Haileeyesus Adamu’s research while affiliated with Addis Ababa University and other places

Background Bovine rotavirus A (BRVA) and bovine coronavirus (BCoV) cause significant diarrhea in young calves, leading to health issues and economic losses in the cattle industry. This study aimed to detect and molecularly characterize BRVA and BCoV in calves from Addis Ababa, Ethiopia. Fecal samples were collected from 105 calves under six months old, both with and without diarrhea. BRVA and BCoV were detected using quantitative real-time Polymerase Chain Reaction (qPCR), followed by genome sequencing for phylogenetic analysis and genotype determination. Results BRVA was found in 3.8% of the calves, while BCoV was detected in 2.9%. The identified rotavirus genotypes included G10, found in diarrheic calves, and G8, found in a non-diarrheic calf. All BCoV infections occurred in diarrheic calves. Phylogenetic analysis of the BCoV spike protein 1 (S1) hypervariable region (HVR) and hemagglutinin esterase (HE) gene revealed close relationships with European and Asian strains. The S1 HVR of the current virus sequence PQ249423 was 100% identical at the nucleotide level to previously reported sequences from Ethiopia. Six amino acid substitutions in the HE gene of the current BCoVs were identified compared to the reference Mebus strain of BCoV. Phylogenetic analysis showed that the current G8 BRVA sequences clustered with bovine, caprine, and human rotavirus strains, while the G10 viruses formed a distinct cluster with bovine strains. The G10 viruses showed a 99.37% nucleotide sequence similarity to a previously reported BRVA from Ethiopia, and the G8 virus displayed the highest nucleotide similarity with a caprine isolate from India. Gene segment analysis of the current BRVA viruses indicated varying similarities with human, bovine, caprine, and porcine rotavirus strains, suggesting a potential reassortment event involving artiodactyl, human, and porcine rotavirus. Conclusions This study demonstrates the presence of BRVA and BCoV in Ethiopian dairy calves and provides insights into their genetic diversity. Genetic analysis of BCoV revealed close relationships with strains from Europe and Asia. G10 and G8 were the identified BRVA genotypes, with G8 reported for the first time in Ethiopia. Future research should focus on broader sampling and molecular characterization to understand genetic diversity and devise effective control measures.

Background Campylobacter is a leading foodborne pathogen posing a significant One Health challenge due to its broad animal reservoirs and serious antibiotic resistance issues. Despite frequent human-animal-environment interactions in Ethiopia, One Health studies on the occurrence and transmission of Campylobacter are crucial but lacking. Methodology/Principal Findings A cross-sectional study from March 2021 to March 2022 in and around Debre Berhan, Ethiopia, examined Campylobacter occurrence, resistance, and risk factors in poultry and humans using a One Health approach. A total of 366 samples from 122 poultry farms were collected, including cloacal swabs, human stools, and poultry house floor sock samples. Epidemiological data on risk factors and respondents awareness were gathered through face-to-face interviews. Campylobacter spp. were isolated following ISO 10272 and confirmed with multiplex PCR, with antimicrobial susceptibility tested by disc diffusion according EUCAST guidelines. Campylobacter spp. were found in 12.5% of samples, highest in poultry (19.6%), followed by human stools (13.1%) and floor socks (4.9%). Campylobacter jejuni was the dominant species (80.4%), followed by C. coli (19.6%). In poultry, mixed farming with cattle increased Campylobacter colonization odds (adjusted odds ratio; AOR=9.5), while all-in/all-out management decreased it (AOR=8.4). In humans, Campylobacter infection was linked to raw milk consumption (AOR=5.5), poultry access to living areas (AOR=6.3), not using personal protective equipment working with poultry (AOR=8.3) and not washing hands after handling poultry and cleaning barn (AOR=5.6). Farm workers had a significant knowledge gap on zoonotic risks, including Campylobacter and One Health. High antibiotic resistance was observed, especially to erythromycin (63.0%), ciprofloxacin (69.5%), tetracycline (89.1%), and oxytetracycline (73.9%), with 69.5% of isolates showing multi-drug resistance. Conclusions/Significance The study revealed widespread occurrence of resistant Campylobacter spp. in poultry, workers, and the environment, highlighting the need for One Health interventions, including better biosecurity, hygiene, education, and stricter antimicrobial use to safeguard animal and human health. Author summary A study conducted in and around Debre Berhan, central Ethiopia, analyzed samples from poultry farms for Campylobacter spp. and their antimicrobial resistance. The highest prevalence of Campylobacter was found in poultry, followed by human and poultry house floor samples. Poor farm biosecurity and management practices were linked to Campylobacter in poultry, while human infections were associated with raw milk consumption and inadequate hygiene practices in poultry farm. The study emphasizes the zoonotic risks of Campylobacter and the need for a One Health approach to address its spread. Campylobacter isolates showed high resistance to common antimicrobials, with many classified as multidrug-resistant. Co-occurrence of C. jejuni in poultry, farm workers, and the environment, all with similar multidrug-resistant patterns, suggests possible transmission between them. These findings underline the widespread antimicrobial resistance in Campylobacter from poultry farms and the urgent need for responsible antibiotic use to control resistant strains. Given the serious implications of antimicrobial resistance, the zoonotic importance of Campylobacter , and the frequent human-animal-environment interactions in Ethiopia, it is crucial to implement a national plan for surveillance, prevention, and control, and along with promoting rational antimicrobial use through a One Health approach

