Detection of Tetracycline Resistant Gen (tet K, tet M ) in Some Coagulase Negative Staphylococci Isolated From Different Clinical Sources In Erbil City

Abstract

Thirty two isolates of coagulase negative staphylococci was isolated and identified from clinical sources ; including eight isolates (12.5%) of each of Staphylococcus hominis and Staphylococcus haemolyticus from (64) patients urine which suffering from urinary tract infection and eight isolates (16%) of each of Staphylococcus epidermidis and Staphylococcus auricularis from (50) ear patients which suffering from otitis in Rizgary teaching hospital in Erbil city were isolated depending on Vitek 2 compact system . The susceptibility tests by using disc diffusion agar method were determined for all isolated coagulase negative Staphylococci to 10 different antibiotics . From obtained results it was observed that all isolates were 100% sensitive to ceftriaxone and novobiocin, while higher resistance was obtained to tetracycline with percentage 50% and they showed differnt resistant to other remaining antibiotics. On the other hand, all isolated Staphylococcus hominis, Staphylococcus haemolyticus , Staphylococcus epidermidis and Staphylococcus auricularis isolates were tested for tetracycline resistant genes tetK and tetM by using PCR and the results showed that 75% of Staphylococcus hominis, Staphylococcus haemolyticus and Staphylococcus epidermidis were carried tetM gene with product size about 158 bp while 50% of Staphylococcus auricularis was carried the above mentioned gen . Also it was found that 50% of Staphylococcus hominis and Staphylococcus haemolyticus isolates in this study were harboring tetK gene with product size 360 bp and no tetK gene was observed in Staphylococcus epidermidis and Staphylococcus auricularis . Also the antibacterial effect of two local species of menthes against resistant isolated bacteria by using the Minimum Inhibitory Concentration (MIC) method were studied . The results showed that the MIC for aqueous extract for both plants Mentha longifolia and Mentha piperita were 1600µg/ml and it were 1400µg/ml for alcoholic extract of both plants against most Staphylococcus speciese except Staphylococcus epidermidis which the MIC was 1200 µg/ml for aqueous and 1000µg/ml for alcoholic extract of Mentha piperita, while it was 1200µg/ml for both the aqueous and alcoholic extracts for Mentha longifolia.