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Assam Agricultural University, Jorhat

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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.

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  • ThesisItemOpen Access
    DIGESTIVE TRACT PROTOZOAN PARASITISM IN DOMESTIC BIRDS WITH SPECIAL REFERENCE TO Trichomonas gallinae IN ASSAM
    (College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati, 2019-07) SAIKIA, MUNMI; Bhattacharjee, Kanta
    The present study was undertaken to ascertain the prevalence of protozoan parasites inhabiting the digestive tract of domestic birds which included pigeon (Columba livia domestica), chicken (Gallus gallus domesticus), duck (Anas platyrhynchos domesticus) and quail (Coturnix coturnix japonica) in the state of Assam, India. The study was conducted for a period of two years w.e.f. April 2017 to March 2019 in 8 districts of Assam viz. Kamrup (Rural and Metro), Dhubri, Barpeta, Nalbari, Darrang, Baksa, Lakhimpur and Dhemaji. A total of 1278 pooled faecal samples and 1207 throat swabs were collected for study. Faecal examination by floatation method for the presence or absence of oocyst of coccidia and by Modified Ziehl- Neelsen staining and Kinyoun’s staining method for detection of Cryptosporidium infection was carried out in domestic birds and overall prevalence of digestive tract protozoa was recorded as 34.66%. Identified species were Eimeria labbeana (26.35%), E. columbarum (8.69%) and E. columbae (3.53%) from pigeon; Eimeria tenella (19.13%), E. acervulina (9.46%), E. necatrix (6.88%), E. maxima (2.36%) and Cryptosporidium baileyi (3.01%) from chicken; Eimeria battakhi (19.86%) from duck and Eimeria tsunodai (13.29%), E. bateri (5.69%), E. uzura (3.16%) and Cryptosporidium meleagridis (4.43%) from quail. Season wise, highest prevalence was recorded from pigeon in pre monsoon (58.33%) and lowest in monsoon (27.17%); in chicken highest in monsoon (57.00%) and lowest in pre monsoon (28.69%); in duck highest in winter (52.45%) and lowest in post monsoon (17.28%); in quail highest prevalence was seen during monsoon (61.11%) and lowest in winter season (14.28%). District wise, highest prevalence (80%) was recorded from Kamrup (rural and metro) and lowest from Dhemaji (22.22%) in pigeon; in chicken highest (82.60%) from Dhubri and lowest from Lakhimpur (28.16%); in case of duck and quail highest prevalence was recorded from Dhubri (51.72%) in duck and (45%) in quail and lowest percentage was recorded from Baksa (22.22%) and (17.85%) from Darrang respectively. Observation on the prevalence of T. gallinae was done by Giemsa staining and culture and overall prevalence was recorded as 28.91%. In pigeon, the prevalence was recorded as high as 71.12% and in chicken it was 6.25% but T. gallinae was not recorded from both duck and quail in natural condition. In pigeon, prevalence was found in squab as 79.47% which was the highest. In young bird, it was 61.11% and in adult, prevalence was 70.00%. Female birds showed a prevalence rate of 75.51% while in male, it was 66.36%. In chicken prevalence rate was 6.73% in females and 6.00% in males. Season wise, highest number of cases (87.12%) in pigeon was recorded in winter and lowest in monsoon (60.58%). In chicken, T. gallinae infection was recorded only in two seasons; post monsoon showed slightly higher prevalence (15.49%) than winter (13.79%). District wise, maximum number of positive samples (78.65%) was recorded from Kamrup (rural and metro) in pigeon and in chicken, highest prevalence of Trichomonas infection was reported from Baksa district (34.78%). Comparative evaluation of direct smear (Giemsa staining) and culture methods (Wet mount) for detection of T. gallinae revealed culture method to be sensitive and superior to direct smear method. Five media, viz. modified Diamond’s media, Medium199, Minimum Essential Medium (MEM), RPMI 1640 and Nutrient broth were used for culture and maintenance 3 of T. gallinae parasite. Medium 199 showed the highest growth of organism upto 144-168 hours with motile