2 research outputs found
Molecular Detection and Characterization of Newcastle Disease Virus from Chickens in Mid-Rift Valley and Central Part of Ethiopia
No full textEsubalew Endale Alemu,1 Bayeta Senbata,2 Melaku Sombo,2 Chala Guyassa,2 Dawit Hailu Alemayehu,3 Eleni Kidane,4 Adane Mihret,3 Andargachew Mulu,3 Hunduma Dinka1 1Department of Applied Biology, Adama Science and Technology University, Adama, Ethiopia; 2Molecular Biology Laboratory, Animal Health Institute (AHI), Sebeta, Ethiopia; 3Biotechnology and Bioinformatics Research Directorate, Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia; 4TB and HIV/AIDS Disease Research Directorate, Ethiopian Public Health Institute (EPHI), Addis Ababa, EthiopiaCorrespondence: Hunduma Dinka; Bayeta Senbata, Email [email protected]; [email protected]: Newcastle disease (ND) is a highly infectious poultry disease that causes major economic losses worldwide. The disease is caused by Newcastle Disease Virus (NDV) and early detection and identification of the viral strain is essential. Having knowledge of the NDV strain genotype that circulates in some regions would help in designing an effective vaccine to control the disease. In this regard, there is little information on NDV strain in chickens in mid Rift Valley and the central part of Ethiopia. Therefore, the purpose of this study was to detect and characterize NDV strain genotype from chickens in mid-Rift Valley and the central part of Ethiopia and test whether this NDV strain genotype matches the vaccine strain currently used in the study area.Methods: A total of 98 samples: 78 (tracheal and cloacal) swabs from chicken pools of five and 20 tissue samples were collected. To detect NDV strain, conserved region of the virus Matrix (M) gene was amplified by qRT-PCR. To characterize NDV strain genotypes, M-gene positive samples were specifically re-amplified by conventional PCR targeting the Fusion (F) gene region and sequenced by Sanger method.Results: 13.26% of tested samples were positive for NDV strain in the study area with statistically significant difference (P< 0.05) among the study sites. Further characterization of the F genes from NDV strain isolates by phylogenetic analysis indicated that one field isolate clustered with genotype VII whereas three of the isolates clustered to genotype I, II, and III. The isolate of the current NDV strain vaccine in use in the study area clustered with genotype II.Conclusion: The current study indicates the existence of different NDV strain genotype from that of the vaccine strain currently used. Even though large-scale characterization of several isolates is required at national level, the current study laid baseline information for the existence of variations between field NDV strain genotype and vaccine strain currently used against ND in the country.Keywords: APMV-1 strain genotype, F gene, mid rift valley, phylogenetic tree, qRT-PC
Phenotypic, molecular detection, and antibiogram analysis of Pseudomonas species from Oreochromis niloticus.L 1758 (Nile Tilapia) from aquaculture pond, Ethiopia
No full textAbstract Background Pseudomonas species, including P. aeruginosa, P. putida, and P. fluorescens, are zoonotic bacterial pathogens responsible for significant disease and mortality in both farmed and wild fish worldwide. In Ethiopia, these bacteria have been identified in Sebeta fish ponds and Rift Valley lakes, yet there is limited data on their molecular and phenotypic characteristics in local aquaculture systems. To address this gap, a cross-sectional study was conducted from November 2022 to May 2023 in selected aquaculture ponds in Ethiopia. Results A total of 637 samples were aseptically collected from the muscle, liver, spleen, and kidney of fish using purposive sampling. Pseudomonas base agar selective medium morphological characteristic and biochemical tests were used to isolate and identify pseudomonas species. Pseudomonas species were isolated from 81 samples, representing 12.7% of the total. Among these isolates, 85.6% displayed virulence traits, including β- hemolysis on 5% sheep blood agar. Additionally, 75 isolates (92.59%) was confirmed using conventional PCR with Pseudomonas-specific primers. Of the PCR-positive samples, 8 (10.66%) were identified as P. aeruginosa, 28 (37.63%) as P. putida, and 39 (52%) as P. fluorescens from Nile Tilapia (O. niloticus). Antibiotic susceptibility testing on ten representative isolates revealed that all strains were sensitive to Ciprofloxacin, Gentamicin, and Ceftriaxone but resistant to Amoxicillin and Penicillin. Conclusions The findings indicate that Pseudomonas species carrying virulence genes, exhibiting β- hemolytic activity, and showing resistance to commonly used antibiotics in both human and veterinary medicine are present in aquaculture. The detection of this pathogen in 75 fish samples raises concerns about potential outbreaks and zoonotic transmission. Therefore, further research on the molecular epidemiology of the disease is necessary to understand inter-host transmission and antibiotic resistance patterns
