PREVALENCE OF BIOFILM-PRODUCING METHICILLIN-RESISTANT Staphylococcus aureus (MRSA) IN DAIRY FARMS ENVIRONMENTS: BIOCIDAL RESISTANCE PATTERNS AND INNOVATIVE ANTIBIOFILM STRATEGIES
Year: 2026
Type: article
Abstract: Methicillin-resistant Staphylococcus aureus (MRSA) represents a significant concern in dairy production due to its multidrug resistance, biofilm-forming capacity, and environmental persistence. This study evaluated the prevalence, antimicrobial resistance, genetic determinants, and biofilm formation of MRSA isolated from dairy farm environments in Qena, Egypt. A total of 240 samples, including raw milk, udder-teat swabs, drinking water troughs, milking equipment, and floor surfaces, were examined. MRSA was confirmed in 84 (35%) of samples, and the highest prevalence was detected in udder-teat swabs (51.0%) and drinking water troughs (41.3%), indicating key contamination points. Antimicrobial susceptibility testing revealed complete resistance to oxacillin (100%), with a considerable proportion of isolates exhibiting multidrug resistance and a multiple antibiotic resistance index reaching 1.00. Molecular characterization confirmed the universal presence of the mecA gene, while the biofilm-associated icaA gene was detected in 57.9% of tested isolates. Additionally, biocide resistance genes qacED1 (68.4%) and qacAB (15.8%) were identified, suggesting potential tolerance to commonly used disinfectants. Phenotypic analysis demonstrated that all MRSA isolates were strong biofilm producers, highlighting their persistence potential in dairy environments. Among tested disinfectants, glutaraldehyde exhibited the highest efficacy, whereas zinc oxide nanoparticles (ZnO NPs) showed significant antibacterial and dose-dependent antibiofilm activity. These findings emphasize the widespread occurrence of multidrug-resistant, biofilm-forming MRSA in dairy farms, and support the potential application of ZnO nanoparticles as an alternative or complementary strategy for controlling resistant pathogens and reducing associated public health risks.
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7208817348