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Theses

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1975 - 197951980 - 19862
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Subject: Veterinary Microbiology × End date: 1986 × Thesis Type: M.V.Sc. ×
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Now showing 1 - 7 of 7
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    ThesisItemOpen Access
    Role of parrots in the epizootiology of newcastle disease
    (Department of Microbiology, College of Veterinary and Animal Sciences,Mannuthy, 1981) Vijayan, V; Sulochana, S
    The incidence, susceptibility, mode of infection and duration of excretion of the new cattle disease virus in the common Indian parrots (psittacula Krameri) were studied in detail. The blood, cloacal and throat swabs of parrots, collected from different parts of the State were screened for the presence of ND antibodies and virus. Seventeen out of 103 blood samples were found to possess HI antibodies. The serum samples which gave positive HI titres belonged to parrots kept as pets in households and allowed to mingle freely with domestic poultry and those housed in Trivandrum Zoo along with pigeons. None of the 70 cloacal and 42 throat swabs were positive for the virus. Experimental infection of parrots with undiluted virulent virus by the intranasal and intraocular routes and by the subcutaneous and intranasal routes with 1:100 dilution of the same virus gave almost the same results. All of them died within a weeks’ time, after showing symptoms of inappettance, leg and wing paralysis and diarrhoea, from day two of infection. Virus could be isolated from the throat and cloacal swabs and also from the tissue of dead birds. Chicks kept along with these infected parrots did not develop symptoms of ND, eventhough they excreted the virus, for a few days, and had a low titre of HI antibodies in their sera. All the contact chicks died of ND with typical symptoms and lesions on challenge with the virulent virus. The parrots that received a mesogenic strain (Komorov) of the virus, also succumbed to the disease, but with less pronounced symptoms and with an extended incubation period. The parrots that were infected with lentogenic strain of the virus (F1) did not develop symptoms of the disease. However multiplication of the virus occurred in these birds as isolations could be made from cloacal and throat swab and a slight increase in H1 titre was noticed sera. However on challenge with a virulent strain of NDV, they showed symptoms of ND. All of them died within eight days and the virus could be isolated from them. Contact infection of parrots from infected chicks were quite effective, as the parrots died with the same symptoms described above, almost within the same time as direct infection. Virus was also isolated from the tissues of the dead parrots. The common Indian parrots were found to be highly susceptible to both velogenic and mesogenic strains of NDV, but they were resistant to the lentogenic strain. Uninfected chicks kept along with the parrots infected with virulent virus picked up the infection, and virus could be isolated from the cloacal and throat swabs of these chicks. They also showed an increase in the antibody titre. The failure to produce clinical disease in chicken might be attributed to a decrease in virulence of the virus on passage in parrots. The carrier state with the lentogenis strain of the virus could not be assessed as they were challenged after 2 weeks. Though a carrier role had been attributed to the parakeets imported from India, the parrots in this study were found to succumb to the disease within a week. This might be due to the variation in the susceptibility of various species of parrots to NDV. The chances of dissemination of the virus could be prevented by quarantining them for a period, not less than ten days.
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    ThesisItemOpen Access
    Characterization of staphylococci isolated from cases of mastitis and study of their R plasmids
    (Department of microbiology, College of veterinary and animal sciences, Mannuthy, 1986) Mathew, E S; KAU; Punnoose, K T
    The emergence of drug resistant staphylococci causing mastitis deserve serious investigation. The work was intended to characterize staphylococci isolated from cases of bovine mastitis and to study their R plasmid transfer in vitro. The characterization was done using glucose and mannitol fermentation, catalase production, coagulase production, Iysostaphin sensitivity and bacteriophage typing. The antibiogram of the isolates was done by agar diffusion method using 14 chemotherapeutic agents (amoxicillin, ampicillin, bacitracin, chloramphenicol, cloxacillin, erythromycin, gentamicin, methicillin, neomycin, nitrofurantoin, penicillin, streptomycin, sulphamethoxazole and tetracycline) and by agar dilution method using eight antibiotics (ampicillin, chloramphenicol, rifampicin, streptomycin, tetracycline , gentamicin, erythromycin and penicillin) The in vitro transfer of R plasmids was tried using selected S.aureus and coagulase-negative staphylococcal isolates as donors and S.aureus RN 450RF and S.epifermidis 131S as recipients. From 360 milk samples collected from cases of bovine mastitis 17 strains of S.aureus and 35 strains of coagulase negative staphylococci were isolated. Lysostaphin sensitivity test was positive for 90.38% of the isolates, but this could not be used to differentiate between coagulase positive and negative staphylococci. The results of phage typing revealed a predominance of group III phages over the other groups and the possible role of human strains of staphylococci in producing mastitis in animals. None of the strains were resistant to mercuric chloride. From the antibiogram rifampicin , bacitracin, neomycin , methicillin, gentamicin, cloxacillin, nitrofurantoin and chloramphenicol were found to be the drugs of choice in the treatment of bovine mastitis caused by staphylococci. When S. aureus Rn 450RF was used as recipient six of the ten selected S.aureus isolates could transfer either one or more drug resistance markers and the mode of transfer was suspected to be by conjugation. All the four selected streptomycin resistant coagulase –negative staphylococcal donors were found to transfer the R plasmid DNA to the recipient., S.aureus RN 450RF, which was established to be through conjugation. The drug resistant S. aureus as well as coagulase negative staphylococcal strains failed t transfer their resistance to S.epidermidis 131S.
