Detection of ESBL/AmpC-Producing and Fosfomycin-Resistant Escherichia coli From Different Sources in Poultry Production in Southern Brazil

Abstract

This study discussed the use of antimicrobials in the commercial chicken production system and the possible factors influencing the presence of Extended-spectrum β-lactamase (ESBL)/AmpC producers strains in the broiler production chain. The aim of this study was to perform longitudinal monitoring of ESBL-producing and fosfomycin-resistant <i>Escherichia coli</i> from poultry farms in southern Brazil (Paraná and Rio Grande do Sul states) and determine the possible critical points that may be reservoirs for these strains. Samples of poultry litter, cloacal swabs, poultry feed, water, and beetles (<i>Alphitobius</i> sp.) were collected during three distinct samplings. Phenotypic and genotypic tests were performed for characterization of antimicrobial resistant strains. A total of 117 strains were isolated and 78 (66%) were positive for ESBL production. The poultry litter presented ESBL positive strains in all three sampled periods, whereas the cloacal swab presented positive strains only from the second period. The poultry litter represents a significant risk factor mainly at the beginning poultry production (odds ratio 6.43, 95% confidence interval 1-41.21, <i>p</i> < 0.05). All beetles presented ESBL positive strains. The predominant gene was <i>bla</i> _<i>CTX-M</i> group 2, which occurred in approximately 55% of the ESBL-producing <i>E. coli</i>. The <i>cit</i> gene was found in approximately 13% of the ESBL-producing <i>E. coli</i> as AmpC type determinants. A total of 19 out of 26 fosfomycin-resistant strains showed the <i>fos</i>A3 gene, all of which produced ESBL. The correlation between <i>fos</i>A3 and <i>bla</i> _<i>CTX-M</i> group 1 (<i>bla</i> _{<i>CTX-M55</i>} ) genes was significant among ESBL-producing <i>E. coli</i> isolated from Paraná (OR 3.66, 95% CI 1.9-9.68) and these genetic determinants can be transmitted by conjugation to broiler chicken microbiota strains. Our data revealed that poultry litter and beetles were critical points during poultry production and the presence of fosfomycin-resistant strains indicate the possibility of risks associated with the use of this antimicrobial during production. Furthermore, the genetic determinants encoding CTX-M and fosA3 enzymes can be transferred to <i>E. coli</i> strains from broiler chicken microbiota, thereby creating a risk to public health.