Identificación y sensibilidad antibiótica de bacilos Gram negativos directamente del hemocultivo positivo

Alvarado L.; Quiroz-Reyna M.E.; Quiroz-Chunga G.S.; Castillo-Aguilar W.F.; Neyra-Neyra R.M.; Quedo-Salazar F.B.; Ramos-Yesquen L.M. · Infectio (2023) · DOI: 10.22354/24223794.1146

Resumen

Objective: The objective was to determine the concordance of the identification and direct antibiotic susceptibility of Gram-negative bacilli-positive blood cultures with the Vitek 2 system vs. the standard procedure. Materials and methods: For the direct procedure, 8 ml of the positive blood culture bottle was extracted, inoculated in a blood extraction tube with separating gel, centrifuged for 10 minutes at 1000g, the pellet was resuspended with 0.5 ml of sterile saline solution and the inoculum for the identification and antibiotic susceptibility cards was prepared. The concordance in identification was evaluated with the Kappa index, antibiotic susceptibility with essential agreement (EA) and categorical agreement (CA). Results: The identification success (%) and kappa(k) index for the five most frequent species was: E. coli 98.0% (48/49) k=0.99, K. pneumoniae 100% (33/33) k=1.0, E. cloacae complex 100% (13/13) k=1.0, A. baumannii 95% (19/20) k=0.97, P. aeruginosa 66.7% (8/12) k=0.79. The essential agreement and categorical agreement values for 2175 bacteria-antibiotic combinations were 97.5% and 97.1% respectively. Conclusion: The direct positive blood culture procedure shows good concordance for the main Gram-negative bacilli species and allows results to be obtained 16 to 24 hours earlier than the standard procedure.