Diversity of the SCCmec types among Staphylococcus epidermidis clinical isolates from intensive care unit patients

To determine different types of staphylococcal cassette chromosome mec (SCCmec) in Staphylococcus epidermidis (S. epidermidis) clinical isolates from intensive care unit patients, Tehran, Iran. A total of 59 S. epidermidis strains were isolated from intensive care unit patients in Tehran, Iran. Isolates of S. epidermidis were identified by conventional biochemical diagnostic tests. The PCR was used to detect the mecA-positive isolates and type the ccr and mec complexes. The mecA gene was amplified in 91.5% of isolates. Moreover, the predominant SCCmec type was the SCCmec type III which was detected in 53.7% of isolates. The frequencies of other SCCmec types were as following: 5.6% in SCCmec type I, 3.7% in SCCmec type II, 5.6% in SCCmec type IV, 7.4% in SCCmec type V and 3.7% in SCCmec type VII. Furthermore, 20.3% of tested isolates were not typeable using the specific primers. SCCmec type III was the most frequent SCCmec type in this study. Eleven of 54 SCCmec types were not classified, among which one isolate possessed mec type A but the ccr type cannot be distinguished with using primers. The frequency of SCCmec type VII was 3.7%, which was reported in S. epidermidis for the first time.