AAU Institutional Repository (AAU-ETD)
Addis Ababa University Institutional repository is an open access repository that collects,preserves, and disseminates scholarly outputs of the university. AAU-ETD archives' collection of master's theses, doctoral dissertations and preprints showcase the wide range of academic research undertaken by AAU students over the course of the University's long history.
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The repository contains scholarly work, both unpublished and published, by current or former AAU faculty, staff, and students, including Works by AAU students as part of their masters, doctoral, or post-doctoral research
- All AAU faculty, staff, and students are invited to submit their work to the repository. Please contact the library at your college.
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Recent Submissions
Production of monoclonal antibody for lumpy skin disease, sheep pox, and goat pox viruses to develop Enzyme-linked immunosorbent assay
(Addis Abeba University, 2024) Kalkidan Asnake; Fufa Dawo
Lumpy skin disease (LSD), sheeppox (SPP), and goatpox (GTP) are economically significant pox disease of ruminants, caused by lumpy skin disease virus (LSDV),
sheeppox virus (SPPV), goatpox virus (GTPV), respectively. The new emergence of disease caused by capripoxviruses and spreading outside of their endemic regions, stressing the urgent need to develop high-throughput serological surveillance tools. This experimental study was conducted to produce Monoclonal antibodies (mAbs) against LSDV, SPPV, and GTPV to development ELISA assay. The study was conducted in African Union Pan African Veterinary Vaccine Centre (AU-PANVAC), from October 2023 to May 2024. The mAbs were produced through immunization of BALB/C mice with purified antigen of LSD, SPP, and GTP, with consecutive booster injection. A hybridoma technology was used to produce the hybridoma clones (LC 5.14 and LC 5.4) which were subsequently mass-produced and tested. These LC 5.14 and LC 5.4 mAbs were precipitated and then quantified through the Bicinchoninic Acid protein assay kit. The isotype for the two mAbs were determined through Pierce™ Rapid Antibody Isotyping Kit, and both mAbs were IgG1. The cross-reaction of the two mAbs with GTPV and SPPV Ag were studied and those two mAbs were cross-reacted with the GTPV Ag but not with the SPPV Ag LC 5.14 and LC 5.4 mAbs were then conjugated with horseradish peroxidase enzyme; hence enzyme linked mAbs were used for ELISA development. The dot blot test was conducted by using of the LSDV, SPPV, and GTPV Ags with the two conjugated mAbs on the nitrocellulose membrane. Finally, the conjugated mAbs (LC 5.14 and LC 5.4) were
titrated to determine the concentration which is required for ELISA test, and the titer of 1/10 for LC 5.14 and titer of 1/5 for LC 5.4 were determined to use for ELISA assay. Further repeated tests with the positive serum from immunized cattle, sheep, and goat and the negative serum from the same species of animals are required to produce the validate kit which can be used as a diagnostic purpose for the capripoxviruses.
Antibiogram study of Salmonella and Escherichia coli isolates and assessment of KAP of poultry producers in conventional poultry farms in Hossana town, central Ethiopia
(Addis Abeba University, 2024) Habtamu Endale; Debela Abdeta; Mesfin Mathewos; Saliman Aliye; Adane Haile
