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.

How to Submit Your Work

The repository contains scholarly work, both unpublished and published, by current or former AAU faculty, staff, and students, including Works by AAU students as part of their masters, doctoral, or post-doctoral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.

You may contact digirep@aau.edu.et.with any questions about the repository

 

Recent Submissions

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Detection and Antimicrobial Resistance Profile of Salmonella Isolated from Cow Milk and its Products in Bishoftu Town, Central Ethiopia: Its Implication for Public Health
(Addis Abeba University, 2024) Lema Temesgen; Dr. Fufa Abunna; Takele Beyene
Salmonella is a significant foodborne pathogen, with milk and milk products commonly implicated in its transmission. However, limited information is available regarding the direct link between antimicrobial use (AMU), dairy hygiene practices, and antimicrobial resistance (AMR) in Salmonella strains isolated from dairy products in Bishoftu town. Cross-sectional research was done from October 2023 to April 2024 to assess dairy farmers' antimicrobial usage (AMU) and hygiene practices and the occurrence of antimicrobial resistance (AMR) profiles of Salmonella isolated from raw cow milk and its products. Two hundred samples were collected from dairy farms, milk vendors, and restaurants and analyzed using standard microbiological methods. Using the OmniLog system, Salmonella enterica was successfully identified. Then, the antimicrobial susceptibility was evaluated using the Kirby-Bauer disc diffusion technique. A structured questionnaire was also used to assess the milk value chain's knowledge, attitude, and practices (KAP) regarding AMU, AMR, and hygiene practices. Data were analyzed using STATA version 14.2. Overall, 2% (n = 4) of the samples tested positive for S. enterica. of the 4 isolates 3 were identified in dairy farm samples, whereas 1 were isolated from milk vendors. However, no Salmonella was identified in cheese or yogurt samples obtained from the restaurants. Regarding the AMR profile, S. enterica isolates were resistant to amoxicillin (75%), streptomycin (75%), and tetracycline (50%). Resistant to two or more antimicrobials were identified in 75% of the isolates. Among 41 dairy farmers interviewed it was found that most of the respondents had sufficient knowledge (78%), desired attitudes (90%), and good practices (76%) regarding AMU and AMR. However, 36% of dairy farms had poor hygienic practices. In conclusion, the current investigation indicated contamination of cow milk and its products with S. enterica. Therefore, appropriate control measures, including awareness creation among personnel and improving hygienic practices at the milk value chains is recommended to mitigate cross-contamination
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Evaluation of Biochemical Determinants of Successful Conception in Dairy Cows in and around Bishoftu, Ethiopia
(Addis Abeba University, 2024) Kutelo Kussia; Prof. Alemayehu Lemma
The influence of biochemical characteristics of cervical mucus at the time of estrus were evaluated on conception rates of normal-cycling and repeat-breeding dairy cows. A total of 62 Holstein-Friesian dairy cows, 38 normal-cycling and 24 repeat-breeding cows, were included in the study. Vaginal electrical resistance (VER) was measured before artificial insemination and cows were categorized into three VER groups (150-180, 181-220 and >220 Ω). The cows were also grouped into three body weight ranges (300-350, 351-400 and 401-450 kg). Cervical fluid parameters including pH, spinnbarkeit, sperm penetration and crystallization patterns were measured or scored and pregnancy was diagnosed by ultrasonography after 30 days post-AI The overall conception rate was 54.84% with a significant difference (P<0.05) between normal cycling cows (63.2%) and repeated breeders (41.7%). The mean (±SD) VER was in the order of 219.03±66.17Ω and 221.67±41.77Ω for normal-cycling and repeated breeding cows, respectively. The average pH and spinnbarkeit value of cervical fluid were 7.38±0.32, 5.76±2.2cm in normal cycling and 7.32±0.27, 5.85±3.77cm in repeat breeder cows, respectively. The mean(±SD) VER of pregnant and nonpregnant cows were 202.15±31.15Ω and 241.79±73.56Ω, respectively. Body weight, timing of insemination and VER showed significant effects (P<0.05). Conception rates were highest for cows weighing 351- 400 kg(75%), inseminated 7-12 hours (71.43%) after standing estrus and VER of 181-220 Ω 84.21%). Interestingly, although there was some tendency for influence of the cervical fluid pH, this was not statistically significant, but sperm penetration, spinnbarkeit value and crystallization patterns of cervical fluid did (P<0.05). Cows with normal sperm penetration (72.2%), spinnbarkeit of 7-9 cm (87.5%) and typical crystallization patterns of cervical mucus (76.47%) had comparatively higher conception rates. In conclusion, sperm penetration, spinnbarkeit, vaginal electrical resistance and crystallization pattern are useful predictors of optimal insemination timing in Holstein cows.
