Publications by authors named "Tesfaye Sisay Tessema"
Enteropathogenic Escherichia coli (EPEC) is a significant bacterial pathogen that causes infantile diarrhea, particularly in low- and middle-income countries. The lack of a reliable diagnostic method greatly contributes to the increased occurrence and severity of the disease. This study aimed at developing of a cost-effective, rapid, and efficient immunodiagnostic assay for detecting EPEC infection.
View Article and Find Full Text PDFBrucellosis is a neglected zoonotic disease affecting livestock and humans that remains endemic in Ethiopia. Despite its prevalence, only a few studies have identified species circulating in livestock in the country. This study aimed to determine the species responsible for infections in livestock in the Afar region of Ethiopia and characterize the isolates using whole-genome single nucleotide polymorphism (wgSNP) analysis and in silico multi-locus sequence typing (MLST).
View Article and Find Full Text PDFBrucellosis is a common zoonotic disease affecting livestock and humans globally. The disease is endemic in Ethiopian livestock. This study was conducted to estimate seropositivity and identify its risk factors in livestock, and practices that may expose pastoralists to the disease.
View Article and Find Full Text PDFEscherichia coli of different pathotypes are frequently involved in morbidity and mortality in animals and humans. The study aimed to identify E. coli pathotypes and determine antimicrobial resistance (AMR) profiles in Ethiopian smallholder livestock households.
View Article and Find Full Text PDFBackground: Early detection and treatment of carbapenem-resistant Klebsiella pneumoniae (CRKP) could reduce the risk of developing life-threatening sepsis in childhood. However, little is known about sepsis caused by CRKP in children under-5 in developing countries. This study aimed to determine the epidemiology, antimicrobial resistance profile, associated risk factors and management of CRKP in children under-5 with sepsis in Ethiopia.
View Article and Find Full Text PDFThis study aimed to comprehensively examine the prevalence of L. monocytogenes and Listeria spp. in dairy products including raw milk, pasteurized milk, and cottage cheese, and identify potential risk factors for contamination throughout the dairy value chain in major milk sheds in Ethiopia.
View Article and Find Full Text PDFArticle Synopsis
- The study investigates the potential of lytic bacteriophages as alternative therapies to combat antibiotic-resistant strains of bacteria, particularly focusing on phages that target E. coli.
- Seven specific phage isolates were identified and analyzed through genome sequencing, revealing they possess double-stranded DNA with varying lengths and coding sequences, with most lacking tRNA genes.
- The findings suggest that these phages could be utilized in treating bacterial infections and provide essential data for developing phage-based control strategies and understanding phage genetics.
Article Synopsis
- Genomic structural variations, especially copy number variations (CNVs), are important for genetic diversity in cattle, yet they have been underexplored in indigenous Ethiopian breeds like Abigar, Fellata, and Gojjam-Highland.
- The study identified 3,893 CNV regions covering 19.15 Mb of the cattle genome, with notable differences among breeds, and validated a significant portion of these findings.
- The analysis revealed candidate genes related to adaptation to high altitudes, heat stress, and tick resistance, highlighting the unique genetic traits of these cattle and their potential implications for breeding and conservation.
Article Synopsis
- Shigellosis is a major health issue in Ethiopia, particularly affecting young children, and is exacerbated by antimicrobial resistance due to misuse of antibiotics and poor hygiene.
- The study utilized whole genome sequencing (WGS) to examine Shigella sonnei strains in Addis Ababa, focusing on antibiotic resistance genes and plasmid types associated with these strains.
- Findings showed a variety of resistance genes and phenotypic resistance patterns, indicating significant genetic diversity in S. sonnei strains, which suggests the need for enhanced monitoring of antimicrobial resistance through WGS.
Article Synopsis
- * A study conducted from June 2021 to December 2023 involved 5 hospitals and found that 10.8% of 5613 women suspected of sepsis had CRKP infections, with high rates of multi-drug resistance (93.9%) and other varying levels of resistance to critical antibiotics.
- * Risk factors such as septic abortion, extended hospitalization, and cesarean wound infections were significantly associated with developing sepsis, and treatment often included combining carbapenem with other antibiotics for resistant strains.
Article Synopsis
- * The study detected and characterized four major pathogens responsible for calf diarrhea using fecal samples from both diarrheic and non-diarrheic calves, identifying various strains of Cryptosporidium, rotavirus A, and bovine coronavirus.
- * Notably, the uncommon G24 genotype of rotavirus A was found for the first time in Ethiopia and Africa, highlighting the need for genetic analysis of these pathogens to improve understanding and control of calf diarrhea.
Campylobacteriosis outbreaks have previously been linked to dairy foods. While the genetic diversity of Campylobacter is well understood in high-income countries, it is largely unknown in low-income countries, such as Ethiopia. This study therefore aimed to conduct the first genomic characterization of Campylobacter isolates from the Ethiopian dairy supply chain to aid in future epidemiological studies.
View Article and Find Full Text PDFThe advancement of genetic engineering has revolutionized the field of immunology by allowing the utilization of intrinsic antibody structures. One of the biologics that are being produced by recombinant antibody technology is single-chain fragments variable (scFv). Genes of variable regions, the heavy and light chains that are genetically linked into a single transcript by a short flexible linker peptide, are used to generate this fragment from cellular and synthetic libraries.
