Comparison between Some Phenotypic and Genotypic Methods for Assessment of Antimicrobial Resistance Trend of Bovine Mastitis <i>Staphylococcus aureus</i> Isolates from Bulgaria
The aim of this study was to assess the resistance of bovine mastitis <i>S. aureus</i> isolates from farms in Bulgaria to different classes of chemotherapeutic drugs by comparison of some phenotypic and genotypic methods by means of Cohen’s kappa statistics. The study comprised 546 milk...
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MDPI AG
2022-07-01
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| Series: | Veterinary Sciences |
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| Online Access: | https://www.mdpi.com/2306-7381/9/8/401 |
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| author | Nikolina Rusenova Nasko Vasilev Anton Rusenov Aneliya Milanova Ivo Sirakov |
| author_facet | Nikolina Rusenova Nasko Vasilev Anton Rusenov Aneliya Milanova Ivo Sirakov |
| author_sort | Nikolina Rusenova |
| collection | DOAJ |
| description | The aim of this study was to assess the resistance of bovine mastitis <i>S. aureus</i> isolates from farms in Bulgaria to different classes of chemotherapeutic drugs by comparison of some phenotypic and genotypic methods by means of Cohen’s kappa statistics. The study comprised 546 milk samples from subclinical and clinical mastitis at 14 farms from 9 districts in the country. A total of 92 <i>Staphylococcus aureus</i> strains were isolated from tested samples and identified by <i>nuc</i> PCR. The results demonstrated high levels of resistance to sulfadimethoxine (87%), followed by resistance to penicillin (33.7%), erythromycin (13%), streptomycin (8.7%), tetracycline (6.5%) and gentamicin (1.1%). The comparison of both phenotypic tests with respect to 9 antimicrobials revealed strong agreement with kappa coefficient 0.836. An almost complete agreement was evidenced between phenotypic resistance to penicillin and <i>blaZ</i> gene presence, to methicillin with <i>mecA</i> gene, to tetracycline with <i>tet</i> genes, but the agreement between erythromycin resistance and <i>erm</i> genes presence was moderate. This study was the first to demonstrate discrepancy between the behaviour to cefoxitin in the disk diffusion test and oxacillin in the MIC test for an isolate shown to carry the <i>mecA</i> gene in the subsequent genetic analysis. Considering the detected discrepancies for some of isolates, an integral evaluation through phenotypic and molecular methods for monitoring of antimicrobial resistance of <i>Staphylococcus aureus</i> is recommended. |
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| issn | 2306-7381 |
| language | English |
| last_indexed | 2024-03-09T12:22:44Z |
| publishDate | 2022-07-01 |
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| record_format | Article |
| series | Veterinary Sciences |
| spelling | doaj.art-5c031cc5e44c48fa80ad95ba5e97ea372023-11-30T22:38:02ZengMDPI AGVeterinary Sciences2306-73812022-07-019840110.3390/vetsci9080401Comparison between Some Phenotypic and Genotypic Methods for Assessment of Antimicrobial Resistance Trend of Bovine Mastitis <i>Staphylococcus aureus</i> Isolates from BulgariaNikolina Rusenova0Nasko Vasilev1Anton Rusenov2Aneliya Milanova3Ivo Sirakov4Department of Veterinary Microbiology, Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, BulgariaDepartment of Obstetrics, Reproduction and Reproductive Disorders, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, BulgariaDepartment of Internal Diseases, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, BulgariaDepartment of Pharmacology, Animal Physiology and Physiological Chemistry, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, BulgariaDepartment of Medical Microbiology, Medical University of Sofia, Faculty of Medicine, 1431 Sofia, BulgariaThe aim of this study was to assess the resistance of bovine mastitis <i>S. aureus</i> isolates from farms in Bulgaria to different classes of chemotherapeutic drugs by comparison of some phenotypic and genotypic methods by means of Cohen’s kappa statistics. The study comprised 546 milk samples from subclinical and clinical mastitis at 14 farms from 9 districts in the country. A total of 92 <i>Staphylococcus aureus</i> strains were isolated from tested samples and identified by <i>nuc</i> PCR. The results demonstrated high levels of resistance to sulfadimethoxine (87%), followed by resistance to penicillin (33.7%), erythromycin (13%), streptomycin (8.7%), tetracycline (6.5%) and gentamicin (1.1%). The comparison of both phenotypic tests with respect to 9 antimicrobials revealed strong agreement with kappa coefficient 0.836. An almost complete agreement was evidenced between phenotypic resistance to penicillin and <i>blaZ</i> gene presence, to methicillin with <i>mecA</i> gene, to tetracycline with <i>tet</i> genes, but the agreement between erythromycin resistance and <i>erm</i> genes presence was moderate. This study was the first to demonstrate discrepancy between the behaviour to cefoxitin in the disk diffusion test and oxacillin in the MIC test for an isolate shown to carry the <i>mecA</i> gene in the subsequent genetic analysis. Considering the detected discrepancies for some of isolates, an integral evaluation through phenotypic and molecular methods for monitoring of antimicrobial resistance of <i>Staphylococcus aureus</i> is recommended.https://www.mdpi.com/2306-7381/9/8/401<i>Staphylococcus aureus</i>mastitiscowsantimicrobial resistanceresistance genes |
| spellingShingle | Nikolina Rusenova Nasko Vasilev Anton Rusenov Aneliya Milanova Ivo Sirakov Comparison between Some Phenotypic and Genotypic Methods for Assessment of Antimicrobial Resistance Trend of Bovine Mastitis <i>Staphylococcus aureus</i> Isolates from Bulgaria Veterinary Sciences <i>Staphylococcus aureus</i> mastitis cows antimicrobial resistance resistance genes |
| title | Comparison between Some Phenotypic and Genotypic Methods for Assessment of Antimicrobial Resistance Trend of Bovine Mastitis <i>Staphylococcus aureus</i> Isolates from Bulgaria |
| title_full | Comparison between Some Phenotypic and Genotypic Methods for Assessment of Antimicrobial Resistance Trend of Bovine Mastitis <i>Staphylococcus aureus</i> Isolates from Bulgaria |
| title_fullStr | Comparison between Some Phenotypic and Genotypic Methods for Assessment of Antimicrobial Resistance Trend of Bovine Mastitis <i>Staphylococcus aureus</i> Isolates from Bulgaria |
| title_full_unstemmed | Comparison between Some Phenotypic and Genotypic Methods for Assessment of Antimicrobial Resistance Trend of Bovine Mastitis <i>Staphylococcus aureus</i> Isolates from Bulgaria |
| title_short | Comparison between Some Phenotypic and Genotypic Methods for Assessment of Antimicrobial Resistance Trend of Bovine Mastitis <i>Staphylococcus aureus</i> Isolates from Bulgaria |
| title_sort | comparison between some phenotypic and genotypic methods for assessment of antimicrobial resistance trend of bovine mastitis i staphylococcus aureus i isolates from bulgaria |
| topic | <i>Staphylococcus aureus</i> mastitis cows antimicrobial resistance resistance genes |
| url | https://www.mdpi.com/2306-7381/9/8/401 |
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