Occurrence, antimicrobial susceptibility, and resistance genes of Staphylococcus aureus in milk and milk products in the Arsi highlands of Ethiopia
Background In Ethiopia, milk production and handling practices often lack proper hygiene measures, leading to the potential contamination of milk and milk products with <i>Staphylococcus aureus</i> (<i>S. aureus</i>), including methicillin-resistant strains, posing significant public health concern...
| Main Authors: | , , , , , , , , |
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| Format: | Journal Article |
| Language: | Inglés |
| Published: |
Springer
2024
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10568/141484 |
| _version_ | 1855514976508182528 |
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| author | Deddefo, A. Mamo, G. Asfaw, M. Edao, A. Hiko, A. Fufa, D. Jafer, M. Sombo, M. Amenu, Kebede |
| author_browse | Amenu, Kebede Asfaw, M. Deddefo, A. Edao, A. Fufa, D. Hiko, A. Jafer, M. Mamo, G. Sombo, M. |
| author_facet | Deddefo, A. Mamo, G. Asfaw, M. Edao, A. Hiko, A. Fufa, D. Jafer, M. Sombo, M. Amenu, Kebede |
| author_sort | Deddefo, A. |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Background
In Ethiopia, milk production and handling practices often lack proper hygiene measures, leading to the potential contamination of milk and milk products with <i>Staphylococcus aureus</i> (<i>S. aureus</i>), including methicillin-resistant strains, posing significant public health concerns. This study aimed to investigate the occurrence, antimicrobial susceptibility profiles and presence of resistance genes in <i>S. aureus</i> strains isolated from milk and milk products.
Methods
A cross-sectional study was conducted in the Arsi highlands, Oromia, Ethiopia from March 2022 to February 2023. A total of 503 milk and milk product samples were collected, comprising 259 raw milk, 219 cottage cheese, and 25 traditional yogurt samples. <i>S. aureus</i> isolation and coagulase-positive staphylococci enumeration were performed using Baird-Parker agar supplemented with tellurite and egg yolk. <i>S. aureus</i> was further characterized based on colony morphology, Gram stain, mannitol fermentation, catalase test, and coagulase test. Phenotypic antimicrobial resistance was assessed using the Kirby–Bauer disc diffusion method, while the polymerase chain reaction (PCR) was employed for confirming the presence of <i>S. aureus</i> and detecting antimicrobial resistance genes.
Results
<i>S. aureus</i> was detected in 24.9% of the milk and milk products, with the highest occurrence in raw milk (40.9%), followed by yogurt (20%), and cottage cheese (6.4%). The geometric mean for coagulase-positive staphylococci counts in raw milk, yogurt, and cottage cheese was 4.6, 3.8, and 3.2 log10 CFU/mL, respectively. Antimicrobial resistance analysis revealed high levels of resistance to ampicillin (89.7%) and penicillin G (87.2%), with 71.8% of the isolates demonstrating multidrug resistance. Of the 16 S. aureus isolates analyzed using PCR, all were found to carry the <i>nuc</i> gene, with the <i>mecA</i> and <i>blaZ</i> genes detected in 50% of these isolates each.
Conclusion
This study revealed the widespread distribution of <i>S. aureus</i> in milk and milk products in the Arsi highlands of Ethiopia. The isolates displayed high resistance to ampicillin and penicillin, with a concerning level of multidrug resistance. The detection of the <i>mecA</i> and <i>blaZ</i> genes in selected isolates is of particular concern, highlighting a potential public health hazard and posing a challenge to effective antimicrobial treatment. These findings highlight the urgent need to enhance hygiene standards in milk and milk product handling and promote the rational use of antimicrobial drugs. Provision of adequate training for all individuals involved in the dairy sector can help minimize contamination. These measures are crucial in addressing the threats posed by <i>S. aureus</i>, including methicillin-resistant strains, and ensuring the safety of milk and its products for consumers. |
| format | Journal Article |
| id | CGSpace141484 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2024 |
| publishDateRange | 2024 |
| publishDateSort | 2024 |
| publisher | Springer |
| publisherStr | Springer |
| record_format | dspace |
