Colistin Resistance in Escherichia coli and Salmonella enterica Strains Isolated from Swine in Brazil

Author(s)

Morales, Adriano Savoia ; de Araujo, Juliana Fragoso ; Demoura Gomes, Vasco Tulio ; Reis Costa, Adrienny Trindade ; Rodrigues, Dalia dos Prazeres ; Porfida Ferreira, Thais Sebastiana ; Nogueira de Lima Filsner, Pedro Henrique ; Felizardo, Maria Roberta ; Moreno, Andrea Micke

• Document type: Journal article
• Source: SCIENTIFIC WORLD JOURNAL; v. N/A, p. 4-pg., 2012-01-01.

Abstract

Reports about acquired resistance to colistin in different bacteria species are increasing, including E. coli of animal origin, but reports of resistance in wild S. enterica of different serotypes from swine are not found in the literature. Results obtained with one hundred and twenty-six E. coli strains from diseased swine and one hundred and twenty-four S. enterica strains from diseased and carrier swine showed a frequency of 6.3% and 21% of colistin-resistant strains, respectively. When comparing the disk diffusion test with the agar dilution test to evaluate the strains, it was confirmed that the disk diffusion test is not recommended to evaluate colistin resistance as described previously. The colistin MIC 90 and MIC 50 values obtained to E. coli were 0.25 mu g/mL and 0.5 mu g/mL, the MIC 90 and MIC 50 to S. enterica were 1 mu g/mL and 8 mu g/mL. Considering the importance of colistin in control of nosocomial human infections with Gram-negative multiresistant bacteria, and the large use of this drug in animal production, the colistin resistance prevalence in enterobacteriaceae of animal origin must be monitored more closely. (AU)

• FAPESP's process: 09/14906-6 - Evaluation of resistance to colistin in E. coli strains from pigs through disk diffusion test and determination of minimal inhibitory concentration
• Grantee: Adriano Savoia Morales
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 09/14939-1 - Evaluation of resistance profile and presence of antimicrobial resistance codifying genes in Salmonella enterica subsp. enterica strains isolated from pigs
• Grantee: Juliana Fragoso de Araújo
• Support Opportunities: Scholarships in Brazil - Scientific Initiation