trophozoites in comparison with other four media in the present study. Polymerase chain reaction (PCR) employed for amplification of Fe hydrogenase gene of Trichomonas gallinae from positive cultured materials of pigeon and chicken showed clear 290 bp band fragment. Molecular characterization of T. gallinae from pigeon and chicken isolate of Assam in the present study showed 100% similarity with isolates of Iran and Austria. To determine the virulent nature of the trichomonads and its transmissibility to different hosts, experiment was performed with or without immunosuppressive drugs in chicken, duck, quails and mice taking pigeon as its natural host. Pigeon strain of T. gallinae orally inoculated at concentration of 4x104 trophozoites in birds and intra peritoneal inoculation in mice revealed presence of parasites in all bird species while mice developed abscess which is an indicator of T. gallinae infection. Pathological lesions like yellowish to whitish masses of caseous necrotic materials were seen in the beak, oral cavity, oeosophagus, crop and proventriculus of pigeon and mild gross alterations were observed in other experimental host. Histopathological alterations were also found more in pigeon than other infected birds. In the present study, five different drugs used for in vitro and in vivo efficacy against T. gallinae were Flagyl 400 (Metronidazole), Ornida (Ornidazole), Tiniba 300 (Tinidazole), Sulcoprim (sulphadiazine and trimethoprim) and Vetfur-TL (Metronidazole, Furazolidone and Loperamide). Concentration of drugs @10, 20 and 30 mg/ml for in vitro study and 20 and 30 mg/kg for in vivo study revealed 100% efficacy of the drugs Metronidazole, Ornidazole and combination of Metronidazole, Furazolidone and Loperamide at 30mg/ml in vitro and 30mg/kg in in vivo condition.
  • ThesisItemOpen Access
    EPIDEMIOLOGY OF BLADDER WORM DISEASES OF PIGS IN ARUNACHAL PRADESH WITH SPECIAL REFRERENCE TO Taenia Solium TAENIASIS IN MAN
    (College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781022, 2017-07) Biswakarma, Badal; Deka, Dilip Kr.
  • ThesisItemOpen Access
    ECTOPARASITES OF POULTRY IN KAMRUP DISTRICT OF ASSAM: AN EXPLORATORY INVESTIGATION
    (College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781022, 2017-07) Bora, Sanjana; Das, Manoranjan
    A study was conducted to record the prevalence of different ectoparasites of poultry in Kamrup (rural and metro) districts of Assam from March, 2016 to February, 2017. Out of 6514 birds; 1896 fowl(local), 4450(broilers), 108 ducks and 60 pigeons, lice infestation was 58.24% in intensive system and 64.09% in free range system, arachnids both tick and mite together was 48.61% in free range system. The lice, Menopon gallinae (52.32%); Lipeurus caponis(45.44%); Menacanthus stramineus (38.88%) and Goniodes gigas(3.68%) and no arachnids could be encountered in intensive system. The lice in free range system were Menopon gallinae (47.21%); Lipeurus caponis(46.59%)and Menacanthus stramineus (27.09%), mites were Dermanyssus gallinae(14.24%); Cnemidocoptes mutans (36.38%); Sarcoptes spp. (6.81%) and some other mites (8.20%) with significant differences amongst seasons and systems of rearing. A hard tick, Haemaphysalis spp. could be found for the first time in India with 3.10% prevalence rate. The ectoparasites of ducks recorded were lice Columbicola columbae (30.56%); Lipeurus caponis (28.70%) and some other mites (30.56%). The ectoparasites encountered in pigeons were Dermanyssus gallinae (20%); Columbicola columbae (50%) and dipteran fly Pseudolynchia canariensis (65%). Myiasis due to Chrysomyia bezziana in broiler chickens of 5-7 weeks old had a prevalence rate of 1.34% in pre-monsoon and monsoon and not in the winter season, this being the first report in North East India. Skin of fowl naturally infested with Dermanyssus gallinae revealed destruction of the superficial layer of epidermis, mild spongiosis in dermal layer characterized by vacuolation alongwith infiltration of eosinophils and heterophils histopathologically. Heavy infiltration of mononuclear cells in the dermis and