| spelling | CGSpace1414842025-12-08T10:06:44Z Occurrence, antimicrobial susceptibility, and resistance genes of Staphylococcus aureus in milk and milk products in the Arsi highlands of Ethiopia Deddefo, A. Mamo, G. Asfaw, M. Edao, A. Hiko, A. Fufa, D. Jafer, M. Sombo, M. Amenu, Kebede antimicrobial resistance animal products dairying Background In Ethiopia, milk production and handling practices often lack proper hygiene measures, leading to the potential contamination of milk and milk products with <i>Staphylococcus aureus</i> (<i>S. aureus</i>), including methicillin-resistant strains, posing significant public health concerns. This study aimed to investigate the occurrence, antimicrobial susceptibility profiles and presence of resistance genes in <i>S. aureus</i> strains isolated from milk and milk products. Methods A cross-sectional study was conducted in the Arsi highlands, Oromia, Ethiopia from March 2022 to February 2023. A total of 503 milk and milk product samples were collected, comprising 259 raw milk, 219 cottage cheese, and 25 traditional yogurt samples. <i>S. aureus</i> isolation and coagulase-positive staphylococci enumeration were performed using Baird-Parker agar supplemented with tellurite and egg yolk. <i>S. aureus</i> was further characterized based on colony morphology, Gram stain, mannitol fermentation, catalase test, and coagulase test. Phenotypic antimicrobial resistance was assessed using the Kirby–Bauer disc diffusion method, while the polymerase chain reaction (PCR) was employed for confirming the presence of <i>S. aureus</i> and detecting antimicrobial resistance genes. Results <i>S. aureus</i> was detected in 24.9% of the milk and milk products, with the highest occurrence in raw milk (40.9%), followed by yogurt (20%), and cottage cheese (6.4%). The geometric mean for coagulase-positive staphylococci counts in raw milk, yogurt, and cottage cheese was 4.6, 3.8, and 3.2 log10 CFU/mL, respectively. Antimicrobial resistance analysis revealed high levels of resistance to ampicillin (89.7%) and penicillin G (87.2%), with 71.8% of the isolates demonstrating multidrug resistance. Of the 16 S. aureus isolates analyzed using PCR, all were found to carry the <i>nuc</i> gene, with the <i>mecA</i> and <i>blaZ</i> genes detected in 50% of these isolates each. Conclusion This study revealed the widespread distribution of <i>S. aureus</i> in milk and milk products in the Arsi highlands of Ethiopia. The isolates displayed high resistance to ampicillin and penicillin, with a concerning level of multidrug resistance. The detection of the <i>mecA</i> and <i>blaZ</i> genes in selected isolates is of particular concern, highlighting a potential public health hazard and posing a challenge to effective antimicrobial treatment. These findings highlight the urgent need to enhance hygiene standards in milk and milk product handling and promote the rational use of antimicrobial drugs. Provision of adequate training for all individuals involved in the dairy sector can help minimize contamination. These measures are crucial in addressing the threats posed by <i>S. aureus</i>, including methicillin-resistant strains, and ensuring the safety of milk and its products for consumers. 2024-04-16 2024-04-16T16:12:18Z 2024-04-16T16:12:18Z Journal Article https://hdl.handle.net/10568/141484 en Open Access Springer Deddefo, A., Mamo, G., Asfaw, M., Edao, A., Hiko, A., Fufa, D., Jafer, M., Sombo, M. and Amenu, K. 2024. Occurrence, antimicrobial susceptibility, and resistance genes of <i>Staphylococcus aureus</i> in milk and milk products in the Arsi highlands of Ethiopia. <i>BMC Microbiology</i> 24: 127. |
| spellingShingle | antimicrobial resistance animal products dairying Deddefo, A. Mamo, G. Asfaw, M. Edao, A. Hiko, A. Fufa, D. Jafer, M. Sombo, M. Amenu, Kebede Occurrence, antimicrobial susceptibility, and resistance genes of Staphylococcus aureus in milk and milk products in the Arsi highlands of Ethiopia |
| title | Occurrence, antimicrobial susceptibility, and resistance genes of Staphylococcus aureus in milk and milk products in the Arsi highlands of Ethiopia |
| title_full | Occurrence, antimicrobial susceptibility, and resistance genes of Staphylococcus aureus in milk and milk products in the Arsi highlands of Ethiopia |
| title_fullStr | Occurrence, antimicrobial susceptibility, and resistance genes of Staphylococcus aureus in milk and milk products in the Arsi highlands of Ethiopia |
| title_full_unstemmed | Occurrence, antimicrobial susceptibility, and resistance genes of Staphylococcus aureus in milk and milk products in the Arsi highlands of Ethiopia |
| title_short | Occurrence, antimicrobial susceptibility, and resistance genes of Staphylococcus aureus in milk and milk products in the Arsi highlands of Ethiopia |
| title_sort | occurrence antimicrobial susceptibility and resistance genes of staphylococcus aureus in milk and milk products in the arsi highlands of ethiopia |
| topic | antimicrobial resistance animal products dairying |
| url | https://hdl.handle.net/10568/141484 |
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