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    ThesisItemOpen Access
    Survey on the incidence of Salmonellae in meat animals
    (Department of Microbiology, College of Veterinary and Animal Sciences, Mannuthy, 1977) James, P C; Abdulla, P K
    Prior to this “Survey on the Incidence of Salmonellae in Meat Animals” the information on the serotypes of Salmonella prevalent and the magnitude of their occurrence in livestock in Kerala had been meagre except for the reports by Sulochana et al. (1973) and Balakrishna Pillai (1975). The work carried out during the present investigation has gathered more information on the prevalence of Salmonella in livestock in Kerala. In this study the prevalence of Salmonella serotypes in the different species of animals was probed. A total of 823 biomaterials, besides 50 drain samples were subjected to cultural screening. This venture resulted in the recovery of 56 strains of Salmonella. Serological identification of many of these strains proved the prevalence of S. typhimurium, S. weltevreden and S. urbana. The preponderatingly prevalent serotypes were found to be the former two. Pathogenicity studies employing S. typhimurium culture in mice, guinea pigs, rabbits, calves and piglets were conducted. All these animals were found to be susceptible to infection by S. typhimurium evincing varying degrees of clinical manifestations. The advantages of employing modified McConkey’s medium (Sharma, 1961) containing Mannitol instead of lactose and composite medium 1 and 11 developed by Chitin is et al. (1972) to differentiate Salmonella at primary screening level have been discussed
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    ThesisItemOpen Access
    Studies on the bacterial species associated with gastroenteritis in goats
    (Department of Microbiology, College of Veterinary and Animal Sciences, Mannuthy, 1979) Sebastian, Joseph; KAU; Abdulla, P K
    The information regarding the incidence, etiology and pathogenicity of enteric pathogens in goats is very meagre in our country. The present study is aimed at the isolation, identification and characterisation of Enterobacterial organisms from cases of enteritis in goats. The study also included, determination of sensitivity pattern of the isolates to various chemotherapeutic agents. A total of 190 specimens, which included rectal swabs (60), intestinal contents, portions of large and small intestines (92) and mesenteric lymph nodes (38) collected from live/dead animals were examined for enteric pathogens. From these specimens examined, 86 isolates of Escherichia coli (45.26 per cent), 39 Enterobacter cloacae (20.33 per cent) and two Salmonella (1.05 per cent) were obtained. Of all the E.coli isolates, only one (EC/11) was found to be haemolytic. In addition to the above specimens, eight samples of heart blood and 34 specimens of lung tissues collected from cases of gastroenteritis were also examined for the presence of bacterial organisms. Seven isolates of Streptococcus pyogenes (from lung tissues only), 15 isolates of Klebsiella Pneumoniae (from lung tissues only), and one isolate of Corynebacterium pyogenes (from lung tissues only) were obtained. The ability of haemolytic E.coli (EC/11) to produce necrotoxin on rabbit skin was tested and the lesions produced were of necrotic changes. The strain was also found to be pathogenic to mice when tested. One isolate of Salmonella (S/1) was also tested for its pathogenicity to mice, and found non – pathogenic. Enterotoxin production in rabbit ileal loop was studied with haemolytic (EC/11) and non – haemolytic (EC/15) E.coli. The test materials included peptone