ABSTRACT
Objective To test the antimicrobial susceptibility of Staphylococcus aureus from children with impetigo,and to assess the differences in randomly amplified polymorphic DNA profiles between sensitive and resistant Staphylococcus aureus strains.Methods Secretion specimens were obtained from the impetiginous lesions of 178 children,and subjected to bacterial culture.The susceptibility of 162 Staphylococcus aureus isolates against 21 antibiotics was tested.Randomly amplified polymorphic DNA PCR(RAPD-PCR)was performed to characterize the genotype of Staphylococcus aureus.Results Totally,180 bacterial strains were isolated from 178 children with impetigo in Chengdu,including 162(90.00％)Staphylococcus aureus strains.Of the 162 Staphylococcus aureus strains,148 were methicillin sensitive Staphylococcus aureus(MSSA),14 methicillin resistant Staphylococcus aureus(MRSA).The most active antibiotic was minocycline,followed by teicoplanin,quinupristin,vancomycin and nitrofurantoin,while the resistance rate to penicillin was highest,followed by that to erythromycin,clindamycin,compound sulfamethoxazole and tetracycline.All the Staphylococcus aureus isolates were sensitive to fusidic acid,nitrofurantoin,vancomycin,minocycline and teicoplanin.According to RAPD-PCR,the 162 Staphylococcus aureus strains were divided into 8 genotypes,with the three most prevalent genotypes being Ⅲ(31.48％),Ⅱ(26.54％)and Ⅵ(25.93％),which accounted for 65.43％(106/162)in all the strains.The 148 MSSA strains fell into 8 genotypes,with genotype Ⅲ(50 strains,33.78％),Ⅵ(39 strains,26.35％)and Ⅱ(33 strains,22.30％)being the most prevalent genotypes;the 14 MRSA strains fell into 3 genotypes,i.e.,genotype Ⅱ(10 strains,71.43％),Ⅵ(3 strains,21.43％),and Ⅲ(1 strain,7.14％).Conclusions Staphylococcus aureus is the most prevalent pathogenic bacteria in children with impetigo in Chengdu area,which is highly sensitive to minocycline,teicoplanin and quinupristin,and falls into 8 genotypes according to RAPD-PCR with genotype Ⅲ being the most common genotype.
ABSTRACT
OBJECTIVE To study the homology of the pandrug-resistant Acinetobactor baumannii(PRABA) by randomly amplificed polymorphic DNA(CRPD) to guide the control of the nosocomial infection and epidemology investigation.METHODS Eighteen strains of PRABA were collected from Jul 2008 to Mar 2009 in our hospital.The bacteria were examined by DADE BEHRING Microscan WalkAway 96SI;DNA extracted from all isolates was amplified by polymerase chain reaction using random primers.In addition epidemology investigation and antimicrobial susceptibility testing were also under taken.RESULTS Fifteen strains were divided into 6 RAPD profiles.There were two clonal strains derived,respectively,from two intensive care units.One strain was isolated from a patient in surgical ward who was transferred from ICU1,showing same homology with that in the ICU1.The homology was different from sensitive strains and drug-resistant strains obviously.CONCLUSIONS An outbreak of PRABA happens in intensive care unit.