Epidemiological Characteristics And Clinical Treatment To Methicillin-Resistant Staphylococcus Aureus In Vivo For Children

Objective To investigate the difference of epidemiological characteristics and resistance to methicillin-resistant Staphylococcus aureus(MRSA)between children and patients over 14 years of age.While to explore the treatment of which to provide etiological basis for clinical treatment of children with infections.Methods Drug sensitivity test were performed on 738 clinical Staphylococcus aureus(SA)isolates.The polymerase chain reaction was used to detect their mecA gene and Panton-Valentine Leukocidin(pvl)gene.Then data on mecA gene,pvl gene,department sources,specimen sources were statistically analyzed by age groups.Sixteen Rabbit tissue-cage infection model Rabbit tissue-cage model were established and randomly divided into four groups(group A,B,C,D)and injected with pvl(+)MRSA,pvl(-)MRSA,ATCC43300,ATCC25923 respectively.Two rabbits from every group were randomly selected to receive linezolid(experiment cages)and the others(control cages)to receive vancomycin.After getting infection,tissue fluids were withdrawn before the treatment and their bacterial concentration is tested after the first three days of reaching steady state.Finally,the analysis of variance with repeated measurement data was used for statistical analysis of the bacterial concentration data.Results MRSA accounted for 17.07%(126/738),pvl gene-positive MRSA accounted for28.57%(36/126).MRSA isolated from children accounted for 20.92%(32/153),pvl gene-positive MRSA(pvl(+)MRSA)accounted for 21.88%(7/32).The detection rate for mecA gene and pvl gene between patients of pediatric group and patients over 14 yearsof age group has no statistical significance(P>0.05).Children infected MRSA mainly came from Burns(31.25%),Surgery(15.63%)and Intensive Care Unit(9.38%).pvl(+)MRSA mainly came from Surgery(57.14%),Neonatal ward(28.57%)and Department of Respiratory Medicine(14.29%).The difference of department sources between the two groups has statistical significance(P<0.05).Children infected MRSA mainly came from pus(31.25%),sputum(25.00%)and wound surface(15.63%).pvl(+)MRSA mainly came from pus(71.43%)and blood(28.57%).The difference of specimen sources between the two groups has statistical significance(P<0.05).Pediatric patients infected pvl(+)MRSA mainly resistant to β-lactams,Macrolides,Aminoglycosides,Tetracyclines and Linkeramides.pvl(-)MRSA mainly resistant toβ-lactams,Linkeramide,Macrolides,gsAminoglycosides,Quinazolones,Sulfonamides and Tetracyclines.After treatment there is statistical significant difference in the experimental cages and control cages between group A and B(group A: P<0.001,group B: P=0.011),but between group C and group D not much significant difference(group C: P=0.308,group D: P=0.349).Conclusions The difference of drug resistance between the two groups has no statistical significance(P>0.05).There was statistical difference of epidemiological characteristics to MRSA between the two groups(P<0.05).These findings suggest that Linezolid should be first recommended when children infected with pvl(+)MRSA.