Open AccessDirect antimicrobial susceptibility testing of Gram-negative bacteria from positive blood cultures
Author(s) -
A. Zappavigna,
Enrica Cavatorta,
Rossana Chiarabini,
Roberta Schiavo,
Daniela Padrini,
Camilla Reboli,
Massimo Confalonieri
Publication year - 2014
Publication title -
microbiologia medica
Language(s) - English
Resource type - Journals
eISSN - 2280-6423
pISSN - 1120-0146
DOI - 10.4081/mm.2013.3272
Subject(s) - tazobactam , piperacillin , amikacin , medicine , piperacillin/tazobactam , meropenem , cefotaxime , blood culture , microbiology and biotechnology , antibiotics , biology , imipenem , bacteria , antibiotic resistance , genetics , pseudomonas aeruginosa
Every year, a great number of people die for bloodstream infections, especially by too late or inappropriate pharmacological treatment. The principal laboratory test for this type of infections is the blood culture; its limit is a turnaround time of about 96 hours. The aim of this work was to compare direct susceptibility testing with the automated VITEK 2 system. Fifty blood cultures, positive for Gram-negative bacteria, were processed for amikacin, ciprofloxacin, ceftazidime, piperacillin-tazobactam, cefotaxime, meropenem and colistin with VITEK 2 and direct susceptibility testing by Kirby-Bauer or E-test methods. We found 93.7% correlation with 5.0% minor errors, 0.5% very major errors and 0.8% major errors. Piperacillin-tazobactam has shown the lowest percentage of correlation (79%) and the highest percentage of errors (21%). To conclude, direct susceptibility testing of positive blood cultures has shown promising results, rendering this method useful for giving to clinicians preliminary informations for therapy