Accuracy of the VITEK® 2 system for a rapid and direct identification and susceptibility testing of Gramnegative rods and Gram-positive cocci in blood samples.

The performance of the VITEK® 2 system for direct rapid identification and antimicrobial susceptibility testing of the bacteria responsible for blood infections was determined. The isolates studied included 166 Gram-negative rods and 74 Gram-positive cocci from inpatients. Specially treated monomicrobial samples from positive blood culture bottles were directly inoculated into the VITEK 2 system and the results were compared with those from cards inoculated with standardized bacterial suspensions. Compared with the standard method, 95.8% of Gram-negative rods were correctly identified by VITEK 2 and the overall level of agreement between the two methods in susceptibility testing was 92.0%. For Gram-positive bacteria, 89.2% were correctly identified by VITEK 2 and susceptibility testing revealed an overall agreement rate of 91.3%. These results suggest that VITEK 2 cards inoculated with fluids sampled directly from positive blood culture bottles are suitable for speedy identification and susceptibility testing of Gram-negative bacilli and Gram-positive cocci.

Accuracy of the VITEK 2 system for a rapid and direct identification and susceptibility testing of Gram-negative rods and Gram-positive cocci in blood samples

The performance of the VITEK 2 system for direct rapid identification and antimicrobial susceptibility testing of the bacteria responsible for blood infections was determined.The isolates studied included 166 Gram-negative rods and 74 Gram-positive cocci from inpatients.Specially treated monomicrobial samples from positive blood culture bottles were directly inoculated into the VITEK 2 system and the results were compared with those from cards inoculated with standardized bacterial suspensions.Compared with the standard method,95.8% of Gram-negative rods were correctly identified by VITEK 2 and the overall level of agreement between the two methods in susceptibility testing was 92.0%.For Gram-positive bacteria,89.2% were correctly identified by VITEK 2 and susceptibility testing revealed an overall agreement rate of 91.3%.These results suggest that VITEK2 cards inoculated with fluids sampled directly from positive blood culture bottles are suitable for speedy identification and susceptibility testing of Gram-negative bacilli and Gram-positive cocci

La performance du systeme VITEK 2 pour une identification et un test de sensibilite aux antimicrobiens rapides et directs des bacteries responsables d'infections sanguines a ete mesuree.Les isolats etudies concernaient 166 batonnets a gram negatif et 74 cocci a gram positif preleves sur des patients hospitalises.Des echantillons monomicrobiens issus de flacons d'hemoculture positifs ayant ete soumis a un traitement special ont ete directement inocules dans le systeme VITEK 2 et les resultats ont ete compares avec ceux issus de cartes inoculees a I'aide de suspensions bacteriennes standards.Par comparaison avec la methode standard,95,8 % des batonnets a gram negatif ont ete correctement identifies par VITEK 2 etle niveau de concordance global entre les deux methodes en matiere de test de sensibilite etait de 92,0 %.Pour les bacteries a gram positif,89,2 % ont ete correctement iclentifiees par VITEK2 etle testdesensibilite a revele un tauxde concordance de 91,3 %.Ces resultats suggerentque les cartes VITEK 2 inoculees a I'aide de liquides preleves directement dans des flacons d'hemoculture positifs sont adaptees a une identification eta un testde sensibilite rapides des bacilles a gram negatif et des cocci a gram positif