areas with haemorrhages alongwith congestion were observed. Perakeratosis of stratum corneum in certain areas of the epidermis without affecting the deeper layers of the skin were noticed. Histopathologically, birds infested with Cnemidocoptes mutans, showed sloughing of the stratum corneum and cross sections of the mite in the affected areas of the epidermis, abnormal thickening of stratum granulosum indicating hyperkeratosis. Infiltration of eosinophil, heterophils and mononuclear cells and focal areas of necrosis were observed in the dermis. Skin sections of fowl infested with Cnemidocoptes mutans showed no reaction in epidermis with Succinic dehydrogenase (SDH),intense reaction in dermis with Succinic dehydrogenase (SDH),Alkaline phosphatase (AKPase) and Acid phosphatase (ACPase) and moderate reaction with AKPase and ACPase in the dermis. Chrysomyia bezziana completes its life cycle in 13 to 18 days in room temperature (28-32°C). The molecular characterization of Chrysomyia bezziana revealed 99% similarity with established database sequences of NCBI in BLAST analysis.
  • ThesisItemOpen Access
    FILARIAL PARASITES IN LIVESTOCK WITH SPECIAL REFERENCE TO Onchocerca armillata
    (College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781022, 2017-07) Rabha, Nidarsana; Islam, Saidul
    A study was conducted to record the prevalence of filarial nematodes in cattle, buffalo and goat in Kamrup district of Assam (Metro and Rural) in local abattoirs in and around Guwahati from January 2016 to January 2017. A total of 792 animals comprising cattle (n=430), buffalo (n=262) and goat (n=100) was examined for this study. In cattle 3 species of adult filarial parasite (Setaria labiato-papillosa, S. digitata and O. armillata) and in buffaloes 2 species (S. labiato-papillosa, S. digitata) of adult filarial parasite could be recorded. Light microscopic morphological studies of these parasites were conducted. Based on the presence of lesion, Stephanofilaria assamensis could be encountered in 16.00% cattle. Setaria species infection was 62.50% in buffaloes. Prevalence of Onchocerca armillata in cattle was 68.40%, more in female Jersey cross bred animals (83.09%). Skin nip examination of cattle revealed presence of O. armillata microfilariae in 28.57% cases of O. armillata infection-positive cases. The molecular identification of ITS1-5.8S rDNA gene of Onchocerca isolate of the present study revealed 95% similarity with O. fasciata which complemented the light microscopic identity of the parasite. The molecular identification of 16S rDNA gene of Wolbachia revealed 99% similarity with O. volvulus, O. ochengi, O. cervicalis and O. gutturosa. Studies on the pathology of O. armillata infected aortae could reveal three major lesion types viz., parasitic migratory tracts in the intimal layer, nodular lesions in both intimal and adventitial layer and umbilical cord-like lesions in the intimal layer. These three lesion types appeared in the aortae either as a single or in combinations. Generally there was mild infiltration of inflammatory cells particularly mononuclear cells admixed with polymorphs and a few giant cells with thickening and edema of intimal layer. Migratory tracts showed empty spaces lined by fibrous connective tissue and proliferation of collagen fibers. Nodular lesions consisted of necrotic parasites and microfilariae inside them and inflammatory cell infiltration predominated by eosinophils. Umbilical cord like lesions exhibited edematous and massive fibrotic areas with calcification. In the present attempt, developmental stages of larvae and pupae of Simulium metatarsale and S. bhutanensis were encountered at 12 different breeding sites, with predominance of the former species. Presence of Wolbachia in Simulium metatarsale could be detected through a molecular identification of Wolbachia specific 16S rDNA gene. The results revealed 99% similarity with Wolbachia of other species obtained from different geographical regions. The Wolbachia obtained from S. metatarsale had 100% similarity with Wolbachia of O. armillata of the present isolate.
