Bacteriological Profile, Antibiogram and Phenotypic Resistance Flagging of Blood Culture Isolates by Automated Methods in a Tertiary Care Hospital

ABSTRACT

Introduction: Microorganism present in blood whethercontinuously or intermittently are threat to every organ in thebody. The surveillance of etiological agents in these infectionsis essential for their prevention and treatment. Awarenessof the baseline microbial resistance specific to a hospitalprevents irrational use of antibiotics in that hospital. Thushelps progress a step forward in the prevention of spread ofantibiotic resistance.Material and methods: A retrospective study was conductedin the department of Microbiology. During the study period,blood samples collected from all age group OPD, IPD andICU patients suspected of bacteremia and septicemia wereanalyzed. All Gram-negative bacilli, Gram-positive cocci andYeast were investigated while anaerobic bacteria and cultureswith mixed growth were excluded.Results: During the study period of Jan 2017-Dec2017, 1885blood cultures were analyzed. 305 (16.1%) were found tobe positive, out of which 236 were from ICU, 58 were fromIPD and 11 from OPD. Among Gram positive cocci, CoNSis commonest followed by Staphylococcus aureus whereas inGram negative bacilli, Klebsiella pneumoniae was commonestorganism followed by Pseudomonas aeruginosa. In our study,90% of Enterobacteraceae were ESBL producers. MRSA wereisolated in 50% and MRCoNS in 71%.Gram-positive isolate were least sensitive to penicillin(10%) while it was most sensitive to tigecycline in 100%followed by vancomycin in 95%. Gram negative isolates ofEnterobacteriaceae were least sensitive to Aztreonam (11%)and while it was most sensitive to Colistin in 87% of cases.Candida species were isolated in 54 (18%) of which NICUaccounted for majority of cases. Candida albicans was leastsensitive to Fluconazole (82%) and Non albicans candida toAmphotericin B (70%) while they were sensitive to all otherantifungals.Conclusion: The retrospective study conducted showed bothgram positive and gram negative bacteria were responsiblefor blood stream infections. Most of the strains were multidrug resistant. Rapid isolation and identification of pathogensby automated blood culture system and antibiogram withminimum inhibitory concentration (MIC) value provides earlyand appropriate treatment to the seriously ill patients leadingto reduce mortality and reduce duration of hospitals.Resistance flagging of the bacterial isolates guides us toperform barrier nursing and isolate the patient to preventspread of infection. The daily analysis of resistance flaggingand MIC values give important information for choosingselective antibiotics leading to good antibiotic stewardshipwhich in turn reduces patient morbidity and mortality.