Methicillin-resistant Staphylococcus Aureus Nosocomial Infection Distribution And Drug Resistance Analysis

Objective:To understand the clinical distribution and antibiotic resistance of methicillin-resistant staphylococcus aureus (MRSA) in ShanXi Provincial People’s Hospital.To study the distribution of mec A gene in MRSA,which would provide reference basis for the use of antibiotics.Testing the spa gene sequence and gene typing were used to analyze the homology characteristics for preventing and controlling the MRSA infection in the hospital.Metheds:(1)The API system of French Biomerieux was Used to seperate the48strains staphylococcus aureus from ShanXi Provincial Peoples Hospital from2010January to2011December.The Kirby-Bauer method of cefoxitin and oxacillin was used to select the MRSA,the Kirby-Bauer method of the other antibiotic were used to confirm antibiotic susceptibility of the MRSA seperated and the data was analyzed by WHONET5.5software.The PCR of mec A were used to select MRSA.(2)The PCR was also used to amplify X-region of the spa gene and the amplicons were analyzed by DNA sequencer.The the database(http://spa.ridom. de) was used to determind the spa types.Result:(1) The21MRSA strains were isolated from48strains of staphylococcus aureus,The carrying rate of MRSA was43.75%.Among all the MRSA isolated.11were collected from respiration department(52.39%).3from Neurosurgery department14.29%).2from general surgery department(9.52%),1from cerebral surgery department(4.76%),1from urology surgery department(4.76%),1from gastroenterology department,1from orthopedics department (4.76%),1from ENT(ear-nose-throat) department(4.76%).The most MRSA strains were seperated from sputum(12/21,57.15%) and the others from wound secretions (6/21,28.57%), etc.MRSA was sensitive to less than30%of the β-lactan,quinolones,macrolides,aminoglyco-sides,but quite sensitive to SMZ.Strains resistant to Vancomycin,Teicoplanin.Q.D and fusidic acid were not found yet.The mec A gene were found in all21MRSA stains.The detection rate of mec A in MRSA strains was100%.(2)t037and t030were the popular types in this hospital.which was accounting for71.4%(15/21) and28.6%(6/21) of all MRSA strains.The main spa type was t037,which came mainly from respiration department,Neurosurgery department and were all hospital acquired infection.Conclusion:(1) The detection rate of MRSA from Staphylococcus aureus in ShanXi Provincial Peoples Hospital was low.The main distribution of isolated strains was in respiration department. The main strains of MRSA came from pulmonary infection and wound infection,etc. The carrying rate of mec A in MRSA was high. MRSA had higher antibiotic resistant rate and more serious multiple drug resistance.Vancomycin,Teicoplanin,SMZ,Q.D、fusidic acid and Nitrofurantion were the first selection of antibiotics.(2)The t037and t030types of MRSA were spreading in ShanXi Provincial People’s Hospital.The main types isolated from MRSA were t037.In different clinical sections of the hospital,the same type of MRSA was be found.The cross-infection might be caused in the hospital probably,which should catch the attention of relevant section in the hospital.