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Updated: Sep 16, 2025
Genotyping of Staphylococcus aureus by Ribosomal Spacer PCR RS-PCR
Published on: November 4, 2016
Prevalence of Methicillin-Resistant Staphylococcus aureus (MRSA) in Egyptian Water Buffaloes and Risk Factors for
Abdelfattah Selim1, Mohamed Marzok2, Hattan S Gattan3,4
1Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, Toukh 13736, Egypt.
Abstract:
Staphylococcus aureus (S. aureus) is one of the main causative agents of mastitis, which results in severe economic losses. In addition, methicillin-resistant S. aureus (MRSA) has been reported in dairy farms and in water buffaloes. The present study aimed to determine the prevalence of subclinical mastitis (SCM) in water buffaloes, associated risk factors for SCM, and prevalence of MRSA in positive milk samples for SCM. Milk samples (n = 385) from buffaloes were examined using the California mastitis test (CMT), and S. aureus was detected in positive milk samples using bacteriological and biochemical tests. In addition, MRSA was identified in positive S. aureus samples using PCR targeting the mecA gene. The results revealed that the prevalence of SCM among water buffaloes in the studied areas was 43.6%, and 61.9% (104/168) were identified as MRSA based on PCR targeting the mecA gene. In vitro antibiotic susceptibility testing found cefoxitin to be resistant and linezolid to be sensitive against MRSA isolates. In addition, the statistical analysis revealed that there was no significant association between the prevalence of SCM and locality or duration of lactation. The prevalence of SCM was strongly associated with age, parity, absence of teat dipping, hand cleaning of milker hands between milking, and in animals with a history of mastitis. Regular CMT can detect early SCM and improve udder sanitation and milking hygiene. In addition, continuous testing of antimicrobial drugs against MRSA isolates is necessary due to the importance of S. aureus in public health and the development of antibiotic resistance, such as methicillin.
Insights
Subclinical mastitis (SCM) affects 43.6% of water buffaloes, with 61.9% of SCM cases caused by methicillin-resistant Staphylococcus aureus (MRSA). Risk factors include age and parity, highlighting the need for improved hygiene and regular testing.
Area of Science:
- Veterinary Microbiology
- Animal Health
- Epidemiology
Background:
- Staphylococcus aureus (S. aureus) is a primary cause of mastitis in dairy animals, leading to significant economic losses.
- Methicillin-resistant S. aureus (MRSA) strains have emerged as a concern in livestock, including water buffaloes.
- Subclinical mastitis (SCM) is prevalent but often undetected, impacting herd health and productivity.
Purpose of the Study:
- To determine the prevalence of SCM in water buffaloes.
- To identify risk factors associated with SCM in this population.
- To ascertain the prevalence of MRSA in SCM milk samples and assess its antibiotic susceptibility.
Main Methods:
- Milk samples (n=385) were analyzed using the California mastitis test (CMT) for SCM detection.
- Bacteriological and biochemical tests identified S. aureus in positive samples.
- Polymerase chain reaction (PCR) targeting the mecA gene was used to detect MRSA.
Main Results:
- The prevalence of SCM was 43.6% among the studied water buffaloes.
- MRSA was identified in 61.9% (104/168) of S. aureus positive milk samples.
- SCM prevalence was significantly associated with animal age, parity, and milking hygiene practices, but not locality or lactation duration.
Conclusions:
- SCM is a significant issue in water buffaloes, with a high proportion of cases linked to MRSA.
- Age, parity, and inadequate milking hygiene are key risk factors for SCM.
- Regular CMT screening, improved udder sanitation, and continuous monitoring of MRSA antibiotic resistance are crucial for disease control and public health.
