Bacteriological profile and multidrug resistance patterns of blood culture isolates in a teaching hospital in South India.

ABSTRACT

Background: Blood stream infections can lead to life threatening sepsis and require rapid antimicrobial treatment . The organisms implicated in these infections vary with the geographical alteration . Further , infections caused by MDR organisms are more likely to increase the risk of death in these patients . Objectives: To study the profile of organisms causing blood stream infections and analyse their antibiotic resistance patterns in our teaching hospital. Materials and methods: Prospective study of 524 blood samples from clinically suspected cases of bacteraemia was performed over a period of three years. The isolates were identified by standard biochemical tests and antimicrobial resistance patterns were determined by CLSI guidelines. Results: Positive blood cultures were obtained in 22.9% of cases. Among the culture positives , gram positive bacteria accounted for 61.5% of cases ; the most common isolate being Staphylococcus aureus(29.2 %) . Of the gram negative isolates , bacteria belonging to Enterobacteriaceae were the predominant isolate , Klebsiella being the commonest isolate.The most sensitive drugs for gram positive isolates were Amikacin, Erythromycin , Ofloxacin and Piperacillin –Tazobactam.And the most sensitive drugs for gram negative isolates were Amoxyclav and Piperacillin – Tazobactam.The prevalence of MRSA in our Staphylococcal isolates was 37.1% and Vancomycin resistance in these isolates was 25.7%. Vancomycin resistance in E nterococcal isolates was 33.3 % .ESBL prevalence was 32.6 %.Conclusion: Increasing incidence of Drug resistant organisms in blood stream infections calls for increased efforts by clinicians to exercise caution in use of these drugs . Vancomycin should be replaced by simpler drugs like Linizolid or Cotrimoxazole to preserve this useful antibiotic and prolong its therapeutic usefulness.