Assessment of antimicrobial use practices and antimicrobial susceptibility of Listeria monocytogenes along the beef value chain in Adama and Modjo, Ethiopia: One Health perspectives.
| dc.contributor.advisor | Takele Beyene | |
| dc.contributor.author | Meskerem Mulisa | |
| dc.date.accessioned | 2026-07-15T13:30:23Z | |
| dc.date.available | 2026-07-15T13:30:23Z | |
| dc.date.issued | 2026 | |
| dc.description.abstract | Listeriosis, caused by Listeria monocytogenes, is a significant foodborne zoonotic disease with serious public health implications. This study assessed antimicrobial use (AMU) practices and antimicrobial susceptibility patterns of L. monocytogenes along the beef value chain in Adama and Modjo, Ethiopia, using a One Health approach. A cross-sectional study was conducted from November 2025 to May 2026. Data were collected through questionnaires (n = 60) and laboratory analysis of 460 samples, including carcass swabs, fecal samples, hand swabs, and environmental samples. Isolation and identification of L. monocytogenes were performed using standard culture methods, biochemical tests, and MALDI-TOF mass spectrometry. Antimicrobial susceptibility testing (AST) was carried out using the disk diffusion method, and detection of the virulence gene (hlyA) was conducted using PCR. The results showed that 74.8% of respondents had poor knowledge of AMU and antimicrobial resistance (AMR), while 88.7% demonstrated a favorable attitude toward the use of antibiotics for growth promotion. Out of 460 samples, 106 (23%) showed presumptive Listeria growth, of which 59 isolates were confirmed by biochemical tests. Of the 29 isolates further analyzed using MALDI-TOF, 6 were confirmed as L. monocytogenes, predominantly from carcass samples (n = 5) and one from a water sample. All confirmed isolates carried the hlyA virulence gene. Antimicrobial susceptibility testing showed that all isolates were fully susceptible to ampicillin, entamicin, ciprofloxacin, cotrimoxazole, streptomycin, and chloramphenicol. However, high levels of resistance were observed to penicillin (100%), vancomycin (66.7%), and tetracycline (50%). In conclusion, poor antimicrobial use practices and the presence of resistant and virulent L. monocytogenes strains indicate a potential public health risk. Strengthening antimicrobial stewardship and improving hygiene practices along the beef value chain are essential. | |
| dc.identifier.uri | https://etd.aau.edu.et/handle/123456789/8659 | |
| dc.language.iso | en_US | |
| dc.publisher | Addis Abeba University | |
| dc.subject | Antimicrobial use | |
| dc.subject | Antimicrobial resistance | |
| dc.subject | Beef values chain | |
| dc.subject | Listeria monocytogenes | |
| dc.subject | One Health. | |
| dc.title | Assessment of antimicrobial use practices and antimicrobial susceptibility of Listeria monocytogenes along the beef value chain in Adama and Modjo, Ethiopia: One Health perspectives. | |
| dc.type | Thesis |