MEDEIROS, K. B.; http://lattes.cnpq.br/4511589315339801; MEDEIROS, Katianny Bezerra de.
Resumo:
The poultry production of meat and eggs in Brazil is growing and generates
employment and income not only for large producers but also for small rural
families, who use these products for subsistence. To maintain the health of these
animals and increase productivity, the use of antimicrobials in an empirical and
uncontrolled way has increased, and as a consequence bacteria have become
reservoirs of antimicrobial resistance genes, characterizing a global public health
problem. Thus, the objectives of this study were to isolate and identify
microorganisms from the cloaca of laying hens and free-range chickens in the
Brazilian semiarid region, characterize the resistance profile and identify
antimicrobial resistance genes of the isolates. A total of 330 cloacal swabs from
laying hens and free-range chickens raised in Brazilian semiarid conditions (165
swabs from laying hens and 165 swabs from free-range chickens) were collected
from September 2019 to September 2020. The samples were subjected to
bacterial culture with subsequent biochemical identification, and in the isolates
were checked for susceptibility to antimicrobials, phenotypic test for ESBL
production and identification of resistance genes, , blaCTX-M and blaCMY. A total of
152 Enterobacteriales were isolated from laying hens and 198 from free-range
hens. The microorganisms most frequently isolated from laying hens were E. coli
(73.7%), Klebsiella spp. (13.2%), Proteus mirabilis (5.3%) and Salmonella spp.
(3.3%), and E. coli (67.5%), Klebsiella spp. (12,5%), Edwardsiella spp. (10.0%)
and Salmonella spp. (3.5%) were the most frequent for free-range chickens.
Bacteria isolated from laying hens and free-range chickens showed higher
susceptibility to tetracycline, ampicillin, norfloxacin, amoxicillin+clavulanic acid,
ertapenem, imipenem and meropenem. Sixty-nine (45.4%) isolates with
multidrug resistance were observed in laying hens and 36 (18%) from free-range
chickens. The genes detected in the samples from laying hens were CTX-M in
eight isolates with the blaCTX-M1-like group (four E. coli and four Klebsiella spp.),
blaCTX-M2-like identified in six isolates (two E. coli, three Klebsiella spp. and one
Salmonella spp.), blaCTX-M8-like in seven isolates (six E. coli and one Klebsiella
spp.), and the CMY-2 gene in nine E. coli and two Klebsiella spp. For free-range
chickens, blaCTX-M1-like, blaCTX-M2-like e blaCMY-2 genes were observed in three E.
coli. We conclude that the emergence and dissemination of bacteria producing
resistance genes, especially the production of CTX-M and CMY in laying hen
cloacae compared to free-range hens, alerts to the possible diffusion of these
resistance genes at the human-animal interface and in the ecosystems studied.