Antimicrobial resistance is a serious health threat to creatures that depend on antimicrobials for the prevention and relief of infections. Foodborne Salmonella and Esherchia coli O157:H7 are critical causes of antimicrobial resistance associated morbidity and mortality. Fast growing poultry production along with antimicrobial misuse is a critical hotspot for the emergence and spread of antimicrobial resistance. A cross-sectional study aimed at investigating the antimicrobial resistance pattern of Salmonella and E. coli O157:H7 by disc diffusion method and assessment of KAP of poultry producers was executed in conventional poultry farms in Hossana Town, Central Ethiopia from October 2023 to May 2024. Up on bacteriological, biochemical and serological tests, 27 Salmonella and 20 E. coli were isolated and identified from a total of 228 cloacal swabs and postmortem samples. In disc diffusion test, all Salmonella and E. coli isolates were resistant to tested antimicrobial agents. Salmonella was resistant to ampicillin (100%), sulfamethoxazole and cefoxitin (85.1%), tetracycline (77.8%), trimethoprim/sulfamethoxazole (74.1%), amoxicillin-clavulanic acid (66.6%), ceftriaxone and streptomycin (55.6%), ciprofloxacin (51.9%), ampicillin/sulbactam (48.1%), trimethoprim (44.4%) and cefotaxime (40.7%). It showed high susceptibility to meropenem (81.48 %), gentamicin (66.67%), chloramphenicol (81.48%) and azithromycin (81.48%). E. coli O157:H7 was resistant to ampicillin (100%), cefotaxime and tetracycline (90.00%), cefoxitin and
trimethoprim (70.00%), sulfamethoxazole (65.00%), amoxicillin clavulanic acid and ceftriaxone (55.0%) and ampicillin/sulbactam (50.00%). It was highly susceptible to azithromycin 90.00%, gentamicin (75.00%), chloramphenicol (60.00%), ciprofloxacin (55.00%) and meropenem (50.00%). All Salmonella and 80.00% of E. coli exhibited MDR. A lower portion, 22.20%, 19.44% and 25.00% of the poultry producers have good knowledge, attitude and practice on AMU and AMR, respectively. Poultry farms in the study site were found crucial hotspots for AMR Salmonella and E. coli and the low KAP levels of the poultry producers further exacerbate antimicrobial misuse and AMR spread. Monitoring antimicrobial dispensing, awareness of stakeholders on AMR prevention, and improving poultry producers' KAP on antimicrobial use and resistance are paramount to tackling this global problem.
Occurrence and antimicrobial susceptibility profile of Staphylococcus aureus from raw cow milk and traditionally processed dairy products in and around Hawassa town, Sidama, Ethiopia
(Addis Abeba University, 2024) Eskedar Wodaje; Eyob Hirpa; Gizat Almaw; Gezahegn Mamo
Staphylococcal foodborne poisoning is a well-known global health concern. This study aimed to investigate the occurrence of Staphylococcus aureus and its antimicrobial susceptibility profiles in raw cow milk and traditionally processed dairy products in Hawassa town, Sidama Region, Ethiopia. A cross-sectional study conducted from December 2023 to May 2024. Totally 386 samples were collected and cultured using standard microbiological techniques and further identification and confirmation of S. aureus was done using MALDITOF method and conventional PCR was used to detect the resistance gene. S. aureus was
isolated and identified in 54 (13.99%) of the samples, with the highest prevalence in raw milk (20.7%), followed by bulk tank milk (5.0%) and yoghurt (2.4%). Number of S. aureus was not detected in cheese samples. Antimicrobial susceptibility testing revealed high resistance to Tetracycline (46.3%), Penicillin G (85.2%), Ampicillin (92.6%), and Amoxicillin (100%). Notably, 87.4% of the S. aureus isolates exhibited multiple drug resistance, posing a significant public health concern. PCR-based detection showed that all 25(46.3%) S. aureus isolates were positive for the nuc gene, but none possessed the mecA or blaZ genes. A questioner survey found that 40(40.0%) of the population consumed raw milk, 61(61.0%) had no food safety knowledge, and 77(77.0%) were unaware of Staphylococci foodborne illness. These findings demonstrate the need for improved food safety and hygiene practices, as well as the development of new antimicrobial containment strategies to address the high prevalence of MDR S. aureus in milk and milk products. Further investigation is warranted to understand the mechanisms of S. aureus resistance to methicillin resistance and β-lactam antibiotics.