  • ThesisItemOpen Access
    INVESTIGATION ON PARASITES OF DUCK IN UPPER ASSAM WITH SPECIAL REFERENCE TO HAEMOPROTOZOA
    (College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781022, 2017-07) Borah, Nanswita; Phukan, Sulekha Choudhury
    A survey was conducted in seven districts of upper Assam for a period of one year from June, 2016 to May, 2017 to study the prevalence of parasites of domestic ducks in upper Assam. Out of a total of 675 numbers of ducks examined, 467 ducks were found positive for different ectoparasites showing the overall prevalence of 69.19 per cent. Ducks from Gaurisagar of Sibsagar district had highest 92.86 per cent and Lahowal of Dibrugarh district had lowest 58.82 per cent prevalence for ectoparasites. Five different lice and two different types mites were recovered from different body parts of duck, of which infestation with Lipeurus caponis (13.33%) was highest followed by Menopon gallinae (12.74%), Menacanthus stramineus (10.67%), Columbicola columbae (8.44%), different feather mites viz. Dubininia melopsittaci, Megninia ginglymura and Bdellorhynchus sp. (5.19%), Goniodes sp. (3.70%) and larva of Trombiculid mite (0.89%), respectively. The three feather mites, larva of the Trombiculid mite and Columbicola columbae were first time reported from Assam in duck. Examination of 724 faecal samples collected from different localities of upper Assam revealed 333 samples to be positive for helminthes with overall prevalence of 45.99 per cent. Out of the positive samples, 314 samples were positive for single and 19 for mixed infection with incidence of 94.29 per cent and 5.71 per cent. Samples from Gaurisagar of Sibsagar district had highest 68.96 per cent of helminthic infection. Helminthic infections of ducks were not recorded from samples collected from Baghchung of Jorhat district and Joysagar of Sigsagar district. Faecal samples collected from ducks reared under free range system had highest prevalence of 57.84 per cent for helminthes followed by semi intensive system of rearing (35.34%) and no helminthic infections were recorded from faecal samples of ducks reared under intensive system. Season wise prevalence of helminths in ducks on the basis of faecal examination revealed highest during pre monsoon (73.56%) and lowest during winter (20.92%). Out of 724 faecal samples examined, 20 samples were positive for Coccidia (Isospora sp.) with the overall prevalence of 2.76 per cent. Post mortem examination of 774 carcasses of ducks from different localities of different districts in upper Assam revealed 518 carcasses to be positive for helminthic infections. The overall prevalence of helminthes was recorded as 66.93 per cent. 232 carcasses were found positive for cestodes (44.79%), 241 for trematodes (46.52%) and 45 for nematodes (8.69%). Carcasses from Demow of Sibsagar district had highest prevalence of 86.05 per cent and lowest from Kakopathar of Tinsukia district with 50.00 per cent prevalence for helminthes. Post mortem examination of ducks reared under free range system revealed highest 78.21 per cent for helminthes followed by semi intensive system of rearing (70.33%). Helminthic infection was not recorded from ducks reared under intensive system. Seasonal prevalence of helminthes on the basis of post mortem examination revealed highest during monsoon (72.28%) and lowest during winter season (51.43%). On the basis of morphological studies, 7 different species of cestodes and 1 larval stage of cestode, 8 different species of trematodes and 5 different species of nematodes were identified and recorded. Highest incidence of cestodes was recorded with Hymenolepis collaris (35.78%) followed by Hymenolepis carioca (35.34%), Fimbriaria fasciolaris (22.41%), Hymenolepis lanceolata (1.74%), Raillietina tetragona (1.29%), Raillietina echinobothridia (1.29%) and Raillietina cesticillus (1.29%) and lowest with plerocercoid (0.86%). Highest incidence of trematodes was recorded with Echinostoma revolutum (24.07%), Hypoderaeum sp. (18.67%), Psilorchis sp. (18.67%), Echinostoma paraulum (16.60%), Paryphostomum sp. (10.79%), Prosthogonimus sp. (8.30%), Tracheophilus cymbius (2.07%) and Psilochasmus sp. (0.83%). Highest incidence of nematodes was recorded