AUTHOR: NWOBODO HUMPHREY AFAM
DEPARTMENT: APPLIED MICROBIOLOGY AND BREWING
AFFILIATION: NNAMDI AZIKIWE UNIVERSITY, AWKA
Goats and sheep production makes a major contribution to the agrarian sector in Nigeria, with disease being the major constraint that impedes their optimal performance. However, natural products have been found effective in management of the disease. Prevalence of Peste des petits ruminants (PPR), a viral disease of small ruminants in Enugu State was studied. The clinical responses of goats to the disease and phytotherapeutic effect of C. paniculatum leaf extracts were also investigated. Six hundred and fifty five (655) serum samples (429 from goats and 226 from sheep) were collected between May, 2010 and April, 2011 from various farms without history of vaccination in Enugu State. The samples were screened for antibodies against PPR virus, using competitive enzymelinked immunosorbent assay (cELISA). In vitro antimicrobial activity of the extracts against selected viruses (New castle disease virus, Peste des petits ruminant virus, Infectious bursal disease virus) and bacteria (Escherichia coli, Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Salmonella typhimurein and Clostridium perfringens) were assayed using embryonated eggs, tissue culture and agar well diffusion test respectively. Five groups of West African Dwarf (WAD) goats (five per group) aged 4-6 months, quarantined for 6 days were used to study the invivo antimicrobial effect of the leaf extracts of the plant. Groups A, B, C and D were infected nasally with 100 μl (containing 6 x 103.7 TCID50/ml) first passage of Nigerian PPRV strain N75/1, while E was not infected. Sixth day post-inoculation (dpi), 10 ml of 500 mg/ml of the extracts were orally administered 6 hourly for 5 days (Group A: aqueous extract, B: acetone extract, C: methanol extract and D: no treatment). The animals were observed daily for a period of 30 days within which nasal and stool specimens collected on 0 and 15th dpi were subjected to bacteriologic analysis, while a goat from each group was euthanized for viral assay.Acetone extract alone was further assayed for phytotherapeutic effect using three groups of WAD goats (X, Y, Z) aged 4-6 months. The goats were quarantined for 6 days. Groups X and Y were infected nasally with 100 μl (containing 6 x 103.7 TCID50/ml) first passage of Nigerian PPRV strain. Group Z was not infected. Sixth dpi, group X was orally treated with 10 ml of 500 mg/ml acetone leaf extract of C. paniculatum 6 hourly for 5 days, while group Y was not treated. Blood samples were collected from each group on 6th, 9th, 12th, 15th, 18th, 21st, 24th, 27th and 30th dpi for immunologic assay while a goat was euthanized from each group on 9th, 12th, 18th and lung/intestine subjected to histologic/histopathologic investigation. The prevalence of the infection varied across local government areas (57% in Enugu-Ezike to 39% in Enugu-East), sexes (56% in females to 33% in male) and age groups (5.3% among those <1 to 78% among those > 3 years of age) with a state specific prevalence of 47% (p<0.01). Extracts of C. paniculatum exhibited no activity against the test viruses but acetone extract inhibited the growth of Salmonella typhimurein and Bacillus cereus in a concentration dependent manner. Clinical symptoms of the infection began in all the groups except group E on the 5 – 7th dpi with an elevated rectal temperature up to 39-41.4oC, conjunctivitis, nasal and lacrymal discharges. The load of Salmonella typhimurein in group B goats reduced from 15.4 x 103 to zero 16th dpi. Blood tinged watery stool and death was equally not recorded unlike in the other groups (A, C and D). PPR virus was isolated from nasal and intestinal preparations of both groups (X and Y) on the 9th, 18th and 30th dpi, with the viral titers of 6, 7and 6 to log2 respectively. There were detectable antibodies against the virus between 6th to 30th dpi in the range of 55% to 75% and 55% to 90% in groups X and Y respectively expressed as percentage inhibition. The histopathology of the lung was similar in X and Y showing severe inflammation and degeneration of epithelial cells. Hemorrhage and areas of ulceration were restricted to the intestine in group Y, whereas inflammation was milder and ulceration/hemorrhage absent in X. Prevalence estimate of 47.0% obtained in this study is significant (p<0.01) and compares with 50% recorded in some Weredas in Ethiopia. Sex, species and age as well as location are of epidemiologic importance. Experimental infection was accompanied with morbidity and mortality rates reaching 100%, implying that the virus is highly virulent. Growth of the viruses in the presence of the extracts invitro and isolation of PPR virus after treatment indicates that the extracts do not have effect against PPR, IBD and ND viruses.Fluctuation of antibody titre as the infection progressed indicated the immunogenic nature of the virus. Histopathologic disorder found in the gastrointestinal and respiratory tract indicates that PPR virus has tropism for cells in these organs than others. Rise in load of Salmonella typhimurein as the infection progressed suggests the involvement of this organism in complicating the infection. Therefore, inhibition of its growth by acetone extract may have forestalled diarrhoea, ulceration of intestine and death in that group of goats. Therefore, vaccination of goats and sheep against PPR virus, use of acetone leaf extract of C. paniculatum in PPR and its subjection to further studies are recommended.
TO VIEW THE FULL CONTENT OF THIS DOCUMENT, PLEASE VISIT THE UNIZIK LIBRARY WEBSITE USING THIS LINK, http://naulibrary.org/dglibrary/admin/book_directory/Thesis/11016.pdf