Rapid detection of methicillin-resistant staphylococci by DNA probe / 临床检验杂志

ABSTRACT

Objective To establish a dot blot hybridization technique for rapid detection of staphylococci and methicillin-resistant staphylococci.Methods Three pairs of primers were designed according to nuc gene of staphylococcus aureus,mecA gene of methicillin-resistance,tuf gene of staphylococci.Specific DNA probes were synthesized by polymerase chain reaction and labeled with biotin.The bacterial DNA inoculated on nitrocellulose filter was hybridized with these probes.The sensitivity and specificity were detected.Results The DNA probes with 270bp,310bp and 370bp were amplified by the three pairs of primers respectively.The probes were specific.Among 50 clinical isolates of staphylococcus aureus tuf and nuc gene were all positive and mecA gene in 22 isolates were positive.Positive rate of tuf,nuc and mecA gene in 30 staphylococcus epidermidis were 100%,0 and 30% (9/30) respectively.No hybridization in other non-staphylococci occurred.The established method could detect as low as 1ng of bacterial DNA.Conclusion The dot blot hybridization is of high value in rapid,effective identification of methicillin-resistant staphylococci.