with Tetrameres sp. (57.78%), Heterakis gallinarum (17.78%), Heterakis dispar (17.78%), Strongyloides avium (4.44%) and Porrocaecum sp. (2.22%). Hymenolepis carioca, Hymenolepis lanceolata, Raillietina tetragona, Hypoderaeum sp., Echinostoma paraulum, Prosthogonimus sp., Psilochasmus sp. and Heterakis dispar were first time reported from Assam in duck. Seasonal prevalence of helminthes according to breeds of duck revealed highest prevalence of helminthes in monsoon season (82.54%) and lowest in winter (26.67%) from Patihanh, highest in pre monsoon (85.26%) and lowest in monsoon (54.29%) from Khaki Campbell, highest in pre monsoon season (85.37%) and lowest in winter (56.52%) from Chara ducks and prevalence of helminthes in Muscovy ducks during monsoon season was 80 per cent. Overall prevalence of helminthes was recorded highest in adults (76.73%) and lowest in young ducks (54.41%). Seasonal prevalence of helminthes according to age of ducks revealed highest prevalence of helminthic infection during pre monsoon (67.83%) and lowest during winter season (34.88%) in youngs and highest prevalence during post monsoon season (85.29%) and lowest during winter season (61.29%) in adults. Overall prevalence was recorded highest in female (67.44%) and lowest in male (66.41%). Seasonal prevalence of helminthes according to sex revealed that males had highest helminthic infection during monsoon (80.41%) and lowest during winter season (43.14%). Similarly, females had highest during pre monsoon season (73.88%) and lowest during winter season (57.41%). Prevalence of haemoprotozoa in ducks revealed that, out of 300 thin blood smears prepared, only 4 showed the presence of Haemoproteus sp. infection in RBC. The overall prevalence of infection was 1.33 per cent. Haematological changes observed due to helminthes and haemoprotozoan parasites of duck revealed decrease in Haemoglobin (9.38±0.13), PCV (27.98±0.36) and TEC (1.69±0.08) with increase in TLC (43.18±1.76) in infected ducks. On post mortem examination, various pathological lesions were found associated with Hymenolepis sp. and Echinostoma sp. in intestines and Tetrameres sp. in proventricles of ducks. Intestines of duck showed catarrhal enteritis and congestion in the mucosal surface of the small intestine for Hymenolepis sp. and haemorrhages and catarrhal enteritis for Echinostoma sp. Microscopic examination revealed marked thickening of intestinal villi with infiltration of inflammatory cells. Some villi showed haemorrhagic patches, degeneration and necrosis. Desquamated epithelial lining of intestinal villi were found to be deposited in the lumen of the intestine. Cross section of Hymenolepid parasite was found attached to the superficial epithelium surrounded by infiltrating cells. Gross examination of infected proventiculus revealed small blackish elevated spots visible from the luminal surface. Microscopic examination revealed cut sections of female parasite inside the proventricular gland. Glandular epithelium surrounding the parasite exhibited pressure atrophy and the lumen of the gland was found dilated. Tunica muscularis around the glands was found thickened and inter glandular spaces was found enlarged and thickened with proliferation of fibrous connective tissue and was found infiltrated with monocytes and polymorphs. The genera Echinostoma sp. (Identified as Echinostoma revolutum on the basis of morphological characteristics) and Hypoderaeum sp. were identified as Echinostoma friedi and Hypoderaeum conoideum on the basis of ITS2 sequence identity. The present isolate of Echinostoma sp. showed 100 % identity with Echinostoma friedi the isolate of Hypoderaeum sp. showed 99% identity with Hypoderaeum conoideum The Molecular characterization of either Echinostoma friedi or Hypoderaeum conoideum could not be accomplished due to unavailability of more than one ITS2 sequence of these species in NCBI database. Probably it might be the first report of Echinostoma friedi in India. The ITS2 sequence based species identification of Psilorchis sp. could not be accomplished due to absence of Psilorchis ITS2 sequence in NCBI database. This might probably be the first report of ITS2 sequencing of Psilorchis sp. either in India and abroad.
