AUTHOR=Menck-Costa Maísa Fabiana , Baptista Ana Angelita Sampaio , Gazal Luiz Eduardo de Souza , Justino Larissa , Sanches Matheus Silva , de Souza Marielen , Nishio Erick Kenji , Queiroz dos Santos Beatriz , Cruz Victor Dellevedove , Berbert João Vitor Monteiro , Gonçalves Bruna Carolina , Andrade Galdino , Vespero Eliana Carolina , Nakazato Gerson , Kobayashi Renata Katsuko Takayama 

TITLE=High-Frequency Detection of fosA3 and blaCTX–M–55 Genes in Escherichia coli From Longitudinal Monitoring in Broiler Chicken Farms

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.846116

DOI=10.3389/fmicb.2022.846116

ISSN=1664-302X

ABSTRACT=<p>Considering the worrying emergence of multidrug resistance, including in animal husbandry and especially in food-producing animals, the need to detect antimicrobial resistance strains in poultry environments is relevant, mainly considering a One Health approach. Thus, this study aimed to conduct longitudinal monitoring of antimicrobial resistance in broiler chicken farms, with an emphasis on evaluating the frequency of resistance to fosfomycin and β-lactams. <italic>Escherichia coli</italic> was isolated from broiler chicken farms (cloacal swabs, meconium, poultry feed, water, poultry litter, and <italic>Alphitobius diaperinus</italic>) in northern Paraná from 2019 to 2020 during three periods: the first period (1st days of life), the second period (20th to 25th days of life), and third period (40th to 42nd days of life). Antibiogram tests and the detection of phenotypic extended-spectrum β-lactamase (ESBL) were performed, and they were confirmed by seaching for genes from the <italic>bla</italic><sub><italic>CTX–M</italic></sub> group. The other resistance genes searched were <italic>mcr-1</italic> and <italic>fosA3</italic>. Some ESBL <italic>bla</italic><sub><italic>CTX–M–</italic>1</sub> group strains were selected for ESBL identification by sequencing and enterobacterial repetitive intergenic consensus-polymerase chain reaction analysis. To determine the transferability of the <italic>bla</italic><sub><italic>CTX–M–</italic>1–</sub> and <italic>fosA3</italic>-carrying plasmids, strains were subjected to conjugation experiments. A total of 507 <italic>E. coli</italic> were analyzed: 360 from cloacal swabs, 24 from meconium samples, 3 from poultry feed samples, 18 from water samples, 69 from poultry litter samples, and 33 from <italic>A. diaperinus</italic> samples. Among the strain isolate, 80% (406/507) were multidrug-resistant (MDR), and 51% (260/507) were ESBL-positive, with the <italic>bla</italic><sub><italic>CTX–M–</italic>1</sub> group being the most frequent. For the <italic>fosA3</italic> gene, 68% (344/507) of the strains isolated were positive, deserves to be highlighted <italic>E. coli</italic> isolated from day-old chickens (OR 6.34, CI 2.34–17.17), when compared with strains isolated from other origins (poultry litter, <italic>A. diaperinus</italic>, water, and poultry feed). This work alerts us to the high frequency of the <italic>fosA3</italic> gene correlated with the CTX-M-1 group (OR 3.57, CI 95% 2.7–4.72, <italic>p</italic> &lt; 0.05), especially the <italic>bla</italic><sub><italic>CTX–M–</italic>55</sub> gene, in broiler chickens. This profile was observed mainly in day-old chicken, with a high percentage of <italic>E. coli</italic> that were MDR. The findings emphasize the importance of conducting longitudinal monitoring to detect the primary risk points during poultry production.</p>