Padronização da coleta do condensado do exalado respiratório utilizando coletor específico para equinos
Standardization of respiratory condensate collection using a specific collector for horses
DOI:
https://doi.org/10.7213/acad.2025.23001Abstract
The lack of standardization in exhaled breath condensate (EBC) collection techniques complicates the comparison of studies due to variations in cooling methods, collection temperatures, and inadequate reporting on nasal cleaning and equipment preparation. This study evaluated the effects of collection temperature on sample volume and the influence of nasal cleaning techniques on sample contamination, using two EBC collectors specifically developed for equines by the authors. Fifteen mixed-breed mares were used to test two cooling methods — solutions 1 (ice) and 2 (ice with salt) — and three nasal cleaning techniques — groups WS (water and soap), NaCl (physiological saline), and G (dry gauze). EBC samples were stored in Stuart transport medium and plated on blood agar and MacConkey agar for bacterial analysis. The average collection temperatures between cooling methods showed no significant differences (p = 0.999). There was no correlation between collection temperature and sample volume for ice without salt (p = 0.276), ice with salt (p = 0.622), or the new collector (p = 0.715). However, ambient temperature and sample volume showed a moderate negative correlation with ice cooling (p = 0.005, r = -0.680) and a strong negative correlation with the new collector (p = 0.013, r = -0.860). In terms of bacterial contamination, all groups exhibited higher numbers of Gram-positive colonies compared to Gram-negative colonies: group G had 4.013 ± 1.073 vs. 1.713 ± 1.349 bacteria (p = 0.001); group NaCl had 4.107 ± 1.216 vs. 2.217 ± 1.701 bacteria (p = 0.006); and group WS had 3.850 ± 1.454 vs. 2.168 ± 1.574 bacteria (p = 0.019). There were no statistical differences between nasal cleaning methods for Gram-positive bacteria (p = 0.990) or Gram-negative bacteria (p = 0.920). In conclusion, given the lack of significant differences among cooling methods, nasal cleaning techniques, and collectors, the use of ice cooling, dry gauze cleaning, and the new collector is recommended for future studies.
