El minihemocultivo como herramienta diagnóstica en sepsis neonatal

Abstract

Objective

To design a blood micro-culture using 200 to 300 μl of blood and compare it with the reference BACTEC peds plus/FTM BD^® blood culture.

Methods

Two batches of HEM-1 and HIM-3 blood micro-cultures, with different composition were prepared. They were quality controlled in the same way as that carried out in the BACTEC, which is the automated reference blood culture. A total of 98 samples taken from Neonatal Intensive Care Unit (NICU) patients with probable sepsis were studied and stratified into two groups. The first 48 samples that were inoculated into HIM-1 and BACTEC paediatric plates, and the second 50 samples in HIM-3 and in paediatric BACTEC plates.

Results

The microorganisms grown in HIM-1 and HIM-3 included: E. coli, K. pneumoniae, P. aeruginosa, and Enterococcus spp up to 10² CFU/ml (which is the minimum recovery concentration of the reference blood culture). Micro-blood cultures did not improve the growth of S. epidermidis, S. aureus and S. pneumoniae of 10² CFU/ml. For Gram negatives, a sensitivity of 80%, specificity of 96%, positive predictive value (PPV) of 80%, and negative predictive value (NPV) of 96%, were obtained.

Conclusions

HIM-1 and HIM-3 are adequate for the diagnosis of early neonatal sepsis in developing countries, mainly by Gram negative, but not for late sepsis, mainly by staphylococci. Compared to BACTEC they save a lot of blood sample.