The Drug Resistant Profile And Spa Homology Analysis For Staphylococcus Aureus

Objective To describe the resistant profile of staphylococcus aureus clinical isolated strains on December of 2007 for the instructions of clinical medication.To analyze the characteristic of homology for the spa gene on the basis of protien A gene polymorphism of Staphylococcus aureus and find out the predominant strains.Methods The resistant profile of these strains were observed through K-B slip diffusion test and the strains were classified into methicillin-resistant staptytococous aureus(MRSA) and methicillin-sensitive staphylococcus aureus(MSSA).While the X region of the spa gene of 21 strains was amplified by PCR and DNA sequences were obtained with an sequencer.Spa types were determined with the database accessible via http://www.ridom.de/spaserver/Results 1.Acording to the resistant profile of staptytococous aureus,the isolations were classified into MRSA and MSSA.Among them,MRSA were 12 strains and MSSA were 9 strains.2.All the strains were resistant to penicilin;Erythromycin-Clindamycin resistant strains were 19(19/21).Levofloxacin and ciprofloxacin resistant strains were 14 respectively(14/21).Gentamicin and oxacillin resistant strains were 12 respectively(12/21).There was no VRSA found. 3.All MRSA was multiple resistant strain.They were all resistant to penicilin,amoxicillin,eryfhromycin,clindamycin;There were 11 levofloxacin and ciprofloxacin resistant strains(11/12),and the Gentamicin-resitant were 10(10/21).All MSSA was resistant to penicilin;There were 7 strains resistant to erythromycin or clindamycin respectively;Levofloxacin and ciprofloxacin resistant strains were 3 respectively(14/21);There was no Amoxicillin-resistant strain found.Except vancomyein,other drugs' resistant strains of MRSA were more than MSSA.4.The most strains in the month were hospital acquared infection.Except penicilin and vancomyein and the resistant strains of the hospital acquared were more than the community acquired.The number of these strains was 11 at least except vancomyein.5.Ten spa types were found.The predominant spa type was t037;there were 4 strains from department of empyrosis,2 from orthopaedics and there was one strain from ICU for Surgery,Gastrointestinal Surgery,ENT(ear-nose-throat)Department,Gerontal Pneumatic Department respectively; 3 trains were t030.All t037 strains were hospital acquired infection.The other types were t4594,t1425,t1367,t284,t701,t159,tl79,t437.6.The t037 strain contained 8 MRSA and 2 MSSA.A11 t037 strain was resistant to penicilin,gentamicin,ciprofloxacin,levofloxacin,erythromycin and clindamycin.The resistant profile was same between MSSA and MRSA,except oxacillin and amoxicillin.7.The t4594 was a novel type of this study.This strain was MSSA and resistant to penicilin,erythromycin and Clindamycin only.The resistant profile was coherent with t159,t1425,t284.Conclusions 1.The resistant degree was serious for these strains.The resistant rate of antibiotics were more than 50%.10 strains of MRSA were only sensitive to vancomyein,and it suggest that treatment of infections caused by Staphylococcus aureus is still a difficult problem.2.The isolations were mainly hospital acquared infection strains.The resistant rate of hospital acquared infection strains was more larger than the community acquired.3.t037 was the predominant type and occupied 47.6%(10/21).There is a remarkably similar resistant profile between MRSA and MSSA All t037 strains were hospital acquired infection and cuased cross-infection probably.4.The t4594 was a novel spa type and its resistant profile was coherent with t159,t1425,t284.The other biological feature will be studied further.