water culture, soft agar culture fluid and acetone precipitated culture fluid. The results of the experiment have shown that, non – haemolytic E.coli produced dilatation reaction, while the haemolytic E.coli did not. The lesions noticed in the ileal segments of positive reaction were typical of enteritis. Antibiotic sensitivity studies were conducted using 11 chemotherapeutic agents (Ampicillin, bacitracin, chloramphenicol, erythromycin, gentamicin, kanamycin, nitrofuran, penicillin, streptomycin, sulphonamide and tetracycline) on E.coli Salmonella and Enterobacter cloacae. The result showed that cent per cent isolates of E.coli were sensitive to gentamicin, 95.35 per cent to nitrofuran, 88.37 per cent to chloramphenicol, 60.47 per cent to kanamycin, 40.70 per cent to streptomycin, 8.14 per cent to tetracycline and 2.33 per cent to erythromycin. All the 39 isolates of Enterobacter closcae tested were sensitive to gentamicin and kanamycin, whereas 30 (76.92 per cent) were sensitive to chloramphenicol and nitrofuran and 15 (38.46 per cent) to streptomycin. The drugs of choice for Salmonella were found to be gentamicin, chloramphenicol, nitrofuran and streptomycin.
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    ThesisItemOpen Access
    Immunology survey on the incidence of infectious bronchitis(IB) and infectious laryngotracheitis (ILT) in poultry in and around Trichur
    (Department of Microbiology, College of Veterinary and Animal Sciences, Mannuthy, 1979) George, M C; KAU; Punnoose, K T
    Infectious bronchitis and infectious laryngotrancheitis are the two viral diseases of poultry responsible for economic loss to the poultry industry by way of decreased egg production, poor quality of eggs, decreased feed efficiency and loss of weight gain. These disease have been reported from the neighbouring states of Kerala. In the present study a serological survey was carried out to understand the prevalence of these two disease in the poultry population in and around Trichur. A total of 2,110 serum samples have been collected from the field, comprising of white leghorn, Rhode Island Red and Desi birds belonging to different age groups. Serum samples were collected from organized farms, from birds kept by farmers and from the birds slaughtered in different hotels at Trichur. These serum samples were tested against the infectious bronchitis and infectious laryngotracheitis by employing agar gel precipitation test. The chorioallantoic membrane and allantoic fluid of infected embryos were used for the preparation of antigens for agar gel precipitation test. The potency of antigens was tested by conducting the agar gel precipitation test with corresponding hyper immuns sera prepared in white leghon male chicks of six to eight weeks of age. A line of precipitation was obtained in both cases which was close and curved towards the antigen well, because of the high concentration of antibody in the sera and due to the high molecular weight of the antigen. In the case of infectious bronchitis the line of precipitation was distinct where as in case of infectious laryngotrachetis it was diffused. The antigen, whose efficiency was tested using hyper immune sera, was used to test samples of sera collected from the field. The samples were pooled to 211 groups and tested for the presence of infectious bronchitis and infectious larygotracheitis precipitating antibodies separately by agar gel precipitation test. None of the samples gave precipitin line either to infectious bronchitis or to infectious larygotracheitis. So it was assumed that both of these viral disease are not prevalent in Trichur and its suburbs.
