S Giguère1, L M I Jordan, K Glass, N D Cohen. 1. Department of Large Animal Medicine, College of Veterinary MedicineUniversity of Georgia, Athens, GA 30602, USA. gigueres@uga.edu
Abstract
BACKGROUND: Isolation of multiple bacterial species is common in foals with Rhodococcus equi pneumonia. HYPOTHESIS: There is no association between isolation of other microorganisms and outcome. ANIMALS: 155 foals with pneumonia caused by R. equi. METHODS: Case records of foals diagnosed with R. equi pneumonia based on culture of the respiratory tract were reviewed at 2 referral hospitals (University of Florida [UF] and Texas A&M University [TAMU]). RESULTS: R. equi was cultured from a tracheobronchial aspirate (TBA) in 115 foals and from lung tissue in 38 foals. Survival was significantly higher at UF (71%; 70/99) than at TAMU (50%; 28/56). R. equi was significantly more likely to grow in pure cultures from samples obtained from foals at UF (55%; 54/99) than from foals at TAMU (23%; 13/56). Microorganisms cultured with R. equi included Gram-positive bacteria in 40, Gram-negative bacteria in 41, and fungi in 23 foals. The most common bacteria isolated were beta-hemolytic streptococci (n = 26) and Escherichia coli (n = 18). Mixed infections were significantly more likely to be encountered in TBA than in lung tissue. Only foals from which R. equi was cultured from a TBA were included in the analysis for association between mixed infection and outcome. After adjusting for the effect of hospital using multivariate logistic regression, mixed culture, mixed bacterial culture, Gram-positive bacteria, beta-hemolytic streptococci, Gram-negative bacteria, enteric Gram-negative bacteria, nonenteric Gram-negative bacteria, and fungi were not significantly associated with outcome. CONCLUSIONS AND CLINICAL IMPORTANCE: Isolation of multiple bacteria or fungi from a TBA along with R. equi does not negatively impact prognosis.
BACKGROUND: Isolation of multiple bacterial species is common in foals with Rhodococcus equi pneumonia. HYPOTHESIS: There is no association between isolation of other microorganisms and outcome. ANIMALS: 155 foals with pneumonia caused by R. equi. METHODS: Case records of foals diagnosed with R. equipneumonia based on culture of the respiratory tract were reviewed at 2 referral hospitals (University of Florida [UF] and Texas A&M University [TAMU]). RESULTS:R. equi was cultured from a tracheobronchial aspirate (TBA) in 115 foals and from lung tissue in 38 foals. Survival was significantly higher at UF (71%; 70/99) than at TAMU (50%; 28/56). R. equi was significantly more likely to grow in pure cultures from samples obtained from foals at UF (55%; 54/99) than from foals at TAMU (23%; 13/56). Microorganisms cultured with R. equi included Gram-positive bacteria in 40, Gram-negative bacteria in 41, and fungi in 23 foals. The most common bacteria isolated were beta-hemolytic streptococci (n = 26) and Escherichia coli (n = 18). Mixed infections were significantly more likely to be encountered in TBA than in lung tissue. Only foals from which R. equi was cultured from a TBA were included in the analysis for association between mixed infection and outcome. After adjusting for the effect of hospital using multivariate logistic regression, mixed culture, mixed bacterial culture, Gram-positive bacteria, beta-hemolytic streptococci, Gram-negative bacteria, enteric Gram-negative bacteria, nonenteric Gram-negative bacteria, and fungi were not significantly associated with outcome. CONCLUSIONS AND CLINICAL IMPORTANCE: Isolation of multiple bacteria or fungi from a TBA along with R. equi does not negatively impact prognosis.
Authors: N D Cohen; S Giguère; A J Burton; J N Rocha; L J Berghaus; C N Brake; A I Bordin; M C Coleman Journal: J Vet Intern Med Date: 2015-12-22 Impact factor: 3.333