Analysis Of Staphylococcus Aureus And Related Genes In Single-center Children

Objective:The changes of drug resistance of staphylococcus aureus isolated from clinical specimens of children with nosocomial infection in JiangXi Children’s Hospital were analyzed and the related genes were analyzed.Methods:1.WHONET5.6 software was used to analyze the date of Staphylococcus aureus isolated from clinical specimens of infected children in JiangXi Children’s Hospital from January 2014 to December 2017,and the change of drug resistance rate to common drugs was counted.2.From January 2018 to December 2018,94 strains of Staphylococcus aureus were isolated from the clinical specimens of children with hospital infection in JiangXi Province.The bacteria were identifide by BD Phonix-100 automatic microbial analyzer was used to common drugs.The results of β-lactamase were confirmed by using penicillin disk diffusion bacteriostatic ringedge test according to the requirements of CLSI 2018 for strains sensitive to cyantoxin.The strains resistant to erythromycin and clindamycin were confirmed by disk diffusion D-ring test to confirm whether there was induced clindamycin resistance,and the resistance rate to commonly used antibiotics was counted after the modified results.The species specific gene femA of Staphylococcus aureus and the specific drug resistance gene mecA,of methicillin resistant Staphylococcus aureus were detected by Real-time PCR after 94 strains were verified by mass spectrometer.Amplification of mecC gene and leukocyte killing factor gene(PVL).The amplification products of mecC and PVL were detected by agarosegel electrophoresis by common PCR,and the results were observed and photographed by gel imaging system.3.According to the drug sensitivity result of cefoxitin or oxacillin,94 cases of Staphylococcus aureus were divided into methicillin resistant Staphylococcus aureus group(MRSA group)and methicillin sensitive Staphylococcus aureus group(MSSA group).4.The drug resistance rate and drug resistance gene carrying rate of common drugs in the two groups were counted and the clinical date of the patients were compared.Results:1.A total of 704 strains of Staphylococcus aureus were isolated from clinical specimens from January 2014 to December 2017.704 strains of Staphylococcus aureus were mainly isolated from purulent fluid(61.7%),blood(15.5%),secretions(15.3%)and sputum(7.5%).The positive rates of MRSA were 41.8%,40.9%,43.4%and 41.8%,respectively.There were no strains resistant to vancomycin,linazoamine and teicoplanin.2.94 strains of Staphylococcus aureus were isolated from clinical specimens from January 2018 to December 2018.Among them,37 strains of methicillin-resistant Staphylococcus aureus was detectde with MRSA,resistance rate of 39.4%(37/94).femA gene was detected in 94 strains of Staphylococcus aureus.mecC gene was detected in 36 of 37 strains of MRSA,mecA gene was not detected in 1 case of MRSA,mecC gene was not detected in 94 strains of Staphylococcus aureus.The detection rate of cytidine(PVL)was 14.9%(14/94).Among them,6 cases were detected in MRSA group and 8 cases in MSSA group.Conclusions:1.The detection rate of MRSA in Staphylococcus aureus isolated from children with infection in JiangXi Children’s Hospital was high and there was no significant decrease trend.2.This study suggested that the resistance rate of erythromycin and clindamycin to erythromycin and clindamycin in MRSA group was significantly higher than that in MSSA group,and the prognosis was worse than that in MSSA group.3.When using PCR method to detect MRSA,it is still suggested to use traditional culture method to detect MRSA at the same time.