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    ThesisItemOpen Access
    Investigation on the aetiology of plague -like disease in ducks In Kerala
    (Department of Microbiology, College of Veterinary and Animal Sciences, Mannuthy, 1978) Krishnan Nair, G; KAU; Sulochana, S
    An investigation was carried out to isolate, characterize and identify the agent responsible for the outbreak of duck plague – like disease in ducks in Kerala. Specimens (liver and spleen) from field cases, were processed for virus isolation and were inoculated into either developing duck or chick embryos, by chorio – allantoic (C.A.M.) or allantoic cavity method. Virus isolation was possible only by C. A. M. inoculation of duck embryos and was confirmed by inoculation of the C.A.M. extracts into duck embryo fibroblast (D.E.F.) cell cultures. The cytopathic changes produced by the field isolate DPV – N; its physico – chemical characteristics such as sensitivity to chloroform and 5 – iodo – 2 deoxyuridine; and the effect of exposure to various pH values such as 4.7, 7.2 and 9.1, were compared with that of a known duck plague virus DPV – K, received from the Veterinary Biological Institute, Mannuthy. In D.E.F. cell cultures, the cytopathic changes produced by DPV – N and DPV – K were rounding and clumping of cells, with characteristic basophilia and granulation of the cytoplasm. Although the initial titers of both DPV - N and DPV - K were only 105 and 106.25, they increased to 107.5 and 108.25 respectively, on further passages. The field isolate DPV – N and the known duck plague virus DPV – K were sensitive to 5% chloroform, with complete inactivation in ten minutes. Similarly, both the strains failed to multiply and produce cytopathis changes in cells treated with IUdR, at the rate of 100 micrograms per ml. However, differences were observed in their thermostability and pH sensitivity. Although DPV – K was inactivated completely at 560 C. in 30 minutes, DPV – N was only partially reduced in titer. DPV – N was also found to be resistant, when both the strains were exposed to pH 4.7, for a period of four hours at room temperature. But both were unaffected at pH 7.2 and got inactivated at pH 9.1. Both the strains also failed to produce any haemagglutination reaction with chicken R.B.C or precipitation reaction in agar gels. Although duck plague specific antiserum neutralized homologous strain DPV – K and the newly isolated strain DPV – N, the serum titers obtained with the latter was only less. Experimental infection studies have shown that one to six week – old ducklings were equally susceptible to DPV – N and DPV- K, either with the spleen extract or with tissue culture passaged sample. The symptoms and lesions produced in both cases, were similar to those described for duck plague and also to those seen during the disease outbreak in Kerala. The virus that caused an outbreak of duck plague - like disease in Kerala is found to be indistinguishable from that of duck plague. It is also strongly felt that the lack of complete protection of birds vaccinated with duck plague vaccine is due to t possible strain variation between the classical duck plague virus DPV – K and the virus as it occurred during this outbreak. However, it needs thorough in vitro cross neutralization and in vivo cross protection tests before any definite conclusions can be made on the strain variation of duck plague virus.
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    ThesisItemOpen Access
    Studies on the bacterial species associated with digestive disturbance in pigs
    (Department of Microbiology, College of Veterinary and Animal Sciences, Mannuthy, 1975) Balakrishna Pillai, K P; KAU; Abdulla, P K
    Prior to this investigation, limited studies conducted in the department of Bacteriology, College of Veterinary and Animal Sciences, Mannuthy, have revealed the association of pathogenic strains of E. coli and Salmonella with enteric disorders of pigs. Therefore, a detailed study of the incidence and magnitude of prevalence of those pathogens was carried out. A total of 274 specimens collected from sick as well as dead animals were examined. Faecal materials collected from living as well as dead animals, mesentric lymphnode, spleen, liver, lungs and heart blood formed the materials for isolation studies. Both enrichment and selective media like selenite and tetrathionate broth, D. H. S. broth and D.H.S. agar, modified MacConkey medium 1 & 11, and composite medium 1 & 11 were employed for isolation of pathogens. A total of 75 strains of E. coli and 24 strains of Salmonella were isolated and studied. Most of the isolations were made from piglings ages 3 – 8 weeks. Out of 75 strains of E. coli only 5 strains were found pathogenic based on various tests like haemolysin, necrotoxin and enterotoxin production and pathogenicity to mice. These isolates belonged to serogroup 05, 017 and 039. Salmonella strains belonged to two serotypes, S. weltevreden and S. typhimurium var coCopenhagen The identity of the isolates were confirmed biochemically and serologically. Pathogenicity studies conducted with two strains of Salmonella weltevreden and Salmonella typhimurium Var Copenhagen have revealed that they were pathogenic to laboratory animals like mice, guinea pigs and rabbits. It has also been observed that these serotypes could produce enteric form of the disease in primary hosts. Invitro drugsensitivity studies were carried out to determine the effectiveness of antibiotic to gastrointestinal disorders the effectiveness of antibiotic to gastrointestinal disorders caused by these species. It has been observed that all E. coli and Salmonella strains tested were sensitive to chloramphenicol. However multiple resistance was observed to penicillin, streptomycin, tetracycline, erythromycin and nitrofurantoin. The significance, possible role of infection by these species and their drug sensitivity reactions are discussed.