  • ThesisItemOpen Access
    STUDIES ON Dirofilaria immitis IN DOGS AND ITS ASSOCIATION WITH Wolbachia SPECIES
    (College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781022, 2013-06) Borthakur, Sonjoy Kumar; Deka, Dilip Kr.
    Dirofilaira immitis is an important canine filarial nematode. An epidemiological study was carried out to record the prevalence of D. immitis in dogs in two different geographical locations viz., Guwahati, Assam and Aizawl, Mizoram of North Eastern Region in India, from February, 2011 to July, 2012. The study also included to evaluate the persistence of Wolbachia endosymbiont with D. immitis. In the present study, dogs were grouped into three categories, i.e., stray, pet and working dogs, their respective numbers being 413, 266 and 103 irrespective of the study regions. Three different methods were used for the study, i.e., microscopy (wet film and KCT), immunological (Ag ELISA by SNAP®4Dx kit) and molecular techniques (PCR). The study revealed overall heartworm prevalence in Guwahati to be higher (18.23%) than in Aizawl (17.68%) irrespective of categories of dogs. Sex-wise, the infection was higher in male (18.12%) than in female (17.90%), though the difference was statistically non-significant. The overall efficacy percentage for detection of heartworm by wet film, KCT, Ag ELISA and PCR test revealed 6.26, 11.38, 18.03 and 13.93 percent, respectively. Ag ELISA test was found to be the best amongst the three types of tests compared. Using molecular tools, prevalence of D. immitis in dogs was 13.52 percent in Guwahati and in Aizawl was 14.62 percent. With PCR, 4 cases of D. repens could be diagnosed in stray dogs from Guwahati. The study revealed overall 22.69 percent occult infection, of which, highest cases were recorded in working dogs (60%). Occult infection was calculated by finding the difference between heartworm prevalence based on Ag ELISA and PCR test. Dot ELISA test using monoclonal antibody of D. immitis for detection of heartworm antigen in dog blood samples was standardized. The test revealed 72% specificity against known positive D. immitis blood samples at SNAP®4Dx commercial kit. Molecular technique using PCR was standardized to detect D. immitis using published primers with slight modification of thermal condition. Two different primers were used viz., specific primers for D. immitis only and another, pan filarial primers for detecting six different canine filariids. Both the primers resulted desired amplification product size against different filarial parasites. Molecular cloning and characterization of D. immitis for ITS-2 region of Guwahati isolates were conducted. The results showed the Guwahati isolates had a close relationship with that of South Asian isolates of D. immitis. Pair-wise homology analysis revealed 98.6 - 98.9% similarity with a few sequences available at NCBI GenBank. Similarly, phylogenetic analysis of D. repens encountered in Guwahati isolate was also done. Endosymbiont Wolbachia association with D. immitis worm as well as in heartworm infected blood was revalidated by PCR method. The findings were substantiated with the presence of the organisms in the worm’s lateral cord by fine structural studies conducted through transmission electron microscopy (TEM). Molecular evidence followed by sequence analysis of Wolbachia revealed 99.4 to 99.8% similarities with other sequences available in NCBI GenBank for Wolbachia endosymbiont of D. immitis. Finding of the present studies establish the endemicity of D. immitis in North East India and validates the association of Wolbachia endosymbiont in D. immitis. Record of D. repens warrants further detail studies owing to its zoonotic significance.
