The first external quality assurance laboratory proficiency assessment study of national antimicrobial resistance surveillance system in Turkey

Abstract

Objective: National Antimicrobial ResistanceSurveillance System (NAMRSS) was established aimingto determine and track the percentage of antimicrobialresistance in Turkey, and in order to assure the reliabilityof the system, an external quality assurance laboratoryproficiency assessment was performed in September2011, for the first time.Methods: Four bacterial strains were sent to77 participating laboratories. The laboratories wereasked to perform the bacterial identification andantimicrobial susceptibility tests (AST) according tostandard operating procedures of NAMRSS and Clinicaland Laboratory Standards Institute. The results werecollected using a web-based questionnaire and the datawere analysed using SPSS 15.00. Bacterial identificationscoring was defined as ten points when genus and specieswere accurately defined, eight points when genus wasaccurate but species was wrong, and zero point whenit was misdiagnosed or not reported or contaminated.AST scoring included ten points per antibiotic when theresult was correct. Two points were subtracted in case ofa minor error (reported as susceptible or resistant whenintermediate) and ten points in the case of a major orvery major error (reported resistant when susceptableor as susceptible when resistant, respectively) duringAST. The threshold value was determined as 70%.Results: From the system, 68 laboratories hadsent data and analysed. For Klebsiella pneumoniae,Streptococcus pneumoniae, Enterococcus faecium andPseudomonas aeruginosa the success percentage for theidentification of were 92.6%; 91.2%; 89.7% and 98.5%,respectively; and for AST the median/maximum score thatcould be achieved were 50/80; 28/50; 40/40 and 60/60,respectively. When the success percentages were classifiedas ≤69.99%; 70.00%-89.99% and ≥90.00%, the distribution ofthe number of the laboratories were 10; 48; and 10 for thesuccess percentage classes, respectively.