Brucellosis is a neglected zoonotic disease affecting livestock and humans that remains endemic in Ethiopia. Despite its prevalence, only a few studies have identified Brucella species circulating in livestock in the country. This study aimed to determine the Brucella 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). Comparisons were made between Ethiopian Brucella and regional and global isolates to determine their phylogenetic relationships. Surveys conducted in May and October–November 2022 in six villages of the Amibara district involved the collection of vaginal swabs (n = 231) and milk samples (n = 17) from 32 sheep and 199 goats kept by 143 pastoral households reporting recent abortions in the animals. Brucella melitensis was detected in three sheep and 32 goats, i.e., 15% (35/231) of animals across 20% (29/143) of households using bacterial culture and PCR-based methods (bcsp31, AMOS, and Bruce-ladder multiplex PCR). Of the 35 positive animals, B. melitensis was isolated from 24 swabs, while the remaining 11 were culture-negative and detected only by PCR. The genomic DNA of the 24 isolates was sequenced using Illumina Novaseq 6000 and assembled using the SPAdes pipeline. Nine- and 21-locus MLST identified 23 isolates as genotype ST12, while one isolate could not be typed. The wgSNP-based phylogenetic analysis revealed that the Ethiopian isolates clustered within the African clade and were closely related to isolates from Somalia. Several virulence factors responsible for adhesion, intracellular survival, and regulatory functions were detected in all isolates. No antimicrobial resistance genes associated with resistance to drugs commonly used for treating brucellosis were detected. Since B. melitensis is prevalent in sheep and goats, vaccination with the B. melitensis Rev-1 vaccine is the recommended strategy in these pastoral systems to protect animal and human health.

Brucellosis is a common zoonotic disease affecting livestock and humans globally. The disease is endemic in Ethiopian livestock. This study was conducted to estimate Brucella seropositivity and identify its risk factors in livestock, and practices that may expose pastoralists to the disease. Data were collected from 2133 animals across 149 households (HHs) in Dubti and Amibara districts, Afar region, Ethiopia. Blood samples from livestock and household data were collected, and interviews were conducted on husbandry and dairy consumption practices. Sera were serially tested using the Rose Bengal test and indirect enzyme-linked immunosorbent assay. The overall seropositivity to anti-Brucella antibodies was 8% (95% CI, 6.6–9.2). The antibodies were found in 12.4%, 6.5%, 6%, and 3% of the goats, cattle, camels, and sheep, respectively. Among the HHs, 59.7% had at least one seropositive animal. A mixed-effects logistic regression analysis revealed species and the acquisition of new animals (in cattle and camels), and age and district (in sheep, goats, and cattle) as significant risk factors. Goats, cattle, and camels had significantly higher odds of Brucella seropositivity than sheep (p < 0.05). Seropositivity was significantly higher (p < 0.05) in adults than in young animals, in acquired than in homebred (cattle and camels), and in those with reproductive disorders than those without. Pastoralists lacked knowledge of brucellosis and its modes of transmission, while practices exposing humans and livestock to brucellosis were common. The findings underscore the need for public awareness campaigns and implementation of brucellosis control measures in pastoral systems.

Different E. coli pathotypes are common zoonotic agents. Some of these pathotypes cause recurrent and widespread calf diarrhea and contribute to significant economic losses in the livestock sector worldwide in addition to putting humans at risk. Here, we investigated the occurrence of E. coli pathotypes in diarrheic calves in Ethiopia kept under various calf management practices. One hundred fecal samples were collected from diarrheic calves in 98 different farms. E. coli was isolated in the samples from 99 of the diarrheic calves, and virulence genes were detected in 80% of the samples. The occurrence of E. coli pathotypes in the samples was 32% ETEC, 23% STEC, 18% STEC/ETEC, 3% EPEC, 2% EAEC, and 1% EHEC. No diarrheic calves were positive for the EIEC and DAEC pathotypes. The occurrence of pathotypes was positively associated with female calves (EPEC, p = 0.006), aged less than 2 weeks (STEC, p = 0.059), and calves fed colostrum via the hand method (STEC, p = 0.008 and EAEC, p = 0.003). This study revealed that several E. coli pathotypes occurred among calves affected with diarrhea. Moreover, the presence of a mixed STEC/ETEC pathotypes infection was present in the studied low-income setting. These findings indicate a considerable risk for the zoonotic transmission from calves to humans and the options to provide the better management for younger calves in order to reduce the economic loss.