  • ThesisItemOpen Access
    STUDIES ON TICKS AND HAEMOPARASITES OF CATTLE IN INDO-BHUTAN BORDER DISTRICTS OF ASSAM
    (College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781022, 2017-07) Mushahary, Dipanjali; Bhattacharjee, Kanta
    Ticks and tick-borne blood parasitic diseases are recognized as a major constraint to livestock production causing clinical and subclinical parasitism and greatly hamper the health of animals worldwide including India. The present study was carried out to record the tick infestation and tick-borne blood parasitic diseases (haemoprotozoal and haemorickettsial) in crossbred and indigenous cattle of four Indo-Bhutan border districts of Assam, viz. Kokrajhar, Chirang, Baksa and Udalguri for one calendar year from April 2016 to March 2017. A total of 533 cattle were examined of which 266 (49.90%) were found infested either with Rhipicephalus (Boophilus) microplus (23.45%) or Haemaphysalis bispinosa (15.75%) or with both the ticks (mixed infestation) (10.69%). Crossbred cattle were found having higher prevalence of tick (53.50%) compared to the indigenous (49.34%) which was statistically non-significant. Tick infestation was the highest in adult cattle of > 3 years of age (56.61%) and the lowest in calves of < 1 year of age (41.74%) while in young cattle of 1- 3 years it was 52.89 %. Higher prevalence of tick infestation was recorded in female cattle (53.57%) than the males (44.80%). Also, tick infestation was recorded higher in indigenous cattle which were free ranged (49.34%) than that of the stall fed crossbred cattle (41.55%). According to the distribution of ticks on different body parts of cattle, infestation was observed highest in inguinal region including udder and scrotum (82.70%) followed by neck (71.42%) and lowest seen in back region (22.55%). Prevalence of haemoparasites determined by microscopic examination of Giemsa stained blood smear followed by confirmation in Polymerase Chain Reaction (PCR) revealed presence of three species, Theileria orientalis (62.85%), Babesia bigemina (1.87%) and Anaplasma marginale (2.62%) with an overall 67.35% haemoparasite prevalence. However, no case of Babesia bovis, Theileria annulata and Trypanosoma evansi was detected during this study by microscopy and PCR. Haemoparasite infection was higher in crossbreds (77.92 %) than the indigenous animals (65.57 %). Adult cattle > 3 years age were found more susceptible to blood parasitic diseases (80.42%) than young (68.11%) and calves (54.85%). Females had higher prevalence (74.02%) compared to the male animal (58.22%). PCR amplified parasite DNA of T. orientalis, B. bigemina, A. marginale showed clear band at 776 bp, 1124 bp and 160 bp respectively. Demonstration of T. orientalis DNA in the eggs laid by female engorged R (B). microplus obtained from T. orientalis positive case suggested the tick species as the vector of the parasite and transmitting it transovarially to the subsequent generations. Screening of 100 sera samples by Indirect ELISA revealed presence of Trypanosoma evansi antibodies in 7 samples with O.D value of 0.45. Phylogenetic analysis of MPSP gene of Theileria orientalis isolate revealed 99.00% similarity with the isolate reported from Thailand and Myanmar. Anaplasma marginale isolate in the present study bear 93.46% similarity with isolates reported from USA and Mexico while the Babesia bigemina isolate has been found to be very distinct molecular type in terms of 18S rRNA gene. The high level of unrelatedness could be due to lack of interaction between the present isolate reported and other isolates. Quantification of Babesia bigemina organisms by Real Time PCR (RT-PCR) revealed presence of 8.01 x 1011 DNA copies µl-1 of B. bigemina. Haematological estimation in both crossbred and indigenous cattle infected with haemoparasites revealed anaemia in terms of lowered Hb and PCV values. This study fairly suggests that R. (B). microplus and H. bispinosa infestation are highly endemic and the blood parasitic diseases, Oriental theileriosis, babesiosis and anaplasmosis are prevalent in subclinical state in cattle in the study areas.
