Antimicrobial resistance surveillance of Salmonella spp. and Escherichia coli isolated from food-producing animals and related products.

Author(s)

Ketrin Cristina da Silva

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2011-10-26

Examining board members

Nilton Erbet Lincopan Huenuman; Anna Sara Shafferman Levin; Flavia Rossi

• Advisor: Nilton Erbet Lincopan Huenuman

Abstract

Emergence of drug-resistant phenotypes in human and veterinary medicine, and in the animal husbandry has epidemiological significance. The aim of this study was to investigate the resistance mechanisms of Salmonella and E. coli strains isolated (2005-2010) from food-producing animals (poultry and swine) and related sources. Among 143 Salmonella spp., 9% strains (3 S. Thyphimurium, 7 S. Schwarzengrund and 2 S. Agona) exhibited resistance to extended-spectrum cephalosporins, which was associated to the presence of the blaCTX-M-2 gene. These strains were clonally related (2 major clusters). Resistance to extended-spectrum cephalosporins among clonally unrelated E. coli strains from swine was associated to the presence of blaCTX-M-2 (n=24), blaCMY-2 (n=2) and blaCTX-M-15 (n=1, new ST belonging to the clonal complex 206) genes. Five E. coli strains (from swine) resistant to fluoroquinolones carried qnr genes. Acquisition and spread of genes conferring resistance to extended-spectrum cephalosporins and fluoroquinolones among Salmonella spp. and E. coli strains from food-producing animals is worrisome and it should be considered a public health issue. (AU)

• FAPESP's process: 09/04975-0 - Screening of antimicrobial resistance mechanisms in Salmonella spp. and Escherichia coli isolated from food-producing animals and related sources
• Grantee: Ketrin Cristina da Silva
• Support Opportunities: Scholarships in Brazil - Master