View Article and Find Full Text PDFArticle Synopsis
- Coagulase-negative Staphylococcus species are increasingly being identified as a cause of intramammary infections in dairy cattle, presenting risks to public health and economics, particularly in Northwestern Ethiopia.
- A study conducted from February to August 2022 isolated these bacteria from 290 milk samples, revealing a prevalence of 28.6% with high resistance to common antibiotics like Amoxicillin and Ampicillin, and notable rates of multidrug resistance.
- The study also detected several virulence genes in the isolates, suggesting a concerning potential for pathogenicity in these antibiotic-resistant strains.
Article Synopsis
- - The study investigates the genetics of Barka cattle, a breed known for its high milk production in challenging semi-arid environments, focusing on specific genes linked to milk traits.
- - Using genome-wide analysis and selective sweep detection methods, researchers identified several key genes consistently associated with milk production and composition.
- - The identified genes play important roles in processes like fatty acid metabolism and mammary gland development, suggesting potential for improving dairy cattle in tropical areas; further studies are needed for selective breeding applications.
Article Synopsis
- * A recent study sequenced DNA from 70 cattle across seven indigenous breeds, producing about 2 terabytes of data and achieving a 99.2% alignment rate with the cattle reference genome.
- * The research identified around 35 million high-quality SNPs, enhancing our understanding of cattle genetics, aiding in the discovery of beneficial mutations, and supporting sustainable cattle management amidst climate change challenges.
Article Synopsis
- Seasonal changes impact foodborne illness and microbial contamination in dairy products, although research on this topic in Ethiopia has been limited.
- This study analyzed the prevalence of contamination in milk and cheese samples across wet and dry seasons in various Ethiopian regions, revealing higher contamination rates during the dry season.
- Findings suggest that to improve dairy product safety in Ethiopia, ongoing education on hygienic practices for milk production should take seasonal variations into account.
Diarrheagenic (DEC) are the leading cause of infectious diarrhea and pose a significant global, regional, and national burden of disease. This study aimed to investigate the prevalence of six DEC pathotypes in children with diarrhea and determine their antibiotic resistance patterns. Samples from 107 diarrheagenic children were collected and processed for ().
View Article and Find Full Text PDFIntroduction: There have been numerous studies that showed the presence of human papillomavirus (HPV) in breast cancer; nonetheless, there is ongoing debate regarding their association. Given few studies in Ethiopia, we aimed to investigate the magnitude of HPV infection in Ethiopian breast cancer patients.
Methods: A total of 120 formalin-fixed paraffin-embedded (FFPE) tissue blocks were obtained, and basic demographic, clinical, and histological data were collected from medical records.
Background: Escherichia coli is a common fecal coliform, facultative aerobic, gram-negative bacterium. Pathogenic strains of such microbes have evolved to cause diarrhea, urinary tract infections, and septicemias. The emergence of antibiotic resistance urged the identification of an alternative strategy.
View Article and Find Full Text PDFArticle Synopsis
- * Researchers examined 15 L. monocytogenes and 55 L. innocua samples from various dairy supply chains in Ethiopia using whole-genome sequencing to understand their genetic diversity and relationships.
- * The study identified 3 L. monocytogenes and 12 L. innocua sequence types, finding both region-specific and widespread strains, with low genetic variation among L. monocytogenes indicating possible selection pressures in the dairy supply chain.
A longitudinal design with a simple random sampling method was used to collect and compare microbial hygiene levels between the dry season (January to April) and wet season (June to August). A total of 456 milk and cottage cheese samples were collected from each site along the dairy value chain from three regions. Enumeration of total aerobic mesophilic bacteria (APC), total coliforms (TCC), and Escherichia coli (EC) was performed according to standard methods.
View Article and Find Full Text PDFArticle Synopsis
- The study examines breast cancer (BC) subtypes across four Ethiopian regions, highlighting a lack of research in areas outside Addis Ababa.
- Researchers analyzed 227 tissue samples using immunohistochemistry to determine the presence of key markers and found high rates of ER and PR negativity, as well as a significant prevalence of triple-negative breast cancer (TNBC) at 33.1%.
- The findings indicate that a substantial proportion of patients may not benefit from standard endocrine treatments, and the high occurrence of aggressive tumors in younger patients suggests a need for tailored treatment approaches.
Article Synopsis
- Indigenous cattle breeds, like the Abigar, show traits such as disease resistance and heat tolerance due to their adaptation to harsh environments, making their genetic study important for sustainable farming.* -
- Whole-genome sequencing of the Abigar revealed high genetic diversity and low inbreeding, highlighting their robust population structure and unique adaptation capabilities.* -
- Researchers identified 83 key genes linked to traits like heat tolerance and immune response, providing a basis for future studies aimed at improving cattle resilience in the face of climate change.*
Introduction: Matrix metalloproteinases (MMPs) play a pathophysiological role in cancer initiation and progression. Numerous studies have examined an association between MMP-2, MMP-9, and MMP-11 expression and clinicopathological characteristics of breast cancer (BC); however, no research has been done on the MMP expression levels in BC cases from Ethiopia.
Materials And Methods: A total of 58 formalin-fixed paraffin-embedded breast tissue samples encompassing 16 benign breast tumors and 42 BC were collected.