RESUMO
In this study, we examined various brain suspension concentrations and viral loads in Neuro-2a cell cultures using 20 rabies-positive bovine samples. The reproducibility of results varied: 65% showed consistent outcomes across all concentrations, while 35% disagreed in at least one. Viral titers ranged from less than 25 × 101 to 25 × 103.50 TCID50/mL, with 20% below 25 × 101 TCID50/mL. Concentrations between 5% and 20% yielded over 90% agreement in positive results, but at 30%, agreement dropped from 85% to 50%. Cell confluence was successfully maintained at 5%, 10%, and 20%, while concentrations of 30% and above led to confluence loss. Low viral loads also negatively impacted reproducibility. These results suggest that sample concentration has a direct influence on preservation of cell confluence and that low viral loads may influence the reproducibility of the rabies tissue culture infection test (RTCIT).
