RESUMO
This study discussed the use of antimicrobials in the commercial chicken production system and the possible factors influencing the presence of Extended-spectrum ß-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 Escherichia coli 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 (Alphitobius 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, p < 0.05). All beetles presented ESBL positive strains. The predominant gene was bla CTX-M group 2, which occurred in approximately 55% of the ESBL-producing E. coli. The cit gene was found in approximately 13% of the ESBL-producing E. coli as AmpC type determinants. A total of 19 out of 26 fosfomycin-resistant strains showed the fosA3 gene, all of which produced ESBL. The correlation between fosA3 and bla CTX-M group 1 (bla CTX-M55 ) genes was significant among ESBL-producing E. coli 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 E. coli strains from broiler chicken microbiota, thereby creating a risk to public health.
RESUMO
The use of antimicrobials in fish farming is a reflection of the fast aquaculture development worldwide. The intensification of aquaculture to achieve market demands could lead to an increase in infectious diseases by pathogenic bacteria. Consequently, antimicrobials act as controls for emerging infectious diseases, but their use must follow the rules and regulations of the country where the activity is performed. Although the regulations impose limits to the use of antimicrobials in fish farming, many studies show that resistant bacteria are isolated from this system. The selection of resistant bacteria is not limited only to the use of antimicrobials, but also to co-selection of resistance genes or even with cross-resistance processes. Resistant bacteria from fish farming are a serious concern because they can be acquired by humans with handling or food chain, which may represent a public health problem. In the present review, we present an overview of antimicrobials use in aquaculture, the antimicrobial resistance and the impact of antimicrobial and bacterial resistance from a public health perspective.(AU)
O uso de antimicrobianos na piscicultura é um reflexo do rápido desenvolvimento da aquicultura em todo o mundo. A intensificação da aquicultura para suprir as demandas do mercado pode levar ao aumento de doenças infecciosas por bactérias patogênicas. Consequentemente, os antimicrobianos atuam no controle de doenças infecciosas emergentes, mas seu uso deve seguir as regras e regulamentos do país onde a atividade é realizada. Embora os regulamentos imponham limites ao uso de antimicrobianos na piscicultura, muitos estudos mostram que bactérias resistentes são isoladas desse sistema. A seleção de bactérias resistentes não se limita apenas ao uso de antimicrobianos, mas também à cosseleção de genes de resistência ou mesmo por meio do processo de resistência cruzada. As bactérias resistentes da piscicultura são uma preocupação séria, uma vez que tais bactérias podem ser adquiridas pelos seres humanos no manuseio ou na cadeia alimentar, o que pode representar um problema de saúde pública. Nesta revisão, apresentamos uma visão geral do uso de antimicrobianos na aquicultura, a resistência antimicrobiana e o impacto da resistência antimicrobiana e bacteriana do ponto de vista da saúde pública.(AU)
