Prevalence and Genetic Diversity of Coagulase Negative Staphylococcus in Food Products Collected from Riyadh Region

Abstract

The goal of this study was to isolate, count, and identify coagulase-negative Staphylococci from meat and dairy products collected in Riyadh, Saudi Arabia, as well as to perform molecular identification of the mecA gene. In addition, the prevalence of these bacteria among the examined food products was determined. Ninety samples of both meat and dairy products were collected and examined between February 2018 and August 2019. Mannitol salt agar and VITEK 2 system were carried out and VITEK 2 system was used to identify all bacterial isolates. Also, the molecular technique was used to detect the target gene of mecA among CoNS. The proportion of samples in which Staphylococcus species isolated is 13.33% (Camel meat), 6.66% (Beef mortadella), 6.66% (Turkish labneh), 33.33% (Cows cheese), 6.66% (Goat labneh), 13.33% (Nabulsy cheese), 13.33% (Haloumi goat cheese) and 6.66% (Akawy white cheese). Counts of coagulase-negative Staphylococcus species (as cfu/gm) of sample were around 11×104, 10×104, 9×104, 12×104, 4×105, 11×104 (Nabulsy cheese), 14×104 and 12×104, respectively. The Prevalence of species in both products was 3.30% (Staphylococcus vitulinus), 53.30% (Staphylococcus saprophyticus), 16.66% (Staphylococcus hominis), 6.66%, (Staphylococcus equorum and Staphylococcus lentus) and 13.33% (Staphylococcus sciuri). Furthermore, results showed methicillin specific mecA gene was harbored in 40 % of the CoNS.

Keywords

• coagulase-negative staphylococci
• meats
• dairy products