  • ThesisItemOpen Access
    EPIDEMIOLOGY OF BLADDER WORM DISEASES OF PIGS IN ARUNACHAL PRADESH WITH SPECIAL REFRERENCE TO Taenia Solium TAENIASIS IN MAN
    (College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781022, 2017-07) Biswakarma, Badal; Deka, Dilip Kr.
  • ThesisItemOpen Access
    TICK FAUNA OF GOAT WITH A REFERENCE TO THEIR VECTOR STATUS AND ACARICIDE RESISTANCE
    (College of Veterinary Science Assam Agricultural University Khanapara, Guwahati-781022, 2016-06) Begam, Rabeya; Talukdar, S. K.
    The present study on tick fauna of goat with a reference to their vector status and acaricide resistance was carried out with an aim to obtain current information on ticks, acaricidal resistance status in ticks and prevalence of haemoparasitic infection in goats reared under different management system from March 2015 to February 2016 in and around Guwahati. Observation on the prevalence of ticks revealed Haemaphysalis bispinosa as the only tick found infesting goat of the study area with 53.98% prevalence out of 528 animals examined and availability throughout the year . Tick prevalence was recorded highest in monsoon (71.67%) and lowest in winter (27.42%).Sex-wise ,female were found mostly infested (61.59%) then male (8.00%) . On the basis of distribution pattern on the body sites of goat ears were found mostly infested (89.82%) and least in tail (12.28%). Acaricide resistance test by in vitro methods AITDD (Adult Immersion Test with Discriminating Doses) was performed against synthetic pyrethroid Deltamethrin which have been used continuously in GRS (Goat Researh Station Burnihat ) for the past 20 years and also against newly used synthetic pyrethroid Cypermethrin in Haemaphysalis bispinosa tick collected from GRS Burnihat. Ticks were also collected from Tetelia goat farm (unorganized farm) to detect acaricide resistance. Results revealed 80% resistance against Deltamethrin and 30% resistance against Cypermethrin in GRS Burnihat and 20% and 0% against Deltamethrin and Cypermethrin in Tetelia farm. Filter paper impregnation method was performed to determine the larvicidal effficacy of Deltamethrin and Cypermethrin at different (0.5,0.1 and 0.2 % concentration) showed 100% mortality of H.bispinosa larvae at 0.2% concentration of Deltamethrin in both GRS and Tetelia farm and 100 % mortality at 0.2% concentration of Cypermethrin at GRS Burnihat but 100% mortality at 0.1and 0.2% concentration of Cypermethrin in Tetelia farm as it was not used there as acaricide, indicating more larvicidal efficacy in Tetelia farm. Prevalence of Theileria sp. was determined by microscopic examination of Giemsa stained blood smear and confirmation through PCR by using genus specific primers .Further sequencing confirms the presence of Theileria luwenshuni as the first caprine Theileria sp. prevalent in the goats of Assam. An attempt was made to determine the T .luwenshuni infection in the salivary gland of the H .bispinosa by PCR assay but was found negative as level of parasitaemia exists in the blood sample less than 0.0001%. So it was not possible to trace the infection in the salivary gland of the tick. A total of 16 clinical theileriasis cases caused by T.luwenshuni were recorded during the period of study irrespective of different breeds of goats (9 cross bred , 7Assam local). All the clinical cases were recorded in unorganized farms and smallholders of goats under semi intensive system of management. Based on the status of the animal clinical theileriasis was recorded in 3 lactating goats and one male buck that was having recent history of castration .Animals positive for clinical theileriasis showed symptoms of anorexia ,depression, fever ,pale mucous membrane and weakness. Haematological changes revealed anaemia in goats. In the present study 39.87% goats irrespective of different breeds were recorded with sub clinical theileriosis without showing any clinical symptoms. Haematological findings revealed moderate anaemia in subclincal carrier goat in comparsion to healthy animals. This suggests that Theileria luwenshuni is first time emerging as a new Theileria species responsible for both clinical theileriasis and subclinical theileriosis in the goats of Assam.