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A Retrospective Study Of Dogs Rabies, Vaccination Coverage And Challenges In Addis Ababa
(Addis Abeba University, 2024) Kirubel Befekadu; Dr. Biruhtesfa Asrade; Dr. Zerihun Assefa
A retrospective and cross-sectional study about the incidence of rabies and the coverage and barriers of rabies vaccination was conducted in Addis Ababa city from October 2023 to April 2024. The objective of this study was to assess the general condition of rabies and its vaccination coverage within Addis Ababa. Data was collected through surveys of dog owners and interviews with veterinarians in various sub-cities across Addis Ababa. Additionally, retrospective analysis of dog bite records from the Ethiopian Public Health Institute and canine vaccination data (2020- 2023) from the Farmers and Urban Agriculture Development Commission were employed. Out of the 206 dog owners who participated in the survey, the majority (66.5%) indicated that their dogs were fully vaccinated. Some of the significant barriers for dog vaccination acknowledged by respondents were poor knowledge of rabies, unrestricted dog movement, and lack of mass vaccination campaign. Interviewed veterinary professionals identified lack of equipment, coordination with other agencies and inadequate long-term planning as the major barriers for vaccination coverage. In Addis Ababa, 3,123 individuals were reported to be bitten by a suspected dog from 2019 to 2023 and overall incidence rate was found to be 12.45. In the same period 92.7% of the victims were reported to have received post-exposure prophylaxis. According to records from the Farmers and Urban Agriculture Development Commission, a total of 96,319 dogs received rabies vaccination in Addis Ababa during the period spanning from 2020 to 2023. In the present study, there was a significant increase in the number of human cases of dog bites receiving post-exposure anti-rabies vaccination. Additionally, this research revealed a lack of awareness regarding rabies vaccination, particularly notable in sub-cities like Arada and Lemi Kura. This study recommends for the scaling-up of periodic mass vaccination campaigns for dogs, coupled with one health initiatives and targeted restrictions on canine movement, as a comprehensive strategy for rabies control.
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Assessment of Farm Management Practices, Antimicrobial Usage, Poultry Health and Welfare: Isolation and Antimicrobial Susceptibility Profile of E. Coli in Poultry Farms at the Starter Phase In Bishoftu, Ethiopia
(Addis Abeba University, 2024) Kebene Temesgen; Hika Waktole
In view of the expanding trend of poultry sector, the starter phase of poultry production requires effective management, health, welfare and judicious antimicrobial usage. Suboptimal practices during the starter phase can result in reduced productivity and increased spread of disease. A cross-sectional study was conducted from October 2023 to May 2024 with the targeted objectives of assessing farm management practices, poultry health and welfare, antimicrobial usage and susceptibility profile of E. coli in poultry farms during the starter phase in Bishoftu town. Methodologically, the study employed questionnaire surveys and bacteriological isolation of E. coli. The questionnaire survey revealed that 69%, 50%, 70%, 42% and 65% of respondents had good management practices in terms of housing and brooding, chick quality and procurement, health and biosecurity, welfare and antimicrobial usage, respectively. The study's findings indicated several managemental practices were not properly addressed. The study found that farmers' educational level, experience and role significantly (p<0.05) impact on the management of housing and brooding, as well as maintenance of health and biosecurity and rational use of antimicrobials. Education also significantly influenced (χ2=28.6; p=0.000) the promotion of chicken welfare within the farms. Risk factors like breed also impact chick quality and procurement management and maintenance of health and biosecurity (p<0.05). Differences in farm size also played a significant (p<0.05) influence in maintaining health and biosecurity, promoting animal welfare and ensuring the rational use of antimicrobials. The present study disclosed that 52.7% (116/220) isolation of E. coli from cloacal swabs. Further, Antimicrobial susceptibility testing revealed all isolates showed 100% resistance to oxacillin and penicillin, 88% to vancomycin, 64% to oxytetracycline, 48% to amoxicillin, 32% to sulphamethoxazole-trimethoprim. To promote effective management of poultry farms, particularly during the starter phase targeted interventions are recommended for effective poultry farm management, focusing on promoting poultry health, and welfare and judicious use of antimicrobials for sustainable farming practices
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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.