Prevalence, Antimicrobial Resistance, and Characterization of Listeria Spp. Isolated from Various Sources in Ethiopia: A Comprehensive Review.

Listeriosis is an important foodborne zoonotic disease affecting humans and animals in Ethiopia. This review aims to synthesize the epidemiology, prevalence, distribution, and antimicrobial resistance of Listeria species in the country. The literature reveals a widespread occurrence of Listeria infection in humans, animals, and food products, with an average prevalence of 21.6% for Listeria species and 6.9% for L. monocytogenes. Three sequence types (STs) of L. monocytogenes (2, 145, and 18) and twelve STs of L. innocua (1489, 1619, 603, 537, 1010, 3186, 492, 3007, 1087, 474, 1008, and 637) were reported from milk and dairy products. Contamination rates ranged from 4.1% to 42.9% across livestock, dairy, slaughterhouses, and processing facilities, indicating faults in production practices. Sporadic human listeriosis outbreaks have occurred since 1967, causing meningitis, perinatal infections, and deaths, with recent studies showing L. monocytogenes isolation in up to 10.4% of febrile patients, confirming foodborne transmission. Non-pathogenic Listeria species were also common on farms and in facilities. Ovine listeriosis poses a threat to Ethiopia's sheep and goat industries, with over 40% seroprevalence in some herds. Comprehensive control measures across the food chain are needed to curb contamination and protect public health. Isolates from various foods show antibiotic resistance to first-line agents but susceptibility to others like gentamicin and cephalosporins. In conclusion, this review synthesizes evidence on Listeria distribution in Ethiopia's food system and disease burden, highlighting the need for improved food safety policies and awareness.

Molecular and Serological Investigation of Infectious Bronchitis Virus in the East Shewa, Central Ethiopia.

Background: Infectious bronchitis (IB) is an economically important disease in poultry with worldwide distribution. The occurrence of IB has been reported both in commercial and backyard poultry in Ethiopia, although comprehensive information lacks available prevalence of the disease and the circulating serotypes. Methods: A cross-sectional study was conducted from November 2021 to June 2022 in seven commercial farms found in East Shewa, Central Ethiopia. Serological assay using indirect ELISA, virus isolation techniques in embryonated eggs, and molecular techniques such as one-step reverse transcriptase polymerase chain reaction (RT-PCR) and nested polymerase chain reaction (PCR) targeting a 466 bp S1 gene were employed. Results: A total of 196 blood samples, 7 pools (35) of swab samples, and 5 pools of tracheal samples were investigated. The results of serological analysis revealed that 97.96% (192/196; 95% CI: 94.86-99.44) of the sera samples were found to be positive for antibodies against IBV. Out of the 7 pools of swab and 5 pools of tracheal tissue samples analyzed using RT-PCR 33.3% (4/12) of them gave positive results all from swab samples. The RT-PCR-positive samples were subjected to a nested PCR yielding 295bp and 154bp indicating the circulation of Mass and 793/B (4/91) strains of IBV, respectively. The 12 pools of samples inoculated into embryonated egg showed cytopathic changes such as congestion, bleeding, and deformation only after three passages. Conclusion: Two serotypes of IBV are circulating in Ethiopian chickens, and molecular identification of the Massachusetts serotype is the first report in Ethiopia. Further epidemiological investigation is needed in order to devise effective control measures.

Isolation and Molecular Identification of Mycobacterium bovis from Slaughtered Cattle in Nekemte Municipality Abattoir, Ethiopia.

Tuberculosis (TB) is a zoonotic disease that can spread from animals to humans as well as from human to human. Little research has been conducted on bovine tuberculosis prevalence and molecular characterization in the western part of Ethiopia. To investigate this, a cross-sectional study was conducted on slaughtered cattle at the Nekemte municipal abattoir between January 2020 and June 2021. A detailed postmortem examination, culture, acid-fast staining technique, molecular characterization using RD4 deletion, and spoligotyping were all carried out. Based on a detailed postmortem examination, the overall prevalence of bovine tuberculosis was 7.8% (80 of 1020). Mycobacterium isolation confirmed only 12.5% (10/80) of the suspected tuberculosis tissue lesions. With acid-fast bacilli staining, all Mycobacterium spp. isolates (n = 10) were positive. However, only 9/10 isolates were confirmed to be M. bovis with RD4 molecular deletion typing. Spoligotyping revealed that 55.6% (5/9) of the isolate patterns had previously been reported, but 44.4% (4/9) of the isolates were new. In the current investigation, it was discovered that 80% (4/5) of the M. bovis strains circulating in the cattle population of study regions were SB2233 (2/5) and SB0134 (2/5), whereas 20% (1/5) of the strains corresponded to SB1176, which is compatible with previously documented M. bovis spoligotypes. These findings suggested that M. bovis was the main cause of bovine tuberculosis in the study area and posed a risk of disease transmission from cattle to humans due to low levels of public health awareness. As such, improved awareness among citizens and the development of control policies are warranted.

Seroprevalence of Bovine Brucellosis and Associated Risk Factors in Western Ethiopia.

BACKGROUND: Brucellosis is a contagious bacterial disease, which affects domestic animals, humans, and wildlife in Ethiopia and other countries. METHODS: A cross-sectional study design using a simple random sampling technique was conducted in Diga, Guto, Gida, and Sibu Sire districts of East Wollega Zone, Western Oromia, from November 2019 to July 2020 to determine the prevalence of bovine brucellosis and identify associated risk factors. A lottery method was used during serum collection and risk factors identified during interview. RESULTS: A total of 1152 serum samples were collected from cattle of 6 months age and above. Serum samples were tested by enzyme linked immunosorbent assay (I-ELISA). An overall seroprevalence of brucellosis was 1.82% (21/1152). Statically significant variation (P<0.05) in seroprevalence of bovine brucellosis was recorded among potential risk factors such as breed [P≤0.05; OR:8.905; CI:1.568-50.573], parity [P≤0.05; OR:0.017; CI:0.042-5.195], retained fetal membrane [P≤0.001; OR:0.018; CI:0.00-2.169], and abortion history [P≤0.001; OR:0.030; CI:0.004-0.212]. Conversely, seroprevalence variations in sex, district, villages, body condition score, and age were statistically insignificant (P>0.05). CONCLUSION: The current study revealed bovine brucellosis is posing a threat to livestock with no strict control and prevention scheme in place. Therefore, public awareness creation about the zoonotic importance of the disease is crucial and the Government should establish legislation, support, control, and prevention of the disease recommended.