amplification of conserved sequences of aroA gene. All the isolates (100 %) were found to possess three virulence-associated genes, namely surface protein A (spa), thermonuclease (nuc) and coagulase (coa) genes, while 58 (96.6%) of the isolates showed the presence of clumping factor A (clfA) gene. Antimicrobial susceptibility testing revealed that all the 60 isolates were resistant to Ampicillin and Cotrimoxazole, while the highest susceptibility (100%) was shown to Gentamicin, Kanamycin and Chloramphenicol followed by Streptomycin (80%). On the other hand, significantly lower susceptibility was shown to Ceftriaxone (13.33%), Tetracycline (8.33%) and Cefapime (1.67%). Out of the total 60 isolates, seven were subjected to PCR-RFLP of the coagulase (coa) gene. Polymorphism was shown by all the isolates (100%) with four different restriction patterns. Ten isolates were subjected to staphylococcal protein A (Spa) typing and PFGE. Spa typing revealed two different types, t165 and t1611. On the basis of phylogenetic analyses based on spa typing and PFGE, it was concluded that isolate number 9 of Spa type t165 is the ancestral strain, the clonal descendents of which are endemic in the study area causing subclinical bovine mastitis.ThesisItem Open Access POLYMORPHISM OF PROLACTIN (PRL) AND PROLACTIN RECEPTOR (PRLR) GENES IN INDIGENOUS DUCKS OF ASSAM(Assam Agricultural University, Khanapara,Guwahati, 2017-07) BASUMATARY, KELESON; Das, BulaThe present study was conducted to investigate the polymorphism of Prolactin (PRL) and Prolactin receptor (PRLR) genes in 101 indigenous ducks of Assam. PCR-RFLP analysis of PRL gene using restriction enzyme DraI revealed three genotypes, arbitrarily designated as AA, AB and BB. Following digestion, the AA genotype yielded two fragments (141 and 316 bp), the AB genotype yielded three fragments (141, 316 and 457 bp), and the BB genotype yielded one fragment (457 bp). The frequencies of A and B alleles were found to be 0.847 and 0.154 respectively and the genotype frequencies for AA, AB and BB genotypes were found to be 0.812, 0.069 and 0.119, respectively. The PCR-RFLP analysis of PRLR gene using restriction enzyme PciI revealed two genotypes, arbitrarily designated as AA and AB. The AA genotype yielded two fragments (108 and 259 bp) and the AB genotype yielded three fragments (108, 259 and 367 bp). The frequencies of A and B alleles were found to be 0.956 and 0.045, respectively and the genotype frequencies for AA and AB genotypes were found to be 0.911 and 0.089, respectively. On the basis of the present study, it was found that the A variant of PRL gene was predominant in the indigenous ducks of Assam with the highest frequency of AA genotype followed by BB genotype (AA>BB>AB). For PRLR gene, the frequency of allele A was higher than that of allele B with a higher frequency of AA genotype (AA>AB). Chi-square (χ2) test revealed that the population under study was not in Hardy-Weinberg Equilibrium for PRL gene, while for PRLR gene, the population was in Hardy-Weinberg equilibrium.ThesisItem Open Access EFFECTS OF CRYOPROTECTANTS IN VITRIFICATION OF GOAT OOCYTES(Assam Agricultural University, Khanapara,Guwahati, 2017-07) Majumdar, Kabita; Biswas, R.K.A total of 1243 ovaries were obtained from local abattoirs and processed for recovery of oocytes by aspiration and slicing techniques from follicles within 2-3 hours of slaughter. A total of 621 and 1124 oocytes were recovered from 545 and 698 ovaries by aspiration and slicing techniques respectively and graded on the basis of cumulus cell layer adhered to the zona pellucida . The mean recovery rate differed significantly between grades of oocytes in both the techniques and interaction between technique and grades of oocytes differed significantly. A total of 1745 immature good quality goat oocytes were vitrified by using cryoprotectants viz., Ethylene Glycol (EG), Propylene Glycol (PG) and DMSO and their combinations i.e., EG+PG, EG+DMSO and PG+DMSO @ 6M, 8M, 10M and 12M concentrations in the vitrification solution with the addition of 0.5M sucrose in basic solution that contained DPBS and FBS (4:1) and Gentamicin (50µg/ml). The equilibration solution was prepared by adding the cryoprotectant at the rate of half of the concentration used for vitrification and 0.25M sucrose in basic solution. The vitrification solution contained 0.5M sucrose and half of the total concentration for each cryoprotectant when vitrification of oocytes was done by combining two cryoprotectants. The mean rate of recovery of morphologically normal oocytes after vitrification differed significantly between concentrations in PG, EG and EG+PG. The highest mean recovery rate of morphologically normal vitrified oocytes was 74.16±4.44 per cent which was obtained in 10M EG+PG (1:1). The mean rate of recovery of morphologically normal vitrified oocytes was the highest (71.82±5.21%) in 0.5M sucrose contained in 5M EG+5M PG, although it did not differ significantly from concentrations of 0.25M, 0.75M and 1M sucrose. The mean percentages of in vitro matured oocytes following vitrification revealing expanded cumulus cells (61.67±2.54) and polar body extrusion (47.04±2.70) were significantly lower for vitrified oocytes as compared to the corresponding values (70.91±1.98% and 63.51±2.83 %) in non-vitrified oocytes .
