Walaa Abdallah Gad, Salama Ahmed Osman, Khaled Abd El-Hamid Abd El-Razik, Ashraf Hassan Soror, Yousef Adel Soliman, Ehab Ali Fouad
{"title":"Prevalence and molecular characterization of resistant <i>Staphylococcus aureus</i> strains in bulk milk tanks of dairy cattle in Northern Egypt.","authors":"Walaa Abdallah Gad, Salama Ahmed Osman, Khaled Abd El-Hamid Abd El-Razik, Ashraf Hassan Soror, Yousef Adel Soliman, Ehab Ali Fouad","doi":"10.30466/vrf.2024.2038109.4398","DOIUrl":null,"url":null,"abstract":"<p><p>Bovine subclinical mastitis represents a major cause of severe economic losses in dairy farms. This research aimed to detect the antimicrobial resistance trends of <i>Staphylococcus aureus</i> and to determine the presence of <i>mecA,</i> <i>mphC, lnuA, tetK</i> and <i>tetL</i> antimicrobial resistance genes in raw bulk milk in the period between December 2023 and February 2024. One hundred raw bulk cow milk samples were gathered from different dairy farms in Egypt. The prevalence of subclinical bovine mastitis was 65.00% using California mastitis test. The prevalence of isolated <i>S. aureus</i> was 46.15% via bacterial culturing and all isolates (n = 30) were confirmed via hemolytic activity, catalase and coagulase test, and gram staining followed by polymerase chain reaction targeting <i>nuc1</i> gene. Antimicrobial sensitivity test was applied on all confirmed <i>S. aureus</i> isolates utilizing the disk diffusion method on Mueller-Hinton agar. The highest resistance was verified for tetracycline at 100% followed by erythromycin and clindamycin at 56.66 and 16.66%, respectively. The highest sensitivity at 100% was verified for amikacin, ampicillin, amoxicillin plus clavulanic acid, ampicillin plus sulbactam, ciprofloxacin, colistin, gentamicin, imipenem, tobramycin, doxycycline and vancomycin. Multidrug resistance was found in 20.00% of the total isolates. Methicillin resistant <i>S. aureus</i> represented by <i>mecA</i> gene was identified in 83.33% of isolates. Macrolides resistant <i>S. aureus</i> represented by <i>mphC</i> gene was identified in 16.66% of isolates. Lincosamide resistant <i>S. aureus</i> represented by <i>inuA</i> gene was identified in 66.66% of isolates. Tetracycline resistant <i>S. aureus</i> represented by <i>tetK</i> and <i>tetL</i> genes was detected in 23.33 and 53.33% of isolates, respectively. This study provided antibiotic-resistant <i>S. aureus</i> profiles to dairy farms to avoid treatment failure, adverse effects on animal health and economic impact for the owner of the animal.</p>","PeriodicalId":23989,"journal":{"name":"Veterinary Research Forum","volume":"16 6","pages":"317-323"},"PeriodicalIF":1.1000,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12295529/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Veterinary Research Forum","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.30466/vrf.2024.2038109.4398","RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/6/15 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"ZOOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Bovine subclinical mastitis represents a major cause of severe economic losses in dairy farms. This research aimed to detect the antimicrobial resistance trends of Staphylococcus aureus and to determine the presence of mecA,mphC, lnuA, tetK and tetL antimicrobial resistance genes in raw bulk milk in the period between December 2023 and February 2024. One hundred raw bulk cow milk samples were gathered from different dairy farms in Egypt. The prevalence of subclinical bovine mastitis was 65.00% using California mastitis test. The prevalence of isolated S. aureus was 46.15% via bacterial culturing and all isolates (n = 30) were confirmed via hemolytic activity, catalase and coagulase test, and gram staining followed by polymerase chain reaction targeting nuc1 gene. Antimicrobial sensitivity test was applied on all confirmed S. aureus isolates utilizing the disk diffusion method on Mueller-Hinton agar. The highest resistance was verified for tetracycline at 100% followed by erythromycin and clindamycin at 56.66 and 16.66%, respectively. The highest sensitivity at 100% was verified for amikacin, ampicillin, amoxicillin plus clavulanic acid, ampicillin plus sulbactam, ciprofloxacin, colistin, gentamicin, imipenem, tobramycin, doxycycline and vancomycin. Multidrug resistance was found in 20.00% of the total isolates. Methicillin resistant S. aureus represented by mecA gene was identified in 83.33% of isolates. Macrolides resistant S. aureus represented by mphC gene was identified in 16.66% of isolates. Lincosamide resistant S. aureus represented by inuA gene was identified in 66.66% of isolates. Tetracycline resistant S. aureus represented by tetK and tetL genes was detected in 23.33 and 53.33% of isolates, respectively. This study provided antibiotic-resistant S. aureus profiles to dairy farms to avoid treatment failure, adverse effects on animal health and economic impact for the owner of the animal.
期刊介绍：
Veterinary Research Forum (VRF) is a quarterly international journal committed to publish worldwide contributions on all aspects of veterinary science and medicine, including anatomy and histology, physiology and pharmacology, anatomic and clinical pathology, parasitology, microbiology, immunology and epidemiology, food hygiene, poultry science, fish and aquaculture, anesthesia and surgery, large and small animal internal medicine, large and small animal reproduction, biotechnology and diagnostic imaging of domestic, companion and farm animals.
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