Evaluation of nasotracheal aspiration as a diagnostic tool forRhodococcus equipneumonia in foals

Abstract

Summary The reliability of preparing bacteriological cultures from nasotracheal aspirates of foals routinely in order to diagnose R. equi pneumonia in foals was studied by isolating Rhodococcus equi from specimens obtained from 96 foals by nasotracheal aspiration with a silicon catheter. Results were compared with specimens obtained from 21 foals by transtracheal aspiration (percutaneous tracheal puncture). These 117 foals showed clinical signs of respiratory tract infection at sampling. R. equi was isolated from 14 of 21 (66.7%) specimens by transtracheal aspiration and from 59 of 96 (61.4%) specimens by nasotracheal aspiration, 649 of 655 isolates (99.1%) from the 73 positive specimens were virulent R. equi, and the culture‐positive foals were diagnosed as having R. equi pneumonia. To assess the contamination of aspirates by organisms from the nasopharynx, the results of R. equi isolation from nasal swabs obtained from 56 of the 96 foals were compared to those obtained by nasotracheal aspiration from the same foals. R. equi was isolated from 2 of the 56 nasal swabs: one from a tracheal aspirate was positive, and the other was not. These results suggest that the nasotracheal aspiration technique, which is noninvasive and not associated with complications, could be used as an alternative to the transtracheal aspiration method, especially for the diagnosis of R. equi pneumonia in foals.

Diagnosis, Treatment, Control, and Prevention of Infections Caused byRhodococcus equiin Foals

“…Furthermore, a negative fecal culture may not be helpful in excluding R. equi infection, because only 5 (17%) of 30 foals with confirmed R. equi pneumonia had positive fecal cultures . Similarly, bacterial culture and PCR amplification of nasal swabs are insensitive for diagnosis of R. equi pneumonia …”

“…9 Similarly, bacterial culture and PCR amplification of nasal swabs are insensitive for diagnosis of R. equi pneumonia. 10,11,16 Treatment…”

Fatores de risco associados a doenças respiratórias em potros Puro Sangue Inglês do nascimento ao sexto mês de vida

“…foi realizada a partir do kit comercial de fermentação de açúcares em microplaca, API 20 STREP (BioMérieux Brasil S/A, São Paulo, SP), constituído por testes bioquímicos com alto poder discriminatório (SILVA & VARGAS, 2006). A caracterização de cepas patogênicas de Rhodococcus equi foi realizada com base no sequenciamento genético da proteína VapA a partir da amplificação pela reação em cadeia da polimerase/PCR (HASHIKURA et al, 2000).…”

Isolation of virulent Rhodococcus equi from Arabian horses in Şanlıurfa, Turkey

“…Some researchers (16,19) have reported a higher R. equi isolation rate in tracheal wash fluids than in nasal swabs. Sellon et al (20) isolated R. equi in tracheal wash fluids from 10 (18.9%) of 54 foals with pneumonia.…”