Determination of the prevalence of antimicrobial resistance to macrolide antimicrobials or rifampin in Rhodococcus equi isolates and treatment outcome in foals infected with antimicrobial-resistant isolates of R equi
| Autor: | Ronald J. Martens, Elliott Williams, Carol C. Clark, Robert P. Franklin, Noah D. Cohen, Steeve Giguère, Natalie D. Halbert, Nathan M. Slovis, Elise Lee, M. Keith Chaffin |
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| Rok vydání: | 2010 |
| Předmět: |
medicine.drug_class
animal diseases Antibiotics Erythromycin Microbial Sensitivity Tests Drug resistance Biology Macrolide Antibiotics Microbiology Antibiotic resistance Rhodococcus equi Drug Resistance Bacterial medicine Animals Horses Antiinfective agent Virulence General Veterinary bacterial infections and mycoses Antimicrobial biology.organism_classification Virology Anti-Bacterial Agents Treatment Outcome Horse Diseases Macrolides Rifampin Actinomycetales Infections medicine.drug |
| Zdroj: | Journal of the American Veterinary Medical Association. 237:74-81 |
| ISSN: | 0003-1488 |
| Popis: | Objective—To determine the prevalence of antimicrobial resistance to macrolide antimicrobials or rifampin in Rhodococcus equi isolates and to describe treatment outcome in foals infected with antimicrobial-resistant isolates of R equi. Design—Cross-sectional study. Sample Population—38 isolates classified as resistant to macrolide antimicrobials or rifampin received from 9 veterinary diagnostic laboratories between January 1997 and December 2008. Procedures—For each isolate, the minimum inhibitory concentration of macrolide antimicrobials (ie, azithromycin, erythromycin, and clarithromycin) and rifampin was determined by use of a concentration-gradient test. Prevalence of R equi isolates from Florida and Texas resistant to macrolide antimicrobials or rifampin was determined. Outcome of antimicrobial treatment in foals infected with antimicrobial-resistant isolates of R equi was determined. Results—Only 24 of 38 (63.2%) isolates were resistant to > 1 antimicrobial. Two isolates were resistant only to rifampin, whereas 22 isolates were resistant to azithromycin, erythromycin, clarithromycin, and rifampin. The overall prevalence of antimicrobial-resistant isolates in submissions received from Florida and Texas was 3.7% (12/328). The survival proportion of foals infected with resistant R equi isolates (2/8 [25.0%]) was significantly less, compared with the survival proportion in foals that received the same antimicrobial treatment from which antimicrobial-susceptible isolates were cultured (55/79 [69.6%]). Odds of nonsurvival for foals infected with resistant R equi isolates were 6.9 (95% confidence interval, 1.3 to 37) times the odds for foals infected with susceptible isolates. Conclusions and Clinical Relevance—Interpretation of the results emphasized the importance of microbiological culture and antimicrobial susceptibility testing in foals with pneumonia caused by R equi. |
| Databáze: | OpenAIRE |
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