Direct detection of staphylococcus aureus in camel milk in the nineveh governorate by using the pcr technique

Abstract

Staphylococcus (S.) aureus is the main facultative organism of contagious intramammary infections from lactating animals. It is considered a major foodborne organism that can cause food poisoning conditions around the world. Camels are very important to the lifestyle of many countries because they can produce milk that contains the major components such as proteins, energy, vitamins, and minerals. The present study used a polymerase chain reaction (PCR) method on a base of the nuc gene as a target gene, which is a specific gene that recognizes the S. aureus amongst other microorganisms. Fifty milk samples have been collected from camels from different areas of the Nineveh Governorate, Iraq. According to the phenotypic characteristics, isolation and identification of S. aureus have been accomplished by characterizing the shape of the colonies, painting the suspected isolates by gram stain, using the biochemical tests such as coagulase and catalase. In this study, S. aureus was isolated from 70% (35/50) camel milk samples. The classical method of identifying the S. aureus isolated from camel milk was consistent with the PCR method. The PCR technique indicated that all positive S. aureus possessed the nuc gene. The increased percentage of S. aureus isolated from the camel milk has a relationship with the type of farm management, poor nutrition, and/or environmental conditions, rather than treatment of the infected camel. The PCR method is considered one of the best-used techniques to identify the S. aureus isolated from camel milk by detection of nuc gene, the specific gene of S. aureus.