Homology analysis of Serratia marcescens strains causing blood stream infection in an intensive care unit / 中华微生物学和免疫学杂志

ABSTRACT

Objective To provide the guidance for the control and treatment of blood stream infec-tion caused by Serratia marcescens strains through analyzing the homology and drug resistant genes of the iso-lates collected from the Intensive Care Unit ( ICU) of Shaoxing County Central Hospital.Methods Serratia marcescens strains were isolated from ICU patients with blood stream infection and also from the hands of health care providers in the ICU from June 1st to September 30th, 2013.The antibiotic susceptibilities of the Serratia marcescens isolates were tested.PCR was performed to amplify the common drug resistant genes. Pulse-field gel electrophoresis ( PFGE) was carried out for analyzing the homology of all isolates.The com-plete clinical data of the patients were collected and statistically analyzed with Spearman′s rank correlation coefficient.Results Seventeen strains were isolated in this study.All of the 17 strains were resistant to the first and second generation Cephalosporin, Gentamicin and Ciprofloxacin, and sensitive to Amikacin and Ceftazidime.The drug resistant rates to Carbapenems ranged from 11.76%to 35.29%.One of the isolates (5.88%) carried the TEM gene.The results of PFGE showed that the phenotypes of all isolates were identi-cal.Conclusion Serratia marcescens strains were critical hospital infectious pathogens.They were able to spread in the hospital and were resistant to multiple antibiotics.Clinical physicians should properly use anti-biotics for the patients based on the result of drug susceptibility test.A control regulation for Serratia marces-cens infection within hospital should be enforced to avoid the cross infection and the outbreak of resistant strains.