Efficiency of Lactoferrin to Eradicate Multidrug Resistant Staphylococcus aureus Isolated from some Dairy Products

Abstract

This investigation was done to detect the percent of multidrug resistant (MDR) Staphylococcus aureus (S. aureus) in some dairy products as well as to assess the effectiveness of lactoferrin (LF) as a bio preservative for yogurt. 150 dairy product samples from yogurt, ice cream and Damietta cheese (50 for each) were collected from Assiut city, Egypt. Antimicrobial susceptibility against antibiotics commonly utilized in human and animals was tried using the disc diffusion method; PCR was applied on (MDR) S. aureus isolates for discovering of blaz, mecA and VanA genes. 38% of yogurt samples had the highest prevalence of S.aureus followed by Damietta cheese (30%) and ice cream (14%). S.aureus isolates appeared high resistance to tetracycline, penicillin, oxacillin, ampicillin, streptomycin, amoxicillin/clavulanate and neomycin, in different percentages. blaz, mecA and VanA genes were detected at 60% for blaz gene, 40% for mecA gene and 20% for vanA gene. Lactoferrin has a satisfactory antibacterial activity Minimum Inhibitory Concentration (MIC) at 10mg/ml and Minimum Lethal Concentration (MLC) at 40mg/ml. The results revealed that 40mg/ml LF in yogurt could inhibit MDR S. aureus at 2nd day while, 20mg/ml at the 4th day. The study concluded that LF can be used as a bio preservative in yogurt due to its highest antimicrobial activity and acceptable sensorial properties.