Seroprevalence of Foot and Mouth Disease and Indigenous Disease Management Practices in Smallholder and Intensive Dairy Cattle Production Systems in Jimma City, Southwest Ethiopia
(Addis Abeba University, 2024) Emraphel Ali; Dr. Ytbarek Getachew; Dr. Haileleul Negussie
Foot and mouth disease (FMD) is a highly contagious viral disease that has a significant economic loss in the livestock sector in Ethiopia. A cross-sectional study was conducted to determine the seroprevalence of FMD, the associated risk factor for its occurrence, and FMDV serotypes circulating in the area. Moreover, efforts were made to assess the traditional FMD management practices in the study area. A total of 384 blood samples were collected from dairy cattle managed under various production systems and subjected to a 3ABC enzyme-linked immune-sorbent assay (ELISA) test to detect antibodies against non- structural proteins of FMD virus. A total of 22 serum samples exhibiting higher antibody titer were further tested using solid-phase competitive ELISA to identify the serotypes circulating in the area. Semi stractured questionnaires were used to collect information on potential risk factors and to extract knowledge, attitudes, and practices among respondents pertinent to the epidemiology of FMD. In this study, the overall seroprevalence of FMDV in dairy cattle of Jimma City was 29.9% (95% CI: 25.4 - 34.8). A multivariable logistic regression analysis revealed that the risk of being FMDV seropositive was four times higher in crossbred cattle (OR = 4.15; 95% CI: 1.67 - 10.3; P = 0.002), three times higher in animals managed extensively (OR = 3.22; 95%CI: 1.33 -7.83; P = 0.01), three times higher in animals uses communal grazing and watering points (OR = 2.5; 95% CI: 1.28-4.86; P 0.007), and two times higher in larger herd sizes (OR = 2.05; 95% CI: 1.059-4.17; P = 0.039). In this study, four FMDV serotypes were identified in which serotype O was the predominant serotype (33%), followed by SAT-2 (27%), serotype A (23%), and SAT-1 (17%). Of the 104 respondents, the majority (84.6%) knew about FMD. Additionally, the indigenous FMD management practice of the respondents demonstrated extensive use of indigenous treatments and herbal remedies such as Solanum Nigrum („Embuay‟) (9.1%), Urtica pilulifera L (“Sama”) (15.2%), suspension of honey with red pepper (42.4%), and tobacco leaves powder (12.1), and salt (21.2%) in managing FMD in cattle. This study demonstrated a high prevalence of FMD in the study area.
Efficacy of Entomopathogenic fungi against Amblyomma Variegatum Ticks and their control practices in and around Bishoftu, Central Oromia, Ethiopia
(Addis Abeba University, 2024) Dereje Tsegaye; Prof. Bersissa Kumsa
Ticks impact the health of animals and humans and are associated with numerous public health and economic problems around the world. The use of chemical acaricides has been the most commonly used method for tick control on livestock in recent years. However, chemical control of ticks has several disadvantages including high expense, lead to toxic residues in meat and milk, lead to acaricidal resistance and cause environmental pollution. The present in vitro experimental study on the efficacy of entomopathogenic fungi against adult Amblyomma variegatum collected from cattle was conducted from September 2023
to April 2024 in Bishoftu town. The entomopathogenic fungi were isolated from the soil samples in different parts central of Ethiopia. Furthermore, the knowledge, attitudes and practices of the animal owners regarding ticks and tick control was assessed through a structured questionnaire survey. Of the total of 80 soil samples examined for the presence of Entomopathogenic fungi, 17 samples from Bishoftu and Burayu were positive of which Metarhizium anisopliae were detected in 10 soil samples while the rest 7 soil samples were positive for Beauveria bassiana.The working concentrations were prepared from
selected positive isolations at three strength levels (1x10 6 , 1x10 7 and 1x10 8) conidia/ml was applied against Amblyomma variegatum while distilled water and Amitraz 12.5% were used as a negative and positive control, respectively. After applying different concentrations separately, and a mortality rate of 93% and 97.5% was recorded at the concentrations 1x10 7 and 1x10 8 conidia/ml respectively for metarhizium anisoplie and 93.33% and 97% for beauveria issiana after 15 days, with the lowest concentration (1x10 6) conidia/ml showing the lowest death percentage (83.25%) for metarhizium anisoplie and 80.7% for beauveria issiana whereas 76.75% mortality was recorded in the positive control Amitraz. The highest efficacy of Entomopathogenic fungi was observed for the
highest concentration and time in increasing manner. The LC50 of 1 x 10 4 (% 95 CI = 1 x 10 3 - 1 x 10 8) conidia/ml for Metarhizium anisopliae and 1 x 10
4 (% 95 CL = 1 x 10 3–1 x 10 6) conidia/ml for Beauveria bassiana, and LC99 of 1x10 9 (% 95 = 1x10 8-1x10 13 conidia/ml for Metarhizium anisopliae and 1x10 9 (%95=1x10 7-1x10 11) conidia/ml for Beauveria bassiana were recorded using probit regression analysis. This suggests that the EPF have great potential as the alternative approach to chemical acaricides for the control of ticks in Ethiopia.