Detection of drug resistance and virulence genes of Staphylococcus aureus isolated from patients with catheter related blood stream infection
Objective To explore the detection of drug resistance and virulence genes of Staphylococcus aureus(SA)isolated from patients with catheter related blood stream infection(CRBSI),and to provide a basis for clinical prevention and treatment of CRBSI.Methods We collected 86 strains of SA isolated from blood samples of CRBSI patients hospitalized in Jinhua People's Hospital from January 2017 to December 2021,and then performed source analysis and drug sensitivity test.The resistance gene mecA and carrying of virulence genes were detected.Results The 86 strains of SA were mainly from the ICU(36.05%),surgery department(26.74%)and gerontology department(12.79%).It was found that 30(34.88%)strains of SA carried mecA,and phenotype identification results showed that they were methicillin-resistant Staphylococcus aureus(MRSA).Drug sensitivity test results displayed that the SA strains were highly resistant to penicillin and erythromycin,with the resistance rates being 80.23%and 73.26%respectively.The SA strains were sensitive to rifampicin,clindamycin,ciprofloxacin,gentamicin,tigecycline,oxacillin and levofloxacin,and completely sensitive to vancomycin and linezolid,with the resistance rates being 0%.sea,seb,pvl,tsst-I,hld,clf A and clfB were detected in the SA strains,with the detection rates being 39.53%,44.19%,50.00%,40.70%,58.14%,59.30%and 55.81%respectively.Co-existence of multiple virulence genes was detected,including sea+seb+pvl+tsst-I+hld+clfA+clfB(18.60%),sea+seb+tsst-I(13.95%),tsst-I+hld+clfA(10.47%)and pvl+clfA(10.47%).Conclusion The SA strains isolated from patients with CRBSI in this hospital are dominated by MRSA strains.The selected sensitive antibiotics include rifampicin,vancomycin and linezolid.The detected virulence genes include sea,seb,pvl,tsst-I,hld,clf A and clfB,with co-existence of multiple virulence genes.
catheter related blood stream infectionStaphylococcus aureusdrug resistancevirulence gene